MZ is back!HEADmain

86 files changed, 34329 insertions, 0 deletions

diff --git a/v4.0/src/DOS/ABORT.ASM b/v4.0/src/DOS/ABORT.ASM
new file mode 100644
index 0000000..43268e3
--- /dev/null
+++ b/v4.0/src/DOS/ABORT.ASM
@@ -0,0 +1,137 @@
+;       SCCSID = @(#)abort.asm  1.4 85/10/02
+TITLE   DOS_ABORT - Internal SFT close all files for proc call for MSDOS
+NAME    DOS_ABORT
+
+; Internal Abort call closes all handles and FCBs associated with a process.
+;  If process has NET resources a close all is sent out over the net.
+;
+;   DOS_ABORT
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xlist
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+Installed = TRUE
+
+        I_Need  PROC_ID,WORD            ; current process ID
+        I_Need  USER_ID,WORD            ; current user ID
+        i_need  CurrentPDB,WORD
+        i_need  sft_addr,DWORD
+        i_need  THISSFT,DWORD
+        i_need  JSHARE,DWORD
+        I_need  sftFCB,DWORD            ; pointer to SFTs for FCB cache
+
+Break   <DOS_ABORT -- CLOSE all files for process>
+
+; Inputs:
+;       [CurrentPDB] set to PID of process aborting
+; Function:
+;       Close all files and free all SFTs for this PID
+; Returns:
+;       None
+; All destroyed except stack
+
+        Procedure   DOS_ABORT,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     ES,[CurrentPDB]
+        MOV     CX,ES:[PDB_JFN_Length]  ; Number of JFNs
+reset_free_jfn:
+        MOV     BX,CX
+        PUSH    CX
+        DEC     BX                      ; get jfn (start with last one)
+
+        invoke  $close
+        POP     CX
+        LOOP    reset_free_jfn          ; and do 'em all
+;
+; Note:  We do need to explicitly close FCBs.  Reasons are as follows:  If we
+; are running in the no-sharing no-network environment, we are simulating the
+; 2.0 world and thus if the user doesn't close the file, that is his problem
+; BUT...  the cache remains in a state with garbage that may be reused by the
+; next process.  We scan the set and blast the ref counts of the FCBs we own.
+;
+; If sharing is loaded, then the following call to close process will
+; correctly close all FCBs.  We will then need to walk the list AFTER here.
+;
+; Finally, the following call to NET_Abort will cause an EOP to be sent to all
+; known network resources.  These resources are then responsible for cleaning
+; up after this process.
+;
+; Sleazy, eh?
+;
+        context DS
+        CallInstall Net_Abort, multNet, 29
+if installed
+        call    JShare + 4 * 4
+else
+        call    mftCloseP
+endif
+        assume  ds:nothing
+;
+; Scan the FCB cache for guys that belong to this process and zap their ref
+; counts.
+;
+        les     di,sftFCB               ; grab the pointer to the table
+        mov     cx,es:[di].sfCount
+        jcxz    FCBScanDone
+        LEA     DI,[DI].sfTable         ; point at table
+        mov     ax,proc_id
+FCBTest:
+        cmp     es:[di].sf_PID,ax       ; is this one of ours
+        jnz     FCBNext                 ; no, skip it
+        mov     es:[di].sf_ref_count,0  ; yes, blast ref count
+FCBNext:
+        add     di,size sf_Entry
+        loop    FCBTest
+FCBScanDone:
+
+;
+; Walk the SFT to eliminate all busy SFT's for this process.
+;
+        XOR     BX,BX
+Scan:
+        push    bx
+        invoke  SFFromSFN
+        pop     bx
+        retc
+        cmp     es:[di].sf_ref_count,0
+        jz      next
+;
+; we have a SFT that is not free.  See if it is for the current process
+;
+        mov     ax,proc_id
+        cmp     es:[di].sf_pid,ax
+        jnz     next
+        mov     ax,user_id
+        cmp     es:[di].sf_uid,ax
+        jnz     next
+;
+; This SFT is labelled as ours.
+;
+        mov     es:[di].sf_ref_count,0
+next:
+        inc     bx
+        jmp     scan
+
+EndProc DOS_Abort
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/ALLOC.ASM b/v4.0/src/DOS/ALLOC.ASM
new file mode 100644
index 0000000..37b6298
--- /dev/null
+++ b/v4.0/src/DOS/ALLOC.ASM
@@ -0,0 +1,392 @@
+;       SCCSID = @(#)alloc.asm  1.1 85/04/09
+TITLE ALLOC.ASM - memory arena manager
+NAME Alloc
+;
+; Memory related system calls and low level routines for MSDOS 2.X.
+; I/O specs are defined in DISPATCH.
+;
+;   $ALLOC
+;   $SETBLOCK
+;   $DEALLOC
+;   $AllocOper
+;   arena_free_process
+;   arena_next
+;   check_signature
+;   Coalesce
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+.lall
+
+SUBTTL memory allocation utility routines
+PAGE
+;
+; arena data
+;
+        i_need  arena_head,WORD         ; seg address of start of arena
+        i_need  CurrentPDB,WORD         ; current process data block addr
+        i_need  FirstArena,WORD         ; first free block found
+        i_need  BestArena,WORD          ; best free block found
+        i_need  LastArena,WORD          ; last free block found
+        i_need  AllocMethod,BYTE        ; how to alloc first(best)last
+        I_need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
+
+;
+; arena_free_process
+; input:    BX - PID of process
+; output:   free all blocks allocated to that PID
+;
+        procedure   arena_free_process,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     DI,arena_signature
+        MOV     AX,[arena_head]
+        CALL    Check_Signature         ; ES <- AX, check for valid block
+
+arena_free_process_loop:
+        retc
+        PUSH    ES
+        POP     DS
+        CMP     DS:[arena_owner],BX     ; is block owned by pid?
+        JNZ     arena_free_next         ; no, skip to next
+        MOV     DS:[arena_owner],DI     ; yes... free him
+
+arena_free_next:
+        CMP     BYTE PTR DS:[DI],arena_signature_end
+                                        ; end of road, Jack?
+        retz                            ; never come back no more
+        CALL    arena_next              ; next item in ES/AX carry set if trash
+        JMP     arena_free_process_loop
+
+EndProc arena_free_process
+
+;
+; arena_next
+; input:    DS - pointer to block head
+; output:   AX,ES - pointers to next head
+;           carry set if trashed arena
+;
+        procedure   arena_next,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     AX,DS                   ; AX <- current block
+        ADD     AX,DS:[arena_size]      ; AX <- AX + current block length
+        INC     AX                      ; remember that header!
+;
+;       fall into check_signature and return
+;
+;       CALL    check_signature         ; ES <- AX, carry set if error
+;       RET
+EndProc arena_next
+
+;
+; check_signature
+; input:    AX - address of block header
+; output:   ES=AX, carry set if signature is bad
+;
+        procedure   check_signature,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     ES,AX                   ; ES <- AX
+        CMP     BYTE PTR ES:[DI],arena_signature_normal
+                                        ; IF next signature = not_end THEN
+        retz                            ;   GOTO ok
+        CMP     BYTE PTR ES:[DI],arena_signature_end
+                                        ; IF next signature = end then
+        retz                            ;   GOTO ok
+        STC                             ; set error
+        return
+
+EndProc Check_signature
+
+;
+; Coalesce - combine free blocks ahead with current block
+; input:    DS - pointer to head of free block
+; output:   updated head of block, AX is next block
+;           carry set -> trashed arena
+;
+        procedure   Coalesce,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        CMP     BYTE PTR DS:[DI],arena_signature_end
+                                        ; IF current signature = END THEN
+        retz                            ;   GOTO ok
+        CALL    arena_next              ; ES, AX <- next block, Carry set if error
+        retc                            ; IF no error THEN GOTO check
+
+coalesce_check:
+        CMP     ES:[arena_owner],DI
+        retnz                           ; IF next block isnt free THEN return
+        MOV     CX,ES:[arena_size]      ; CX <- next block size
+        INC     CX                      ; CX <- CX + 1 (for header size)
+        ADD     DS:[arena_size],CX      ; current size <- current size + CX
+        MOV     CL,ES:[DI]              ; move up signature
+        MOV     DS:[DI],CL
+        JMP     coalesce                ; try again
+EndProc Coalesce
+
+SUBTTL $Alloc - allocate space in memory
+PAGE
+;
+;   Assembler usage:
+;           MOV     BX,size
+;           MOV     AH,Alloc
+;           INT     21h
+;         AX:0 is pointer to allocated memory
+;         BX is max size if not enough memory
+;
+;   Description:
+;           Alloc returns  a  pointer  to  a  free  block of
+;       memory that has the requested  size  in  paragraphs.
+;
+;   Error return:
+;           AX = error_not_enough_memory
+;              = error_arena_trashed
+;
+        procedure   $ALLOC,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        EnterCrit   critMem
+        XOR     AX,AX
+        MOV     DI,AX
+
+        MOV     [FirstArena],AX         ; init the options
+        MOV     [BestArena],AX
+        MOV     [LastArena],AX
+
+        PUSH    AX                      ; alloc_max <- 0
+        MOV     AX,[arena_head]         ; AX <- beginning of arena
+        CALL    Check_signature         ; ES <- AX, carry set if error
+        JC      alloc_err               ; IF error THEN GOTO err
+
+alloc_scan:
+        PUSH    ES
+        POP     DS                      ; DS <- ES
+        CMP     DS:[arena_owner],DI
+        JZ      alloc_free              ; IF current block is free THEN examine
+
+alloc_next:
+        CMP     BYTE PTR DS:[DI],arena_signature_end
+                                        ; IF current block is last THEN
+        JZ      alloc_end               ;   GOTO end
+        CALL    arena_next              ; AX, ES <- next block, Carry set if error
+        JNC     alloc_scan              ; IF no error THEN GOTO scan
+
+alloc_err:
+        POP     AX
+
+alloc_trashed:
+        LeaveCrit   critMem
+        error   error_arena_trashed
+
+alloc_end:
+        CMP     [FirstArena],0
+        JNZ     alloc_do_split
+
+alloc_fail:
+        invoke  get_user_stack
+        POP     BX
+        MOV     [SI].user_BX,BX
+        LeaveCrit   critMem
+        error   error_not_enough_memory
+
+alloc_free:
+        CALL    coalesce                ; add following free block to current
+        JC      alloc_err               ; IF error THEN GOTO err
+        MOV     CX,DS:[arena_size]
+
+        POP     DX                      ; check for max found size
+        CMP     CX,DX
+        JNA     alloc_test
+        MOV     DX,CX
+
+alloc_test:
+        PUSH    DX
+        CMP     BX,CX                   ; IF BX > size of current block THEN
+        JA      alloc_next              ;   GOTO next
+
+        CMP     [FirstArena],0
+        JNZ     alloc_best
+        MOV     [FirstArena],DS         ; save first one found
+alloc_best:
+        CMP     [BestArena],0
+        JZ      alloc_make_best         ; initial best
+        PUSH    ES
+        MOV     ES,[BestArena]
+        CMP     ES:[arena_size],CX      ; is size of best larger than found?
+        POP     ES
+        JBE     alloc_last
+alloc_make_best:
+        MOV     [BestArena],DS          ; assign best
+alloc_last:
+        MOV     [LastArena],DS          ; assign last
+        JMP     alloc_next
+
+;
+; split the block high
+;
+alloc_do_split_high:
+        MOV     DS,[LastArena]
+        MOV     CX,DS:[arena_size]
+        SUB     CX,BX
+        MOV     DX,DS
+        JE      alloc_set_owner         ; sizes are equal, no split
+        ADD     DX,CX                   ; point to next block
+        MOV     ES,DX                   ; no decrement!
+        DEC     CX
+        XCHG    BX,CX                   ; bx has size of lower block
+        JMP     alloc_set_sizes         ; cx has upper (requested) size
+
+;
+; we have scanned memory and have found all appropriate blocks
+; check for the type of allocation desired; first and best are identical
+; last must be split high
+;
+alloc_do_split:
+        CMP     BYTE PTR [AllocMethod], 1
+        JA      alloc_do_split_high
+        MOV     DS,[FirstArena]
+        JB      alloc_get_size
+        MOV     DS,[BestArena]
+alloc_get_size:
+        MOV     CX,DS:[arena_size]
+        SUB     CX,BX                   ; get room left over
+        MOV     AX,DS
+        MOV     DX,AX                   ; save for owner setting
+        JE      alloc_set_owner         ; IF BX = size THEN (don't split)
+        ADD     AX,BX
+        INC     AX                      ; remember the header
+        MOV     ES,AX                   ; ES <- DS + BX (new header location)
+        DEC     CX                      ; CX <- size of split block
+alloc_set_sizes:
+        MOV     DS:[arena_size],BX      ; current size <- BX
+        MOV     ES:[arena_size],CX      ; split size <- CX
+        MOV     BL,arena_signature_normal
+        XCHG    BL,DS:[DI]              ; current signature <- 4D
+        MOV     ES:[DI],BL              ; new block sig <- old block sig
+        MOV     ES:[arena_owner],DI
+
+alloc_set_owner:
+        MOV     DS,DX
+        MOV     AX,[CurrentPDB]
+        MOV     DS:[arena_owner],AX
+        MOV     AX,DS
+        INC     AX
+        POP     BX
+        LeaveCrit   critMem
+        transfer    SYS_RET_OK
+
+EndProc $alloc
+
+SUBTTL $SETBLOCK - change size of an allocated block (if possible)
+PAGE
+;
+;   Assembler usage:
+;           MOV     ES,block
+;           MOV     BX,newsize
+;           MOV     AH,setblock
+;           INT     21h
+;         if setblock fails for growing, BX will have the maximum
+;         size possible
+;   Error return:
+;           AX = error_invalid_block
+;              = error_arena_trashed
+;              = error_not_enough_memory
+;              = error_invalid_function
+;
+        procedure   $SETBLOCK,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        EnterCrit   critMem
+        MOV     DI,arena_signature
+        MOV     AX,ES
+        DEC     AX
+        CALL    check_signature
+        JNC     setblock_grab
+
+setblock_bad:
+        JMP     alloc_trashed
+
+setblock_grab:
+        MOV     DS,AX
+        CALL    coalesce
+        JC      setblock_bad
+        MOV     CX,DS:[arena_size]
+        PUSH    CX
+        CMP     BX,CX
+        JBE     alloc_get_size
+        JMP     alloc_fail
+EndProc $setblock
+
+SUBTTL $DEALLOC - free previously allocated piece of memory
+PAGE
+;
+;   Assembler usage:
+;           MOV     ES,block
+;           MOV     AH,dealloc
+;           INT     21h
+;
+;   Error return:
+;           AX = error_invalid_block
+;              = error_arena_trashed
+;
+        procedure   $DEALLOC,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        EnterCrit   critMem
+        MOV     DI,arena_signature
+        MOV     AX,ES
+        DEC     AX
+        CALL    check_signature
+        JC      dealloc_err
+        MOV     ES:[arena_owner],DI
+        LeaveCrit   critMem
+        transfer    SYS_RET_OK
+
+dealloc_err:
+        LeaveCrit   critMem
+        error   error_invalid_block
+EndProc $DEALLOC
+
+SUBTTL $AllocOper - get/set allocation mechanism
+PAGE
+;
+;   Assembler usage:
+;           MOV     AH,AllocOper
+;           MOV     BX,method
+;           MOV     AL,func
+;           INT     21h
+;
+;   Error return:
+;           AX = error_invalid_function
+;
+        procedure   $AllocOper,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        CMP     AL,1
+        JB      AllocOperGet
+        JZ      AllocOperSet
+        MOV     EXTERR_LOCUS,errLoc_mem ; Extended Error Locus
+        error   error_invalid_function
+AllocOperGet:
+        MOV     AL,BYTE PTR [AllocMethod]
+        XOR     AH,AH
+        transfer    SYS_RET_OK
+AllocOperSet:
+        MOV     [AllocMethod],BL
+        transfer    SYS_RET_OK
+EndProc $AllocOper
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/BUF.ASM b/v4.0/src/DOS/BUF.ASM
new file mode 100644
index 0000000..f6a6b7d
--- /dev/null
+++ b/v4.0/src/DOS/BUF.ASM
@@ -0,0 +1,982 @@
+;       SCCSID = @(#)buf.asm    1.1 85/04/09
+TITLE   BUF - MSDOS buffer management
+NAME    BUF
+; Low level routines for buffer cache management
+;
+;   GETCURHEAD
+;   SET_MAP_PAGE
+;   SAVE_MAP
+;   RESTORE_MAP
+;   SETVISIT
+;   ScanPlace
+;   PLACEBUF
+;   PLACEHEAD
+;   PointComp
+;   GETBUFFR
+;   GETBUFFRB
+;   FlushBuf
+;   BufWrite
+;   SKIPVISIT
+;   SET_RQ_SC_PARMS
+;
+;   Revision history:
+;
+;       AN000  version 4.00  Jan. 1988
+;       A004   PTM 3765 -- Disk reset failed
+
+;       NEW PROCS FOR BUFFERS FIX:
+
+;               SAVE_USER_MAP
+;               RESTORE_USER_MAP
+;               DETECT_COLLISION
+;               SETUP_EMS_BUFFERS
+;
+
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+INCLUDE dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  BuffHead,DWORD
+        i_need  PreRead,WORD
+        i_need  LastBuffer,DWORD
+        i_need  CurBuf,DWORD
+        i_need  WPErr,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  FAILERR,BYTE
+        i_need  HIGH_SECTOR,WORD             ; DOS 4.00 >32mb                   ;AN000;
+        i_need  CurHashEntry,DWORD           ; DOS 4.00 current Hash entry      ;AN000;
+        i_need  BUF_HASH_PTR,DWORD           ; DOS 4.00 Hash table pointer      ;AN000;
+        i_need  BUF_HASH_COUNT,WORD          ; DOS 4.00 Hash table entries      ;AN000;
+        i_need  SC_CACHE_PTR,DWORD           ; DOS 4.00 seconadary cache table  ;AN000;
+        i_need  SC_CACHE_COUNT,WORD          ; DOS 4.00 secondary cache entries ;AN000;
+        i_need  BUF_EMS_MODE,BYTE            ; DOS 4.00 EMS mode                ;AN000;
+        i_need  BUF_EMS_HANDLE,WORD          ; DOS 4.00 buffer EMS handle       ;AN000;
+        i_need  SC_SECTOR_SIZE,WORD          ; DOS 4.00 sector size             ;AN000;
+        i_need  SC_DRIVE,BYTE                ; DOS 4.00 drive                   ;AN000;
+        i_need  ACT_PAGE,WORD                ; DOS 4.00 active logical EMS page ;AN000;
+        i_need  DOS34_FLAG,WORD              ; DOS 4.00 common flag             ;AN000;
+        i_need  BUF_EMS_SEG_CNT,WORD         ; DOS 4.00 EMS seg count           ;AN000;
+        i_need  BUF_EMS_MAP_BUFF,BYTE        ; DOS 4.00 EMS map buffer          ;AN000;
+        i_need  FIRST_BUFF_ADDR,WORD         ; DOS 4.00 beginning of the chain  ;AN000;
+        i_need  BUF_EMS_PAGE_FRAME,WORD      ; DOS 4.00 EMS page frame          ;AN000;
+
+IF      BUFFERFLAG
+        i_need  BUF_EMS_PFRAME,WORD
+        i_need  BUF_EMS_LAST_PAGE,WORD
+        i_need  BUF_EMS_FIRST_PAGE,WORD
+        i_need  BUF_EMS_SAFE_FLAG,byte
+        i_need  BUF_EMS_NPA640,WORD
+        i_need  NEXTADD,WORD
+        i_need  DMAADD,DWORD
+        i_need  BYTCNT1,WORD
+        i_am    BUF_EMS_MAP_BUF,12,<0,0,0,0,0,0,0,0,0,0,0,0>         
+        i_am    CURADD,WORD
+        i_am    low_ems_buf,512
+        extrn   SAVE_USER_MAP:near
+        extrn   RESTORE_USER_MAP:near
+ENDIF
+
+
+Break   <GETCURHEAD -- Get current buffer header>
+
+; Inputs:
+;       DX= sector number (LOW)
+;       [HIGH_SECTOR]= sector number (HIGH)
+; Function:
+;       Hash into a buffer group and activate the extended memory if
+;       necessary
+; Outputs:
+;       [CurHashEntry] = current Hash entry addr
+;       DS:DI = 1st buffer addr of the current Hash entry
+; No other registers altered
+
+        procedure   GETCURHEAD,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DX                        ;LB. save regs                        ;AN000;
+        PUSH    AX                        ;LB.                                  ;AN000;
+        PUSH    BX                        ;LB.                                  ;AN000;
+        MOV     AX,DX                     ;LB.                                  ;AN000;
+;       MOV     DX,[HIGH_SECTOR]          ;LB. HASH(sector#) and get entry #    ;AN000;
+        XOR     DX,DX                     ;LB. to avoid divide overflow         ;AN000;
+        DIV     [BUF_HASH_COUNT]          ;LB. get remainder                    ;AN000;
+        ADD     DX,DX                     ;LB. 8 bytes per entry                ;AN000;
+        ADD     DX,DX                     ;LB.                                  ;AN000;
+        ADD     DX,DX                     ;LB. times 8                          ;AN000;
+
+        LDS     DI,[BUF_HASH_PTR]         ;LB. get Hash Table addr              ;AN000;
+        ADD     DI,DX                     ;LB position to entry                 ;AN000;
+Map_Entry2:
+        MOV     WORD PTR [CurHashEntry+2],DS ;LB. update current Hash entry ptr ;AN000;
+        MOV     WORD PTR [CurHashEntry],DI ;LB.                                 ;AN000;
+        MOV     WORD PTR [LASTBUFFER],-1   ;LB. invalidate last buffer          ;AN000;
+        MOV     BX,[DI.EMS_PAGE_NUM]      ;LB. logical page                     ;AN000;
+
+IF      NOT     BUFFERFLAG
+        LDS     DI,[DI.BUFFER_BUCKET]     ;LB. ds:di is 1st buffer addr         ;AN000;
+        MOV     [FIRST_BUFF_ADDR],DI      ;LB. 1/19/88 save first buffer addr   ;AN000;
+        CALL    SET_MAP_PAGE              ;LB. activate handle if EMS there     ;AN000;
+ELSE
+        push    ax
+        mov     ax, [NEXTADD]
+        mov     [CURADD], ax
+        pop     ax
+        CALL    SET_MAP_PAGE              ;LB. activate handle if EMS there     ;AN000;
+        LDS     DI,[DI.BUFFER_BUCKET]     ;LB. ds:di is 1st buffer addr         ;AN000;
+        MOV     [FIRST_BUFF_ADDR],DI      ;LB. 1/19/88 save first buffer addr   ;AN000;
+ENDIF
+
+                                                                                ;AN000;
+        POP     BX                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB.                                  ;AN000;
+        POP     DX                        ;LB.                                  ;AN000;
+        return                            ;LB.                                  ;AN000;
+EndProc GETCURHEAD                                                              ;AN000;
+
+                                                                                ;AN000;
+Break   <SET_MAP_PAGE - map handle and page >                                   ;AN000;
+; Inputs:                                                                       ;AN000;
+;       BX= logical page                                                        ;AN000;
+; Function:                                                                     ;AN000;
+;       Map handle and logical page to frame 0 page 0                           ;AN000;
+; Outputs:                                                                      ;AN000;
+;       AH=0 success                                                            ;AN000;
+; No other registers altered                                                    ;AN000;
+                                                                                ;AN000;
+Procedure   SET_MAP_PAGE,NEAR                                                   ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+
+;       int     3
+                                                                                ;AN000;
+        CMP     [BUF_EMS_MODE],-1         ;LB. EMS support                      ;AN000;
+        JZ      No_map                    ;LB. no                               ;AN000;
+
+IF      NOT BUFFERFLAG
+        CMP     [ACT_PAGE],BX             ;LB. already mapped ?                 ;AN000;
+        JZ      No_map                    ;LB. yes                              ;AN000;
+ENDIF
+        MOV     [ACT_PAGE],BX             ;LB. save active page mapped          ;AN000;
+
+IF      BUFFERFLAG      
+        cmp     [BUF_EMS_SAFE_FLAG], 1
+        je      no_coll
+;       int     3
+        call    detect_collision
+no_coll:
+ENDIF
+
+        MOV     DX,[BUF_EMS_HANDLE]       ;LB.                                  ;AN000;
+        MOV     AH,44H                    ;LB. activate current handle          ;AN000;
+        MOV     AL,BYTE PTR [BUF_EMS_PAGE_FRAME]  ;LB. page frame number        ;AN000;
+        INT     67H                       ;LB.                                  ;AN000;
+No_map:                                                                         ;AN000;
+        return                                                                  ;AN000;
+EndProc SET_MAP_PAGE                                                            ;AN000;
+                                                                                ;AN000;
+
+IF      BUFFERFLAG
+
+Break   <SAVE_MAP - save map >                                                  ;AN000;
+; Inputs:                                                                       ;AN000;
+;       none                                                                    ;AN000;
+; Function:                                                                     ;AN000;
+;       save map                                                                ;AN000;
+; Outputs:                                                                      ;AN000;
+;       none                                                                    ;AN000;
+; No other registers altered                                                    ;AN000;
+                                                                                ;AN000;
+Procedure   SAVE_MAP,NEAR                                                        ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+                                                                                ;AN000;
+        CMP     [BUF_EMS_MODE],-1         ;LB. EMS support                      ;AN000;
+        JZ      No_save                   ;LB. no                               ;AN000;
+        MOV     [ACT_PAGE],-1             ;LB. invalidate active page           ;AN000;
+        MOV     WORD PTR [LASTBUFFER],-1  ;LB.  and last buffer pointer         ;AN000;
+        PUSH    AX                        ;LB. save regs                        ;AN000;
+        PUSH    DS                        ;LB. save regs                        ;AN000;
+        PUSH    ES                        ;LB.                                  ;AN000;
+        PUSH    SI                        ;LB.                                  ;AN000;
+        PUSH    DI                        ;LB.                                  ;AN000;
+        MOV     SI,OFFSET DOSGROUP:BUF_EMS_SEG_CNT     ;LB.                     ;AN000;
+        MOV     DI,OFFSET DOSGROUP:BUF_EMS_MAP_BUF     ;LB.                     ;AN000;
+
+        PUSH    CS
+        POP     ES
+        PUSH    CS                        ;LB.                                  ;AN000;
+        POP     DS                        ;LB. ds:si -> ems seg count           ;AN000;
+
+        MOV     AX,4F00H                  ;LB. save map                         ;AN000;
+        EnterCrit  critDisk               ;LB. enter critical section           ;AN000;
+        INT     67H                       ;LB.                                  ;AN000;
+        LeaveCrit  critDisk               ;LB. leave critical section           ;AN000;
+        POP     DI                        ;LB.                                  ;AN000;
+        POP     SI                        ;LB. restore regs                     ;AN000;
+        POP     ES                        ;LB.                                  ;AN000;
+        POP     DS                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB. restore                          ;AN000;
+No_save:                                                                         ;AN000;
+        return                                                                  ;AN000;
+EndProc SAVE_MAP                                                                 ;AN000;
+                                                                                ;AN000;
+
+Break   <RESTORE_MAP- retore map >                                              ;AN000;
+; Inputs:                                                                       ;AN000;
+;       none                                                                    ;AN000;
+; Function:                                                                     ;AN000;
+;       restore_map                                                             ;AN000;
+; Outputs:                                                                      ;AN000;
+;       none                                                                    ;AN000;
+; No other registers altered                                                    ;AN000;
+                                                                                ;AN000;
+Procedure   RESTORE_MAP,NEAR                                                     ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+                                                                                ;AN000;
+        CMP     [BUF_EMS_MODE],-1         ;LB. EMS support                      ;AN000;
+        JZ      No_restore                ;LB. no                               ;AN000;
+        PUSH    AX                        ;LB. save regs                        ;AN000;
+        PUSH    DS                        ;LB. save regs                        ;AN000;
+        PUSH    SI                        ;LB.                                  ;AN000;
+        MOV     SI,OFFSET DOSGROUP:BUF_EMS_MAP_BUF     ;LB.                     ;AN000;
+
+        PUSH    CS
+        POP     DS
+        MOV     AX,4F01H                  ;LB. restore map                      ;AN000;
+        EnterCrit  critDisk               ;LB. enter critical section           ;AN000;
+        INT     67H                       ;LB.                                  ;AN000;
+        LeaveCrit  critDisk               ;LB. leave critical section           ;AN000;
+        POP     SI                        ;LB. restore regs                     ;AN000;
+        POP     DS                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB.                                  ;AN000;
+No_restore:                                                                      ;AN000;
+        return                                                                  ;AN000;
+EndProc RESTORE_MAP                                                              ;AN000;
+
+ENDIF
+                                                                                ;AN000;
+                                                                                ;AN000;
+
+Break   <SCANPLACE, PLACEBUF -- PUT A BUFFER BACK IN THE POOL>
+
+; Inputs:
+;       Same as PLACEBUF
+; Function:
+;       Save scan location and call PLACEBUF
+; Outputs:
+;       DS:DI Points to saved scan location
+; SI destroyed, other registers unchanged
+
+        procedure   ScanPlace,near
+ASSUME  DS:NOTHING,ES:NOTHING
+
+;;      PUSH    ES
+;;      LES     SI,[DI.buf_link]        ; Save scan location
+        MOV     SI,[DI.buf_next]        ; Save scan location
+        CALL    PLACEBUF
+;;      PUSH    ES
+;;      POP     DS                      ; Restore scan location
+        MOV     DI,SI
+;;      POP     ES
+        return
+EndProc ScanPlace
+
+; Rewritten PLACEBUF (LKR), eliminates loops
+;
+; Input:
+;       DS:DI points to buffer (DS->BUFFINFO array, DI=offset in array)
+; Function:
+;       Remove buffer from queue and re-insert it in proper place.
+; NO registers altered
+
+        procedure   PLACEBUF,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+;       invoke  save_world
+        push    AX                              ;Save only regs we modify       ;AN000;
+        push    BX                                                              ;AN000;
+        push    SI                                                              ;AN000;
+        push    ES                                                              ;AN000;
+
+        les     SI,[CurHashEntry]               ;ES:SI -> Current Hash entry    ;AN000;
+        mov     BX,word ptr ES:[SI.BUFFER_BUCKET] ;BX = offset of head of list  ;AN000;
+
+        cmp     [DI.buf_next],BX                ;Buf = last?                    ;AN000;
+        je      nret                            ;Yes, special case              ;AN000;
+        cmp     DI,BX                           ;Buf = first?                   ;AN000;
+        je      bufloop                         ;Yes, special case              ;AN000;
+        mov     SI,[DI.buf_prev]                ;No, SI = prior Buf             ;AN000;
+        mov     AX,[DI.buf_next]                ;Now delete Buf from list       ;AN000;
+        mov     [SI.buf_next],AX                                                ;AN000;
+        push    SI                              ;Save si                        ;AN000;
+        mov     SI,[DI.buf_next]                ;Update backward pointer        ;AN000;
+        mov     AX,[DI.buf_prev]                ;                               ;AN000;
+        mov     [SI.buf_prev],AX                ;                               ;AN000;
+        pop     si                              ;Restore si                     ;AN000;
+lookend:                                ;(label is now a misnomer)              ;AN000;
+        mov     SI,[BX.buf_prev]                ;SI-> last buffer               ;AN000;
+        mov     [SI.buf_next],DI                ;Add Buf to end of list         ;AN000;
+        mov     [BX.buf_prev],DI                                                ;AN000;
+        mov     [DI.buf_prev],SI                ;Update linkage in Buf too      ;AN000;
+        mov     [DI.buf_next],BX                                                ;AN000;
+nret:                                                                           ;AN000;
+                                                                                ;AN000;
+;       invoke  restore_world                                                   ;AN000;
+        pop     ES                              ;Restore regs we modified       ;AN000;
+        pop     SI                                                              ;AN000;
+        pop     BX                                                              ;AN000;
+        pop     AX                                                              ;AN000;
+                                                                                ;AN000;
+        cmp     [DI.buf_ID],-1                  ; Buffer FREE?                  ;AN000;
+        retnz                                   ; No                            ;AN000;
+        invoke  PLACEHEAD                       ; Buffer is free, belongs at hea;AN000;
+        return                                                                  ;AN000;
+bufloop:                                ;(label is now a misnomer)              ;AN000;
+        mov     BX,[DI.buf_next]                ;Set new head position          ;AN000;
+        mov     word ptr ES:[SI.BUFFER_BUCKET],BX                               ;AN000;
+        jmp     nret                            ;Continue with repositioning    ;AN000;
+
+EndProc PLACEBUF
+
+; SAME AS PLACEBUF except places buffer at head
+;  NOTE:::::: ASSUMES THAT BUFFER IS CURRENTLY THE LAST
+;       ONE IN THE LIST!!!!!!!
+; Rewritten PLACEBUF, takes buffer from end of list to head of list
+
+        procedure   PLACEHEAD,NEAR                                              ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+        push    ES                                                              ;AN000;
+        push    SI                                                              ;AN000;
+        les     SI,[CurHashEntry]                                               ;AN000;
+        mov     word ptr ES:[SI.BUFFER_BUCKET],DI                               ;AN000;
+        pop     SI                                                              ;AN000;
+        pop     ES                                                              ;AN000;
+        return                                                                  ;AN000;
+EndProc PLACEHEAD                                                               ;AN000;
+
+
+Break   <POINTCOMP -- 20 BIT POINTER COMPARE>
+
+; Compare DS:SI to ES:DI (or DS:DI to ES:SI) for equality
+; DO NOT USE FOR < or >
+; No Registers altered
+
+        procedure   PointComp,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        CMP     SI,DI
+        retnz
+        PUSH    CX
+        PUSH    DX
+        MOV     CX,DS
+        MOV     DX,ES
+        CMP     CX,DX
+        POP     DX
+        POP     CX
+        return
+EndProc PointComp
+
+Break   <GETBUFFR -- GET A SECTOR INTO A BUFFER>
+
+; Input:
+;       AL = 0 means sector must be pre-read
+;          ELSE no pre-read
+;       DX = Desired physical sector number           (LOW)
+;       [HIGH_SECTOR]= Desired physical sector number (HIGH)
+;       ES:BP = Pointer to drive parameters
+;       [ALLOWED] set in case of INT 24
+; Function:
+;       Get the specified local sector into one of the I/O buffers
+;       And shuffle the queue
+; Output:
+;       [CURBUF] Points to the Buffer for the sector
+;       THE BUFFER TYPE FIELD OF buf_flags = 0, caller must set it
+;       Carry set if error (currently user FAILed to INT 24)
+; DS,DX,ES:BP unchanged, all other registers destroyed
+
+        procedure   GETBUFFR,NEAR
+        DOSAssume   CS,<DS>,"GetBuffr"
+        ASSUME  ES:NOTHING
+
+        XOR     SI,SI
+
+        entry   GETBUFFRB
+
+        Assert  ISDPB,<ES,BP>,"GetBuffr"
+        MOV     [PREREAD],AX
+        MOV     AL,ES:[BP.dpb_drive]
+        LDS     DI,[LASTBUFFER]
+ASSUME  DS:NOTHING
+        MOV     CX,[HIGH_SECTOR]                ; F.C. >32mb                    ;AN000;
+        CMP     DI,-1                           ; Recency pointer valid?
+        JZ      SKBUF                           ; No
+
+        CMP     DX,WORD PTR [DI.buf_sector]
+        JNZ     SKBUF                           ; Wrong sector
+        CMP     CX,WORD PTR [DI.buf_sector+2]   ; F.C. >32mb                    ;AN000;
+        JNZ     SKBUF                           ; F.C. >32mb                    ;AN000;
+        CMP     AL,[DI.buf_ID]
+        JNZ     SKBUF                           ; Wrong Drive
+
+        JMP     JUSTBUF                         ; Just asked for same buffer
+SKBUF:
+        CALL    GETCURHEAD                      ;LB. get cuurent Hash entry     ;AN000;
+;       LDS     DI,[BUFFHEAD]
+NXTBFF:
+        CMP     DX,WORD PTR [DI.buf_sector]     ; F.C. >32mb                    ;AN000;
+        JNZ     BUMP
+        CMP     CX,WORD PTR [DI.buf_sector+2]   ; F.C. >32mb                    ;AN000;
+        JNZ     BUMP                            ; F.C. >32mb                    ;AN000;
+        CMP     AL,[DI.buf_ID]
+if      not bufferflag
+        JZ      SETINF
+else
+        jnz     bump
+        jmp     setinf
+endif
+BUMP:
+        mov     DI,[DI.buf_next]                ;;;;;;1/19/88                   ;AN000;
+        cmp     DI,[FIRST_BUFF_ADDR]            ;;;;;;1/19/88                   ;AN000;
+        JNZ     NXTBFF
+;;;;    LDS     DI,[CurHashEntry]               ;LB. secondary cache's use      ;AN000;
+;;;;    LDS     DI,[DI.BUFFER_BUCKET]           ;LB.                            ;AN000;
+ ;      LDS     DI,[BUFFHEAD]
+        PUSH    [HIGH_SECTOR]                   ;F.C. >32mb                     ;AN000;
+        PUSH    SI
+        PUSH    DX
+        PUSH    BP
+        PUSH    ES
+        CALL    BUFWRITE        ; Write out the dirty buffer
+        POP     ES
+        POP     BP
+        POP     DX
+        POP     SI
+        POP     [HIGH_SECTOR]                   ;F.C. >32mb                     ;AN000;
+if      not bufferflag
+        JC      GETBERR
+else
+        jnc     skip_getberr
+        jmp     getberr
+skip_getberr:
+endif
+        CALL    SET_RQ_SC_PARMS                 ;LB. set parms                  ;AN000;
+        XOR     AH,AH                   ; initial flags
+        TEST    BYTE PTR [PREREAD],-1   ; Read in the new sector
+        JNZ     SETBUF
+        LEA     BX,[DI.BufInSiz]        ; Point at buffer
+        MOV     CX,1
+        PUSH    SI
+        PUSH    DI
+        PUSH    DX
+; Note:  As far as I can tell, all disk reads into buffers go through this point.  -mrw 10/88
+if      bufferflag
+;       int     3
+        cmp     [buf_ems_mode], -1
+        jz      normread
+        push    bx
+        push    ds              ; save ds:bx --> ems_buffer
+        push    cs
+        pop     ds
+        mov     bx, offset dosgroup:low_ems_buf ; ds:bx --> low_ems_buffer
+normread:
+endif
+        OR      SI,SI
+        JZ      NORMSEC
+        invoke  FATSECRD
+        MOV     AH,buf_isFAT            ; Set buf_flags
+        JMP     SHORT GOTTHESEC         ; Buffer is marked free if read barfs
+NORMSEC:
+        invoke  DREAD                   ; Buffer is marked free if read barfs
+        MOV     AH,0                    ; Set buf_flags to no type, DO NOT XOR!
+GOTTHESEC:                              ; Carry set by either FATSECRD or DREAD
+if      bufferflag
+        pushf
+        jc      skipreadtrans
+        cmp     [buf_ems_mode], -1
+        je      skipreadtrans
+
+        popf
+        pop     ds
+        pop     bx              ; restore ems_buffer pointer
+        pushf
+
+        push    cx              ; save regs to be used by rep mov
+        push    ds
+        push    es
+
+        mov     di, bx
+        push    ds              
+        pop     es              ; es:di --> ems_buf
+        mov     si, offset dosgroup:low_ems_buf
+        push    cs
+        pop     ds              ; ds:si --> low_ems_buf
+        mov     cx, 512/2
+        rep movsw
+
+        pop     es              ; restore regs.
+        pop     ds
+        pop     cx
+skipreadtrans:
+        popf
+endif
+        POP     DX
+        POP     DI
+        POP     SI
+        JC      GETBERR
+SETBUF:
+        MOV     CX,[HIGH_SECTOR]               ; F.C. >32mb                     ;AN000;
+        MOV     WORD PTR [DI.buf_sector+2],CX  ; F.C. >32mb                     ;AN000;
+        MOV     WORD PTR [DI.buf_sector],DX    ; F.C. >32mb                     ;AN000;
+        MOV     WORD PTR [DI.buf_DPB],BP
+        MOV     WORD PTR [DI.buf_DPB+2],ES
+        MOV     AL,ES:[BP.dpb_drive]
+        MOV     WORD PTR [DI.buf_ID],AX         ; Sets buf_flags too, to AH
+SETINF:
+        MOV     [DI.buf_wrtcnt],1               ; Default to not a FAT sector   ;AC000;
+        XOR     AX,AX                           ;>32mb                          ;AN000;
+        OR      SI,SI
+        JZ      SETSTUFFOK
+        MOV     AL,ES:[BP.dpb_FAT_count]
+        MOV     [DI.buf_wrtcnt],AL              ;>32mb                          ;AN000;
+        MOV     AX,ES:[BP.dpb_FAT_size]
+SETSTUFFOK:
+        MOV     [DI.buf_wrtcntinc],AX           ;>32mb                          ;AC000;
+        CALL    PLACEBUF
+JUSTBUF:
+        MOV     WORD PTR [CURBUF+2],DS
+        MOV     WORD PTR [LASTBUFFER+2],DS
+        MOV     WORD PTR [CURBUF],DI
+        MOV     WORD PTR [LASTBUFFER],DI
+        CLC
+GETBERR:
+        Context DS
+        return
+EndProc GETBUFFR
+
+Break   <FLUSHBUF -- WRITE OUT DIRTY BUFFERS>
+
+; Input:
+;       DS = DOSGROUP
+;       AL = Physical unit number local buffers only
+;          = -1 for all units and all remote buffers
+; Function:
+;       Write out all dirty buffers for unit, and flag them as clean
+;       Carry set if error (user FAILed to I 24)
+;           Flush operation completed.
+; DS Preserved, all others destroyed (ES too)
+
+        procedure   FlushBuf,NEAR
+        DOSAssume   CS,<DS>,"FlushBuf"
+        ASSUME  ES:NOTHING
+
+        MOV     AH,-1
+;       LDS     DI,[BUFFHEAD]
+ASSUME  DS:NOTHING
+
+        LDS     DI,[BUF_HASH_PTR]         ;LB. get Hash Table addr              ;AN000;
+        MOV     CX,[BUF_HASH_COUNT]       ;LB. get Hash entry count             ;AN000;
+        XOR     DX,DX                     ;LB. set initial index to 0           ;AN000;
+
+NXTBUFF2:
+        PUSH    CX                           ;LB. save Hash entry count         ;AN000;
+        TEST    [DOS34_FLAG],FROM_DISK_RESET ;MS. from disk reset               ;AN004;
+        JNZ     Zapzap                       ;MS. yes                           ;AN004;
+        CMP     [DI.Dirty_Count],0           ;LB. dirty entry ?                 ;AN000;
+        JZ      getnext                      ;LB. no                            ;AN000;
+Zapzap:                                                                         ;AN004;
+        PUSH    DS                           ;LB. save regs                     ;AN000;
+        PUSH    DI                           ;LB.                               ;AN000;
+        invoke  Map_Entry                    ;LB. ds:di -> first buffer addr    ;AN000;
+NXTBUFF:
+        CALL    CHECKFLUSH      ; Ignore Carry return from CHECKFLUSH.
+                                ; FAILERR is set if user FAILed.
+        PUSH    AX
+        MOV     AL,[DI.buf_ID]
+        CMP     AL,BYTE PTR [WPERR]
+        JZ      ZAP
+        TEST    [DOS34_FLAG],FROM_DISK_RESET ;MS. from disk reset               ;AN000;
+        JNZ     Zap                          ;MS. yes                           ;AN000;
+
+NOZAP:
+        POP     AX
+        mov     DI,[DI.buf_next]             ;;;;1/19/88                        ;AN000;
+        CMP     DI,[FIRST_BUFF_ADDR]         ;;;;1/19/88                        ;AN000;
+        JNZ     NXTBUFF
+
+        POP     DI                           ;LB.                               ;AN000;
+        POP     DS                           ;LB.                               ;AN000;
+getnext:
+        ADD     DI,size BUFFER_HASH_ENTRY    ;LB. position to next entry        ;AN000;
+        POP     CX                           ;LB. restore entry count           ;AN000;
+        LOOP    NXTBUFF2                     ;LB. get next entry buffer         ;AN000;
+        Context DS
+        CMP     [FAILERR],0
+        JNZ     FLSHBad         ; Carry clear if JMP
+        return
+FlshBad:
+        STC                     ; Return error if user FAILed
+        return
+Zap:
+        MOV     WORD PTR [DI.buf_ID],00FFH ; Invalidate buffer, it is inconsistent
+        JMP     NoZap
+
+EndProc FlushBuf
+
+        procedure CHECKFLUSH,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+; Carry set if problem (currently user FAILed to I 24)
+
+        Assert  ISBUF,<DS,DI>,"CheckFlush"
+        CMP     [DI.buf_ID],AH
+        retz                            ; Skip free buffers, carry clear
+        CMP     AH,AL
+        JZ      DOBUFFER                ; Do all dirty buffers
+        CMP     AL,[DI.buf_ID]
+        CLC
+        retnz                           ; Buffer not for this unit or SFT
+DOBUFFER:
+        TEST    [DI.buf_flags],buf_dirty
+        retz                            ; Buffer not dirty, carry clear by TEST
+        PUSH    AX
+        PUSH    WORD PTR [DI.buf_ID]
+        CALL    BUFWRITE
+        POP     AX
+        JC      LEAVE_BUF               ; Leave buffer marked free (lost).
+        AND     AH,NOT buf_dirty        ; Buffer is clean, clears carry
+        MOV     WORD PTR [DI.buf_ID],AX
+LEAVE_BUF:
+        POP     AX                      ; Search info
+        return
+EndProc CHECKFLUSH
+
+Break   <BUFWRITE -- WRITE OUT A BUFFER IF DIRTY>
+
+; Input:
+;       DS:DI Points to the buffer
+; Function:
+;       Write out all the buffer if dirty.
+; Output:
+;       Buffer marked free
+;       Carry set if error (currently user FAILed to I 24)
+; DS:DI Preserved, ALL others destroyed (ES too)
+
+        procedure   BufWrite,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISBUF,<DS,DI>,"BufWrite"
+        MOV     AX,00FFH
+        XCHG    AX,WORD PTR [DI.buf_ID] ; Free, in case write barfs
+        CMP     AL,0FFH
+        retz                            ; Buffer is free, carry clear.
+        TEST    AH,buf_dirty
+        retz                            ; Buffer is clean, carry clear.
+        invoke  DEC_DIRTY_COUNT         ; LB. decrement dirty count
+        CMP     AL,BYTE PTR [WPERR]
+        retz                            ; If in WP error zap buffer
+        MOV     [SC_DRIVE],AL           ;LB. set it for invalidation            ;AN000;
+        LES     BP,[DI.buf_DPB]
+        LEA     BX,[DI.BufInSiz]        ; Point at buffer
+        MOV     DX,WORD PTR [DI.buf_sector]     ;F.C. >32mb                     ;AN000;
+        MOV     CX,WORD PTR [DI.buf_sector+2]   ;F.C. >32mb                     ;AN000;
+        MOV     [HIGH_SECTOR],CX                ;F.C. >32mb                     ;AN000;
+        MOV     CL,[DI.buf_wrtcnt]              ;>32mb                          ;AC000;
+;       MOV     AL,CH                   ; [DI.buf_wrtcntinc]
+        XOR     CH,CH
+        MOV     AX,[DI.buf_wrtcntinc]           ;>32mb                          ;AC000;
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL
+        TEST    [DI.buf_flags],buf_isDATA
+        JZ      NO_IGNORE
+        OR      [ALLOWED],allowed_IGNORE
+NO_IGNORE:
+        PUSH    DI              ; Save buffer pointer
+        XOR     DI,DI           ; Indicate failure
+WRTAGAIN:
+        SaveReg <DI,CX,AX>
+        MOV     CX,1
+        SaveReg <BX,DX,DS>
+; Note:  As far as I can tell, all disk reads into buffers go through this point.  -mrw 10/88
+
+if      bufferflag
+;       int     3
+        cmp     [buf_ems_mode], -1
+        jz      skipwritetrans
+
+        push    es
+        push    di
+        push    si
+        push    cx
+
+        mov     si, bx          ; ds:si --> ems_buffer
+        mov     di, offset dosgroup:low_ems_buf
+        push    cs
+        pop     es              ; es:di --> low_ems_buffer
+        mov     cx, 512/2
+        rep     movsw
+
+        pop     cx
+        pop     si
+        pop     di
+        pop     es
+
+        push    ds
+        push    bx
+        mov     bx, offset dosgroup:low_ems_buf
+        push    cs
+        pop     ds              ; ds:bx --> low_ems_buffer
+skipwritetrans:
+endif
+
+        invoke  DWRITE          ; Write out the dirty buffer
+
+if      bufferflag
+        pushf                   ; save carry flag from DWRITE
+        cmp     [buf_ems_mode], -1
+        jz      normwrite
+        popf                    ; need to get at stack
+        pop     bx              ; ds:bx --> ems_buffer
+        pop     ds
+        pushf                   ; put it back, so we can pop it
+normwrite:
+        popf                    ; restore carry flag
+endif
+
+        RestoreReg  <DS,DX,BX>
+        RestoreReg  <AX,CX,DI>
+        JC      NOSET
+        INC     DI              ; If at least ONE write succeedes, the operation
+NOSET:                          ;       succeedes.
+        ADD     DX,AX
+        LOOP    WRTAGAIN
+        OR      DI,DI           ; Clears carry
+        JNZ     BWROK           ; At least one write worked
+        STC                     ; DI never got INCed, all writes failed.
+BWROK:
+        POP     DI
+        return
+EndProc BufWrite
+
+Break   <SET_RQ_SC_PARMS-set requesting drive for SC>
+
+; Input:
+;       ES:BP = drive parameter block
+; Function:
+;       Set requesting drive, and sector size
+; Output:
+;       [SC_SECTOR_SIZE]= drive sector size
+;       [SC_DRIVE]= drive #
+;
+; All registers preserved
+
+        procedure   SET_RQ_SC_PARMS,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        CMP     [SC_CACHE_COUNT],0  ;LB. do it only secondary cache exists      ;AN000;
+        JZ      nosec               ;LB.                                        ;AN000;
+        PUSH    DX                  ;LB. save dx                                ;AN000;
+        MOV     DX,ES:[BP.dpb_sector_size]            ;LB. save sector size     ;AN000;
+        MOV     [SC_SECTOR_SIZE],DX                   ;LB.                      ;AN000;
+        MOV     DL,ES:[BP.dpb_drive]                  ;LB. save drive #         ;AN000;
+        MOV     [SC_DRIVE],DL                         ;LB.                      ;AN000;
+                                                                                ;AN000;
+        POP     DX                                    ;LB. restore dx           ;AN000;
+
+nosec:
+        return
+EndProc SET_RQ_SC_PARMS                               ;LB. return               ;AN000;
+
+Break   <INC_DIRTY_COUNT-increment dirty count>
+
+; Input:
+;       none
+; Function:
+;       increment dirty buffers count
+; Output:
+;       dirty buffers count in the current hash entry is incremented
+;
+; All registers preserved
+
+        procedure   INC_DIRTY_COUNT,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS                  ;LB. save regs                              ;AN000;
+        PUSH    SI                  ;LB.                                        ;AN000;
+        LDS     SI,[CurHashEntry]   ;LB. get current hash entry                 ;AN000;
+        INC     [SI.Dirty_Count]    ;LB. add 1                                  ;AN000;
+        POP     SI                  ;LB. restore regs                           ;AN000;
+        POP     DS                  ;LB.                                        ;AN000;
+        return
+EndProc INC_DIRTY_COUNT             ;LB. return                                 ;AN000;
+
+Break   <DEC_DIRTY_COUNT-decrement dirty count>
+
+; Input:
+;       none
+; Function:
+;       decrement dirty buffers count
+; Output:
+;       dirty buffers count in the current hash entry is decremented
+;
+; All registers preserved
+
+        procedure   DEC_DIRTY_COUNT,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS                  ;LB. save regs                              ;AN000;
+        PUSH    SI                  ;LB.                                        ;AN000;
+        LDS     SI,[CurHashEntry]   ;LB. get current hash entry                 ;AN000;
+        CMP     [SI.Dirty_Count],0  ;LB. in case if 0                           ;AN000;
+        JZ      nodec               ;LB. do nothing                             ;AN000;
+        DEC     [SI.Dirty_Count]    ;LB. sub 1                                  ;AN000;
+nodec:
+        POP     SI                  ;LB. restore regs                           ;AN000;
+        POP     DS                  ;LB.                                        ;AN000;
+        return
+EndProc DEC_DIRTY_COUNT             ;LB. return                                 ;AN000;
+
+
+Break   <MAP_ENTRY- map the buffers of this entry>
+
+; Input:
+;       DS:DI ponits to hash entry
+; Function:
+;       map the buferrs of this entry
+; Output:
+;       the buffers are mapped
+;
+; All registers preserved
+
+        procedure   Map_Entry,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DX                        ;LB. save regs                        ;AN000;
+        PUSH    AX                        ;LB.                                  ;AN000;
+        PUSH    BX                        ;LB.                                  ;AN000;
+        JMP     Map_Entry2                ;LB.                                  ;AN000;
+EndProc Map_Entry                         ;LB.                                  ;AN000;
+
+
+IF      BUFFERFLAG
+
+;-------------------------------------------------------------------------
+;       Procedure name  :       detect collision
+;       Inputs          :       [DMAADD] - user Xaddr
+;                               [CURADD] - current offset
+;                               [BYTCNT1] - for partial sector read
+;                               SAFE_FLAG - cleared - indicating that the
+;                               current page is unsafe.
+;
+;       Outputs         :       es - physical page segment to use
+;                               di - corresponding page number
+;                               SAFE_FLAG is set is a collision is detected
+;                               and the current page is switched form 
+;                               LAST_PAGE to FIRST_PAGE.
+;---------------------------------------------------------------------------
+;                               
+
+Procedure       detect_collision, near
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        push    ax
+        push    bx
+        push    cx
+
+        cmp     [BUF_EMS_MODE], -1
+        jz      fin_detect_coll
+
+        mov     ax, [CURADD]    ; current offset 
+
+        cmp     [BYTCNT1], 0
+        je      no_partial_sector
+        add     ax, [BYTCNT1]
+
+no_partial_sector:
+        mov     cl, 4
+        shr     ax, cl          ; convert to paragraphs
+        mov     bx, word ptr [DMAADD+2] ; get original segment 
+        add     ax, bx          ; get current segment
+
+        and     ax, 0fc00h      ; get ems page of current segment
+        cmp     ax, [BUF_EMS_LAST_PAGE] ; is the current segment = last segment
+        jne     fin_detect_coll ; page is still safe
+
+;       int     3
+        push    ax
+        mov     ax, word ptr [DMAADD]
+        mov     ax, [NEXTADD]
+        mov     ax, [CURADD]
+        mov     ax, [BYTCNT1]
+        pop     ax
+
+        call    restore_user_map
+        mov     word ptr [LASTBUFFER], -1
+        mov     ax, [BUF_EMS_FIRST_PAGE]
+        mov     [BUF_EMS_PFRAME], ax
+        mov     ax, [BUF_EMS_FIRST_PAGE+2]
+        mov     [BUF_EMS_PAGE_FRAME], ax
+        mov     [BUF_EMS_SAFE_FLAG], 1
+        call    Setup_EMS_buffers
+        call    save_user_map
+
+fin_detect_coll:
+        pop     cx
+        pop     bx
+        pop     ax
+        ret
+
+EndProc detect_collision
+
+Procedure Setup_EMS_Buffers,Near
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+
+        cmp     [BUF_EMS_MODE], -1
+        jz      setup_ems_ret
+
+        push    bx
+        push    cx
+        push    ax
+        push    ds
+        push    di
+
+        mov     bx, [BUF_HASH_COUNT]    ; # of hash table entries
+        lds     di, [BUF_HASH_PTR]      ; ds:di -> hash table
+
+        xor     cx, cx
+
+next_bucket:
+        mov     ax, [BUF_EMS_PFRAME]
+        mov     word ptr ds:[di.BUFFER_BUCKET+2], ax
+        add     di, 8                   ; next has entry.
+        inc     cx
+        cmp     cx, bx
+        jne     next_bucket
+
+        pop     di
+        pop     ds
+        pop     ax
+        pop     cx
+        pop     bx
+
+setup_ems_ret:
+        ret
+
+EndProc Setup_EMS_Buffers
+
+ENDIF
+
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/CLOSE.ASM b/v4.0/src/DOS/CLOSE.ASM
new file mode 100644
index 0000000..8156ac8
--- /dev/null
+++ b/v4.0/src/DOS/CLOSE.ASM
@@ -0,0 +1,432 @@
+;       SCCSID = @(#)close.asm  1.1 85/04/09
+TITLE   DOS_CLOSE/COMMIT - Internal SFT close and commit call for MSDOS
+NAME    DOS_CLOSE
+; Internal Close and Commit calls to close a local or NET SFT.
+;
+;   DOS_CLOSE
+;   DOS_COMMIT
+;   FREE_SFT
+;   SetSFTTimes
+;
+;   Revision history:
+;
+;       AN000  version 4.00  Jan. 1988
+;       A005   PTM 3718 --- lost clusters when fastopen installed
+;       A011   PTM 4766 --- C2 fastopen problem
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+Installed = TRUE
+
+        I_need  Attrib,BYTE
+        i_need  THISSFT,DWORD
+        i_need  CURBUF,DWORD
+        i_need  THISDRV,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  EXTERR_LOCUS,BYTE
+        I_need  FailErr,BYTE
+        I_Need  PROC_ID,WORD
+        I_Need  USER_ID,WORD
+        i_need  JShare,DWORD
+        i_need  HIGH_SECTOR,WORD         ;F.C. >32mb
+        i_need  OLD_FIRSTCLUS,WORD        ;F.O. >32mb
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+Break <DOS_CLOSE -- CLOSE FILE from SFT>
+
+; Inputs:
+;       [THISSFT] set to the SFT for the file being used
+; Function:
+;       Close the indicated file via the SFT
+; Returns:
+;       sf_ref_count decremented otherwise
+;       ES:DI point to SFT
+;       Carry set if error
+;           AX has error code
+; DS preserved, others destroyed
+
+        procedure   DOS_CLOSE,NEAR
+        DOSAssume   CS,<DS>,"DOS_Close"
+        ASSUME  ES:NOTHING
+
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,<"DOS_CLOSE">
+        fmt     TypAccess,LevBUSY,<"$p: CLOSE SFT: $x:$x\n">,<ES,DI>
+        MOV     BX,ES:[DI.sf_flags]
+;
+; Network closes are handled entirely by the net code.
+;
+        TEST    BX,sf_isnet
+        JZ      LocalClose
+;       invoke  OWN_SHARE                   ;IFS. IFS owns share ?              ;AN000;
+;       JZ      noshare                     ;IFS. yes                           ;AN000;
+;       EnterCrit   critDisk                ;IFS.                               ;AN000;
+;       CALL    SetSFTTimes                 ;IFS. set time for all SFT          ;AN000;
+;       LeaveCrit   critDisk                ;IFS.                               ;AN000;
+noshare:
+        CallInstall Net_Close,multnet,6
+;       JC      nomore                      ;IFS. error                         ;AN000;
+;       invoke  OWN_SHARE                   ;IFS. IFS owns share ?              ;AN000;
+;       JZ      nomore                      ;IFS. yes                           ;AN000;
+;       invoke  ShareEnd                    ;IFS. remove SFT entry from share   ;AN000;
+nomore:
+        return
+
+;
+; All closes release the sharing information.
+; No commit releases sharing information
+;
+; All closes decrement the ref count.
+; No commit decrements the ref count.
+;
+LocalClose:
+        EnterCrit   critDisk
+        CALL    SetSFTTimes
+        CALL    Free_SFT                ; dec ref count or mark as busy
+
+        TEST    BX,devid_device        ;FS. device ?                            ;AN000;
+        JNZ     nofastsk               ;FS. yes                                 ;AN000;
+        MOV     CX,ES:[DI.sf_firclus]  ;FS. cx= first cluster                   ;AN000;
+        OR      CX,CX                  ;FS. cx=0 ?                              ;AN000;
+        JZ      nofastsk               ;FS. yes, dont do it                     ;AN000;
+        LDS     SI,ES:[DI.sf_devptr]   ;FS.                                     ;AN000;
+        MOV     DL,[SI.dpb_drive]      ;FS. dl= drive                           ;AN000;
+        invoke  FastSeek_Close         ;FS. invoke fastseek                     ;AN000;
+nofastsk:
+        Context DS
+        SaveReg <AX,BX>
+        invoke  ShareEnd
+        RestoreReg  <BX,AX>
+;
+; Commit enters here.  AX from commit MUST be <> 1, BX is flags word
+;
+CloseEntry:
+        PUSH    AX
+;
+; File clean or device does not get stamped nor disk looked at.
+;
+        TEST    BX,devid_file_clean + devid_device
+        JZ      rdir
+        JMP     Free_SFT_OK             ; either clean or device
+;
+; Retrieve the directory entry for the file
+;
+rdir:
+        CALL    DirFromSFT
+ASSUME  DS:NOTHING
+        MOV     AL,error_access_denied
+        JNC     clook
+        JMP     CloseFinish             ; pretend the close worked.
+clook:
+;
+; ES:DI points to entry
+; DS:SI points to SFT
+; ES:BX points to buffer header
+;
+        SaveReg <DI,SI>
+        LEA     SI,[SI].sf_name
+;
+; ES:DI point to directory entry
+; DS:SI point to unpacked name
+;
+        invoke  XCHGP
+;
+; ES:DI point to unpacked name
+; DS:SI point to directory entry
+;
+        invoke  MetaCompare
+        invoke  XCHGP
+        RestoreReg  <SI,DI>
+        JZ      CLOSE_GO                ; Name OK
+Bye:    MOV     DI,SI
+        PUSH    DS
+        POP     ES                      ; ES:DI points to SFT
+        PUSH    SS
+        POP     DS
+        STC
+        MOV     AL,error_file_not_found
+        JMP     CloseFinish
+
+CLOSE_GO:
+        TEST    [SI].sf_mode,sf_isfcb   ; FCB ?
+        JZ      nofcb                   ; no, set dir attr, sf_attr
+        MOV     CH,ES:[DI].dir_attr
+        MOV     AL,[SI].sf_attr
+        MOV     Attrib,AL
+        invoke  MatchAttributes
+        JNZ     Bye                     ; attributes do not match
+        JMP     SHORT setattr           ;FT.
+nofcb:
+        MOV     AL,[SI].sf_attr         ;FT.                                    ;AN000;
+        MOV     ES:[DI].dir_attr,AL     ;FT.                                    ;AN000;
+setattr:
+        OR      BYTE PTR ES:[DI.dir_attr],attr_archive  ;Set archive
+        MOV     AX,ES:[DI.dir_first]    ;AN011;F.O. save old first clusetr
+        MOV     [OLD_FIRSTCLUS],AX      ;AN011;F.O. save old first clusetr
+
+        MOV     AX,[SI.sf_firclus]
+        MOV     ES:[DI.dir_first],AX    ;Set firclus pointer
+        MOV     AX,WORD PTR [SI.sf_size]
+        MOV     ES:[DI.dir_size_l],AX   ;Set size
+        MOV     AX,WORD PTR [SI.sf_size+2]
+        MOV     ES:[DI.dir_size_h],AX
+        MOV     AX,[SI.sf_date]
+        MOV     ES:[DI.dir_date],AX     ;Set date
+        MOV     AX,[SI.sf_time]
+        MOV     ES:[DI.dir_time],AX     ;Set time
+;; File Tagging
+
+;       MOV     AX,[SI.sf_codepage]        ;AN000;
+;       MOV     ES:[DI.dir_codepg],AX      ;AN000;Set code page
+;       MOV     AX,[SI.sf_extcluster]      ;AN000;
+;       MOV     ES:[DI.dir_extcluster],AX  ;AN000;   ;Set XA cluster
+;       MOV     AL,[SI.sf_attr_hi]         ;AN000;
+;       MOV     ES:[DI.dir_attr2],AL       ;AN000;   ;Set high attr
+
+;; File Tagging
+        TEST    ES:[BX.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[BX.buf_flags],buf_dirty ;Buffer dirty
+yesdirty:
+        SaveReg  <DS,SI>
+        MOV     CX,[SI.sf_firclus]      ; do this for Fastopen
+        MOV     AL,[THISDRV]
+;;; 10/1/86  update fastopen cache
+        PUSH    DX
+        MOV     AH,0                    ; dir entry update
+        MOV     DL,AL                   ; drive number A=0, B=1,,,
+        OR      CX,CX                     ;AN005; first cluster 0; may be truncated
+        JNZ     do_update2                ;AN005; no, do update
+        MOV     AH,3                      ;AN005; do a delete cache entry
+        MOV     DI,WORD PTR [SI.sf_dirsec]   ;AN005; cx:di = dir sector
+        MOV     CX,WORD PTR [SI.sf_dirsec+2] ;AN005;
+        MOV     DH,[SI.sf_dirpos]            ;AN005; dh= dir pos
+        JMP     SHORT do_update         ;AN011;F.O.
+do_update2:                             ;AN011;F.O.
+        CMP     CX,[OLD_FIRSTCLUS]      ;AN011;F.O. same as old first clusetr?
+        JZ      do_update               ;AN011;F.O. yes
+        MOV     AH,2                    ;AN011;F.O. delete the old entry
+        MOV     CX,[OLD_FIRSTCLUS]      ;AN011;F.O.
+do_update:                                ;AN005;
+        Context DS
+        invoke  FastOpen_Update         ; invoke fastopen
+        POP     DX
+
+;;; 10/1/86  update fastopen cache
+        invoke  FLUSHBUF                ; flush all relevant buffers
+        RestoreReg  <DI,ES>
+        MOV     AL,error_access_denied
+        JC      CloseFinish
+FREE_SFT_OK:
+        CLC                             ; signal no error.
+CloseFinish:
+;
+; Indicate to the device that the SFT is being closed.
+;
+;;;; 7/21/86
+        PUSHF                           ; save flag from DirFromSFT
+        invoke  Dev_Close_SFT
+        POPF
+;;;; 7/21/86
+;
+; See if the ref count indicates that we have busied the SFT.  If so, mark the
+; SFT as being free.  Note that we do NOT need to be in critSFT as we are ONLY
+; going to be moving from busy to free.
+;
+        POP     CX                      ; get old ref count
+        PUSHF
+        fmt     TypAccess,LevBUSY,<"$p: DOSFreeSFT: $x:$x from $x\n">,<ES,DI,AX>
+        DEC     CX                      ; if cx != 1
+        JNZ     NoFree                  ; then do NOT free SFT
+        Assert  ISSFT,<ES,DI>,"DOS_FREE_SFT"
+        MOV     ES:[DI].sf_ref_Count,CX
+NoFree:
+        LeaveCrit   critDisk
+        POPF
+        return
+EndProc DOS_Close
+
+;
+; ES:DI -> SFT. Decs sft_ref_count.  If the count goes to 0, mark it as busy.
+; Flags preserved.  Return old ref count in AX
+;
+; Note that busy is indicated by the SFT ref count being -1.
+;
+Procedure   FREE_SFT,NEAR
+        DOSAssume   CS,<DS>,"Free_SFT"
+        ASSUME  ES:NOTHING
+
+        PUSHF           ; Save carry state
+        MOV     AX,ES:[DI.sf_ref_count]
+        DEC     AX
+        JNZ     SetCount
+        DEC     AX
+SetCount:
+        XCHG    AX,ES:[DI.sf_ref_count]
+        POPF
+        return
+
+EndProc Free_SFT
+
+;
+;   DirFromSFT - locate a directory entry given an SFT.
+;
+;   Inputs:     ES:DI point to SFT
+;               DS = DOSGroup
+;   Outputs:
+;               EXTERR_LOCUS = errLOC_Disk
+;               CurBuf points to buffer
+;               Carry Clear -> operation OK
+;                   ES:DI point to entry
+;                   ES:BX point to buffer
+;                   DS:SI point to SFT
+;               Carry SET   -> operation failed
+;                   registers trashified
+;   Registers modified: ALL
+
+Procedure   DirFromSFT,NEAR
+        ASSUME  DS:DOSGroup,ES:NOTHING
+
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        SaveReg <ES,DI>
+        MOV     DX,WORD PTR ES:[DI.sf_dirsec+2]  ;F.C. >32mb
+        MOV     [HIGH_SECTOR],DX                 ;F.C. >32mb
+        MOV     DX,WORD PTR ES:[DI.sf_dirsec]
+
+        PUSH    [HIGH_SECTOR]                    ;F.C. >32mb
+        PUSH    DX
+        invoke  FATREAD_SFT             ; ES:BP points to DPB, [THISDRV] set
+                                        ; [THISDPB] set
+        POP     DX
+        POP     [HIGH_SECTOR]                    ;F.C. >32mb
+        JC      PopDone
+        XOR     AL,AL                   ; Pre read
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        invoke  GETBUFFR
+        JC      PopDone
+        RestoreReg  <SI,DS>             ; Get back SFT pointer
+        ASSUME  DS:NOTHING
+        LES     DI,Curbuf
+        OR      ES:[DI.buf_flags],buf_isDIR
+        MOV     BX,DI                   ; ES:BX point to buffer header
+        LEA     DI,[DI].BUFINSIZ        ; Point to buffer
+        MOV     AL,SIZE dir_entry
+        MUL     [SI].sf_DirPos
+        ADD     DI,AX                   ; Point at the entry
+
+        return                          ; carry is clear
+PopDone:
+        RestoreReg  <DI,ES>
+        return
+EndProc DirFromSFT
+
+Break   <DOS_Commit - update directory entries>
+
+; Inputs:
+;       Same as DOS_CLOSE
+; Function:
+;       Commit the file
+; Returns:
+;       Same as DOS_CLOSE except ref_count field is not altered
+; DS preserved, others destroyed
+
+        procedure   DOS_COMMIT,NEAR
+        DOSAssume   CS,<DS>,"DOS_Commit"
+        ASSUME  ES:NOTHING
+
+        LES     DI,[THISSFT]
+        MOV     BX,ES:[DI.sf_flags]
+        TEST    BX,devid_file_clean + devid_device      ;Clears carry
+        retnz
+        TEST    BX,sf_isnet
+        JZ      LOCAL_COMMIT
+IF NOT Installed
+        transfer NET_COMMIT
+ELSE
+        MOV     AX,(multNET SHL 8) OR 7
+        INT     2FH
+        return
+ENDIF
+
+;
+; Perform local commit operation by doing a close but not releaseing the SFT.
+; There are three ways we can do this.  One is to enter a critical section to
+; protect a potential free.  The second is to increment the ref count to mask
+; the close decrementing.
+;
+; The proper way is to let the caller's of close decide if a decrement should
+; be done.  We do this by providing another entry into close after the
+; decrement and after the share information release.
+;
+LOCAL_COMMIT:
+        EnterCrit   critDisk
+        EnterCrit   critDisk            ;PTM.                                   ;AN000;
+        call    SetSFTTimes
+        MOV     AX,-1
+        call    CloseEntry
+        PUSHF                           ;PTM.                                   ;AN000;
+        invoke  DEV_OPEN_SFT            ;PTM.  increment device count           ;AN000;
+        POPF                            ;PTM.                                   ;AN000;
+        LeaveCrit CritDisk              ;PTM.                                   ;AN000;
+        return
+
+EndProc DOS_COMMIT
+
+Break   <SetSFTTimes - signal a change in the times for an SFT>
+
+;
+;   SetSFTTimes - Examine the flags for a SFT and set the time appropriately.
+;   Reflect these times in other SFT's for the same file.
+;
+;   Inputs:     ES:DI point to SFT
+;               BX = sf_flags set apprpriately
+;   Outputs:    Set sft times to current time iff File & dirty & !nodate
+;   Registers modified: All except ES:DI, BX, AX
+;
+
+Procedure   SetSFTTimes,NEAR
+        Assert  ISSFT,<ES,DI>,"SetSFTTimes"
+;
+; File clean or device does not get stamped nor disk looked at.
+;
+        TEST    BX,devid_file_clean + devid_device
+        retnz                           ; clean or device => no timestamp
+;
+; file and dirty.  See if date is good
+;
+        TEST    BX,sf_close_nodate
+        retnz                           ; nodate => no timestamp
+        SaveReg <AX,BX>
+        invoke  DATE16                  ; Date/Time to AX/DX
+        MOV     ES:[DI.sf_date],AX
+        MOV     ES:[DI.sf_time],DX
+        XOR     AX,AX
+if installed
+        call    JShare + 14 * 4
+else
+        call    ShSU
+endif
+        RestoreReg  <BX,AX>
+        return
+EndProc SetSFTTimes
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/CPMIO.ASM b/v4.0/src/DOS/CPMIO.ASM
new file mode 100644
index 0000000..9878d4d
--- /dev/null
+++ b/v4.0/src/DOS/CPMIO.ASM
@@ -0,0 +1,448 @@
+;       SCCSID = @(#)cpmio.asm  1.1 85/04/10
+TITLE   CPMIO - device IO for MSDOS
+NAME    CPMIO
+;
+; Standard device IO for MSDOS (first 12 function calls)
+;
+
+.xlist
+.xcref
+include dosseg.asm
+.cref
+.list
+
+;
+; Old style CP/M 1-12 system calls to talk to reserved devices
+;
+;   $Std_Con_Input_No_Echo
+;   $Std_Con_String_Output
+;   $Std_Con_String_Input
+;   $RawConIO
+;   $RawConInput
+;   RAWOUT
+;   RAWOUT2
+;
+;   Revision history:
+;
+;     A000     version 4.00 - Jan 1988
+;     A002     PTM    -- dir >lpt3 hangs
+;
+;
+;
+;
+;
+;
+;
+;
+;
+;
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+.xlist
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include doscntry.inc                    ;AN000          2/12/KK
+.list
+.cref
+
+IFNDEF  KANJI
+KANJI   EQU     0       ;FALSE
+ENDIF
+
+; The following routines form the console I/O group (funcs 1,2,6,7,8,9,10,11).
+; They assume ES and DS NOTHING, while not strictly correct, this forces data
+; references to be SS or CS relative which is desired.
+
+    i_need  CARPOS,BYTE
+    i_need  STARTPOS,BYTE
+    i_need  INBUF,128
+    i_need  INSMODE,BYTE
+    i_need  user_SP,WORD
+    EXTRN   EscChar:BYTE                ; lead byte for function keys
+    EXTRN   CanChar:BYTE                ; Cancel character
+    EXTRN   OUTCHA:NEAR                 ;AN000 char out with status check 2/11/KK
+    i_need  Printer_Flag,BYTE
+    i_need  SCAN_FLAG,BYTE
+    i_need  DATE_FLAG,WORD
+    i_need  Packet_Temp,WORD            ; temporary packet used by readtime
+    i_need  DEVCALL,DWORD
+    i_need  InterChar,BYTE              ;AN000;interim char flag ( 0 = regular char)
+    i_need  InterCon,BYTE               ;AN000;console flag ( 1 = in interim mode )
+    i_need  SaveCurFlg,BYTE             ;AN000;console out ( 1 = print and do not advance)
+    i_need  COUNTRY_CDPG,byte           ;AN000;         2/12/KK
+    i_need  TEMP_VAR,WORD               ;AN000;         2/12/KK
+    i_need  DOS34_FLAG,WORD             ;AN000;         2/12/KK
+
+
+
+Break
+ IF  DBCS                                                         ;AN000;
+
+;-------------------------------- Start of Korean Support 2/11/KK
+        procedure   $STD_CON_INPUT_NO_ECHO,NEAR   ;System call 8  ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                     ;AN000;
+
+StdCILop:                                                         ;AN000;
+        invoke  INTER_CON_INPUT_NO_ECHO                           ;AN000;
+        transfer InterApRet             ; go to return fuction    ;AN000;
+
+EndProc $STD_CON_INPUT_NO_ECHO                                    ;AN000;
+
+        procedure   INTER_CON_INPUT_NO_ECHO,NEAR                  ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                     ;AN000;
+;-----------------------------------End of Korean Support 2/11/KK
+
+; Inputs:
+;       None
+; Function:
+;       Same as $STD_CON_INPUT_NO_ECHO but uses interim character read from
+;       the device.
+; Returns:
+;       AL = character
+;       Zero flag SET if interim character, RESET otherwise
+
+ ELSE                                                             ;AN000;
+
+
+;
+; Inputs:
+;       None
+; Function:
+;       Input character from console, no echo
+; Returns:
+;       AL = character
+
+        procedure   $STD_CON_INPUT_NO_ECHO,NEAR   ;System call 8
+ASSUME  DS:NOTHING,ES:NOTHING
+
+ ENDIF
+        PUSH    DS
+        PUSH    SI
+INTEST:
+        invoke  STATCHK
+        JNZ     Get
+;*************************************************************************
+        cmp     [Printer_Flag],0        ; is printer idle?
+        jnz     no_sys_wait
+        mov     ah,5                    ; get input status with system wait
+        invoke  IOFUNC
+no_sys_wait:
+;**************************************************************************
+        MOV     AH,84h
+        INT     int_IBM
+
+;;; 7/15/86  update the date in the idle loop
+;;; Dec 19, 1986 D.C.L. changed following CMP to Byte Ptr from Word Ptr
+;;;;             to shorten loop in consideration of the PC Convertible
+
+        CMP     byte ptr [DATE_FLAG],-1 ; date is updated may be every
+        JNZ     NoUpdate                ; 65535 x ? ms if no one calls
+        PUSH    AX
+        PUSH    BX                      ; following is tricky,
+        PUSH    CX                      ; it may be called by critical handler
+        PUSH    DX                      ; at that time, DEVCALL is used by
+                                        ; other's READ or WRITE
+        PUSH    DS                      ; save DS = SFT's sgement
+        PUSH    CS                      ; READTIME must use DS=CS
+        POP     DS
+
+        MOV     AX,0                    ; therefore, we save DEVCALL
+        CALL    Save_Restore_Packet     ; save DEVCALL packet
+        invoke  READTIME                ; readtime
+        MOV     AX,1
+        CALL    Save_Restore_Packet     ; restore DEVCALL packet
+
+        PUSH    BX                      ; the follwing code is to
+        MOV     BX,OFFSET DOSGROUP:DATE_FLAG
+        ADD     BX,2                    ; check the TAG
+        CMP     word ptr CS:[BX],22642
+        JZ      check_ok
+        invoke  DOSINIT                 ; should never come here
+check_ok:
+        POP     BX
+
+        POP     DS                      ; restore DS
+        POP     DX
+        POP     CX
+        POP     BX
+        POP     AX
+NoUpdate:
+        INC     [DATE_FLAG]
+
+;;; 7/15/86 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+        JMP     Intest
+Get:
+        XOR     AH,AH
+        invoke  IOFUNC
+        POP     SI
+        POP     DS
+;;; 7/15/86
+        MOV     BYTE PTR [SCAN_FLAG],0
+        CMP     AL,0        ; extended code ( AL )
+        JNZ     noscan
+        MOV     BYTE PTR [SCAN_FLAG],1  ; set this flag for ALT_Q key
+
+noscan:
+;;; 7/15/86
+ IF  DBCS                           ;AN000;
+        cmp     cs:[InterChar],1    ;AN000; set the zero flag if the character3/31/KK ;AN000;
+ ENDIF                              ;AN000;
+        return
+ IF  DBCS                           ;AN000;
+EndProc INTER_CON_INPUT_NO_ECHO     ;AN000;  ;2/11/KK                                 ;AN000;
+ ELSE                               ;AN000;
+EndProc $STD_CON_INPUT_NO_ECHO
+ ENDIF                              ;AN000;
+
+Break
+
+; Inputs:
+;       DS:DX Point to output string '$' terminated
+; Function:
+;       Print the string on the console device
+; Returns:
+;       None
+
+        procedure   $STD_CON_STRING_OUTPUT,NEAR   ;System call 9
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     SI,DX
+STRING_OUT1:
+        LODSB
+ IF  DBCS                               ;AN000;
+        invoke  TESTKANJ                ;AN000;               2/11/KK            ;AN000;
+        jz      SBCS00                  ;AN000;               2/11/KK            ;AN000;
+        invoke  OUTT                    ;AN000;               2/11/KK            ;AN000;
+        LODSB                           ;AN000;               2/11/KK            ;AN000;
+        JMP     NEXT_STR1               ;AN000;               2/11/KK            ;AN000;
+SBCS00:                                 ;AN000;               2/11/KK            ;AN000;
+ ENDIF                                  ;AN000;
+        CMP     AL,'$'
+        retz
+NEXT_STR1:
+        invoke  OUTT
+        JMP     STRING_OUT1
+
+EndProc $STD_CON_STRING_OUTPUT
+
+IF  DBCS                                ;AN000;
+include kstrin.asm                      ;AN000;
+ELSE                                    ;AN000;
+include strin.asm
+ENDIF                                   ;AN000;
+
+Break
+
+; Inputs:
+;       DL = -1 if input
+;       else DL is output character
+; Function:
+;       Input or output raw character from console, no echo
+; Returns:
+;       AL = character
+
+        procedure   $RAW_CON_IO,NEAR   ; System call 6
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     AL,DL
+        CMP     AL,-1
+        JZ      RAW22                                 ;AN000;
+        JMP     RAWOUT                                ;AN000;
+RAW22:                                                ;AN000;
+        LES     DI,DWORD PTR [user_SP]                ; Get pointer to register save area
+        XOR     BX,BX
+        invoke  GET_IO_SFT
+        retc
+ IF  DBCS                               ;AN000;
+        push    word ptr [Intercon]     ;AN000;
+        mov     [Intercon],0            ;AN000; disable interim characters
+ ENDIF                                  ;AN000;
+        MOV     AH,1
+        invoke  IOFUNC
+        JNZ     RESFLG
+ IF  DBCS                               ;AN000;
+        pop     word ptr [InterCon]     ;AN000; restore interim flag
+ ENDIF                                  ;AN000;
+        invoke  SPOOLINT
+        OR      BYTE PTR ES:[DI.user_F],40H ; Set user's zero flag
+        XOR     AL,AL
+        return
+
+RESFLG:
+        AND     BYTE PTR ES:[DI.user_F],0FFH-40H    ; Reset user's zero flag
+ IF  DBCS                               ;AN000;
+        XOR     AH,AH                   ;AN000;
+        invoke  IOFUNC                  ;AN000; get the character
+        pop     word ptr [InterCon]     ;AN000;
+        return                          ;AN000;
+ ENDIF                                  ;AN000;                                 ;AN000;
+
+RILP:
+        invoke  SPOOLINT
+
+; Inputs:
+;       None
+; Function:
+;       Input raw character from console, no echo
+; Returns:
+;       AL = character
+
+        entry   $RAW_CON_INPUT        ; System call 7
+
+        PUSH    BX
+        XOR     BX,BX
+        invoke  GET_IO_SFT
+        POP     BX
+        retc
+        MOV     AH,1
+        invoke  IOFUNC
+        JNZ     Got
+        MOV     AH,84h
+        INT     int_IBM
+        JMP     RILP
+Got:
+        XOR     AH,AH
+        invoke  IOFUNC
+ IF  DBCS                               ;AN000;
+        cmp     [InterChar],1           ;AN000;    2/11/KK
+;                                                               2/11/KK
+;       Sets the application zero flag depending on the         2/11/KK
+;       zero flag upon entry to this routine. Then returns      2/11/KK
+;       from system call.                                       2/11/KK
+;                                                               2/11/KK
+entry   InterApRet                      ;AN000;                 2/11/KK         ;AN000;
+        pushf                           ;AN000; 3/16/KK
+        push    ds                      ;AN000; 3/16/KK
+        push    bx                      ;AN000; 3/16/KK
+        Context DS                      ;AN000; 3/16/KK
+        MOV     BX,offset DOSGROUP:COUNTRY_CDPG.ccDosCodePage
+        cmp     word ptr [bx],934       ;AN000; 3/16/KK       korean code page ?
+        pop     bx                      ;AN000; 3/16/KK
+        pop     ds                      ;AN000; 3/16/KK
+        je      do_koren                ;AN000; 3/16/KK
+        popf                            ;AN000; 3/16/KK
+        return                          ;AN000; 3/16/KK
+do_koren:                               ;AN000; 3/16/KK
+        popf                            ;AN000;
+        LES     DI,DWORD PTR [user_SP]  ;AN000; Get pointer to register save area KK
+        jnz     sj0                     ;AN000;                       2/11/KK
+        OR      BYTE PTR ES:[DI.user_F],40H     ;AN000; Set user's zero flag  2/11/KK
+        return                          ;AN000;                 2/11/KK
+sj0:                                    ;AN000;                 2/11/KK
+        AND     BYTE PTR ES:[DI.user_F],0FFH-40H ;AN000; Reset user's zero flag 2/KK
+ ENDIF                                           ;AN000;
+        return                                   ;AN000;
+;
+;       Output the character in AL to stdout
+;
+        entry   RAWOUT
+
+        PUSH    BX
+        MOV     BX,1
+
+        invoke  GET_IO_SFT
+        JC      RAWRET1
+
+        MOV     BX,[SI.sf_flags]
+
+ ;
+ ; If we are a network handle OR if we are not a local device then go do the
+ ; output the hard way.
+ ;
+
+        AND     BX,sf_isNet + devid_device
+        CMP     BX,devid_device
+        JNZ     RawNorm
+ IF  DBCS                                       ;AN000;
+        TEST    [SaveCurFlg],01H                ;AN000; print but no cursor adv?
+        JNZ     RAWNORM                         ;AN000;    2/11/KK
+ ENDIF                                          ;AN000;
+
+;       TEST    BX,sf_isnet                     ; output to NET?
+;       JNZ     RAWNORM                         ; if so, do normally
+;       TEST    BX,devid_device                 ; output to file?
+;       JZ      RAWNORM                         ; if so, do normally
+
+        PUSH    DS
+        LDS     BX,[SI.sf_devptr]               ; output to special?
+        TEST    BYTE PTR [BX+SDEVATT],ISSPEC
+        POP     DS
+        JZ      RAWNORM                         ; if not, do normally
+        INT     int_fastcon                     ; quickly output the char
+RAWRET:
+        CLC
+RAWRET1:
+        POP     BX
+        return
+RAWNORM:
+        CALL    RAWOUT3
+        JMP     RAWRET
+
+;
+;       Output the character in AL to handle in BX
+;
+        entry   RAWOUT2
+
+        invoke  GET_IO_SFT
+        retc
+RAWOUT3:
+        PUSH    AX
+        JMP     SHORT RAWOSTRT
+ROLP:
+        invoke  SPOOLINT
+        OR      [DOS34_FLAG],CTRL_BREAK_FLAG ;AN002; set control break
+        invoke  DSKSTATCHK                   ;AN002; check control break
+RAWOSTRT:
+        MOV     AH,3
+        invoke  IOFUNC
+        JZ      ROLP
+        POP     AX
+        MOV     AH,2
+        invoke  IOFUNC
+        CLC                     ; Clear carry indicating successful
+        return
+EndProc $RAW_CON_IO
+
+; Inputs:
+;       AX=0 save the DEVCALL request packet
+;         =1 restore the DEVCALL request packet
+; Function:
+;       save or restore the DEVCALL packet
+; Returns:
+;       none
+
+        procedure   Save_Restore_Packet,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS
+        PUSH    ES
+        PUSH    SI
+        PUSH    DI
+        CMP     AX,0            ; save packet
+        JZ      save_packet
+restore_packet:
+        MOV     SI,OFFSET DOSGROUP:Packet_Temp   ;sourec
+        MOV     DI,OFFSET DOSGROUP:DEVCALL       ;destination
+        JMP     set_seg
+save_packet:
+        MOV     DI,OFFSET DOSGROUP:Packet_Temp   ;destination
+        MOV     SI,OFFSET DOSGROUP:DEVCALL       ;source
+set_seg:
+        MOV     AX,CS           ; set DS,ES to DOSGROUP
+        MOV     DS,AX
+        MOV     ES,AX
+        MOV     CX,11           ; 11 words to move
+        REP     MOVSW
+
+        POP     DI
+        POP     SI
+        POP     ES
+        POP     DS
+        return
+EndProc Save_Restore_Packet
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/CPMIO2.ASM b/v4.0/src/DOS/CPMIO2.ASM
new file mode 100644
index 0000000..2b31689
--- /dev/null
+++ b/v4.0/src/DOS/CPMIO2.ASM
@@ -0,0 +1,354 @@
+;       SCCSID = @(#)cpmio2.asm 1.1 85/04/11
+TITLE   CPMIO2 - device IO for MSDOS
+NAME    CPMIO2
+
+.xlist
+.xcref
+include dosseg.asm
+.cref
+.list
+
+;
+; Old style CP/M 1-12 system calls to talk to reserved devices
+;
+;   $Std_Con_Input
+;   $Std_Con_Output
+;   OUTT
+;   TAB
+;   BUFOUT
+;   $Std_Aux_Input
+;   $Std_Aux_Output
+;   $Std_Printer_Output
+;   $Std_Con_Input_Status
+;   $Std_Con_Input_Flush
+;
+;   Revision History:
+;
+;       AN000    version 4.00 - Jan. 1988
+;
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+.xlist
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.list
+.cref
+
+; The following routines form the console I/O group (funcs 1,2,6,7,8,9,10,11).
+; They assume ES and DS NOTHING, while not strictly correct, this forces data
+; references to be SS or CS relative which is desired.
+
+    i_need  CARPOS,BYTE
+    i_need  CHARCO,BYTE
+    i_need  PFLAG,BYTE
+    i_need  CurrentPDB,WORD                      ;AN000;
+    i_need  InterCon,BYTE                        ;AN000;
+    i_need  SaveCurFlg,BYTE                      ;AN000;
+
+
+Break
+
+; Inputs:
+;       None
+; Function:
+;       Input character from console, echo
+; Returns:
+;       AL = character
+
+        procedure   $STD_CON_INPUT,NEAR   ;System call 1
+ASSUME  DS:NOTHING,ES:NOTHING
+
+ IF  DBCS                                       ;AN000;
+        push    word ptr [InterCon]             ;AN000;
+        mov     [InterCon],01H                  ;AN000;
+        invoke  INTER_CON_INPUT_NO_ECHO         ;AN000;
+        pop     word ptr [InterCon]             ;AN000;
+        pushf                                   ;AN000;
+        push    AX                              ;AN000;
+        mov     [SaveCurFlg],0                  ;AN000;
+        jnz     sj0                             ;AN000;
+        mov     [SaveCurFlg],1                  ;AN000;
+sj0:                                            ;AN000;
+        invoke  OUTT                            ;AN000;
+        mov     [SaveCurFLg],0                  ;AN000;
+        pop     AX                              ;AN000;
+        popf                                    ;AN000;
+        jz      $STD_CON_INPUT                  ;AN000;
+ ELSE                                           ;AN000;
+        invoke  $STD_CON_INPUT_NO_ECHO
+        PUSH    AX
+        invoke  OUTT
+        POP     AX
+ ENDIF                                          ;AN000;
+        return
+EndProc $STD_CON_INPUT
+
+Break
+
+; Inputs:
+;       DL = character
+; Function:
+;       Output character to console
+; Returns:
+;       None
+
+        procedure   $STD_CON_OUTPUT,NEAR   ;System call 2
+        public  OUTCHA                         ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     AL,DL
+
+        entry   OUTT
+        CMP     AL,20H
+        JB      CTRLOUT
+        CMP     AL,c_DEL
+        JZ      OUTCH
+OUTCHA:                                    ;AN000;
+        INC     BYTE PTR [CARPOS]
+OUTCH:
+        PUSH    DS
+        PUSH    SI
+        INC     BYTE PTR [CHARCO]               ;invoke  statchk...
+        AND     BYTE PTR [CHARCO],00111111B     ;AN000; every 64th char
+        JNZ     OUTSKIP
+        PUSH    AX
+        invoke  STATCHK
+        POP     AX
+OUTSKIP:
+        invoke  RAWOUT                          ;output the character
+        POP     SI
+        POP     DS
+ IF  DBCS                               ;AN000;
+        TEST    [SaveCurFlg],01H        ;AN000;print but no cursor adv? 2/13/KK
+        retnz                           ;AN000;if so then do not send to prt2/13/KK
+ ENDIF
+        TEST    BYTE PTR [PFLAG],-1
+        retz
+        PUSH    BX
+        PUSH    DS
+        PUSH    SI
+        MOV     BX,1
+        invoke  GET_IO_SFT
+        JC      TRIPOPJ
+        MOV     BX,[SI.sf_flags]
+        TEST    BX,sf_isnet                     ; output to NET?
+        JNZ     TRIPOPJ                         ; if so, no echo
+        TEST    BX,devid_device                 ; output to file?
+        JZ      TRIPOPJ                         ; if so, no echo
+        MOV     BX,4
+        invoke  GET_IO_SFT
+        JC      TRIPOPJ
+        TEST    [SI.sf_flags],sf_net_spool      ; StdPrn redirected?
+        JZ      LISSTRT2J                       ; No, OK to echo
+        MOV     BYTE PTR [PFLAG],0              ; If a spool, NEVER echo
+TRIPOPJ:
+        JMP     TRIPOP
+
+LISSTRT2J:
+        JMP     LISSTRT2
+
+CTRLOUT:
+        CMP     AL,c_CR
+        JZ      ZERPOS
+        CMP     AL,c_BS
+        JZ      BACKPOS
+        CMP     AL,c_HT
+        JNZ     OUTCH
+        MOV     AL,[CARPOS]
+        OR      AL,0F8H
+        NEG     AL
+
+        entry   TAB
+
+        PUSH    CX
+        MOV     CL,AL
+        MOV     CH,0
+        JCXZ    POPTAB
+TABLP:
+        MOV     AL," "
+        invoke  OUTT
+        LOOP    TABLP
+POPTAB:
+        POP     CX
+        return
+
+ZERPOS:
+        MOV     BYTE PTR [CARPOS],0
+        JMP     OUTCH
+OUTJ:   JMP     OUTT
+
+BACKPOS:
+        DEC     BYTE PTR [CARPOS]
+        JMP     OUTCH
+
+        entry   BUFOUT
+        CMP     AL," "
+        JAE     OUTJ            ;Normal char
+        CMP     AL,9
+        JZ      OUTJ            ;OUT knows how to expand tabs
+
+;DOS 3.3  7/14/86
+        CMP     AL,"U"-"@"      ; turn ^U to section symbol
+        JZ      CTRLU
+        CMP     AL,"T"-"@"      ; turn ^T to paragraph symbol
+        JZ      CTRLU
+NOT_CTRLU:
+;DOS 3.3  7/14/86
+
+        PUSH    AX
+        MOV     AL,"^"
+        invoke  OUTT            ;Print '^' before control chars
+        POP     AX
+        OR      AL,40H          ;Turn it into Upper case mate
+CTRLU:
+        invoke  OUTT
+        return
+EndProc $STD_CON_OUTPUT
+
+Break
+
+; Inputs:
+;       None
+; Function:
+;       Returns character from aux input
+; Returns:
+;       Character in AL
+
+        procedure   $STD_AUX_INPUT,NEAR   ;System call 3
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        invoke  STATCHK
+        MOV     BX,3
+        invoke  GET_IO_SFT
+        retc
+        JMP     SHORT TAISTRT
+AUXILP:
+        invoke  SPOOLINT
+TAISTRT:
+        MOV     AH,1
+        invoke  IOFUNC
+        JZ      AUXILP
+        XOR     AH,AH
+        invoke  IOFUNC
+        return
+EndProc $STD_AUX_INPUT
+
+Break
+
+; Inputs:
+;       Character in DL
+; Function:
+;       Output character to aux output
+; Returns:
+;       Nothing
+
+        procedure   $STD_AUX_OUTPUT,NEAR   ;System call 4
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    BX
+        MOV     BX,3
+        JMP     SHORT SENDOUT
+
+EndProc $STD_AUX_OUTPUT
+
+Break
+
+; Inputs:
+;       DL = Character
+; Function:
+;       Output the character to the list device
+; Returns:
+;       None
+
+        procedure   $STD_PRINTER_OUTPUT,NEAR   ;System call 5
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    BX
+        MOV     BX,4
+
+SENDOUT:
+        MOV     AL,DL
+        PUSH    AX
+        invoke  STATCHK
+        POP     AX
+        PUSH    DS
+        PUSH    SI
+LISSTRT2:
+        invoke  RAWOUT2
+TRIPOP:
+        POP     SI
+        POP     DS
+        POP     BX
+        return
+EndProc $STD_PRINTER_OUTPUT
+
+Break
+
+; Inputs:
+;       None
+; Function:
+;       Check console input status
+; Returns:
+;       AL = -1 character available, = 0 no character
+
+        procedure   $STD_CON_INPUT_STATUS,NEAR   ;System call 11
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        invoke  STATCHK
+        MOV     AL,0                    ; no xor!!
+        retz
+        OR      AL,-1
+        return
+EndProc $STD_CON_INPUT_STATUS
+
+Break
+
+; Inputs:
+;       AL = DOS function to be called after flush (1,6,7,8,10)
+; Function:
+;       Flush console input buffer and perform call in AL
+; Returns:
+;       Whatever call in AL returns or AL=0 if AL was not 1,6,7,8 or 10
+
+        procedure   $STD_CON_INPUT_FLUSH,NEAR   ;System call 12
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    AX
+        PUSH    DX
+        XOR     BX,BX
+        invoke  GET_IO_SFT
+        JC      BADJFNCON
+        MOV     AH,4
+        invoke  IOFUNC
+
+BADJFNCON:
+        POP     DX
+        POP     AX
+        MOV     AH,AL
+        CMP     AL,1
+        JZ      REDISPJ
+        CMP     AL,6
+        JZ      REDISPJ
+        CMP     AL,7
+        JZ      REDISPJ
+        CMP     AL,8
+        JZ      REDISPJ
+        CMP     AL,10
+        JZ      REDISPJ
+        MOV     AL,0
+        return
+
+REDISPJ:
+ IF  DBCS                         ;AN000;
+        mov     ds,[CurrentPDB]   ;AN000;
+                                  ;AN000; set DS same as one from COMMAND entry
+ ENDIF
+        CLI
+        transfer    REDISP
+EndProc $STD_CON_INPUT_FLUSH
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/CREATE.ASM b/v4.0/src/DOS/CREATE.ASM
new file mode 100644
index 0000000..6983e29
--- /dev/null
+++ b/v4.0/src/DOS/CREATE.ASM
@@ -0,0 +1,380 @@
+;       SCCSID = @(#)create.asm 1.6 85/08/19
+TITLE   DOS_CREATE/DOS_CREATE_NEW - Internal CREATE calls for MS-DOS
+NAME    DOS_CREATE
+; Internal Create and Create new to create a local or NET file and SFT.
+;
+;   DOS_CREATE
+;   DOS_CREATE_NEW
+;   SET_MKND_ERR
+;   SET_Media_ID
+;   SET_EXT_Mode
+;
+;   Revision history:
+;
+;       A000 version 4.00     Jan. 1988
+;       A001  D490 -- Change IOCTL subfunctios from 63h,43h to 66h, 46h
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  NoSetDir,BYTE
+        i_need  THISSFT,DWORD
+        i_need  THISCDS,DWORD
+        I_need  EXTERR,WORD
+        I_Need  ExtErr_locus,BYTE
+        I_need  JShare,DWORD
+        I_need  VOLCHNG_FLAG,BYTE
+        I_need  SATTRIB,BYTE
+        I_need  CALLVIDM,DWORD
+        I_need  OpenBuf,128
+        I_need  EXTOPEN_ON,BYTE                   ;AN000; extended open
+        I_need  NAME1,BYTE                        ;AN000;
+        I_need  NO_NAME_ID,BYTE                   ;AN000;
+        I_need  Packet_Temp,WORD                  ;AN000;
+        I_need  DOS34_FLAG,WORD                   ;AN000;
+        I_need  SAVE_BX,WORD                      ;AN000;
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [THISSFT] Points to SFT to fill in if file created
+;               (sf_mode field set so that FCB may be detected)
+;       [SATTRIB] Is attribute of search, determines what files can be found
+;       AX is Attribute to create
+; Function:
+;       Try to create the specified file truncating an old one that exists
+; Outputs:
+;       sf_ref_count is NOT altered
+;       CARRY CLEAR
+;           THISSFT filled in.
+;               sf_mode = unchanged for FCB, sharing_compat + open_for_both
+;       CARRY SET
+;           AX is error code
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       Attempt to re-create read only file , or
+;                       create a second volume id or create a dir
+;               error_sharing_violation
+;                       The sharing mode was correct but not allowed
+;                       generates an INT 24
+; DS preserved, others destroyed
+
+        procedure   DOS_Create,NEAR
+        DOSAssume   CS,<DS>,"DOS_Create"
+        ASSUME  ES:NOTHING
+
+        XOR     AH,AH           ; Truncate is OK
+Create_inter:
+        TEST    AL,NOT (attr_all + attr_ignore + attr_volume_id)
+                                ; Mask out any meaningless bits
+        JNZ     AttErr
+        TEST    AL,attr_volume_id
+        JZ      NoReset
+        OR      [DOS34_FLAG],DBCS_VOLID      ;AN000;FOR dbcs volid
+        MOV     AL,attr_volume_id
+NoReset:
+        OR      AL,attr_archive ; File changed
+        TEST    AL,attr_directory + attr_device
+        JZ      ATT_OK
+AttErr:
+        MOV     AX,5            ; Attribute problem
+        MOV     Exterr_Locus,errLOC_Unk
+        JMP     SHORT SET_MKND_ERR ; Gotta use MKDIR to make dirs, NEVER allow
+                                   ;    attr_device to be set.
+ATT_OK:
+        LES     DI,[THISSFT]
+        PUSH    ES
+        LES     SI,[THISCDS]
+        CMP     SI,-1
+        JNZ     TEST_RE_NET
+        POP     ES
+
+;Extended open hooks
+        TEST    [EXTOPEN_ON],ext_open_on    ;AN000;EO. from extnded open
+        JZ      NOEXTOP                     ;AN000;EO. no, do normal
+IFS_extopen:                                ;AN000;EO.
+        PUSH    AX                          ;AN000;EO. pass create attr
+        MOV     AX,(multNET SHL 8) OR 46    ;AN000;EO. issue extended open verb
+        INT     2FH                         ;AN000;EO.
+        POP     BX                          ;AN000;EO. trash bx
+        MOV     [EXTOPEN_ON],0              ;AN000;EO.
+        return                              ;AN000;EO.
+NOEXTOP:                                    ;AN000;
+;Extended open hooks
+
+IF NOT Installed
+        transfer NET_SEQ_CREATE
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 24
+        INT     2FH
+        POP     BX                      ; BX is trashed anyway
+        return
+ENDIF
+
+TEST_RE_NET:
+        TEST    ES:[SI.curdir_flags],curdir_isnet
+        POP     ES
+        JZ      LOCAL_CREATE
+
+        CALL    Set_EXT_mode                ;AN000;EO.
+        JC      SHORT dochk                 ;AN000;EO.
+        OR      ES:[DI.sf_mode],sharing_compat + open_for_both ;IFS.
+dochk:
+ ;      invoke  IFS_SHARE_CHECK             ;AN000;IFS. check share
+ ;      JC      nomore                      ;AN000;IFS. share violation
+
+;Extended open hooks
+        TEST    [EXTOPEN_ON],ext_open_on    ;AN000;EO. from extnded open
+        JNZ     IFS_extopen                 ;AN000;EO. yes, issue extended open
+;Extended open hooks
+
+IF NOT Installed
+        transfer NET_CREATE
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 23
+        INT     2FH
+        POP     BX                      ; BX is trashed anyway
+nomore:
+        return
+ENDIF
+
+LOCAL_CREATE:
+        CALL    Set_EXT_mode           ;AN000;EO. set mode if from extended open
+        JC      setdone                ;AN000;EO.
+        OR      ES:[DI].sf_mode,sharing_compat+open_for_both
+setdone:
+        EnterCrit   critDisk
+        invoke  MakeNode
+        JNC     Create_ok
+        mov     [VOLCHNG_FLAG],-1       ; indicate no change in volume label
+        LeaveCrit   critDisk
+
+        entry   SET_MKND_ERR
+        DOSAssume   CS,<DS>,"Set_MkNd_Err"
+        ASSUME  ES:NOTHING
+; Looks up MakeNode errors and converts them. AL is MakeNode
+; error, SI is GetPath bad spot return if path_not_found error.
+
+        MOV     BX,OFFSET DOSGROUP:CRTERRTAB
+        XLAT
+CreatBadRet:
+        STC
+        return
+
+TABLE   SEGMENT
+Public CREAT001S,CREAT001E
+CREAT001S  label  byte
+CRTERRTAB LABEL BYTE            ; Lookup table for MakeNode returns
+        DB      ?                       ; none
+        DB      error_access_denied     ; MakeNode error 1
+        DB      error_cannot_make       ; MakeNode error 2
+        DB      error_file_exists       ; MakeNode error 3
+        DB      error_path_not_found    ; MakeNode error 4
+        DB      error_access_denied     ; MakeNode error 5
+        DB      error_sharing_violation ; MakeNode error 6
+        DB      error_file_not_found    ; MakeNode error 7
+CREAT001E  label byte
+TABLE   ENDS
+
+;
+; We have just created a new file.  This results in the truncation of old
+; files.  We must inform the sharer to slash all the open SFT's for this
+; file to the current size.
+;
+Create_ok:
+; If we created a volume id on the diskette, set the VOLCHNG_FLAG to logical
+; drive number to force a Build BPB after Media Check.
+
+;;; FASTOPEN 8/29/86
+        invoke  FastOpen_Delete
+;;; FASTOPEN 8/29/86
+        mov     al,[SATTRIB]
+        test    al,attr_volume_id
+        jz      NoVolLabel
+        LES     DI,[THISCDS]
+        mov     ah,byte ptr ES:[DI]     ; get drive letter
+        sub     ah,'A'                  ; convert to drive letter
+        mov     [VOLCHNG_FLAG],ah       ;Set flag to indicate volid change
+        MOV     BH,1                    ;AN000;>32mb set volume id to boot record
+        CALL    Set_Media_ID            ;AN000;>32mb
+
+        EnterCrit CritDisk
+        invoke  FatRead_CDS             ; force a media check
+        LeaveCrit CritDisk
+NoVolLabel:
+        MOV     ax,2
+        LES     DI,ThisSFT
+if installed
+        call    JShare + 14 * 4
+else
+        Call    ShSU
+endif
+        LeaveCrit   critDisk
+        transfer SET_SFT_MODE
+
+EndProc DOS_Create
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [THISSFT] Points to SFT to fill in if file created
+;               (sf_mode field set so that FCB may be detected)
+;       [SATTRIB] Is attribute of search, determines what files can be found
+;       AX is Attribute to create
+; Function:
+;       Try to create the specified file truncating an old one that exists
+; Outputs:
+;       sf_ref_count is NOT altered
+;       CARRY CLEAR
+;           THISSFT filled in.
+;               sf_mode = sharing_compat + open_for_both for Non-FCB SFT
+;       CARRY SET
+;           AX is error code
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       Create a second volume id or create a dir
+;               error_file_exists
+;                       Already a file by this name
+; DS preserved, others destroyed
+
+        procedure   DOS_Create_New,NEAR
+        DOSAssume   CS,<DS>,"DOS_Create_New"
+        ASSUME  ES:NOTHING
+
+        MOV     AH,1            ; Truncate is NOT OK
+        JMP     Create_inter
+
+EndProc DOS_Create_New
+
+
+; Inputs:
+;       NAME1= Volume ID
+;       BH= 0, delete volume id
+;           1, set new volume id
+;       DS= DOSGROUP
+; Function:
+;       Set Volume ID to DOS 4.00 Boot record.
+; Outputs:
+;       CARRY CLEAR
+;           volume id set
+;       CARRY SET
+;           AX is error code
+
+        procedure   Set_Media_ID,NEAR              ;AN000;
+        DOSAssume   CS,<DS>,"DOS_Create_New"       ;AN000;
+        ASSUME  ES:NOTHING                         ;AN000;
+
+        PUSH    AX              ;AN000;;>32mb
+        PUSH    ES              ;AN000;;>32mb
+        PUSH    DI              ;AN000;;>32mb
+
+        INC     AH              ;AN000;;>32mb  bl=drive #
+        MOV     BL,AH           ;AN000;;>32mb  bl=drive # (A=1,B=2,,,)
+        MOV     AL,0DH          ;AN000;;>32mb  generic IOCTL
+        MOV     CX,0866H        ;AN001;;>32mb  get media id
+        MOV     DX,OFFSET DOSGROUP:PACKET_TEMP  ;AN000;>32mb
+
+        PUSH    BX              ;AN000;;>32mb
+        PUSH    DX              ;AN000;;>32mb
+        XOR     BH,BH           ;AN000;;>32mb
+
+        invoke  $IOCTL          ;AN000;;>32mb
+        POP     DX              ;AN000;;>32mb
+        POP     BX              ;AN000;;>32mb
+        JC      geterr          ;AN000;;>32mb
+
+        OR      BH,BH           ;AN000;;>32mb delete volume id
+        JZ      NoName          ;AN000;>32mb yes
+        MOV     SI,OFFSET DOSGROUP:NAME1   ;AN000;>32mb
+        JMP     SHORT doset     ;AN000;>32mb yes
+Noname:                         ;AN000;
+        MOV     SI,OFFSET DOSGROUP:NO_NAME_ID  ;AN000;>32mb
+doset:                                         ;AN000;
+        MOV     DI,DX           ;AN000;;>32mb
+        ADD     DI,MEDIA_LABEL  ;AN000;;>32mb
+        PUSH    CS              ;AN000;;>32mb  move new volume id to packet
+        POP     DS              ;AN000;;>32mb
+        PUSH    CS              ;AN000;;>32mb
+        POP     ES              ;AN000;;>32mb
+        MOV     CX,11           ;AN000;;>32mb
+        REP     MOVSB           ;AN000;;>32mb
+        MOV     CX,0846H        ;AN001;;>32mb
+        MOV     AL,0DH          ;AN000;;>32mb
+        XOR     BH,BH           ;AN000;;>32mb
+        invoke  $IOCTL          ;AN000;;>32mb  set volume id
+geterr:                         ;AN000;
+        PUSH    CS              ;AN000;>32mb
+        POP     DS              ;AN000;>32mb   ds= dosgroup
+
+        POP     DI              ;AN000;;>32mb
+        POP     ES              ;AN000;;>32mb
+        POP     AX              ;AN000;;>32mb
+        return                  ;AN000;>32mb
+
+EndProc Set_Media_ID            ;AN000;
+
+
+; Inputs:
+;       [EXTOPEN_ON]= flag for extende open
+;       SAVE_BX= mode specified in Extended Open
+; Function:
+;       Set mode in ThisSFT
+; Outputs:
+;       carry set,mode is set if from Extended Open
+;       carry clear, mode not set yet
+
+IF      NOT IBMCOPYRIGHT
+        public Set_EXT_mode
+ENDIF
+
+        procedure   Set_EXT_mode,NEAR       ;AN000;
+        ASSUME  ES:NOTHING,DS:NOTHING       ;AN000;
+
+        TEST    [EXTOPEN_ON],ext_open_on    ;AN000;EO. from extnded open
+        JZ      NOTEX                       ;AN000;EO. no, do normal
+        PUSH    AX                          ;AN000;EO.
+        MOV     AX,[SAVE_BX]                ;AN000;EO.
+        OR      ES:[DI.sf_mode],AX          ;AN000;EO.
+        POP     AX                          ;AN000;EO.
+        STC                                 ;AN000;EO.
+NOTEX:                                      ;AN000;
+        return                              ;AN000;EO.
+
+EndProc Set_EXT_mode                        ;AN000;
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/CRIT.ASM b/v4.0/src/DOS/CRIT.ASM
new file mode 100644
index 0000000..dfb1ccd
--- /dev/null
+++ b/v4.0/src/DOS/CRIT.ASM
@@ -0,0 +1,92 @@
+;       SCCSID = @(#)crit.asm   1.1 85/04/10
+TITLE CRIT - Critical Section Routines
+NAME  CRIT
+;
+; Critical Section Routines
+;
+;   Critical section handlers
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:NOTHING,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+.cref
+.list
+
+        I_need  User_In_AX,WORD
+        i_need  CurrentPDB,WORD
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+Break   <Critical section handlers>
+
+;
+;   Each handler must leave everything untouched; including flags!
+;
+;   Sleaze for time savings:  first instruction is a return.  This is patched
+;   by the sharer to be a PUSH AX to complete the correct routines.
+;
+Procedure   EcritDisk,NEAR
+        public  EcritMem
+        public  EcritSFT
+ECritMEM    LABEL   NEAR
+ECritSFT    LABEL   NEAR
+        RET
+;       PUSH    AX
+        fmt     TypSect,LevReq,<"PDB $x entering $x">,<CurrentPDB,sect>
+        MOV     AX,8000h+critDisk
+        INT     int_ibm
+        POP     AX
+        return
+EndProc EcritDisk
+
+Procedure   LcritDisk,NEAR
+        public  LcritMem
+        public  LcritSFT
+LCritMEM    LABEL   NEAR
+LCritSFT    LABEL   NEAR
+        RET
+;       PUSH    AX
+        fmt     TypSect,LevReq,<"PDB $x entering $x">,<CurrentPDB,sect>
+        MOV     AX,8100h+critDisk
+        INT     int_ibm
+        POP     AX
+        return
+EndProc LcritDisk
+
+Procedure   EcritDevice,NEAR
+        RET
+;       PUSH    AX
+        fmt     TypSect,LevReq,<"PDB $x entering $x">,<CurrentPDB,sect>
+        MOV     AX,8000h+critDevice
+        INT     int_ibm
+        POP     AX
+        return
+EndProc EcritDevice
+
+Procedure   LcritDevice,NEAR
+        RET
+;       PUSH    AX
+        MOV     AX,8100h+critDevice
+        INT     int_ibm
+        POP     AX
+        return
+EndProc LcritDevice
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/CTRLC.ASM b/v4.0/src/DOS/CTRLC.ASM
new file mode 100644
index 0000000..5a79e04
--- /dev/null
+++ b/v4.0/src/DOS/CTRLC.ASM
@@ -0,0 +1,771 @@
+;       SCCSID = @(#)ctrlc.asm  1.4 85/08/16
+; Low level routines for detecting special characters on CON input,
+;       the ^C exit/int code, the Hard error INT 24 code, the
+;       process termination code, and the INT 0 divide overflow handler.
+;
+;   FATAL
+;   FATAL1
+;   reset_environment
+;   DSKSTATCHK
+;   SPOOLINT
+;   STATCHK
+;   CNTCHAND
+;   DIVOV
+;   CHARHARD
+;   HardErr
+;
+;   Revision history:
+;
+;       AN000   version 4.0   Jan 1988
+;       A002    PTM    -- dir >lpt3 hangs
+;       A003    PTM 3957- fake version for IBMCAHE.COM
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+        I_need  SFN,WORD
+        I_NEED  pJFN,DWORD
+        i_need  DevIOBuf,BYTE
+        i_need  DidCTRLC,BYTE
+        i_need  INDOS,BYTE
+        i_need  DSKSTCOM,BYTE
+        i_need  DSKSTCALL,BYTE
+        i_need  DSKSTST,WORD
+        i_need  BCON,DWORD
+        i_need  DSKCHRET,BYTE
+        i_need  DSKSTCNT,WORD
+        i_need  IDLEINT,BYTE
+        i_need  CONSWAP,BYTE
+        i_need  user_SS,WORD
+        i_need  user_SP,WORD
+        i_need  User_In_AX,WORD
+        i_need  ERRORMODE,BYTE
+        i_need  ConC_spsave,WORD
+        i_need  Exit_type,BYTE
+        i_need  PFLAG,BYTE
+        i_need  ExitHold,DWORD
+        i_need  WPErr,BYTE
+        i_need  ReadOp,BYTE
+        i_need  CONTSTK,WORD
+        i_need  Exit_Code,WORD
+        i_need  CurrentPDB,WORD
+        i_need  DIVMES,BYTE
+        i_need  DivMesLen,WORD
+        i_need  ALLOWED,BYTE
+        i_need  FAILERR,BYTE
+        i_need  EXTERR,WORD
+        i_need  ERR_TABLE_24,BYTE
+        I_need  ErrMap24,BYTE
+        I_need  ErrMap24End,BYTE
+        I_need  fAborting,BYTE
+        I_need  AUXStack,BYTE
+        I_need  SCAN_FLAG,BYTE
+        I_need  EXTOPEN_ON,BYTE               ;AN000; DOS 4.0
+        I_need  InterCon,BYTE                 ;AN000; DOS 4.0
+        I_need  DOS34_FLAG,WORD               ;AN000; DOS 4.0
+        I_need  ACT_PAGE,WORD                 ;AN000; DOS 4.0
+        I_need  Special_Version,WORD          ;AN007; DOS 4.0
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+IF      BUFFERFLAG
+        extrn   restore_user_map:near
+ENDIF
+
+Break   <Checks for ^C in CON I/O>
+
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        procedure   DSKSTATCHK,NEAR     ; Check for ^C if only one level in
+        CMP     BYTE PTR [INDOS],1
+        retnz                           ; Do NOTHING
+        PUSH    CX
+        PUSH    ES
+        PUSH    BX
+        PUSH    DS
+        PUSH    SI
+        PUSH    CS
+        POP     ES
+        Context DS
+        DOSAssume   CS,<DS>,"DskStatChk"
+        MOV     BYTE PTR [DSKSTCOM],DEVRDND
+        MOV     BYTE PTR [DSKSTCALL],DRDNDHL
+        MOV     [DSKSTST],0
+ IF  DBCS                               ;AN000;
+        MOV     AL, [InterCon]          ;AN000;get type of status read 2/13/KK
+        MOV     BYTE PTR [DSKCHRET],AL  ;AN000; load interim flag into packet
+ ENDIF                                  ;AN000;
+        MOV     BX,OFFSET DOSGROUP:DSKSTCALL
+        LDS     SI,[BCON]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2
+        TEST    [DSKSTST],STBUI
+        JZ      GotCh                   ; No characters available
+        XOR     AL,AL                   ; Set zero
+RET36:
+        POP     SI
+        POP     DS
+        POP     BX
+        POP     ES
+        POP     CX
+        return
+
+GotCh:
+        MOV     AL,BYTE PTR [DSKCHRET]
+DSK1:
+        CMP     AL,"C"-"@"
+        JNZ     RET36
+        MOV     BYTE PTR [DSKSTCOM],DEVRD
+        MOV     BYTE PTR [DSKSTCALL],DRDWRHL
+        MOV     BYTE PTR [DSKCHRET],CL
+        MOV     [DSKSTST],0
+        MOV     [DSKSTCNT],1
+        invoke  DEVIOCALL2              ; Eat the ^C
+        POP     SI
+        POP     DS
+        POP     BX                      ; Clean stack
+        POP     ES
+        POP     CX
+        JMP     CNTCHAND
+
+NOSTOP:
+        CMP     AL,"P"-"@"
+        JNZ     check_next
+        CMP     BYTE PTR [SCAN_FLAG],0        ; ALT_Q ?
+        JZ      INCHKJ                        ; no
+        return
+check_next:
+        IF      NOT TOGLPRN
+        CMP     AL,"N"-"@"
+        JZ      INCHKJ
+        ENDIF
+
+        CMP     AL,"C"-"@"
+        JZ      INCHKJ
+check_end:
+        return
+
+INCHKJ:
+        JMP     INCHK
+
+EndProc DSKSTATCHK
+
+;
+; SpoolInt - signal processes that the DOS is truly idle.  We are allowed to
+; do this ONLY if we are working on a 1-12 system call AND if we are not in
+; the middle of an INT 24.
+;
+procedure   SPOOLINT,NEAR
+        PUSHF
+        test    IdleInt,-1
+        jz      POPFRet
+        test    ErrorMode,-1
+        jnz     POPFRet
+;
+; Note that we are going to allow an external program to issue system calls
+; at this time.  We MUST preserve IdleInt across this.
+;
+        PUSH    WORD PTR IdleInt
+        INT     int_spooler
+        POP     WORD PTR IdleInt
+POPFRET:
+        POPF
+        return
+EndProc SPOOLINT
+
+        procedure   STATCHK,NEAR
+
+        invoke  DSKSTATCHK              ; Allows ^C to be detected under
+                                        ; input redirection
+        PUSH    BX
+        XOR     BX,BX
+        invoke  GET_IO_SFT
+        POP     BX
+        retc
+        MOV     AH,1
+        invoke  IOFUNC
+        JZ      SPOOLINT
+        CMP     AL,"S"-"@"
+        JNZ     NOSTOP
+
+        CMP     BYTE PTR [SCAN_FLAG],0        ;AN000; ALT_R ?
+        JNZ     check_end                     ;AN000; yes
+        XOR     AH,AH
+        invoke  IOFUNC                  ; Eat Cntrl-S
+        JMP     SHORT PAUSOSTRT
+PRINTOFF:
+PRINTON:
+        NOT     BYTE PTR [PFLAG]
+        PUSH    BX
+        MOV     BX,4
+        invoke  GET_IO_SFT
+        POP     BX
+        retc
+        PUSH    ES
+        PUSH    DI
+        PUSH    DS
+        POP     ES
+        MOV     DI,SI                   ; ES:DI -> SFT
+        TEST    ES:[DI.sf_flags],sf_net_spool
+        JZ      NORM_PR                 ; Not redirected, echo is OK
+        Callinstall NetSpoolEchoCheck,MultNet,38,<AX>,<AX> ; See if allowed
+        JNC     NORM_PR                 ; Echo is OK
+        MOV     BYTE PTR [PFLAG],0      ; If not allowed, disable echo
+        Callinstall NetSpoolClose,MultNet,36,<AX>,<AX> ; and close
+        JMP     SHORT RETP6
+
+NORM_PR:
+        CMP     BYTE PTR [PFLAG],0
+        JNZ     PRNOPN
+        invoke  DEV_CLOSE_SFT
+        JMP     SHORT RETP6
+
+PRNOPN:
+        invoke  DEV_OPEN_SFT
+RETP6:
+        POP     DI
+        POP     ES
+        return
+
+PAUSOLP:
+        CALL    SPOOLINT
+PAUSOSTRT:
+        MOV     AH,1
+        invoke  IOFUNC
+        JZ      PAUSOLP
+INCHK:
+        PUSH    BX
+        XOR     BX,BX
+        invoke  GET_IO_SFT
+        POP     BX
+        retc
+        XOR     AH,AH
+        invoke  IOFUNC
+        CMP     AL,"P"-"@"
+;;;;;  7/14/86  ALT_Q key fix
+
+        JZ      PRINTON                       ; no! must be CTRL_P
+
+NOPRINT:
+;;;;;  7/14/86  ALT_Q key fix
+        IF      NOT TOGLPRN
+        CMP     AL,"N"-"@"
+        JZ      PRINTOFF
+        ENDIF
+        CMP     AL,"C"-"@"
+        retnz
+EndProc STATCHK
+
+        procedure   CNTCHAND,NEAR
+; Ctrl-C handler.
+; "^C" and CR/LF is printed.  Then the user registers are restored and the
+; user CTRL-C handler is executed.  At this point the top of the stack has 1)
+; the interrupt return address should the user CTRL-C handler wish to allow
+; processing to continue; 2) the original interrupt return address to the code
+; that performed the function call in the first place.  If the user CTRL-C
+; handler wishes to continue, it must leave all registers unchanged and RET
+; (not IRET) with carry CLEAR.  If carry is SET then an terminate system call
+; is simulated.
+        TEST    [DOS34_FLAG],CTRL_BREAK_FLAG  ;AN002; from RAWOUT
+        JNZ     around_deadlock               ;AN002;
+        MOV     AL,3                    ; Display "^C"
+        invoke  BUFOUT
+        invoke  CRLF
+around_deadlock:                              ;AN002;
+        Context DS
+        CMP     BYTE PTR [CONSWAP],0
+        JZ      NOSWAP
+        invoke  SWAPBACK
+NOSWAP:
+        CLI                             ; Prepare to play with stack
+        MOV     SS,[user_SS]            ; User stack now restored
+ASSUME  SS:NOTHING
+        MOV     SP,[user_SP]
+        invoke  restore_world           ; User registers now restored
+ASSUME  DS:NOTHING
+        MOV     BYTE PTR [INDOS],0      ; Go to known state
+        MOV     BYTE PTR [ERRORMODE],0
+        MOV     [ConC_spsave],SP        ; save his SP
+        CLC
+        INT     int_ctrl_c              ; Execute user Ctrl-C handler
+;
+; The user has returned to us.  The circumstances we allow are:
+;
+;   IRET        We retry the operation by redispatching the system call
+;   CLC/RETF    POP the stack and retry
+;   ...         Exit the current process with ^C exit
+;
+; User's may RETURN to us and leave interrupts on.  Turn 'em off just to be
+; sure
+;
+        CLI
+        MOV     [user_IN_AX],ax         ; save the AX
+        PUSHF                           ; and the flags (maybe new call)
+        POP     AX
+;
+; See if the input stack is identical to the output stack
+;
+        CMP     SP,[ConC_spsave]
+        JNZ     ctrlc_try_new           ; current SP not the same as saved SP
+;
+; Repeat the operation by redispatching the system call.
+;
+ctrlc_repeat:
+        MOV     AX,User_In_AX
+        transfer    COMMAND
+;
+; The current SP is NOT the same as the input SP.  Presume that he RETF'd
+; leaving some flags on the stack and examine the input
+;
+ctrlc_try_new:
+        ADD     SP,2                    ; pop those flags
+        TEST    AX,f_carry              ; did he return with carry?
+        JZ      Ctrlc_Repeat            ; no carry set, just retry
+;
+; Well...  time to abort the user.  Signal a ^C exit and use the EXIT system
+; call..
+;
+ctrlc_abort:
+        MOV     AX,(EXIT SHL 8) + 0
+        MOV     DidCTRLC,-1
+        transfer    COMMAND             ; give up by faking $EXIT
+
+EndProc CNTCHAND
+
+Break   <DIVISION OVERFLOW INTERRUPT>
+
+; Default handler for division overflow trap
+        procedure   DIVOV,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     SI,OFFSET DOSGROUP:DIVMES
+        MOV     BX,DivMesLen
+        MOV     AX,CS
+        MOV     SS,AX
+        MOV     SP,OFFSET DOSGROUP:AUXSTACK ; Enough stack for interrupts
+        CALL    OutMes
+        JMP     ctrlc_abort             ; Use Ctrl-C abort on divide overflow
+EndProc DIVOV
+
+;
+; OutMes: perform message output
+; Inputs:   SS:SI points to message
+;           BX has message length
+; Outputs:  message to BCON
+;
+procedure   OutMes,NEAR
+
+        Context ES                      ; get ES addressability
+        Context DS                      ; get DS addressability
+
+        MOV     BYTE PTR [DskStCom],DevWrt
+        MOV     BYTE PTR [DskStCall],DRdWrHL
+        MOV     [DskSTST],0
+        MOV     [DskStCnt],BX
+        MOV     BX,OFFSET DOSGROUP:DskStCall
+        MOV     WORD PTR [DskChRet+1],SI    ; transfer address (need an EQU)
+        LDS     SI,[BCON]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2
+        MOV     WORD PTR [DskChRet+1],OFFSET DOSGROUP:DevIOBuf
+        MOV     [DskStCnt],1
+        return
+EndProc OutMes
+
+Break   <CHARHRD,HARDERR,ERROR -- HANDLE DISK ERRORS AND RETURN TO USER>
+
+        procedure   CHARHARD,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+
+; Character device error handler
+; Same function as HARDERR
+
+        OR      AH,allowed_FAIL + allowed_IGNORE + allowed_RETRY
+        MOV     Allowed,AH
+        MOV     WORD PTR [EXITHOLD+2],ES
+        MOV     WORD PTR [EXITHOLD],BP
+        PUSH    SI
+        AND     DI,STECODE
+        MOV     BP,DS                   ; Device pointer is BP:SI
+        CALL    FATALC
+        POP     SI
+        return
+EndProc CHARHARD
+
+; Hard disk error handler. Entry conditions:
+;       DS:BX = Original disk transfer address
+;       DX = Original logical sector number
+;       CX = Number of sectors to go (first one gave the error)
+;       AX = Hardware error code
+;       DI = Original sector transfer count
+;       ES:BP = Base of drive parameters
+;       [READOP] = 0 for read, 1 for write
+;       [ALLOWED] Set with allowed responses to this error (other bits MUST BE 0)
+; Output:
+;       [FAILERR] will be set if user responded FAIL
+
+        procedure   HardErr,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        XCHG    AX,DI                   ; Error code in DI, count in AX
+        AND     DI,STECODE              ; And off status bits
+        CMP     DI,error_I24_write_protect ; Write Protect Error?
+        JNZ     NOSETWRPERR
+        PUSH    AX
+        MOV     AL,ES:[BP.dpb_drive]
+        MOV     BYTE PTR [WPERR],AL     ; Flag drive with WP error
+        POP     AX
+NOSETWRPERR:
+        SUB     AX,CX                   ; Number of sectors successfully transferred
+        ADD     DX,AX                   ; First sector number to retry
+        PUSH    DX
+        MUL     ES:[BP.dpb_sector_size] ; Number of bytes transferred
+        POP     DX
+        ADD     BX,AX                   ; First address for retry
+        XOR     AH,AH                   ; Flag disk section in error
+        CMP     DX,ES:[BP.dpb_first_FAT]    ; In reserved area?
+        JB      ERRINT
+        INC     AH                      ; Flag for FAT
+        CMP     DX,ES:[BP.dpb_dir_sector]   ; In FAT?
+        JAE     TESTDIR                 ; No
+        MOV     ES:[BP.dpb_free_cnt],-1 ; Err in FAT must force recomp of freespace
+        JMP     SHORT ERRINT
+
+TESTDIR:
+        INC     AH
+        CMP     DX,ES:[BP.dpb_first_sector] ; In directory?
+        JB      ERRINT
+        INC     AH                      ; Must be in data area
+ERRINT:
+        SHL     AH,1                    ; Make room for read/write bit
+        OR      AH,BYTE PTR [READOP]    ; Set bit 0
+; If we have a write protect error when writing on a critical area on disk,
+; do not allow a retry as this may write out garbage on any subsequent disk.
+        ;test   ah,1
+        ;jz     Not_Crit
+        ;cmp    ah,5
+        ;ja     Not_Crit
+        ;and    [ALLOWED],NOT Allowed_RETRY
+Not_Crit:
+        OR      AH,[ALLOWED]            ; Set the allowed_ bits
+        entry   FATAL
+        MOV     AL,ES:[BP.dpb_drive]    ; Get drive number
+        entry   FATAL1
+        MOV     WORD PTR [EXITHOLD+2],ES
+        MOV     WORD PTR [EXITHOLD],BP  ; The only things we preserve
+        LES     SI,ES:[BP.dpb_driver_addr]
+        MOV     BP,ES                   ; BP:SI points to the device involved
+;
+; DI has the INT-24-style extended error.  We now map the error code for this
+; into the normalized get extended error set by using the ErrMap24 table as an
+; translate table.  Note that we translate ONLY the device returned codes and
+; leave all others beyond the look up table alone.
+;
+FATALC:
+        call    SET_I24_EXTENDED_ERROR
+        CMP     DI,error_I24_gen_failure
+        JBE     GOT_RIGHT_CODE          ; Error codes above gen_failure get
+        MOV     DI,error_I24_gen_failure ; mapped to gen_failure. Real codes
+                                        ;  Only come via GetExtendedError
+
+        entry   NET_I24_ENTRY
+; Entry point used by REDIRector on Network I 24 errors.
+;
+;       ASSUME  DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+;
+; ALL I 24 regs set up. ALL Extended error info SET. ALLOWED Set.
+;     EXITHOLD set for restore of ES:BP.
+
+GOT_RIGHT_CODE:
+        CMP     BYTE PTR [ERRORMODE],0  ; No INT 24s if already INT 24
+        JZ      NoSetFail
+        MOV     AL,3
+        JMP     FailRet
+NoSetFail:
+IF      BUFFERFLAG
+        invoke  RESTORE_USER_MAP                ;AN000;LB. restore user's EMS map
+ENDIF
+        MOV     [CONTSTK],SP
+        Context ES
+        fmt TypINT24,LevLog,<"INT 24: AX = $x DI = $x\n">,<AX,DI>
+;
+; Wango!!!  We may need to free some user state info...  In particular, we
+; may have locked down a JFN for a user and he may NEVER return to us.  Thus,
+; we need to free it here and then reallocate it when we come back.
+;
+        CMP     SFN,-1
+        JZ      NoFree
+        SaveReg <DS,SI>
+        LDS     SI,pJFN
+        MOV     BYTE PTR [SI],0FFH
+        RestoreReg  <SI,DS>
+NoFree:
+        CLI                             ; Prepare to play with stack
+        INC     BYTE PTR [ERRORMODE]    ; Flag INT 24 in progress
+        DEC     BYTE PTR [INDOS]        ; INT 24 handler might not return
+;; Extneded Open hooks
+        TEST    [DOS34_FLAG],Force_I24_Fail   ;AN000;IFS. form IFS Call Back          ;AN000;
+        JNZ     faili24                       ;AN000;IFS.                             ;AN000;
+        TEST    [EXTOPEN_ON],EXT_OPEN_I24_OFF ;AN000;IFS.I24 error disabled           ;AN000;
+        JZ      i24yes                        ;AN000;IFS.no                           ;AN000;
+faili24:                                      ;AN000;
+        MOV     AL,3                          ;AN000;IFS.fake fail                    ;AN000;
+        JMP     passi24                       ;AN000;IFS.exit                         ;AN000;
+i24yes:                                       ;AN000;
+
+;; Extended Open hooks
+        MOV     SS,[user_SS]
+ASSUME  SS:NOTHING
+        MOV     SP,ES:[user_SP]         ; User stack pointer restored
+        INT     int_fatal_abort         ; Fatal error interrupt vector, must preserve ES
+        MOV     ES:[user_SP],SP         ; restore our stack
+        MOV     ES:[user_SS],SS
+        MOV     BP,ES
+        MOV     SS,BP
+ASSUME  SS:DOSGROUP
+passi24:                                ;AN000;
+        MOV     SP,[CONTSTK]
+        INC     BYTE PTR [INDOS]        ; Back in the DOS
+        MOV     BYTE PTR [ERRORMODE],0  ; Back from INT 24
+        STI
+;;      MOV     [ACT_PAGE],-1           ;LB. invalidate DOS active page         ;AN000;
+;;      invoke  SAVE_MAP                ;LB. save user's EMS map                ;AN000;
+        fmt TypINT24,LevLog,<"INT 24: User reply = $x\n">,<AX>
+FAILRET:
+        LES     BP,[EXITHOLD]
+ASSUME  ES:NOTHING
+;
+; Triage the user's reply.
+;
+        CMP     AL,1
+        JB      CheckIgnore             ; 0 => ignore
+        JZ      CheckRetry              ; 1 => retry
+        CMP     AL,3                    ; 3 => fail
+        JNZ     DoAbort                 ; 2, invalid => abort
+;
+; The reply was fail.  See if we are allowed to fail.
+;
+        TEST    [ALLOWED],allowed_FAIL  ; Can we?
+        JZ      DoAbort                 ; No, do abort
+DoFail:
+        MOV     AL,3                    ; just in case...
+        TEST    [EXTOPEN_ON],EXT_OPEN_I24_OFF ;AN000;EO. I24 error disabled
+        JNZ     cleanup                       ;AN000;EO. no
+        INC     [FAILERR]               ; Tell everybody
+CleanUp:
+        MOV     WpErr,-1
+        CMP     SFN,-1
+        retz
+        SaveReg <DS,SI,AX>
+        MOV     AX,SFN
+        LDS     SI,pJFN
+        MOV     [SI],AL
+        RestoreReg  <AX,SI,DS>
+        return
+;
+; The reply was IGNORE.  See if we are allowed to ignore.
+;
+CheckIgnore:
+        TEST    [ALLOWED],allowed_IGNORE ; Can we?
+        JZ      DoFail                  ; No, do fail
+        JMP     CleanUp
+;
+; The reply was RETRY.  See if we are allowed to retry.
+;
+CheckRetry:
+        TEST    [ALLOWED],allowed_RETRY ; Can we?
+        JZ      DoFail                  ; No, do fail
+        JMP     CleanUp
+;
+; The reply was ABORT.
+;
+DoAbort:
+        Context DS
+        CMP     BYTE PTR [CONSWAP],0
+        JZ      NOSWAP2
+        invoke  SWAPBACK
+NOSWAP2:
+;
+; See if we are to truly abort.  If we are in the process of aborting, turn
+; this abort into a fail.
+;
+        TEST    fAborting,-1
+        JNZ     DoFail
+;
+; Set return code
+;
+        MOV     BYTE PTR [exit_Type],Exit_hard_error
+        XOR     AL,AL
+;
+; we are truly aborting the process.  Go restore information from the PDB as
+; necessary.
+;
+        Transfer    exit_inner
+;
+; reset_environment checks the DS value against the CurrentPDB.  If they are
+; different, then an old-style return is performed.  If they are the same,
+; then we release jfns and restore to parent.  We still use the PDB at DS:0 as
+; the source of the terminate addresses.
+;
+; Some subtlety:  We are about to issue a bunch of calls that *may* generate
+; INT 24s.  We *cannot* allow the user to restart the abort process; we may
+; end up aborting the wrong process or turn a terminate/stay/resident into a
+; normal abort and leave interrupt handlers around.  What we do is to set a
+; flag that will indicate that if any abort code is seen, we just continue the
+; operation.  In essence, we dis-allow the abort response.
+;
+; output:   none.
+;
+        entry   reset_environment
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        invoke  Reset_Version           ;AN007;MS. reset version number
+        PUSH    DS                      ; save PDB of process
+
+;
+; There are no critical sections in force.  Although we may enter here with
+; critical sections locked down, they are no longer relevant.  We may safely
+; free all allocated resources.
+;
+        MOV     AH,82h
+        INT     int_IBM
+
+        MOV     fAborting,-1            ; signal abort in progress
+
+        CallInstall NetResetEnvironment, multNet, 34  ;DOS 4.00 doesn't need it
+                                        ; Allow REDIR to clear some stuff
+                                        ;   On process exit.
+        MOV     AL,int_Terminate
+        invoke  $Get_interrupt_vector   ; and who to go to
+
+        POP     CX                      ; get ThisPDB
+        SaveReg <ES,BX>                 ; save return address
+
+        MOV     BX,[CurrentPDB]         ; get currentPDB
+        MOV     DS,BX
+        MOV     AX,DS:[PDB_Parent_PID]  ; get parentPDB
+
+;
+; AX = parentPDB, BX = CurrentPDB, CX = ThisPDB
+; Only free handles if AX <> BX and BX = CX and [exit_code].upper is not
+; Exit_keep_process
+;
+        CMP     AX,BX
+        JZ      reset_return            ; parentPDB = CurrentPDB
+        CMP     BX,CX
+        JNZ     reset_return            ; CurrentPDB <> ThisPDB
+        PUSH    AX                      ; save parent
+        CMP     BYTE PTR [exit_type],Exit_keep_process
+        JZ      reset_to_parent         ; keeping this process
+;
+; We are truly removing a process.  Free all allocation blocks belonging to
+; this PDB
+;
+        invoke  arena_free_process
+;
+; Kill off remainder of this process.  Close file handles and signal to
+; relevant network folks that this process is dead.  Remember that CurrentPDB
+; is STILL the current process!
+;
+        invoke  DOS_ABORT
+
+reset_to_parent:
+        POP     [CurrentPDB]            ; set up process as parent
+
+reset_return:                           ; come here for normal return
+        PUSH    CS
+        POP     DS
+        ASSUME  DS:DOSGROUP
+        MOV     AL,-1
+;
+; make sure that everything is clean In this case ignore any errors, we cannot
+; "FAIL" the abort, the program being aborted is dead.
+;
+        EnterCrit   critDisk
+        invoke  FLUSHBUF
+        LeaveCrit   critDisk
+;
+; Decrement open ref. count if we had done a virtual open earlier.
+;
+        invoke  CHECK_VIRT_OPEN
+IF      BUFFERFLAG
+        invoke  RESTORE_USER_MAP                ;AN000;LB. restore user's EMS map
+ENDIF
+        CLI
+        MOV     BYTE PTR [INDOS],0      ; Go to known state
+        MOV     BYTE PTR [WPERR],-1     ; Forget about WP error
+        MOV     fAborting,0             ; let aborts occur
+        POP     WORD PTR ExitHold
+        POP     WORD PTR ExitHold+2
+;
+; Snake into multitasking... Get stack from CurrentPDB person
+;
+        MOV     DS,[CurrentPDB]
+        ASSUME  DS:NOTHING
+        MOV     SS,WORD PTR DS:[PDB_user_stack+2]
+        MOV     SP,WORD PTR DS:[PDB_user_stack]
+
+        ASSUME  SS:NOTHING
+        invoke  restore_world
+        ASSUME  ES:NOTHING
+        MOV     User_SP,AX
+        POP     AX                      ; suck off CS:IP of interrupt...
+        POP     AX
+        POP     AX
+        MOV     AX,0F202h               ; STI
+        PUSH    AX
+        PUSH    WORD PTR [EXITHOLD+2]
+        PUSH    WORD PTR [EXITHOLD]
+        MOV     AX,User_SP
+        IRET                            ; Long return back to user terminate address
+EndProc HardErr
+
+;
+; This routine handles extended error codes.
+; Input : DI = error code from device
+; Output: All EXTERR fields are set
+;
+Procedure SET_I24_EXTENDED_ERROR,NEAR
+        PUSH    AX
+        MOV     AX,OFFSET DOSGroup:ErrMap24End
+        SUB     AX,OFFSET DOSGroup:ErrMap24
+;
+; AX is the index of the first unavailable error.  Do not translate if
+; greater or equal to AX.
+;
+        CMP     DI,AX
+        MOV     AX,DI
+        JAE     NoTrans
+        MOV     AL,ErrMap24[DI]
+        XOR     AH,AH
+NoTrans:
+        MOV     [EXTERR],AX
+        POP     AX
+;
+; Now Extended error is set correctly.  Translate it to get correct error
+; locus class and recommended action.
+;
+        PUSH    SI
+        MOV     SI,OFFSET DOSGROUP:ERR_TABLE_24
+        invoke  CAL_LK                  ; Set other extended error fields
+        POP     SI
+        ret
+EndProc SET_I24_EXTENDED_ERROR
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/DELETE.ASM b/v4.0/src/DOS/DELETE.ASM
new file mode 100644
index 0000000..c5473c0
--- /dev/null
+++ b/v4.0/src/DOS/DELETE.ASM
@@ -0,0 +1,777 @@
+;       SCCSID = @(#)delete.asm 1.3 85/10/18
+;       SCCSID = @(#)delete.asm 1.3 85/10/18
+TITLE   DOS_DELETE - Internal DELETE call for MS-DOS
+NAME    DOS_DELETE
+; Low level routine for deleting files
+;
+;   DOS_DELETE
+;   REN_DEL_Check
+;   FastOpen_Delete            ; DOS 3.3
+;   FastOpen_Update            ; DOS 3.3
+;   FastSeek_Open              ; DOS 4.00
+;   FSeek_dispatch             ; DOS 4.00
+;   FastSeek_Close             ; DOS 4.00
+;   FastSeek_Delete            ; DOS 4.00
+;   Delete_FSeek               ; DOS 4.00
+;   FastSeek_Lookup            ; DOS 4.00
+;   FastSeek_Insert            ; DOS 4.00
+;   FastSeek_Truncate          ; DOS 4.00
+;   FS_doit                    ; DOS 4.00
+;
+;   Revision history:
+;
+;   A000  version 4.00  Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+INCLUDE FASTOPEN.INC
+INCLUDE fastseek.inc
+INCLUDE fastxxxx.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  NoSetDir,BYTE
+        i_need  Creating,BYTE
+        i_need  DELALL,BYTE
+        i_need  THISDPB,DWORD
+        i_need  THISSFT,DWORD
+        i_need  THISCDS,DWORD
+        i_need  CURBUF,DWORD
+        i_need  ATTRIB,BYTE
+        i_need  SATTRIB,BYTE
+        i_need  WFP_START,WORD
+        i_need  FoundDel,BYTE
+        i_need  AUXSTACK,BYTE
+        i_need  VOLCHNG_FLAG,BYTE
+        i_need  JShare,DWORD
+        i_need  FastOpenTable,BYTE                ; DOS 3.3
+        i_need  FastTable,BYTE                    ; DOS 4.00
+        i_need  FSeek_drive,BYTE                  ; DOS 4.00
+        i_need  FSeek_firclus,WORD                ; DOS 4.00
+        i_need  FSeek_logclus,WORD                ; DOS 4.00
+        i_need  FSeek_logsave,WORD                ; DOS 4.00
+        i_need  FastSeekflg,BYTE                  ; DOS 4.00
+        i_need  Del_ExtCluster,WORD               ; DOS 4.00
+        i_need  SAVE_BX,WORD                      ; DOS 4.00
+        i_need  DMAADD,DWORD
+        i_need  RENAMEDMA,BYTE
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [SATTRIB] Is attribute of search, determines what files can be found
+; Function:
+;       Delete the specified file(s)
+; Outputs:
+;       CARRY CLEAR
+;               OK
+;       CARRY SET
+;           AX is error code
+;               error_file_not_found
+;                       Last element of path not found
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       Attempt to delete device or directory
+;               ***error_sharing_violation***
+;                       Deny both access required, generates an INT 24.
+;                       This error is NOT returned. The INT 24H is generated,
+;                         and the file is ignored (not deleted). Delete will
+;                         simply continue on looking for more files.
+;                         Carry will NOT be set in this case.
+; DS preserved, others destroyed
+
+fileFound   = 01h
+fileDeleted = 10h
+
+        procedure   DOS_DELETE,NEAR
+        DOSAssume   CS,<DS>,"DOS_Delete"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     LOCAL_DELETE
+;       invoke  OWN_SHARE2                     ;IFS. IFS owns share ?           ;AN000;
+;       JZ      ifsshare                       ;IFS. yes                        ;AN000;
+;       PUSH    WORD PTR [DMAADD+2]            ;IFS. save DMAADD                ;AN000;
+;       PUSH    WORD PTR [DMAADD]              ;IFS.                            ;AN000;
+;       CALL    IFS_SEARCH_FIRST               ;IFS. do search first            ;AN000;
+;       JC      nofiles                        ;IFS. file not existing          ;AN000;
+delete_next_file:                              ;IFS.                            ;AN000;
+;       CALL    IFS_REN_DEL_CHECK              ;IFS. do REN_DEL_CHECK           ;AN000;
+;       JNC     share_okok                     ;IFS. share ok                   ;AN000;
+;       MOV     AX,error_sharing_violation     ;IFS. share violation            ;AN000;
+;       JMP     SHORT nofiles                  ;IFS.                            ;AN000;
+share_okok:
+;       MOV     AX,(multNET SHL 8) OR 19       ;IFS. delete it now              ;AN000;
+;;      INT     2FH                            ;IFS.                            ;AN000;
+;       JC      nofiles                        ;IFS. error                      ;AN000;
+;       invoke  DOS_SEARCH_NEXT                ;IFS. get next entry             ;AN000;
+;       JNC     delete_next_file               ;IFS.                            ;AN000;
+;       CLC                                    ;IFS. no more files              ;AN000;
+nofiles:
+;       POP     WORD PTR [DMAADD]              ;IFS. retor DMAADD               ;AN000;
+;       POP     WORD PTR [DMAADD+2]            ;IFS.                            ;AN000;
+;       ret                                    ;IFS. return
+ifsshare:
+
+
+IF NOT Installed
+        transfer NET_DELETE
+ELSE
+        MOV     AX,(multNET SHL 8) OR 19
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_DELETE:
+        MOV     [FoundDel],00   ; No files found and no files deleted
+        EnterCrit   critDisk
+        MOV     WORD PTR [CREATING],0E500H  ; Assume not del *.*
+        MOV     SI,[WFP_START]
+SKPNUL:
+        LODSB
+        OR      AL,AL
+        JNZ     SKPNUL                      ; go to end
+        SUB     SI,4                        ; Back over possible "*.*"
+        CMP     WORD PTR [SI],("." SHL 8 OR "*")
+        JNZ     TEST_QUEST
+        CMP     BYTE PTR [SI+2],"*"
+        JZ      CHECK_ATTS
+TEST_QUEST:
+        SUB     SI,9            ; Back over possible "????????.???"
+        XCHG    DI,SI
+        context ES
+        MOV     AX,"??"
+        MOV     CX,4            ; four sets of "??"
+        REPE    SCASW
+        JNZ     NOT_ALL
+        XCHG    DI,SI
+        LODSW
+        CMP     AX,("?" SHL 8) OR "."
+        JNZ     NOT_ALL
+        LODSW
+        CMP     AX,"??"
+        JNZ     NOT_ALL
+CHECK_ATTS:
+        MOV     AL,BYTE PTR [SATTRIB]
+        AND     AL,attr_hidden+attr_system+attr_directory+attr_volume_id+attr_read_only
+                                        ; Look only at hidden bits
+        CMP     AL,attr_hidden+attr_system+attr_directory+attr_volume_id+attr_read_only
+                                        ; All must be set
+        JNZ     NOT_ALL
+
+; NOTE WARNING DANGER-----
+;    This DELALL stuff is not safe. It allows directories to be deleted.
+;       It should ONLY be used by FORMAT in the ROOT directory.
+;
+
+        MOV     [DELALL],0           ; DEL *.* - flag deleting all
+NOT_ALL:
+        MOV     [NoSetDir],1
+        invoke  GetPathNoSet
+        ASSUME  ES:NOTHING
+        JNC     Del_found
+        JNZ     bad_path
+        OR      CL,CL
+        JZ      bad_path
+No_file:
+        MOV     AX,error_file_not_found
+ErrorReturn:
+        STC
+        LeaveCrit   critDisk
+        return
+
+bad_path:
+        MOV     AX,error_path_not_found
+        JMP     ErrorReturn
+
+Del_found:
+        JNZ     NOT_DIR                 ; Check for dir specified
+        CMP     DelAll,0                ; DelAll = 0 allows delete of dir.
+        JZ      Not_Dir
+Del_access_err:
+        MOV     AX,error_access_denied
+        JMP     ErrorReturn
+
+NOT_DIR:
+        OR      AH,AH           ; Check if device name
+        JS      Del_access_err  ; Can't delete I/O devices
+;
+; Main delete loop.  CURBUF+2:BX points to a matching directory entry.
+;
+DELFILE:
+        OR      [FoundDel],fileFound    ; file found, not deleted yet
+;
+; If we are deleting the Volume ID, then we set VOLUME_CHNG flag to make
+; DOS issue a build BPB call the next time this drive is accessed.
+;
+        PUSH    DS
+        MOV     AH,[DELALL]
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+;; Extended Attributes
+;       PUSH    AX                       ;FT. save cluster of XA                ;AN000;
+;       MOV     AX,DS:[BX.dir_ExtCluster];FT.                                   ;AN000;
+;       MOV     [Del_ExtCluster],AX      ;FT.                                   ;AN000;
+;       POP     AX                       ;FT,                                   ;AN000;
+
+;; Extended Attributes
+        TEST    [Attrib],attr_read_only ; are we deleting RO files too?
+        JNZ     DoDelete                ; yes
+        TEST    DS:[BX.dir_attr],attr_read_only
+        JZ      DoDelete                ; not read only
+        POP     DS
+        JMP     SHORT DelNxt            ; Skip it (Note ES:BP not set)
+
+DoDelete:
+        call    REN_DEL_Check           ; Sets ES:BP = [THISDPB]
+        JNC     DEL_SHARE_OK
+        POP     DS
+        JMP     SHORT DelNxt            ; Skip it
+
+DEL_SHARE_OK:
+        Assert  ISBUF,<DS,DI>,"Del_Share_OK"
+        TEST    [DI.buf_flags],buf_dirty  ;LB. if already dirty                 ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      [DI.buf_flags],buf_dirty
+yesdirty:
+        MOV     [BX],AH                 ; Put in E5H or 0
+        MOV     BX,[SI]                 ; Get firclus pointer
+        POP     DS
+        DOSAssume   CS,<DS>,"Del_Share_OK"
+        OR      [FoundDel],fileDeleted  ; Deleted file
+        CMP     BX,2
+        JB      DELEXT                  ; File has invalid FIRCLUS (too small)
+        CMP     BX,ES:[BP.dpb_max_cluster]
+        JA      DELEXT                  ; File has invalid FIRCLUS (too big)
+;; FastSeek 10/27/86
+        CALL    Delete_FSeek            ; delete the fastseek entry
+;; FastSeek 10/27/86
+
+        invoke  RELEASE                 ; Free file data
+        JC      No_fileJ
+; DOS 3.3  FastOpen
+
+        CALL    FastOpen_Delete         ; delete the dir info in fastopen
+
+
+; DOS 3.3  FastOpen
+;; Extended Attributes
+DELEXT:
+
+;       MOV     BX,[Del_ExtCluster]     ;FT. delete XA cluster chain            ;AN000;
+;       CMP     BX,2                    ;FT.                                    ;AN000;
+;       JB      DELNXT                  ;FT. XA has invalid cluster (too small) ;AN000;
+;       CMP     BX,ES:[BP.dpb_max_cluster];FT.                                  ;AN000;
+;       JA      DELNXT                  ;FT. XA has invalid cluster (too big)   ;AN000;
+;       invoke  RELEASE                 ;FT. Free extended attrs cluster        ;AN000;
+;       JC      No_fileJ                ;FT.                                    ;AN000;
+
+;; Extended Attributes
+DELNXT:
+        LES     BP,[THISDPB]            ; Possible to get here without this set
+        invoke  GETENTRY                ; Registers need to be reset
+        JC      No_fileJ
+        invoke  NEXTENT
+if DEBUG
+        JC      Flsh
+        JMP     DelFile
+flsh:
+ELSE
+        JNC     DELFILE
+ENDIF
+        LES     BP,[THISDPB]            ; NEXTENT sets ES=DOSGROUP
+        MOV     AL,ES:[BP.dpb_drive]
+        invoke  FLUSHBUF
+        JC      No_fileJ
+;
+; Now we need to test FoundDel for our flags.  The cases to consider are:
+;
+;   not found not deleted               file not found
+;   not found     deleted               *** impossible ***
+;       found not deleted               access denied (read-only)
+;       found     deleted               no error
+;
+        TEST    FoundDel,fileDeleted    ; did we delete a file?
+        JZ      DelError                ; no, figure out what's wrong.
+; We set VOLCHNG_FLAG to indicate that we have changed the volume label
+; and to force the DOS to issue a media check.
+        TEST    [Attrib],attr_volume_id
+        jz      No_Set_Flag
+        PUSH    AX
+        PUSH    ES
+        PUSH    DI
+        LES     DI,[THISCDS]
+ASSUME  ES:NOTHING
+        MOV     AH,BYTE PTR ES:[DI]     ; Get drive
+        SUB     AH,'A'                  ; Convert to 0-based
+        mov     byte ptr [VOLCHNG_FLAG],AH
+        XOR     BH,BH                   ;>32mb delte volume id from boot record ;AN000;
+        invoke  Set_Media_ID            ;>32mb set voulme id to boot record     ;AN000;
+        invoke  FATRead_CDS             ; force media check
+        POP     DI
+        POP     ES
+        POP     AX
+No_Set_Flag:
+        LeaveCrit   critDisk            ; carry is clear
+        return
+DelError:
+        TEST    FoundDel,fileFound      ; not deleted.  Did we find file?
+        JNZ     Del_access_errJ         ; yes. Access denied
+No_fileJ:
+        JMP     No_file                 ; Nope
+Del_Access_errJ:
+        JMP     Del_access_err
+
+EndProc DOS_DELETE
+
+Break   <REN_DEL_Check - check for access for rename and delete>
+
+; Inputs:
+;       [THISDPB] set
+;       [CURBUF+2]:BX points to entry
+;       [CURBUF+2]:SI points to firclus field of entry
+;       [WFP_Start] points to name
+; Function:
+;       Check for Exclusive access on given file.
+;         Used by RENAME, SET_FILE_INFO, and DELETE.
+; Outputs:
+;       ES:BP = [THISDPB]
+;       NOTE: The WFP string pointed to by [WFP_Start] Will be Modified.  The
+;               last element will be loaded from the directory entry.  This is
+;               so the name given to the sharer doesn't have any meta chars in
+;               it.
+;       Carry set if sharing violation, INT 24H generated
+;           NOTE THAT AX IS NOT error_sharing_violation.
+;               This is because input AX is preserved.
+;               Caller must set the error if needed.
+;       Carry clear
+;               OK
+; AX,DS,BX,SI,DI preserved
+
+        procedure  REN_DEL_Check,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS
+        PUSH    DI
+        PUSH    AX
+        PUSH    BX
+        PUSH    SI              ; Save CURBUF pointers
+        context ES
+ASSUME  ES:DOSGROUP
+        MOV     DI,[WFP_START]  ; ES:DI -> WFP
+        MOV     SI,BX
+        MOV     DS,WORD PTR [CURBUF+2]  ; DS:SI -> entry (FCB style name)
+        MOV     BX,DI           ; Set backup limit for skipback
+        ADD     BX,2            ; Skip over d: to point to leading '\'
+        invoke  StrLen          ; CX is length of ES:DI including NUL
+        DEC     CX              ; Don't include nul in count
+        ADD     DI,CX           ; Point to NUL at end of string
+        invoke  SkipBack        ; Back up one element
+        INC     DI              ; Point to start of last element
+        MOV     [SAVE_BX],DI    ;IFS. save for DOS_RENAME                          ;AN000;
+        invoke  PackName        ; Transfer name from entry to ASCIZ tail.
+        POP     SI              ; Get back entry pointers
+        POP     BX
+        PUSH    BX
+        PUSH    SI              ; Back on stack
+        context DS
+ASSUME  DS:DOSGROUP
+;
+; Close the file if possible by us.
+;
+if installed
+        Call    JShare + 13 * 4
+else
+        Call    ShCloseFile
+endif
+        MOV     WORD PTR [THISSFT+2],DS
+        MOV     WORD PTR [THISSFT],OFFSET DOSGROUP:AUXSTACK - (SIZE sf_entry)
+                                ; Scratch space
+        XOR     AH,AH           ; Indicate file to DOOPEN (high bit off)
+        invoke  DOOPEN          ; Fill in SFT for share check
+        LES     DI,[THISSFT]
+        MOV     ES:[DI.sf_mode],sharing_deny_both   ; requires exclusive access
+        MOV     ES:[DI.sf_ref_count],1  ; Pretend open
+        invoke  ShareEnter
+        jc      CheckDone
+        LES     DI,[THISSFT]
+        MOV     ES:[DI.sf_ref_count],0  ; Pretend closed and free
+        invoke  SHAREEND                ; Tell sharer we're done with THISSFT
+        CLC
+CheckDone:
+        LES     BP,[THISDPB]
+        POP     SI
+        POP     BX
+        POP     AX
+        POP     DI
+        POP     DS
+        return
+
+EndProc REN_DEL_Check
+
+Break   <FastOpen_Delete - delete dir info in fastopen>
+
+; Inputs:
+;       None
+; Function:
+;       Call FastOpen to delete the dir info.
+; Outputs:
+;       None
+;
+;
+
+        procedure  FastOpen_Delete,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+        PUSHF                   ; save flag
+        PUSH    SI              ; save registers
+        PUSH    BX
+        PUSH    AX
+
+        MOV     SI,[WFP_Start]                         ; ds:si points to path name
+        MOV     AL,FONC_delete                         ; al = 3
+fastinvoke:
+        MOV     BX,OFFSET DOSGROUP:FastTable + 2
+        CALL    DWORD PTR [BX]                         ; call fastopen
+
+        POP     AX              ; restore registers
+        POP     BX
+        POP     SI
+        POPF                    ; restore flag
+        return
+EndProc FastOpen_Delete
+
+
+Break   <FastOpen_Update - update dir info in fastopen>
+
+; Inputs:
+;       DL     drive number (A=0,B=1,,,)
+;       CX     first cluster #
+;       AH     0 updates dir entry
+;              1 updates CLUSNUM  , BP = new CLUSNUM
+;       ES:DI  directory entry
+; Function:
+;       Call FastOpen to update the dir info.
+; Outputs:
+;       None
+;
+;
+
+        procedure  FastOpen_Update,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+        PUSHF                   ; save flag
+        PUSH    SI
+        PUSH    BX              ; save regs
+        PUSH    AX
+
+        MOV     AL,FONC_update                         ; al = 4
+        JMP     fastinvoke
+
+EndProc FastOpen_Update
+
+Break   <FastSeek_Open - create a file extent cache entry>
+
+; Inputs:
+;       DL     drive number (0=A,1=B,,,)
+;       CX     first cluster #
+; Function:
+;       Create a file extent cache entry
+; Outputs:
+;       None
+;
+;
+
+        procedure  FastSeek_Open,NEAR                                           ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+                                                                                ;AN000;
+        TEST    [FastSeekflg],Fast_yes         ; Fastseek installed ?           ;AN000;
+        JZ      fs_no11                        ; no                             ;AN000;
+        PUSH    SI                             ; save regs                      ;AN000;
+        PUSH    AX                                                              ;AN000;
+        MOV     AL,FSEC_open                   ; al = 11                        ;AN000;
+fseek_disp:                                                                     ;AN000;
+        CALL    FSeek_dispatch                 ; call fastseek                  ;AN000;
+        POP     AX                             ; restore regs                   ;AN000;
+        POP     SI                                                              ;AN000;
+fs_no11:                                                                        ;AN000;
+        return                                 ; return                         ;AN000;
+EndProc FastSeek_Open                                                           ;AN000;
+
+; Inputs:
+;       none
+; Function:
+;       Call Fastseek
+; Outputs:
+;       Output of Fastseek
+;
+
+        procedure  FSeek_dispatch,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+                                                                                ;AN000;
+        MOV     AH,FastSeek_ID                ; fastseek ID  = 1                ;AN000;
+ entry Fast_Dispatch                          ; future fastxxxx entry           ;AN000;
+        PUSH    AX                            ; save ax                         ;AN000;
+        MOV     AL,AH                         ; al=fastseek ID                  ;AN000;
+        XOR     AH,AH                         ;                                 ;AN000;
+        DEC     AX                            ;                                 ;AN000;
+        SHL     AX,1                          ; times 4 to get entry offset     ;AN000;
+        SHL     AX,1                                                            ;AN000;
+                                                                                ;AN000;
+        MOV     SI,OFFSET DOSGROUP:FastTable + 2        ; index to the          ;AN000;
+        ADD     SI,AX                                   ; fastxxxx entry        ;AN000;
+        POP     AX                                      ; restore ax            ;AN000;
+        CALL    DWORD PTR CS:[SI]                       ; call fastseek         ;AN000;
+        return
+EndProc FSeek_dispatch
+
+Break   <FastSeek_Close -  close a file extent entry>
+
+; Inputs:
+;       DL     drive number (0=A,1=B,,,)
+;       CX     first cluster #
+; Function:
+;       Close a file extent entry
+; Outputs:
+;       None
+;
+;
+
+        procedure  FastSeek_Close,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+
+        TEST    [FastSeekflg],Fast_yes         ; Fastseek installed ?           ;AN000;
+        JZ      fs_no2                         ; no                             ;AN000;
+        PUSH    SI                             ; save regs                      ;AN000;
+        PUSH    AX                             ;                                ;AN000;
+        MOV     AL,FSEC_close                  ; al = 12                        ;AN000;
+        JMP     fseek_disp                     ; call fastseek                  ;AN000;
+EndProc FastSeek_Close                                                          ;AN000;
+
+Break   <FastSeek_Delete - delete a file extent  entry>
+
+; Inputs:
+;       DL     drive number (0=A,1=B,,,)
+;       CX     first cluster #
+; Function:
+;       Delete a file extent entry
+; Outputs:
+;       None
+;
+;
+
+        procedure  FastSeek_Delete,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+                                                                                ;AN000;
+        TEST    [FastSeekflg],Fast_yes         ; Fastseek installed ?           ;AN000;
+        JZ      fs_no2                         ; no                             ;AN000;
+        PUSH    SI                             ; save regs                      ;AN000;
+        PUSH    AX                                                              ;AN000;
+        MOV     AL,FSEC_delete                 ; al=13                          ;AN000;
+        JMP     fseek_disp                     ; call fastseek                  ;AN000;
+EndProc FastSeek_Delete                                                         ;AN000;
+                                                                                ;AN000;
+; Inputs:
+;       FastSeekflg= 0 , not installed
+;                    1 , installed
+;       BX= first cluster number
+;       ES:BP = addr of DPB
+; Function:
+;       Delete a file extent entry
+; Outputs:
+;       None
+;
+
+        procedure  Delete_FSeek,NEAR                                            ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+        TEST    [FastSeekflg],Fast_yes         ; Fastseek installed ?           ;AN000;
+        JZ      fs_no2                         ; no                             ;AN000;
+        PUSH    CX                      ; save regs                             ;AN000;
+        PUSH    DX                                                              ;AN000;
+        MOV     CX,BX                   ; first cluster #                       ;AN000;
+        MOV     DL,ES:[BP.dpb_drive]    ; drive #                               ;AN000;
+        CALL    FastSeek_Delete         ; call fastseek to delete an entry      ;AN000;
+        POP     DX                      ; restore regs                          ;AN000;
+        POP     CX                                                              ;AN000;
+fs_no2:                                                                         ;AN000;
+        return                          ; exit                                  ;AN000;
+EndProc Delete_FSeek                                                            ;AN000;
+
+Break   <FastSeek_Lookup - look up a cluster number>
+
+; Inputs:
+;       FSeek_drive : drive number (0=A,1=B,,,)
+;       FSeek_firclus: first cluster #
+;       FSeek_logclus: logical cluster #
+; Function:
+;       Look up a physical cluster #
+; Outputs:
+;       carry clear, DI = physical cluster #, FSeek_logsave=DI-1
+;       carry set,
+;                  partially found, DI=last physical cluster #
+;                     FSeek_logsave=last logical cluster #
+
+        procedure  FastSeek_Lookup,NEAR                                         ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+
+        PUSH    AX                      ; save ax                               ;AN000;
+        MOV     AL,FSEC_lookup          ; al = 14                               ;AN000;
+        PUSH    BX                      ; save bx                               ;AN000;
+        CALL    FS_doit                 ; call fastseek                         ;AN000;
+        MOV     [FSeek_logsave],BX      ; save returned BX                      ;AN000;
+        POP     BX                      ; restore bx                            ;AN000;
+        POP     AX                      ; restore ax                            ;AN000;
+        return                                                                  ;AN000;
+EndProc FastSeek_Lookup                                                         ;AN000;
+                                                                                ;AN000;
+
+Break   <FastSeek_Insert - insert a cluster number>
+
+; Inputs:
+;       FSeek_drive : drive number (0=A,1=B,,,)
+;       FSeek_firclus: first cluster #
+;       FSeek_logclus: logical cluster #
+;       DI: physical cluster # to be inserted
+; Function:
+;       insert a physical cluster #
+; Outputs:
+;       none
+;
+
+        procedure  FastSeek_Insert,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        TEST    [FastSeekflg],FS_insert         ; insert mode set ?             ;AN000;
+        JZ      no_insert                       ; no                            ;AN000;
+                                                                                ;AN000;
+        PUSH    AX                              ; save regs                     ;AN000;
+        PUSH    BX                                                              ;AN000;
+        MOV     AL,FSEC_insert                  ; al = 15                       ;AN000;
+FSentry:                                                                        ;AN000;
+        CALL    FS_doit                         ; call fastseek                 ;AN000;
+        POP     BX                              ; restore regs                  ;AN000;
+        POP     AX                                                              ;AN000;
+no_insert:
+        return
+EndProc FastSeek_insert
+
+Break   <FastSeek_Truncate - truncate cluster numbers>
+
+; Inputs:
+;       FSeek_drive : drive number (0=A,1=B,,,)
+;       FSeek_firclus: first cluster #
+;       FSeek_logclus: logical cluster #
+; Function:
+;       truncate physical cluster #s starting from FSeek_logclus
+; Outputs:
+;       none
+;
+
+        procedure  FastSeek_Truncate,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+                                                                                ;AN000;
+        TEST    [FastSeekflg],Fast_yes         ; Fastseek installed ?           ;AN000;
+        JZ      fs_no                          ; no                             ;AN000;
+        PUSH    AX                             ; save regs                      ;AN000;
+        PUSH    BX                                                              ;AN000;
+        MOV     AL,FSEC_truncate               ; al = 16                        ;AN000;
+        JMP     FSentry                        ; call fastseek                  ;AN000;
+fs_no:                                                                          ;AN000;
+        return                                                                  ;AN000;
+EndProc FastSeek_Truncate                                                       ;AN000;
+
+; Inputs:
+;       FSeek_drive : drive number (0=A,1=B,,,)
+;       FSeek_firclus: first cluster #
+;       FSeek_logclus: logical cluster #
+; Function:
+;       set up parameters and call fastseek
+; Outputs:
+;       outputs of fastseek
+;
+        procedure  FS_doit,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+                                                                                ;AN000;
+        PUSH    CX                      ; save regs                             ;AN000;
+        PUSH    DX                                                              ;AN000;
+        PUSH    SI                                                              ;AN000;
+        MOV     DL,[FSeek_drive]        ; set drive #                           ;AN000;
+        MOV     CX,[FSeek_firclus]      ; set 1st cluster #                     ;AN000;
+        MOV     BX,[FSeek_logclus]      ; set logical cluster #                 ;AN000;
+                                                                                ;AN000;
+        CALL    FSeek_dispatch          ; call fastseek                         ;AN000;
+                                                                                ;AN000;
+                                        ; carry clear if found in DI            ;AN000;
+        POP     SI                      ; otherwise, carry set                  ;AN000;
+                                                                                ;AN000;
+        POP     DX                      ; restore regs                          ;AN000;
+        POP     CX                                                              ;AN000;
+        return                                                                  ;AN000;
+EndProc FS_doit                                                                 ;AN000;
+
+
+; Inputs:
+;       same as DOS_SEARCH_FIRST
+; Function:
+;       do a IFS search first
+; Outputs:
+;       same as DOS_SEARCH_FIRST
+;
+        procedure  IFS_SEARCH_FIRST,NEAR                                        ;AN000;
+        DOSAssume   CS,<DS>,"IFS_SEARCH_FIRST"                                  ;AN000;
+        ASSUME  ES:NOTHING                                                      ;AN000;
+
+;       MOV     WORD PTR [DMAADD+2],DS         ;IFS. replace with scratch area  ;AN000;;AN000;
+;       MOV     WORD PTR [DMAADD],OFFSET DOSGROUP:RENAMEDMA     ;IFS.           ;AN000;
+;       invoke  SET_THISDPB                    ;IFS. THISDPB set                ;AN000;
+;       invoke  DOS_SEARCH_FIRST               ;IFS. search first               ;AN000;
+;       return                                                                  ;AN000;
+EndProc IFS_SEARCH_FIRST                                                        ;AN000;
+
+
+; Inputs:
+;       THISDPB set
+;       WFP_Start points to name
+; Function:
+;       do a IFS REN_DEL_CHECK
+; Outputs:
+;       same as REN_DEL_CHECK
+;
+        procedure  IFS_REN_DEL_CHECK,NEAR                                       ;AN000;
+        DOSAssume   CS,<DS>,"IFS_REN_DEL_CHECK"                                 ;AN000;
+        ASSUME  ES:NOTHING                                                      ;AN000;
+
+;       MOV     AX,WORD PTR [DMAADD+2]         ;IFS. set up                     ;AN000;;AN000;
+;       MOV     WORD PTR [CURBUF+2],AX         ;IFS. curbuf+2 : bx -> dir entry ;AN000;
+;       MOV     BX,WORD PTR [DMAADD]           ;IFS.                            ;AN000;
+;       ADD     BX,21                          ;IFS.                            ;AN000;
+;       MOV     SI,BX                          ;IFS. curbuf+2:si -> dir_first   ;AN000;
+;       ADD     SI,dir_first                   ;IFS.                            ;AN000;
+;       EnterCrit   critDisk                   ;IFS. enter critical section     ;AN000;
+;       CALL    REN_DEL_Check                  ;IFS. share check                ;AN000;
+;       LeaveCrit   critDisk                   ;IFS. leave critical section     ;AN000;
+;       return                                                                  ;AN000;
+EndProc IFS_REN_DEL_CHECK                                                       ;AN000;
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/DEV.ASM b/v4.0/src/DOS/DEV.ASM
new file mode 100644
index 0000000..20c3f74
--- /dev/null
+++ b/v4.0/src/DOS/DEV.ASM
@@ -0,0 +1,841 @@
+;       SCCSID = @(#)dev.asm    1.2 85/07/23
+;       SCCSID = @(#)dev.asm    1.2 85/07/23
+TITLE   DEV - Device call routines
+NAME    Dev
+; Misc Routines to do 1-12 low level I/O and call devices
+;
+;   IOFUNC
+;   DEVIOCALL
+;   SETREAD
+;   SETWRITE
+;   DEVIOCALL2
+;   DEV_OPEN_SFT
+;   DEV_CLOSE_SFT
+;   RW_SC
+;   IN_SC
+;   INVALIDATE_SC
+;   VIRREAD
+;   SC2BUF
+;
+;   Revision history:
+;
+;       A000  version 4.00     Jan. 1988
+;       A010  disable change line for SHARE /NC
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+        i_need  IOXAD,DWORD
+        i_need  IOSCNT,WORD
+        i_need  DEVIOBUF,4
+        i_need  IOCALL,BYTE
+        i_need  IOMED,BYTE
+        i_need  IORCHR,BYTE
+        i_need  CALLSCNT,WORD
+        i_need  DMAAdd,DWORD
+        i_need  CallDevAd,DWORD
+        i_need  CallXAD,DWORD
+        i_need  DPBHead,DWORD
+        i_need  ThisSFT,DWORD
+        i_need  ThisDPB,DWORD
+        i_need  DevCall,DWORD
+        i_need  VerFlg,BYTE
+        i_need  HIGH_SECTOR,WORD               ;AN000;
+        i_need  CALLSSEC,WORD                  ;AN000;
+        i_need  CALLNEWSC,DWORD                ;AN000;
+        i_need  SC_CACHE_COUNT,WORD            ;AN000;
+        i_need  SC_CACHE_PTR,DWORD             ;AN000;
+        i_need  CURSC_SECTOR,WORD              ;AN000;
+        i_need  SEQ_SECTOR,DWORD               ;AN000;
+        i_need  SC_SECTOR_SIZE,WORD            ;AN000;
+        i_need  CURSC_DRIVE,BYTE               ;AN000;
+        i_need  SC_DRIVE,BYTE                  ;AN000;
+        i_need  SC_STATUS,WORD                 ;AN000;
+        i_need  SC_FLAG,BYTE                   ;AN000;
+        i_need  TEMP_VAR,WORD                  ;AN000;
+        i_need  TEMP_VAR2,WORD                 ;AN000;
+        i_need  InterChar,BYTE  ;AN000; interim character flag 2/13/KK
+        i_need  InterCon,BYTE   ;AN000; Console mode flag(1:interim mode) 2/13/KK
+        i_need  SaveCurFlg,BYTE ;AN000; Console out mode(1:print & don't adv cursor) 2 /13/KK
+        i_need  DDMOVE,BYTE     ;AN000; flag for DWORD move
+        i_need  DOS34_FLAG,WORD ;AN000;
+        i_need  fshare,BYTE     ;AN010; share flag
+
+Break   <IOFUNC -- DO FUNCTION 1-12 I/O>
+
+; Inputs:
+;       DS:SI Points to SFT
+;       AH is function code
+;               = 0 Input
+;               = 1 Input Status
+;               = 2 Output
+;               = 3 Output Status
+;               = 4 Flush
+;               = 5 Input Status - System WAIT invoked for K09 if no char
+;                                  present.
+;       AL = character if output
+; Function:
+;       Perform indicated I/O to device or file
+; Outputs:
+;       AL is character if input
+;       If a status call
+;               zero set if not ready
+;               zero reset if ready (character in AL for input status)
+; For regular files:
+;       Input Status
+;               Gets character but restores position
+;               Zero set on EOF
+;       Input
+;               Gets character advances position
+;               Returns ^Z on EOF
+;       Output Status
+;               Always ready
+; AX altered, all other registers preserved
+
+        procedure   IOFUNC,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISSFT,<DS,SI>,"IOFUNC"
+        MOV     WORD PTR [IOXAD+2],SS
+        MOV     WORD PTR [IOXAD],OFFSET DOSGROUP:DEVIOBUF
+        MOV     WORD PTR [IOSCNT],1
+        MOV     WORD PTR [DEVIOBUF],AX
+        TEST    [SI.sf_flags],sf_isnet
+        JZ      IOTO22                                                          ;AN000;
+        JMP     IOTOFILE                                                        ;AN000;
+IOTO22:
+        TEST    [SI.sf_flags],devid_device
+        JNZ     IOTo33                                                          ;AN000;
+        JMP     IOTOFILE                                                        ;AN000;
+IOTO33:
+        invoke  save_world
+        MOV     DX,DS
+        MOV     BX,SS
+        MOV     DS,BX
+        MOV     ES,BX
+        ASSUME  DS:DOSGroup
+        XOR     BX,BX
+        cmp     ah,5                ; system wait enabled?
+        jnz     no_sys_wait
+        or      bx,0400H            ; Set bit 10 in status word for driver
+                                    ; It is up to device driver to carry out
+                                    ; appropriate action.
+no_sys_wait:
+        MOV     [IOCALL.REQSTAT],BX
+        XOR     BX,BX
+        MOV     BYTE PTR [IOMED],BL
+
+Table   Segment
+Public DEV001S, DEV001E                 ; Pathgen labels
+DEV001s:
+;               length of packets
+LenTab  DB      DRDWRHL, DRDNDHL, DRDWRHL, DSTATHL, DFLSHL, DRDNDHL
+
+;               Error   Function
+
+CmdTab  DB      86h,    DEVRD           ; 0 input
+        DB      86h,    DEVRDND         ; 1 input status
+        DB      87h,    DEVWRT          ; 2 output
+        DB      87h,    DEVOST          ; 3 output status
+        DB      86h,    DEVIFL          ; 4 input flush
+        DB      86H,    DEVRDND         ; 5 input status with system WAIT
+DEV001E:
+Table   ENDS
+
+        MOV     BL,AH                   ; get function
+        MOV     AH,LenTab[BX]
+        SHL     BX,1
+        MOV     CX,WORD PTR CmdTab[BX]
+
+        MOV     BX,OFFSET DOSGROUP:IOCALL
+
+        MOV     [IOCALL.REQLEN],AH
+        MOV     [IOCALL.REQFUNC],CH
+ IF  DBCS                               ;AN000;
+;----------------------------- Start of DBCS 2/13/KK
+        PUSH    CX                      ;AN000;
+        MOV     CL, [InterCon]          ;AN000;
+        CMP     CH, DEVRD               ;AN000; 0 input
+        JZ      SETIN                   ;AN000;
+        CMP     CH, DEVRDND             ;AN000; 1(5) input status without(with) system WAIT
+        JZ      SETIN                   ;AN000;
+        MOV     CL, [SaveCurflg]        ;AN000;
+        CMP     CH, DEVWRT              ;AN000; 2 output
+        JZ      CHKERROUT               ;AN000;
+        XOR     CL,CL                   ;AN000; else, do normal
+SETIN:                                  ;AN000;
+        MOV     BYTE PTR [IoMed], CL    ;AN000; set interim I/O indication
+        POP     CX                      ;AN000;
+;----------------------------- End of DBCS 2/13/KK
+ ENDIF                                  ;AN000;
+        MOV     DS,DX
+ASSUME  DS:NOTHING
+        CALL    DEVIOCALL
+        MOV     DI,[IOCALL.REQSTAT]
+        TEST    DI,STERR
+        JNZ     DevErr
+OkDevIO:
+        MOV     AX,SS
+        MOV     DS,AX
+        ASSUME  DS:DOSGroup
+ IF  DBCS                       ;AN000;
+        MOV     [InterChar],0   ;AN000; reset interim character flag  2/13/KK
+        TEST    DI,Ddkey        ;AN000; is this a dead key (interim char)? 2/13/KK
+        JZ      NotInterim      ;AN000; no, flag already reset...          2/13/KK
+        INC     [InterChar]     ;AN000; yes, set flag for future           2/13/KK
+NotInterim:                     ;AN000;                                    2/13/KK
+ ENDIF                          ;AN000;
+        CMP     CH,DEVRDND
+        JNZ     DNODRD
+        MOV     AL,BYTE PTR [IORCHR]
+        MOV     [DEVIOBUF],AL
+
+DNODRD: MOV     AH,BYTE PTR [IOCALL.REQSTAT+1]
+        NOT     AH                      ; Zero = busy, not zero = ready
+        AND     AH,STBUI SHR 8
+
+QuickReturn:                            ;AN000; 2/13/KK
+        invoke  restore_world
+ASSUME  DS:NOTHING
+        MOV     AX,WORD PTR [DEVIOBUF]
+        return
+
+;IOTOFILEJ:
+;       JMP     SHORT IOTOFILE
+ IF  DBCS                               ;AN000;
+;------------------------------ Start of DBCS 2/13/KK
+CHKERROUT:                              ;AN000;
+        MOV     DS, DX                  ;AN000;
+        TEST    [SI.sf_flags], devid_device_con_out     ;AN000; output to console ?
+        JNZ     GOOD                    ;AN000; yes
+        CMP     CL, 01                  ;AN000; write interim ?
+        JNZ     GOOD                    ;AN000; no,
+        POP     CX                      ;AN000;
+        JMP     SHORT QuickReturn       ;AN000; avoid writting interims to other than
+                                        ;AN000; console device
+GOOD:                                   ;AN000;
+        PUSH    SS                      ;AN000;
+        POP     DS                      ;AN000;
+        JMP     SETIN                   ;AN000;
+;------------------------------ End of DBCS 2/13/KK
+ ENDIF                                  ;AN000;
+DevErr:
+        TEST    CS:[DOS34_FLAG],X25_Special ;AN000; from disk.asm
+        JZ      notx25                   ;AN000; no
+        PUSH    AX                       ;AN000; unknown command ?
+        MOV     AX,DI                    ;AN000;
+        AND     AX,error_I24_bad_command ;AN000;
+        CMP     AL,error_I24_bad_command ;AN000;
+        POP     AX                       ;AN000;
+        JNZ     notx25                   ;AN000; no, then error
+        JMP     okDevIO                  ;AN000;
+notx25:
+        MOV     AH,CL
+        invoke  CHARHARD
+        CMP     AL,1
+        JNZ     NO_RETRY
+        invoke  restore_world
+        JMP     IOFUNC
+
+NO_RETRY:
+;   Know user must have wanted Ignore OR Fail.  Make sure device shows ready
+;   so that DOS doesn't get caught in a status loop when user simply wants
+;   to ignore the error.
+        AND     BYTE PTR [IOCALL.REQSTAT+1], NOT (STBUI SHR 8)
+        JMP     OKDevIO
+
+IOTOFILE:
+ASSUME  DS:NOTHING
+        OR      AH,AH
+        JZ      IOIN
+        DEC     AH
+        JZ      IOIST
+        DEC     AH
+        JZ      IOUT
+        return                          ; NON ZERO FLAG FOR OUTPUT STATUS
+
+IOIST:
+        PUSH    WORD PTR [SI.sf_position]   ; Save position
+        PUSH    WORD PTR [SI.sf_position+2]
+        CALL    IOIN
+        POP     WORD PTR [SI.sf_position+2] ; Restore position
+        POP     WORD PTR [SI.sf_position]
+        return
+
+IOUT:
+        CALL    SETXADDR
+        invoke  DOS_WRITE
+        CALL    RESTXADDR               ; If you change this into a jmp don't
+        return                          ; come crying to me when things don't
+                                        ; work ARR
+
+IOIN:
+        CALL    SETXADDR
+        OR      [DOS34_FLAG],Disable_EOF_I24   ;AN000;
+        invoke  DOS_READ
+        AND     [DOS34_FLAG],NO_Disable_EOF_I24   ;AN000;
+        OR      CX,CX                   ; Check EOF
+        CALL    RESTXADDR
+        MOV     AL,[DEVIOBUF]           ; Get byte from trans addr
+        retnz
+        MOV     AL,1AH                  ; ^Z if no bytes
+        return
+
+SETXADDR:
+        POP     WORD PTR [CALLSCNT]     ; Return address
+        invoke  save_world
+        PUSH    WORD PTR [DMAADD]       ; Save Disk trans addr
+        PUSH    WORD PTR [DMAADD+2]
+        MOV     WORD PTR [THISSFT+2],DS
+        Context DS
+        MOV     WORD PTR [THISSFT],SI   ; Finish setting SFT pointer
+        MOV     CX,WORD PTR [IOXAD+2]
+        MOV     WORD PTR [DMAADD+2],CX
+        MOV     CX,WORD PTR [IOXAD]
+        MOV     WORD PTR [DMAADD],CX    ; Set byte trans addr
+        MOV     CX,[IOSCNT]             ; ioscnt specifies length of buffer
+        JMP     SHORT RESTRET           ; RETURN ADDRESS
+
+RESTXADDR:
+        DOSAssume   CS,<DS>,"RestXAddr"
+        POP     WORD PTR [CALLSCNT]     ; Return address
+        POP     WORD PTR [DMAADD+2]     ; Restore Disk trans addr
+        POP     WORD PTR [DMAADD]
+        invoke  restore_world
+ASSUME  DS:NOTHING
+RESTRET:JMP     WORD PTR [CALLSCNT]     ; Return address
+EndProc IOFUNC
+
+Break <DEV_OPEN_SFT, DEV_CLOSE_SFT - OPEN or CLOSE A DEVICE>
+
+; Inputs:
+;       ES:DI Points to SFT
+; Function:
+;       Issue an OPEN call to the correct device
+; Outputs:
+;       None
+; ALL preserved
+
+        procedure   DEV_OPEN_SFT,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"Dev_Open_SFT"
+        invoke  Save_World
+        MOV     AL,DEVOPN
+        JMP     SHORT DO_OPCLS
+
+EndProc DEV_OPEN_SFT
+
+; Inputs:
+;       ES:DI Points to SFT
+; Function:
+;       Issue a CLOSE call to the correct device
+; Outputs:
+;       None
+; ALL preserved
+
+        procedure   DEV_CLOSE_SFT,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"Dev_Close_SFT"
+        invoke  Save_World
+        MOV     AL,DEVCLS
+
+;
+; Main entry for device open and close.  AL contains the function requested.
+; Subtlety:  if Sharing is NOT loaded then we do NOT issue open/close to block
+; devices.  This allows networks to function but does NOT hang up with bogus
+; change-line code.
+;
+        entry   DO_OPCLS
+;
+; Is the SFT for the net?  If so, no action necessary.
+;
+        invoke  Test_IFS_Remote                                                 ;AC000;
+        JNZ     OPCLS_DONE              ; NOP on net SFTs
+        XOR     AH,AH                   ; Unit
+        TEST    ES:[DI.sf_flags],devid_device
+        LES     DI,ES:[DI.sf_devptr]    ; Get DPB or device
+        JNZ     Got_Dev_Addr
+;
+; We are about to call device open/close on a block driver.  If no sharing
+; then just short circuit to done.
+;
+;;;;;   invoke  CheckShare
+        CMP     fshare,1                ;AN010; /NC or no SHARE
+        JBE     opCLs_Done              ;AN010; yes
+        MOV     AH,ES:[DI.dpb_UNIT]
+        MOV     CL,ES:[DI.dpb_drive]
+        LES     DI,ES:[DI.dpb_driver_addr]  ; Get device
+GOT_DEV_ADDR:                           ; ES:DI -> device
+        TEST    ES:[DI.SDEVATT],DEVOPCL
+        JZ      OPCLS_DONE              ; Device can't
+        PUSH    ES
+        POP     DS
+        MOV     SI,DI                   ; DS:SI -> device
+OPCLS_RETRY:
+        Context ES
+        MOV     DI,OFFSET DOSGROUP:DEVCALL
+        MOV     BX,DI
+        PUSH    AX
+        MOV     AL,DOPCLHL
+        STOSB                           ; Length
+        POP     AX
+        XCHG    AH,AL
+        STOSB                           ; Unit
+        XCHG    AH,AL
+        STOSB                           ; Command
+        MOV     WORD PTR ES:[DI],0      ; Status
+        PUSH    AX                      ; Save Unit,Command
+        invoke  DEVIOCALL2
+        MOV     DI,ES:[BX.REQSTAT]
+        TEST    DI,STERR
+        JZ      OPCLS_DONEP             ; No error
+        TEST    [SI.SDEVATT],DEVTYP
+        JZ      BLKDEV
+        MOV     AH,86H                  ; Read error in data, Char dev
+        JMP     SHORT HRDERR
+
+BLKDEV:
+        MOV     AL,CL                   ; Drive # in AL
+        MOV     AH,6                    ; Read error in data, Blk dev
+HRDERR:
+        invoke  CHARHARD
+        CMP     AL,1
+        JNZ     OPCLS_DONEP             ; IGNORE or FAIL
+                                        ;  Note that FAIL is essentually IGNORED
+        POP     AX                      ; Get back Unit, Command
+        JMP     OPCLS_RETRY
+
+OPCLS_DONEP:
+        POP     AX                      ; Clean stack
+OPCLS_DONE:
+        invoke  Restore_World
+        return
+
+EndProc DEV_CLOSE_SFT
+
+Break   <DEVIOCALL, DEVIOCALL2 - CALL A DEVICE>
+
+; Inputs:
+;       DS:SI Points to device SFT
+;       ES:BX Points to request data
+; Function:
+;       Call the device
+; Outputs:
+;       DS:SI -> Device driver
+; DS:SI,AX destroyed, others preserved
+
+        procedure   DEVIOCALL,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISSFT,<DS,SI>,"DevIOCall"
+        LDS     SI,[SI.sf_devptr]
+
+        entry   DEVIOCALL2
+
+        EnterCrit   critDevice
+
+        TEST    [SI.SDEVATT],DevTyp    ;AN000; >32mb   block device ?
+        JNZ     chardev2               ;AN000; >32mb   no
+        CMP     ES:[BX.REQFUNC],DEVRD  ;AN000; >32mb   read ?
+        JZ      chkext                 ;AN000; >32mb   yes
+        CMP     ES:[BX.REQFUNC],DEVWRT ;AN000; >32mb   write ?
+        JZ      chkext                 ;AN000; >32mb   yes
+        CMP     ES:[BX.REQFUNC],DEVWRTV;AN000; >32mb   write/verify ?
+        JNZ     chardev2               ;AN000; >32mb   no
+chkext:
+        CALL    RW_SC                  ;AN000;LB. use secondary cache if there
+        JC      dev_exit               ;AN000;LB. done
+
+        TEST    [SI.SDEVATT],EXTDRVR   ;AN000;>32mb   extended driver?
+        JZ      chksector              ;AN000;>32mb   no
+        ADD     BYTE PTR ES:[BX],8     ;AN000;>32mb   make length to 30
+        MOV     AX,[CALLSSEC]          ;AN000;>32mb
+        MOV     [CALLSSEC],-1          ;AN000;>32mb   old sector  =-1
+        MOV     WORD PTR [CALLNEWSC],AX   ;AN000;>32mb   new sector  =
+        MOV     AX,[HIGH_SECTOR]       ;AN000; >32mb   low sector,high sector
+        MOV     WORD PTR [CALLNEWSC+2],AX  ;AN000; >32mb
+        JMP     chardev2               ;AN000; >32mb
+chksector:                             ;AN000; >32mb
+        CMP     [HIGH_SECTOR],0        ;AN000; >32mb   if >32mb
+        JZ      chardev2               ;AN000; >32mb   then fake error
+        MOV     ES:[BX.REQSTAT],STERR+STDON+ERROR_I24_NOT_DOS_DISK  ;AN000; >32mb
+        JMP     SHORT dev_exit         ;AN000; >32mb
+
+chardev2:                              ;AN000;
+; As above only DS:SI points to device header on entry, and DS:SI is preserved
+        MOV     AX,[SI.SDEVSTRAT]
+        MOV     WORD PTR [CALLDEVAD],AX
+        MOV     WORD PTR [CALLDEVAD+2],DS
+        CALL    DWORD PTR [CALLDEVAD]
+        MOV     AX,[SI.SDEVINT]
+        MOV     WORD PTR [CALLDEVAD],AX
+        CALL    DWORD PTR [CALLDEVAD]
+        CALL    VIRREAD                 ;AN000;LB. move data from SC to buffer
+        JC      chardev2                ;AN000;LB. bad sector or exceeds max sec
+dev_exit:
+        LeaveCrit   critDevice
+        return
+EndProc DEVIOCALL
+
+Break   <SETREAD, SETWRITE -- SET UP HEADER BLOCK>
+
+; Inputs:
+;       DS:BX = Transfer Address
+;       CX = Record Count
+;       DX = Starting Record
+;       AH = Media Byte
+;       AL = Unit Code
+; Function:
+;       Set up the device call header at DEVCALL
+; Output:
+;       ES:BX Points to DEVCALL
+; No other registers effected
+
+        procedure   SETREAD,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DI
+        PUSH    CX
+        PUSH    AX
+        MOV     CL,DEVRD
+SETCALLHEAD:
+        MOV     AL,DRDWRHL
+        PUSH    SS
+        POP     ES
+        MOV     DI,OFFSET DOSGROUP:DEVCALL
+        STOSB                           ; length
+        POP     AX
+        STOSB                           ; Unit
+        PUSH    AX
+        MOV     AL,CL
+        STOSB                           ; Command code
+        XOR     AX,AX
+        STOSW                           ; Status
+        ADD     DI,8                    ; Skip link fields
+        POP     AX
+        XCHG    AH,AL
+        STOSB                           ; Media byte
+        XCHG    AL,AH
+        PUSH    AX
+        MOV     AX,BX
+        STOSW
+        MOV     AX,DS
+        STOSW                           ; Transfer addr
+        POP     CX                      ; Real AX
+        POP     AX                      ; Real CX
+        STOSW                           ; Count
+        XCHG    AX,DX                   ; AX=Real DX, DX=real CX, CX=real AX
+        STOSW                           ; Start
+        XCHG    AX,CX
+        XCHG    DX,CX
+        POP     DI
+        MOV     BX,OFFSET DOSGROUP:DEVCALL
+        return
+
+        entry   SETWRITE
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       DS:BX = Transfer Address
+;       CX = Record Count
+;       DX = Starting Record
+;       AH = Media Byte
+;       AL = Unit Code
+; Function:
+;       Set up the device call header at DEVCALL
+; Output:
+;       ES:BX Points to DEVCALL
+; No other registers effected
+
+        PUSH    DI
+        PUSH    CX
+        PUSH    AX
+        MOV     CL,DEVWRT
+        ADD     CL,[VERFLG]
+        JMP     SHORT SETCALLHEAD
+EndProc SETREAD
+
+
+Break   <RW_SC -- Read Write Secondary Cache>
+
+; Inputs:
+;        [SC_CACHE_COUNT]= secondary cache count
+;        [SC_STATUS]= SC validity status
+;        [SEQ_SECTOR]= last sector read
+; Function:
+;       Read from or write through secondary cache
+; Output:
+;       ES:BX Points to DEVCALL
+;       carry clear, I/O is not done
+;                    [SC_FLAG]=1 if continuos sectors will be read
+;       carry set, I/O is done
+
+
+        procedure   RW_SC,NEAR          ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING           ;AN000;
+
+        CMP     [SC_CACHE_COUNT],0      ;AN000;LB. secondary cache exists?
+        JZ      scexit4                 ;AN000;LB. no, do nothing
+        CMP     [CALLSCNT],1            ;AN000;LB. sector count = 1 (buffer I/O)
+        JNZ     scexit4                 ;AN000;LB. no, do nothing
+        PUSH    CX                          ;AN000;;LB.
+        PUSH    DX                          ;AN000;;LB. yes
+        PUSH    DS                          ;AN000;;LB. save registers
+        PUSH    SI                          ;AN000;;LB.
+        PUSH    ES                          ;AN000;;LB.
+        PUSH    DI                          ;AN000;;LB.
+        MOV     DX,WORD PTR [CALLSSEC]      ;AN000;;LB.  starting sector
+        CMP     BYTE PTR [DEVCALL.REQFUNC],DEVRD ;AN000;LB. read ?                    ;AN000;
+        JZ      doread                  ;AN000;LB. yes                                ;AN000;
+        CALL    INVALIDATE_SC               ;AN000;LB. invalidate SC                  ;AN000;
+        JMP     scexit2                     ;AN000;LB. back to normal                 ;AN000;
+scexit4:                                    ;AN000;                                    ;AN000;
+        CLC                                 ;AN000;LB. I/O not done yet           ;AN000;
+        return                              ;AN000;LB.                            ;AN000;
+doread:                                     ;AN000;                                    ;AN000;
+        CALL    SC2BUF                      ;AN000;LB. check if in SC                 ;AN000;
+        JC      readSC                      ;AN000;LB.                                    ;AN000;
+        MOV     [DEVCALL.REQSTAT],STDON     ;AN000;LB. fake done and ok           ;AN000;
+        STC                                 ;AN000;LB. set carry                  ;AN000;
+        JMP     saveseq                     ;AN000;LB. save seq. sector #         ;AN000;
+readSC:                                     ;AN000;
+        MOV     AX,WORD PTR [HIGH_SECTOR]   ;AN000;;LB. subtract sector num from
+        MOV     CX,WORD PTR [CALLSSEC]      ;AN000;;LB. saved sequential sector
+        SUB     CX,WORD PTR [SEQ_SECTOR]    ;AN000;;LB. number
+        SBB     AX,WORD PTR [SEQ_SECTOR+2]  ;AN000;;LB.
+        CMP     AX,0                        ;AN000;;LB. greater than 64K
+        JNZ     saveseq2                    ;AN000;;LB. yes,save seq. sector #
+chklow:                                                                         ;AN000;
+        CMP     CX,1                        ;AN000;;LB. <= 1
+        JA      saveseq2                    ;AN000;;LB. no, not sequential
+        MOV     [SC_STATUS],-1              ;AN000;;LB. prsume all SC valid
+        MOV     AX,[SC_CACHE_COUNT]         ;AN000;;LB. yes, sequential
+        MOV     [CALLSCNT],AX               ;AN000;;LB. read continuous sectors
+readsr:
+        MOV     AX,WORD PTR [CALLXAD+2]     ;AN000;;LB. save buffer addr
+        MOV     [TEMP_VAR2],AX              ;AN000;;LB. in temp vars
+        MOV     AX,WORD PTR [CALLXAD]       ;AN000;;LB.
+        MOV     [TEMP_VAR],AX               ;AN000;;LB.
+                                                                                ;AN000;
+        MOV     AX,WORD PTR [SC_CACHE_PTR]  ;AN000;LB. use SC cache addr as           ;AN000;
+        MOV     WORD PTR [CALLXAD],AX       ;AN000;LB. transfer addr                  ;AN000;
+        MOV     AX,WORD PTR [SC_CACHE_PTR+2]  ;AN000;LB.                              ;AN000;
+        MOV     WORD PTR [CALLXAD+2],AX       ;AN000;LB.                              ;AN000;
+        MOV     [SC_FLAG],1                   ;AN000;LB. flag it for later            ;AN000;
+        MOV     AL,[SC_DRIVE]               ;AN000;;LB. current drive
+        MOV     [CURSC_DRIVE],AL            ;AN000;;LB. set current drive
+        MOV     AX,WORD PTR [CALLSSEC]      ;AN000;;LB. current sector
+        MOV     [CURSC_SECTOR],AX           ;AN000;;LB. set current sector
+        MOV     AX,WORD PTR [CALLSSEC+2]    ;AN000;;LB.
+        MOV     [CURSC_SECTOR+2],AX         ;AN000;;LB.
+saveseq2:                                   ;AN000;
+        CLC                                 ;AN000;LB. clear carry                    ;AN000;
+saveseq:                                    ;AN000;                                    ;AN000;
+        MOV     AX,[HIGH_SECTOR]            ;AN000;LB. save current sector #      ;AN000;
+        MOV     WORD PTR [SEQ_SECTOR+2],AX  ;AN000;LB. for access mode ref.       ;AN000;
+        MOV     AX,[CALLSSEC]               ;AN000;LB.                            ;AN000;
+        MOV     WORD PTR [SEQ_SECTOR],AX    ;AN000;LB.                            ;AN000;
+        JMP     scexit                      ;AN000;LB.                            ;AN000;
+                                                                                ;AN000;
+scexit2:                                    ;AN000;LB.                                ;AN000;
+        CLC                                 ;AN000;LB.         clear carry            ;AN000;
+scexit:                                     ;AN000;                                    ;AN000;
+        POP     DI                          ;AN000;;LB.
+        POP     ES                          ;AN000;;LB. restore registers
+        POP     SI                          ;AN000;;LB.
+        POP     DS                          ;AN000;;LB.
+        POP     DX                          ;AN000;;LB.
+        POP     CX                          ;AN000;;LB.
+        return                              ;AN000;;LB.
+                                                                                ;AN000;
+EndProc RW_SC                               ;AN000;
+
+Break   <IN_SC -- check if in secondary cache>
+
+; Inputs:  [SC_DRIVE]= requesting drive
+;          [CURSC_DRIVE]= current SC drive
+;          [CURSC_SECTOR] = starting scetor # of SC
+;          [SC_CACHE_COUNT] = SC count
+;          [HIGH_SECTOR]:DX= sector number
+; Function:
+;       Check if the sector is in secondary cache
+; Output:
+;       carry clear, in SC
+;          CX= the index in the secondary cache
+;       carry set, not in SC
+;
+
+        procedure   IN_SC,NEAR              ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING               ;AN000;
+
+        MOV     AL,[SC_DRIVE]               ;AN000;;LB. current drive
+        CMP     AL,[CURSC_DRIVE]            ;AN000;;LB. same as SC drive
+        JNZ     outrange2                   ;AN000;;LB. no
+        MOV     AX,WORD PTR [HIGH_SECTOR]   ;AN000;;LB. subtract sector num from
+        MOV     CX,DX                       ;AN000;;LB. secondary starting sector
+        SUB     CX,WORD PTR [CURSC_SECTOR]    ;AN000;;LB. number
+        SBB     AX,WORD PTR [CURSC_SECTOR+2]  ;AN000;;LB.
+        CMP     AX,0                        ;AN000;;LB. greater than 64K
+        JNZ     outrange2                   ;AN000;;LB. yes
+        CMP     CX,[SC_CACHE_COUNT]         ;AN000;;LB. greater than SC count
+        JAE     outrange2                   ;AN000;;LB. yes
+        CLC                                 ;AN000;;LB. clear carry
+        JMP     short inexit                ;AN000;;LB. in SC
+outrange2:                                  ;AN000;;LB. set carry
+        STC                                 ;AN000;;LB.
+inexit:                                     ;AN000;;LB.
+        return                              ;AN000;;LB.
+
+EndProc IN_SC                               ;AN000;
+
+Break   <INVALIDATE_SC - invalide secondary cache>
+
+; Inputs:  [SC_DRIVE]= requesting drive
+;          [CURSC_DRIVE]= current SC drive
+;          [CURSC_SECTOR] = starting scetor # of SC
+;          [SC_CACHE_COUNT] = SC count
+;          [SC_STAUS] = SC status word
+;          [HIGH_SECTOR]:DX= sceotor number
+;
+; Function:
+;       invalidate secondary cache if in there
+; Output:
+;       [SC_STATUS] is updated
+;
+
+        procedure   INVALIDATE_SC,NEAR      ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING               ;AN000;
+
+        CALL    IN_SC                       ;AN000;;LB. in secondary cache
+        JC      outrange                    ;AN000;;LB. no
+        MOV     AX,1                        ;AN000;;LB. invalidate the sector
+        SHL     AX,CL                       ;AN000;;LB. in the secondary cache
+        NOT     AX                          ;AN000;;LB.
+        AND     [SC_STATUS],AX              ;AN000;;LB. save the status
+outrange:                                   ;AN000;;LB.
+        return                              ;AN000;;LB.
+
+EndProc INVALIDATE_SC                       ;AN000;
+
+
+Break   <VIRREAD- virtually read data into buffer>
+
+; Inputs:  SC_FLAG = 0 , no sectors were read into SC
+;                    1, continous sectors were read into SC
+; Function:
+;          Move data from SC to buffer
+; Output:
+;        carry clear, data is moved to buffer
+;        carry set, bad sector or exceeds maximum sector
+;          SC_FLAG =0
+;          CALLSCNT=1
+;          SC_STATUS= -1 if succeeded
+;                      0 if failed
+
+        procedure   VIRREAD,NEAR            ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING               ;AN000;
+
+        CMP     [SC_FLAG],0                 ;AN000;;LB.  from SC fill
+        JZ      sc2end                      ;AN000;;LB.  no
+        MOV     AX,[TEMP_VAR2]              ;AN000;;LB. restore buffer addr
+        MOV     WORD PTR [CALLXAD+2],AX     ;AN000;;LB.
+        MOV     AX,[TEMP_VAR]               ;AN000;;LB.
+        MOV     WORD PTR [CALLXAD],AX       ;AN000;;LB.
+        MOV     [SC_FLAG],0                 ;AN000;;LB.  reset sc_flag
+        MOV     [CALLSCNT],1                ;AN000;;LB.  one sector transferred
+
+        TEST    [DEVCALL.REQSTAT],STERR     ;AN000;;LB.  error?
+        JNZ     scerror                     ;AN000;;LB. yes
+        PUSH    DS                          ;AN000;;LB.
+        PUSH    SI                          ;AN000;;LB.
+        PUSH    ES                          ;AN000;;LB.
+        PUSH    DI                          ;AN000;;LB.
+        PUSH    DX                          ;AN000;;LB.
+        PUSH    CX                          ;AN000;;LB.
+        XOR     CX,CX                       ;AN000;;LB. we want first sector in SC
+        CALL    SC2BUF2                     ;AN000;;LB. move data from SC to buffer
+        POP     CX                          ;AN000;;LB.
+        POP     DX                          ;AN000;;LB.
+        POP     DI                          ;AN000;;LB.
+        POP     ES                          ;AN000;;LB.
+        POP     SI                          ;AN000;;LB.
+        POP     DS                          ;AN000;;LB.
+        JMP     SHORT sc2end                ;AN000;;LB. return
+
+scerror:                                    ;AN000;
+        MOV     [CALLSCNT],1                ;AN000;;LB. reset sector count to 1
+        MOV     [SC_STATUS],0               ;AN000;;LB. invalidate all SC sectors
+        MOV     [CURSC_DRIVE],-1            ;AN000;;LB. invalidate drive
+        STC                                 ;AN000;;LB. carry set
+        return                              ;AN000;;LB.
+
+sc2end:                                     ;AN000;
+        CLC                                 ;AN000;;LB. carry clear
+        return                              ;AN000;;LB.
+
+EndProc VIRREAD                             ;AN000;
+
+Break   <SC2BUF- move data from SC to buffer>
+
+; Inputs:  [SC_STATUS] = SC validity status
+;          [SC_SECTOR_SIZE] = request sector size
+;          [SC_CACHE_PTR] = pointer to SC
+; Function:
+;          Move data from SC to buffer
+; Output:
+;          carry clear, in SC  and data is moved
+;          carry set, not in SC and data is not moved
+
+        procedure   SC2BUF,NEAR             ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING               ;AN000;
+
+        CALL    IN_SC                       ;AN000;;LB. in secondary cache
+        JC      noSC                        ;AN000;;LB. no
+        MOV     AX,1                        ;AN000;;LB. check if valid sector
+        SHL     AX,CL                       ;AN000;;LB. in the secondary cache
+        TEST    [SC_STATUS],AX              ;AN000;;LB.
+        JZ      noSC                        ;AN000;;LB. invalid
+entry SC2BUF2                               ;AN000;
+        MOV     AX,CX                       ;AN000;;LB. times index with
+        MUL     [SC_SECTOR_SIZE]            ;AN000;;LB. sector size
+        ADD     AX,WORD PTR [SC_CACHE_PTR]  ;AN000;;LB. add SC starting addr
+        ADC     DX,WORD PTR [SC_CACHE_PTR+2];AN000;;LB.
+        MOV     DS,DX                       ;AN000;    ;LB. DS:SI-> SC sector addr
+        MOV     SI,AX                       ;AN000;    ;LB.
+        MOV     ES,WORD PTR [CALLXAD+2]     ;AN000;    ;LB. ES:DI-> buffer addr
+        MOV     DI,WORD PTR [CALLXAD]       ;AN000;    ;LB.
+        MOV     CX,[SC_SECTOR_SIZE]         ;AN000;    ;LB. count= sector size
+        SHR     CX,1                        ;AN000;    ;LB. may use DWORD move for 386
+entry MOVWORDS                              ;AN000;
+        CMP     [DDMOVE],0                  ;AN000;    ;LB. 386 ?
+        JZ      nodd                        ;AN000;    ;LB. no
+        SHR     CX,1                        ;AN000;    ;LB. words/2
+        DB      66H                         ;AN000;    ;LB. use double word move
+nodd:
+        REP     MOVSW                       ;AN000;    ;LB. move to buffer
+        CLC                                 ;AN000;    ;LB. clear carry
+        return                              ;AN000;    ;LB. exit
+noSC:                                       ;AN000;
+        STC                                 ;AN000;    ;LB. set carry
+sexit:                                      ;AN000;
+        return                              ;AN000;    ;LB.
+
+EndProc SC2BUF
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/DINFO.ASM b/v4.0/src/DOS/DINFO.ASM
new file mode 100644
index 0000000..10738b1
--- /dev/null
+++ b/v4.0/src/DOS/DINFO.ASM
@@ -0,0 +1,131 @@
+;       SCCSID = @(#)dinfo.asm  1.1 85/04/10
+;       SCCSID = @(#)dinfo.asm  1.1 85/04/10
+TITLE   DISK_INFO - Internal Get Disk Info
+NAME    DISK_INFO
+; Low level routine for returning disk drive information from a local
+;   or NET device
+;
+; DISK_INFO
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  THISCDS,DWORD
+        i_need  CURBUF,DWORD
+        i_need  EXTERR_LOCUS,BYTE
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+Break   <DISK_INFO -- Get Disk Drive Information>
+
+; Inputs:
+;       [THISCDS] Points to the Macro List Structure of interest
+;               (It MAY NOT be NUL, error not detected)
+; Function:
+;       Get Interesting Drive Information
+; Returns:
+;       DX = Number of free allocation units
+;       BX = Total Number of allocation units on disk
+;       CX = Sector size
+;       AL = Sectors per allocation unit
+;       AH = FAT ID BYTE
+;       Carry set if error (currently user FAILed to I 24)
+; Segs except ES preserved, others destroyed
+
+        procedure   DISK_INFO,NEAR
+        DOSAssume   CS,<DS>,"Disk_Info"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     LOCAL_INFO
+IF NOT Installed
+        transfer NET_DISK_INFO
+ELSE
+        MOV     AX,(multNET SHL 8) OR 12
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_INFO:
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        EnterCrit   critDisk
+        invoke  FATREAD_CDS             ; perform media check.
+        JC      CRIT_LEAVE
+        MOV     BX,2
+        invoke  UNPACK                  ; Get first FAT sector into CURBUF
+        JC      CRIT_LEAVE
+        LDS     SI,[CURBUF]
+ASSUME  DS:NOTHING
+        MOV     AH,[SI].bufinsiz        ; get FAT ID BYTE
+        context DS
+        MOV     CX,ES:[BP.dpb_max_cluster]
+;
+; Examine the current free count.  If it indicates that we have an invalid
+; count, do the expensive calculation.
+;
+        MOV     DX,ES:[BP.dpb_free_cnt] ; get free count
+        CMP     DX,-1                   ; is it valid?
+        JZ      DoScan
+;
+; Check to see if it is in a reasonalbe range.  If so, trust it and return.
+; Otherwise, we need to blast out an internal error message and then recompute
+; the count.
+;
+        CMP     DX,CX                   ; is it in a reasonable range?
+        JB      GotVal                  ; yes, trust it.
+        fmt     TypInt,LevLog,<"Internal error: MaxClus <= FreeClus\n">
+DoScan:
+        XOR     DX,DX
+        DEC     CX
+SCANFREE:
+        invoke  UNPACK
+        JC      Crit_Leave
+        JNZ     NOTFREECLUS
+        INC     DX                      ; A free one
+NOTFREECLUS:
+        INC     BX                      ; Next cluster
+        LOOP    SCANFREE
+        DEC     BX                      ; BX was next cluster.  Convert to
+ReturnVals:
+        DEC     BX                      ; count
+        MOV     AL,ES:[BP.dpb_cluster_mask]
+        INC     AL                      ; Sectors/cluster
+        MOV     CX,ES:[BP.dpb_sector_size]  ; Bytes/sector
+        MOV     ES:[BP.dpb_free_cnt],DX
+        CLC
+CRIT_LEAVE:
+        LeaveCrit   critDisk
+        return
+;
+; We have correctly computed everything previously.  Load up registers for
+; return.
+;
+GotVal: MOV     BX,CX                   ; get cluster count
+        JMP     ReturnVals
+
+EndProc DISK_INFO
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/DIR.ASM b/v4.0/src/DOS/DIR.ASM
new file mode 100644
index 0000000..2a86997
--- /dev/null
+++ b/v4.0/src/DOS/DIR.ASM
@@ -0,0 +1,445 @@
+;       SCCSID = @(#)dir.asm    1.1 85/04/10
+;       SCCSID = @(#)dir.asm    1.1 85/04/10
+TITLE   DIR - Directory and path cracking
+NAME    Dir
+; Main Path cracking routines, low level search routines
+;
+;   FindEntry
+;   SEARCH
+;   Srch
+;   NEXTENT
+;   MetaCompare
+;   NEXTENTRY
+;   GETENTRY
+;   GETENT
+;   SETDIRSRCH
+;   SETROOTSRCH
+;
+;   Revision history:
+;
+;       A000   version 4.00    Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+include fastopen.inc
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+.cref
+.list
+
+asmvar  Kanji
+
+        i_need  EntFree,WORD
+        i_need  DirStart,WORD
+        i_need  LastEnt,WORD
+        i_need  ClusNum,WORD
+        i_need  CurBuf,DWORD
+        i_need  Attrib,BYTE
+        i_need  DelAll,BYTE
+        i_need  VolID,BYTE
+        i_need  Name1,BYTE
+        i_need  ThisDPB,DWORD
+        i_need  EntLast,WORD
+        i_need  Creating,BYTE
+        i_need  SecClusPos,BYTE
+        i_need  ClusFac,BYTE
+        i_need  NxtClusNum,WORD
+        i_need  DirSec,DWORD                    ;AN000;
+        I_need  FastOpenFlg,BYTE                ;AN000;
+        I_need  HIGH_SECTOR,WORD                ;AN000;
+
+Break   <FINDENTRY -- LOOK FOR AN ENTRY>
+
+; Inputs:
+;       [THISDPB] set
+;       [SECCLUSPOS] = 0
+;       [DIRSEC] = Starting directory sector number
+;       [CLUSNUM] = Next cluster of directory
+;       [CLUSFAC] = Sectors/Cluster
+;       [NAME1] = Name to look for
+; Function:
+;       Find file name in disk directory.
+;       "?" matches any character.
+; Outputs:
+;       Carry set if name not found
+;       ELSE
+;       Zero set if attributes match (always except when creating)
+;       AH = Device ID (bit 7 set if not disk)
+;       [THISDPB] = Base of drive parameters
+;       DS = DOSGROUP
+;       ES = DOSGROUP
+;       [CURBUF+2]:BX = Pointer into directory buffer
+;       [CURBUF+2]:SI = Pointer to First Cluster field in directory entry
+;       [CURBUF] has directory record with match
+;       [NAME1] has file name
+;       [LASTENT] is entry number of the entry
+; All other registers destroyed.
+
+        procedure   SEARCH,near
+
+        entry   FindEntry
+        DOSAssume   CS,<DS>,"FindEntry"
+        ASSUME  ES:NOTHING
+
+        invoke  STARTSRCH
+        MOV     AL,Attrib
+        AND     AL,NOT attr_ignore      ; Ignore useless bits
+        CMP     AL,attr_volume_id       ; Looking for vol ID only ?
+        JNZ     NOTVOLSRCH              ; No
+        CALL    SETROOTSRCH             ; Yes force search of root
+NOTVOLSRCH:
+        CALL    GETENTRY
+        JNC     Srch
+        JMP     SETESRET
+
+        entry   Srch
+
+        PUSH    DS
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+        MOV     AH,BYTE PTR [BX]
+        OR      AH,AH                   ; End of directory?
+        JZ      FREE
+        CMP     AH,BYTE PTR [DELALL]    ; Free entry?
+        JZ      FREE
+        TEST    BYTE PTR [BX+11],attr_volume_id
+                                        ; Volume ID file?
+        JZ      CHKFNAM                 ; NO
+        INC     BYTE PTR [VOLID]
+CHKFNAM:
+;       Context ES
+        ASSUME  ES:DOSGroup
+        MOV     SI,SS
+        MOV     ES,SI
+        MOV     SI,BX
+        MOV     DI,OFFSET DOSGROUP:NAME1
+;;;;; 7/29/86
+        CMP     BYTE PTR [NAME1],0E5H    ; special char check
+        JNZ     NO_E5
+        MOV     BYTE PTR [NAME1],05H
+NO_E5:
+;;;;; 7/29/86
+        CALL    MetaCompare
+        JZ      FOUND
+        POP     DS
+
+        entry   NEXTENT
+        DOSAssume   CS,<DS>,"NextEnt"
+
+        Assert  ISDPB,<<WORD PTR THISDPB+2>,<WORD PTR THISDPB>>,"NextEnt"
+        LES     BP,[THISDPB]
+ASSUME  ES:NOTHING
+        CALL    NEXTENTRY
+        JNC     SRCH
+        JMP     SHORT SETESRET
+
+FREE:
+        POP     DS
+        DOSAssume   CS,<DS>,"DIR/Free"
+        MOV     CX,[LASTENT]
+        CMP     CX,[ENTFREE]
+        JAE     TSTALL
+        MOV     [ENTFREE],CX
+TSTALL:
+        CMP     AH,BYTE PTR [DELALL]    ; At end of directory?
+NextEntJ:
+        JZ      NEXTENT                 ; No - continue search
+        MOV     [ENTLAST],CX
+        STC
+        JMP     SHORT SETESRET
+
+FOUND:
+;
+; We have a file with a matching name.  We must now consider the attributes:
+; ATTRIB        Action
+; ------        ------
+; Volume_ID     Is Volume_ID in test?
+; Otherwise     If no create then Is ATTRIB+extra superset of test?
+;               If create then Is ATTRIB equal to test?
+;
+        MOV     CH,[SI]                 ; Attributes of file
+        POP     DS
+        DOSAssume   CS,<DS>,"DIR/found"
+        MOV     AH,Attrib               ; Attributes of search
+        AND     AH,NOT attr_ignore
+        LEA     SI,[SI+Dir_First-Dir_Attr]  ; point to firclus field
+        TEST    CH,attr_volume_id       ; Volume ID file?
+        JZ      check_one_volume_id     ; Nope check other attributes
+        TEST    AH,attr_volume_id       ; Can we find Volume ID?
+        JZ      NEXTENTJ                ; Nope, (not even $FCB_CREATE)
+        XOR     AH,AH                   ; Set zero flag for $FCB_CREATE
+        JMP     SHORT RETFF             ; Found Volume ID
+check_one_volume_id:
+        CMP     AH,attr_volume_id       ; Looking only for Volume ID?
+        JZ      NEXTENTJ                ; Yes, continue search
+        invoke  MatchAttributes
+        JZ      RETFF
+        TEST    BYTE PTR [CREATING],-1  ; Pass back mismatch if creating
+        JZ      NEXTENTJ                ; Otherwise continue searching
+RETFF:
+        LES     BP,[THISDPB]
+        MOV     AH,ES:[BP.dpb_drive]
+SETESRET:
+        PUSH    SS
+        POP     ES
+        return
+EndProc Search
+
+; Inputs:
+;       DS:SI -> 11 character FCB style name NO '?'
+;           Typically this is a directory entry.  It MUST be in upper case
+;       ES:DI -> 11 character FCB style name with possible '?'
+;           Typically this is a FCB or SFT.  It MUST be in upper case
+; Function:
+;       Compare FCB style names allowing for ? match to any char
+; Outputs:
+;       Zero if match else NZ
+; Destroys CX,SI,DI all others preserved
+
+        procedure   MetaCompare,near
+ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     CX,11
+ IF  DBCS                               ;AN000;
+;-------------------- Start of DBCS     ;AN000;
+        CMP     BYTE PTR DS:[SI],05H    ;AN000;; Special case for lead byte of 05h
+        JNE     WILDCRD2                ;AN000;; Compare as normal if not an 05h
+        CMP     BYTE PTR ES:[DI],0E5H   ;AN000;; 05h and 0E5h equivalent for lead byte
+        JNE     WILDCRD2                ;AN000;; Compare as normal if not an 05h
+        DEC     CX                      ;AN000;; One less byte to compare
+        INC     SI                      ;AN000;; Bypass lead byte in source and
+        INC     DI                      ;AN000;;  destination when 05h and 0E5h found.
+WILDCRD2:                               ;AN000;
+        PUSH    AX                      ;AN000;;KK. save ax
+cagain:                                 ;AN000;;KK.
+        CMP     CX,0                    ;AN000;;KK. end of compare ?
+        JLE     metaend2                ;AN000;;KK. yes
+        MOV     AL,[SI]                 ;AN000;;KK. is it a Kanji
+        invoke  testkanj                ;AN000;;KK.
+        JZ      notdb                   ;AN000;;KK. no
+        MOV     AX,'??'                 ;AN000;;KK.
+        CMP     ES:[DI],AX              ;AN000;;KK. is es:di pointing to '??'
+        JNZ     metaend3                ;AN000;;KK. no
+        ADD     SI,2                    ;AN000;;KK.
+        ADD     DI,2                    ;AN000;;KK. update pointers and count
+subcx:                                  ;AN000;
+        SUB     CX,2                    ;AN000;;KK.
+        JMP     cagain                  ;AN000;;KK.
+metaend3:                               ;AN000;;KK.
+        CMPSW                           ;AN000;;KK.
+        JNZ     metaend2                ;AN000;;KK.
+        JMP     subcx                   ;AN000;;KK.
+notdb:                                  ;AN000;
+        CMPSB                           ;AN000;;KK. same code ?
+        JZ      sameco                  ;AN000;;KK. yes
+        CMP     BYTE PTR ES:[DI-1],"?"  ;AN000;;KK. ?
+        JNZ     metaend2                ;AN000;;KK. no
+sameco:                                 ;AN000;
+        DEC     CX                      ;AN000;;KK. decrement count
+        JMP     cagain                  ;AN000;;KK.
+
+metaend2:                               ;AN000;
+        POP     AX                      ;AN000;;KK.
+;-------------------- End of DBCS       ;AN000; KK.
+ ELSE                                   ;AN000;
+WILDCRD:
+        REPE    CMPSB
+        JZ      MetaRet                 ; most of the time we will fail.
+CHECK_META:
+        CMP     BYTE PTR ES:[DI-1],"?"
+        JZ      WildCrd
+MetaRet:
+ ENDIF                                  ;AN000;
+        return                          ; Zero set, Match
+EndProc MetaCompare
+
+Break   <NEXTENTRY -- STEP THROUGH DIRECTORY>
+
+; Inputs:
+;       Same as outputs of GETENTRY, above
+; Function:
+;       Update BX, and [LASTENT] for next directory entry.
+;       Carry set if no more.
+
+Procedure NextEntry
+        DOSAssume   CS,<DS>,"NextEntry"
+        ASSUME  ES:NOTHING
+
+        MOV     AX,[LASTENT]
+        CMP     AX,[ENTLAST]
+        JZ      NONE
+        INC     AX
+        LEA     BX,[BX+32]
+        CMP     BX,DX
+        JB      HAVIT
+        MOV     BL,BYTE PTR [SECCLUSPOS]
+        INC     BL
+        CMP     BL,BYTE PTR [CLUSFAC]
+        JB      SAMECLUS
+        MOV     BX,[NXTCLUSNUM]
+        Invoke  IsEOF
+        JAE     NONE
+        CMP     BX,2
+        JB      NONE
+        JMP     GETENT
+
+NONE:
+        STC
+        return
+
+HAVIT:
+        MOV     [LASTENT],AX
+        CLC
+        return
+
+SAMECLUS:
+        MOV     BYTE PTR [SECCLUSPOS],BL
+        MOV     [LASTENT],AX
+        PUSH    DS
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        MOV     DX,WORD PTR [DI.buf_sector+2]   ;AN000; >32mb
+        MOV     [HIGH_SECTOR],DX                ;AN000; >32mb
+        MOV     DX,WORD PTR [DI.buf_sector]     ;AN000; >32mb
+
+        ADD     DX,1                            ;AN000; >32mb
+        ADC     [HIGH_SECTOR],0                 ;AN000; >32mb
+        POP     DS
+        DOSAssume   CS,<DS>,"DIR/SameClus"
+        invoke  FIRSTCLUSTER
+        XOR     BX,BX
+        JMP     SETENTRY
+EndProc NextEntry
+
+; Inputs:
+;       [LASTENT] has directory entry
+;       ES:BP points to drive parameters
+;       [DIRSEC],[CLUSNUM],[CLUSFAC],[ENTLAST] set for DIR involved
+; Function:
+;       Locates directory entry in preparation for search
+;       GETENT provides entry for passing desired entry in AX
+; Outputs:
+;       [CURBUF+2]:BX = Pointer to next directory entry in CURBUF
+;       [CURBUF+2]:DX = Pointer to first byte after end of CURBUF
+;       [LASTENT] = New directory entry number
+;       [NXTCLUSNUM],[SECCLUSPOS] set via DIRREAD
+;       Carry set if error (currently user FAILed to I 24)
+
+Procedure GETENTRY,NEAR
+        DOSAssume   CS,<DS>,"GetEntry"
+        ASSUME  ES:NOTHING
+
+        MOV     AX,[LASTENT]
+
+        entry   GETENT
+
+        Assert  ISDPB,<ES,BP>,"GetEntry/GetEnt"
+        MOV     [LASTENT],AX
+;
+; Convert the entry number in AX into a byte offset from the beginning of the
+; directory.
+;
+        mov     cl,5                    ; shift left by 5 = mult by 32
+        rol     ax,cl                   ; keep hight order bits
+        mov     dx,ax
+        and     ax, NOT (32-1)          ; mask off high order bits
+        and     dx, 32-1                ; mask off low order bits
+;
+; DX:AX contain the byte offset of the required directory entry from the
+; beginning of the directory.  Convert this to a sector number.  Round the
+; sector size down to a multiple of 32.
+;
+        MOV     BX,ES:[BP.dpb_sector_size]
+        AND     BL,255-31               ; Must be multiple of 32
+        DIV     BX
+        MOV     BX,DX                   ; Position within sector
+        PUSH    BX
+        invoke  DIRREAD
+        POP     BX
+        retc
+SETENTRY:
+        MOV     DX,WORD PTR [CURBUF]
+        ADD     DX,BUFINSIZ
+        ADD     BX,DX
+        ADD     DX,ES:[BP.dpb_sector_size]  ; Always clears carry
+        return
+EndProc GetEntry
+
+Break   <SETDIRSRCH SETROOTSRCH -- Set Search environments>
+
+; Inputs:
+;       BX cluster number of start of directory
+;       ES:BP Points to DPB
+;       DI next cluster number from fastopen extended info. DOS 3.3 only
+; Function:
+;       Set up a directory search
+; Outputs:
+;       [DIRSTART] = BX
+;       [CLUSFAC],[CLUSNUM],[SECCLUSPOS],[DIRSEC] set
+;       Carry set if error (currently user FAILed to I 24)
+; destroys AX,DX,BX
+
+        procedure SETDIRSRCH
+        DOSAssume   CS,<DS>,"SetDirSrch"
+        ASSUME  ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"SetDirSrch"
+        OR      BX,BX
+        JZ      SETROOTSRCH
+        MOV     [DIRSTART],BX
+        MOV     AL,ES:[BP.dpb_cluster_mask]
+        INC     AL
+        MOV     BYTE PTR [CLUSFAC],AL
+; DOS 3.3 for FastOPen  F.C. 6/12/86
+        SaveReg <SI>
+        TEST    [FastOpenFlg],Lookup_Success
+        JNZ     UNP_OK
+
+; DOS 3.3 for FastOPen  F.C. 6/12/86
+        invoke  UNPACK
+        JNC     UNP_OK
+        RestoreReg  <SI>
+        return
+
+UNP_OK:
+        MOV     [CLUSNUM],DI
+        MOV     DX,BX
+        XOR     BL,BL
+        MOV     BYTE PTR [SECCLUSPOS],BL
+        invoke  FIGREC
+        RestoreReg  <SI>
+        PUSH    DX                         ;AN000; >32mb
+        MOV     DX,[HIGH_SECTOR]           ;AN000; >32mb
+        MOV     WORD PTR [DIRSEC+2],DX     ;AN000; >32mb
+        POP     DX                         ;AN000; >32mb
+        MOV     WORD PTR [DIRSEC],DX
+        CLC
+        return
+
+entry   SETROOTSRCH
+        DOSAssume   CS,<DS>,"SetRootSrch"
+        ASSUME  ES:NOTHING
+        XOR     AX,AX
+        MOV     [DIRSTART],AX
+        MOV     BYTE PTR [SECCLUSPOS],AL
+        DEC     AX
+        MOV     [CLUSNUM],AX
+        MOV     AX,ES:[BP.dpb_first_sector]
+        MOV     DX,ES:[BP.dpb_dir_sector]
+        SUB     AX,DX
+        MOV     BYTE PTR [CLUSFAC],AL
+        MOV     WORD PTR [DIRSEC],DX                  ;F.C. >32mb
+        MOV     WORD PTR [DIRSEC+2],0                 ;F.C. >32mb
+        CLC
+        return
+EndProc SETDIRSRCH
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/DIR2.ASM b/v4.0/src/DOS/DIR2.ASM
new file mode 100644
index 0000000..1346f43
--- /dev/null
+++ b/v4.0/src/DOS/DIR2.ASM
@@ -0,0 +1,1353 @@
+;       SCCSID = @(#)dir2.asm   1.2 85/07/23
+;       SCCSID = @(#)dir2.asm   1.2 85/07/23
+TITLE   DIR2 - Directory and path cracking
+NAME    Dir2
+; Main Path cracking routines, low level search routines and device
+;   name detection routines
+;
+;   GETPATH
+;   GetPathNoSet
+;   CHKDEV
+;   ROOTPATH
+;   FINDPATH
+;   StartSrch
+;   MatchAttributes
+;   DEVNAME
+;   Build_device_ent
+;   Validate_CDS
+;   CheckThisDevice
+;
+;   Revision history:
+;
+;       A000  version 4.00  Jan. 1988
+;       A001  PTM 3564 -- search using fastopen
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include devsym.inc
+include fastopen.inc                   ;DOS 3.3
+.cref
+.list
+
+asmvar  Kanji
+
+        i_need  NoSetDir,BYTE
+        i_need  EntFree,WORD
+        i_need  DirStart,WORD
+        i_need  LastEnt,WORD
+        i_need  WFP_START,WORD
+        i_need  CURR_DIR_END,WORD
+        i_need  CurBuf,DWORD
+        i_need  THISCDS,DWORD
+        i_need  Attrib,BYTE
+        i_need  SAttrib,BYTE
+        i_need  VolID,BYTE
+        i_need  Name1,BYTE
+        i_need  ThisDPB,DWORD
+        i_need  EntLast,WORD
+        i_need  Creating,BYTE
+        i_need  NULDEV,DWORD
+        i_need  DEVPT,DWORD
+        i_need  DEVFCB,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  EXTERR_LOCUS,BYTE
+        I_need  FastOpenFlg,BYTE          ;DOS 3.3
+        I_need  FastOpenTable,BYTE        ;DOS 3.3
+        I_need  Dir_Info_Buff,BYTE        ;DOS 3.3
+        I_need  FastOpen_Ext_Info,BYTE    ;DOS 3.3
+        I_need  CLUSNUM,WORD              ;DOS 3.3
+        I_need  Next_Element_Start,WORD   ;DOS 3.3
+        I_need  HIGH_SECTOR,WORD          ;AN000;>32mb
+        I_need  DOS34_FLAG,WORD           ;AN000;>32mb
+
+
+Break   <GETPATH -- PARSE A WFP>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:\" must be first 3 chars, NUL
+;               terminated; d:/ (note forward slash) indicates a real device).
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;       [SATTRIB] Is attribute of search, determines what files can be found
+;       [NoSetDir] set
+;       [THISDPB] set to DPB if disk otherwise garbage.
+; Function:
+;       Crack the path
+; Outputs:
+;       Sets EXTERR_LOCUS = errLOC_Disk if disk file
+;       Sets EXTERR_LOCUS = errLOC_Unk if char device
+;       ID1 field of [THISCDS] updated appropriately
+;       [ATTRIB] = [SATTRIB]
+;       ES:BP Points to DPB
+;       Carry set if bad path
+;          SI Points to path element causing failure
+;          Zero set
+;             [DIRSTART],[DIRSEC],[CLUSNUM], and [CLUSFAC] are set up to
+;             start a search on the last directory
+;             CL is zero if there is a bad name in the path
+;             CL is non-zero if the name was simply not found
+;                [ENTFREE] may have free spot in directory
+;                [NAME1] is the name.
+;                CL = 81H if '*'s or '?' in NAME1, 80H otherwise
+;          Zero reset
+;             File in middle of path or bad name in path or attribute mismatch
+;               or path too long or malformed path
+;       ELSE
+;          [CurBuf] = -1 if root directory
+;          [CURBUF] contains directory record with match
+;          [CURBUF+2]:BX Points into [CURBUF] to start of entry
+;          [CURBUF+2]:SI Points into [CURBUF] to dir_first field for entry
+;          AH = device ID
+;             bit 7 of AH set if device SI and BX
+;             will point DOSGROUP relative The firclus
+;             field of the device entry contains the device pointer
+;          [NAME1] Has name looked for
+;          If last element is a directory zero is set and:
+;             [DIRSTART],[SECCLUSPOS],[DIRSEC],[CLUSNUM], and [CLUSFAC]
+;             are set up to start a search on it.
+;             unless [NoSetDir] is non zero in which case the return is
+;             like that for a file (except for zero flag)
+;          If last element is a file zero is reset
+;             [DIRSEC],[CLUSNUM],[CLUSFAC],[NXTCLUSNUM],[SECCLUSPOS],
+;             [LASTENT], [ENTLAST] are set to continue search of last
+;             directory for furthur matches on NAME1 via the NEXTENT
+;             entry point in FindEntry (or GETENT entry in GETENTRY in
+;             which case [NXTCLUSNUM] and [SECCLUSPOS] need not be valid)
+; DS preserved, Others destroyed
+
+        procedure   GETPATH,near
+        DOSAssume   CS,<DS>,"GetPath"
+        ASSUME  ES:NOTHING
+
+        MOV     WORD PTR [CREATING],0E500H  ; Not Creating, not DEL *.*
+
+;Same as GetPath only CREATING and DELALL already set
+        entry   GetPathNoSet
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        MOV     WORD PTR CurBuf,-1      ; initial setting
+;
+; See if the input indicates a device that has already been detected.  If so,
+; go build the guy quickly.  Otherwise, let findpath find the device.
+;
+        MOV     DI,Wfp_Start            ; point to the beginning of the name
+        CMP     WORD PTR [DI+1],'\' SHL 8 + ':'
+        JZ      CrackIt
+;
+; Let ChkDev find it in the device list
+;
+        ADD     DI,3
+        MOV     SI,DI                   ; let CHKDEV see the original name
+        CALL    CHKDEV
+        JC      InternalError
+Build_devJ:
+        MOV     AL,SAttrib
+        MOV     Attrib,AL
+        MOV     [EXTERR_LOCUS],errLOC_Unk ; In the particular case of
+                                        ; "finding" a char device
+                                        ; set LOCUS to Unknown. This makes
+                                        ; certain idiotic problems reported
+                                        ; by a certain 3 letter OEM go away.
+;
+; Take name in name1 and pack it back into where wfp_start points.  This
+; guarantees wfp_start pointing to a canonical representation of a device.
+; We are allowed to do this as GetPath is *ALWAYS* called before entering a
+; wfp into the share set.
+;
+; We copy chars from name1 to wfp_start remembering the position of the last
+; non-space seen +1.  This position is kept in DX.
+;
+        Context ES
+        mov     si,offset DOSGroup:Name1
+        mov     di,wfp_start
+        mov     dx,di
+        mov     cx,8                    ; 8 chars in device name
+MoveLoop:
+        lodsb
+        stosb
+        cmp     al," "
+        jz      nosave
+ IF  DBCS                               ;AN000;;
+;       cmp     al,81h                  ;AN000;; 2/23/KK
+;       jne     notKanji                ;AN000;; 2/23/KK
+;       cmp     cx,1                    ;AN000; 2/23/KK
+;       je      notKanji                ;AN000; 2/23/KK
+;       cmp     byte ptr [si],40h       ;AN000; 2/23/KK
+;       jne     notKanji                ;AN000;; 2/23/KK
+;       lodsb                           ;AN000;; 2/23/KK
+;       stosb                           ;AN000;; 2/23/KK
+;       dec     cx                      ;AN000;; 2/23/KK
+;       jmp     nosave                  ;AN000;; 2/23/KK
+;notKanji:                              ;AN000;; 2/23/KK
+ ENDIF
+        mov     dx,di
+NoSave:
+        loop    MoveLoop
+;
+; DX is the position of the last seen non-space + 1.  We terminate the name
+; at this point.
+;
+        mov     di,dx
+        mov     byte ptr [di],0         ; end of string
+        invoke  Build_device_ent        ; Clears carry sets zero
+        INC     AL                      ; reset zero
+        return
+
+        assume  es:nothing
+
+InternalError:
+        JMP     InternalError           ; freeze
+
+;
+; Start off at the correct spot.  Optimize if the current dir part is valid.
+;
+CrackIt:
+        MOV     SI,[CURR_DIR_END]       ; get current directory pointer
+        CMP     SI,-1                   ; valid?
+        JNZ     LOOK_SING               ; Yes, use it.
+        LEA     SI,[DI+3]               ; skip D:\
+LOOK_SING:
+        Assert  ISDPB,<<WORD PTR THISDPB+2>,<WORD PTR THISDPB>>,"Crackit"
+        MOV     Attrib,attr_directory+attr_system+attr_hidden
+                                        ; Attributes to search through Dirs
+        LES     DI,[THISCDS]
+        MOV     AX,-1
+        MOV     BX,ES:[DI.curdir_ID]
+        MOV     SI,[CURR_DIR_END]
+;
+; AX = -1
+; BX = cluster number of current directory.  THis number is -1 if the media
+;      has been uncertainly changed.
+; SI = offset in DOSGroup into path to end of current directory text.  This
+;      may be -1 if no current directory part has been used.
+;
+        CMP     SI,AX                   ; if Current directory is not part
+        JZ      NO_CURR_D               ; then we must crack from root
+        CMP     BX,AX                   ; is the current directory cluster valid
+
+; DOS 3.3  6/25/86
+        JZ      NO_CURR_D               ; no, crack form the root
+        TEST    [FastOpenFlg],FastOpen_Set     ; for fastopen ?
+        JZ      GOT_SEARCH_CLUSTER             ; no
+        PUSH    ES                      ; save registers
+        PUSH    DI
+        PUSH    CX
+        PUSH    [SI-1]                  ; save \ and 1st char of next element
+        PUSH    SI
+        PUSH    BX
+
+        MOV     BYTE PTR [SI-1],0       ; call fastopen to look up cur dir info
+        MOV     SI,[Wfp_Start]
+        MOV     BX,OFFSET DOSGROUP:FastOpenTable
+        MOV     DI,OFFSET DOSGROUP:Dir_Info_Buff
+        MOV     CX,OFFSET DOSGROUP:FastOpen_Ext_Info
+        MOV     AL,FONC_look_up
+        PUSH    DS
+        POP     ES
+        CALL    DWORD PTR [BX.FASTOPEN_NAME_CACHING]
+        JC      GO_Chk_end1                     ;fastopen not installed, or wrong drive. Go to Got_Srch_cluster
+        CMP     BYTE PTR [SI],0                 ;fastopen has current dir info?
+        JE      GO_Chk_end                      ;yes. Go to got_serch_cluster
+        stc
+        jmp     short GO_Chk_end                ;Go to No_Curr_D
+GO_Chk_end1:
+        clc
+GO_Chk_end:                                     ; restore registers
+        POP     BX
+        POP     SI
+        POP     [SI-1]
+        POP     CX
+        POP     DI
+        POP     ES
+        JNC     GOT_SEARCH_CLUSTER              ; crack based on cur dir
+
+; DOS 3.3  6/25/86
+;
+; We must cract the path beginning at the root.  Advance pointer to beginning
+; of path and go crack from root.
+;
+NO_CURR_D:
+        MOV     SI,[WFP_START]
+        LEA     SI,[SI+3]               ; Skip "d:/"
+        LES     BP,[THISDPB]            ; Get ES:BP
+        JMP     ROOTPATH
+;
+; We are able to crack from the current directory part.  Go set up for search
+; of specified cluster.
+;
+GOT_SEARCH_CLUSTER:
+        LES     BP,[THISDPB]            ; Get ES:BP
+        invoke  SETDIRSRCH
+        JC      SETFERR
+        JMP     FINDPATH
+
+SETFERR:
+        XOR     CL,CL                   ; set zero
+        STC
+        Return
+
+EndProc GETPATH
+
+; Check to see if the name at DS:DI is a device.  Returns carry set if not a
+;   device.
+; Blasts CX,SI,DI,AX,BX
+
+Procedure   ChkDev,NEAR
+        ASSUME  ES:Nothing,DS:NOTHING
+
+        MOV     SI,DI
+        MOV     DI,SS
+        MOV     ES,DI
+        ASSUME  ES:DOSGroup             ; Now here is where ES is DOSGroup
+
+        MOV     DI,OFFSET DOSGROUP:NAME1
+        MOV     CX,9
+TESTLOOP:
+        invoke  GETLET
+ IF  DBCS                               ;AN000;
+        invoke  Testkanj                ;AN000;; 2/13/KK
+        jz      Notkanja                ;AN000;; 2/13/KK
+        stosb                           ;AN000;; Skip second byte   2/13/KK
+        dec     cx                      ;AN000;; 2/13/KK
+        jcxz    notdev                  ;AN000;; 2/13/KK
+        lodsb                           ;AN000;; 2/13/KK
+        jmp     short stowit            ;AN000;; 2/13/KK
+Notkanja:                               ;AN000;
+ ENDIF                                  ;AN000;
+        CMP     AL,'.'
+        JZ      TESTDEVICE
+        invoke  PATHCHRCMP
+        JZ      NOTDEV
+        OR      AL,AL
+        JZ      TESTDEVICE
+stowit:
+        STOSB
+        LOOP    TESTLOOP
+NOTDEV:
+        STC
+        return
+
+TESTDEVICE:
+        ADD     CX,2
+        MOV     AL,' '
+        REP     STOSB
+        MOV     AX,SS
+        MOV     DS,AX
+        invoke  DEVNAME
+        return
+EndProc ChkDev
+
+Break   <ROOTPATH, FINDPATH -- PARSE A PATH>
+
+; Inputs:
+;       Same as FINDPATH but,
+;       SI Points to asciz string of path which is assumed to start at
+;               the root (no leading '/').
+; Function:
+;       Search from root for path
+; Outputs:
+;       Same as FINDPATH but:
+;       If root directory specified, [CURBUF] and [NAME1] are NOT set, and
+;       [NoSetDir] is ignored.
+
+        procedure   ROOTPATH,near
+
+        DOSAssume   CS,<DS>,"RootPath"
+        ASSUME  ES:NOTHING
+
+        invoke  SETROOTSRCH
+        CMP     BYTE PTR [SI],0
+        JNZ     FINDPATH
+
+; Root dir specified
+        MOV     AL,SAttrib
+        MOV     Attrib,AL
+        XOR     AH,AH                   ; Sets "device ID" byte, sets zero
+                                        ; (dir), clears carry.
+        return
+
+; Inputs:
+;       [ATTRIB] Set to get through directories
+;       [SATTRIB] Set to find last element
+;       ES:BP Points to DPB
+;       SI Points to asciz string of path (no leading '/').
+;       [SECCLUSPOS] = 0
+;       [DIRSEC] = Phys sec # of first sector of directory
+;       [CLUSNUM] = Cluster # of next cluster
+;       [CLUSFAC] = Sectors per cluster
+;       [NoSetDir] set
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;       [CREATING] and [DELALL] set
+; Function:
+;       Parse path name
+; Outputs:
+;       ID1 field of [THISCDS] updated appropriately
+;       [ATTRIB] = [SATTRIB]
+;       ES:BP Points to DPB
+;       [THISDPB] = ES:BP
+;       Carry set if bad path
+;          SI Points to path element causing failure
+;          Zero set
+;             [DIRSTART],[DIRSEC],[CLUSNUM], and [CLUSFAC] are set up to
+;             start a search on the last directory
+;             CL is zero if there is a bad name in the path
+;             CL is non-zero if the name was simply not found
+;                [ENTFREE] may have free spot in directory
+;                [NAME1] is the name.
+;                CL = 81H if '*'s or '?' in NAME1, 80H otherwise
+;          Zero reset
+;             File in middle of path or bad name in path
+;               or path too long or malformed path
+;       ELSE
+;          [CURBUF] contains directory record with match
+;          [CURBUF+2]:BX Points into [CURBUF] to start of entry
+;          [CURBUF+2]:SI Points to fcb_FIRCLUS field for entry
+;          [NAME1] Has name looked for
+;          AH = device ID
+;             bit 7 of AH set if device SI and BX
+;             will point DOSGROUP relative The firclus
+;             field of the device entry contains the device pointer
+;          If last element is a directory zero is set and:
+;             [DIRSTART],[SECCLUSPOS],[DIRSEC],[CLUSNUM], and [CLUSFAC]
+;             are set up to start a search on it,
+;             unless [NoSetDir] is non zero in which case the return is
+;             like that for a file (except for zero flag)
+;          If last element is a file zero is reset
+;             [DIRSEC],[CLUSNUM],[CLUSFAC],[NXTCLUSNUM],[SECCLUSPOS],
+;             [LASTENT], [ENTLAST] are set to continue search of last
+;             directory for furthur matches on NAME1 via the NEXTENT
+;             entry point in FindEntry (or GETENT entry in GETENTRY in
+;             which case [NXTCLUSNUM] and [SECCLUSPOS] need not be valid)
+; Destroys all other registers
+
+    entry   FINDPATH
+        DOSAssume   CS,<DS>,"FindPath"
+        ASSUME  ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"FindPath"
+        PUSH    ES                      ; Save ES:BP
+        PUSH    SI
+        MOV     DI,SI
+        MOV     CX,[DIRSTART]           ; Get start clus of dir being searched
+        CMP     [CURR_DIR_END],-1
+        JZ      NOIDS                   ; No current dir part
+        CMP     DI,[CURR_DIR_END]
+        JNZ     NOIDS                   ; Not to current dir end yet
+        LES     DI,[THISCDS]
+        MOV     ES:[DI.curdir_ID],CX    ; Set current directory currency
+NOIDS:
+;
+; Parse the name off of DS:SI into NAME1.  AL = 1 if there was a meta
+; character in the string.  CX,DI  may be destroyed.
+;
+;       invoke  NAMETRANS
+;       MOV     CL,AL
+;
+; The above is the slow method.  The name has *already* been munged by
+; TransPath so no special casing needs to be done.  All we do is try to copy
+; the name until ., \ or 0 is hit.
+;
+        MOV     AX,SS
+        MOV     ES,AX
+        MOV     DI,OFFSET DOSGroup:Name1
+        MOV     AX,'  '
+        STOSB
+        STOSW
+        STOSW
+        STOSW
+        STOSW
+        STOSW
+        MOV     DI,OFFSET DOSGroup:Name1
+        XOR     AH,AH                   ; bits for CL
+ IF  DBCS                               ;AN000;
+;-------------------------- Start of DBC;AN000;S 2/13/KK
+        XOR     CL,CL                   ;AN000;; clear count for volume id
+        LODSB                           ;AN000;;IBMJ fix 9/04/86
+        CMP     AL,05h                  ;AN000;;IBMJ fix 9/04/86
+        JNE     GetNam2                 ;AN000;;IBMJ fix 9/04/86
+        PUSH    AX                      ;AN000;        ;IBMJ fix 9/04/86
+        MOV     AL,0E5h                 ;AN000;;IBMJ fix 9/04/86
+        Invoke  TestKanj                ;AN000;;IBMJ fix 9/04/86
+        POP     AX                      ;AN000;        ;IBMJ fix 9/04/86
+        JZ      Notkanjb                ;AN000;        ;IBMJ fix 9/04/86
+        JMP     SHORT GetNam3           ;AN000;;IBMJ fix 9/04/86
+;-------------------------- End of DBCS ;AN000;2/13/KK
+ ENDIF
+GetNam:
+        INC     CL                      ;AN000; KK incrment volid count
+        LODSB
+ IF  DBCS                               ;AN000;
+GetNam2:                                ;AN000;; 2/13/KK
+        invoke  Testkanj                ;AN000;; 2/13/KK
+        jz      Notkanjb                ;AN000;; 2/13/KK
+GetNam3:                                ;AN000;; 2/13/KK
+        STOSB                           ;AN000;; 2/13/KK
+        INC     CL                      ;AN000;; KK incrment volid count
+        LODSB                           ;AN000;; 2/13/KK
+        TEST    [DOS34_FLAG],DBCS_VOLID ;AN000;; 2/13/KK
+        JZ      notvol                  ;AN000;; 2/13/KK
+        CMP     CL,8                    ;AN000;; 2/13/KK
+        JNZ     notvol                  ;AN000;; 2/13/KK
+        CMP     AL,'.'                  ;AN000;; 2/13/KK
+        JNZ     notvol                  ;AN000;; 2/13/KK
+        LODSB                           ;AN000;; 2/13/KK
+notvol:                                 ;AN000;
+        jmp     short StoNam            ;AN000;; 2/13/KK
+Notkanjb:                               ;AN000;; 2/13/KK
+ ENDIF                                  ;AN000;
+        CMP     AL,'.'
+        JZ      setExt
+        OR      AL,AL
+        JZ      GetDone
+        CMP     AL,'\'
+        JZ      GetDone
+        CMP     AL,'?'
+        JNZ     StoNam
+        OR      AH,1
+StoNam: STOSB
+        JMP     GetNam
+SetExt:
+        MOV     DI,OFFSET DOSGroup:Name1+8
+GetExt:
+        LODSB
+ IF  DBCS                               ;AN000;
+        invoke  TestKanj                ;AN000;; 2/13/KK
+        jz      Notkanjc                ;AN000;; 2/13/KK
+        STOSB                           ;AN000;; 2/13/KK
+        LODSB                           ;AN000;; 2/13/KK
+        jmp     short StoExt            ;AN000;; 2/13/KK
+Notkanjc:                               ;AN000;; 2/13/KK
+ ENDIF                                  ;AN000;
+        OR      AL,AL
+        JZ      GetDone
+        CMP     AL,'\'
+        JZ      GetDone
+        CMP     AL,'?'
+        JNZ     StoExt
+        OR      AH,1
+StoExt: STOSB
+        JMP     GetExt
+GetDone:
+        DEC     SI
+        MOV     CL,AH
+
+
+        OR      CL,80H
+        POP     DI                      ; Start of this element
+        POP     ES                      ; Restore ES:BP
+        CMP     SI,DI
+        JNZ     check_device
+        JMP     BADPATH                 ; NUL parse (two delims most likely)
+check_device:
+        PUSH    SI                      ; Start of next element
+        MOV     AL,BYTE PTR [SI]
+        OR      AL,AL
+        JNZ     NOT_LAST
+
+;
+; for last element of the path switch to the correct search attributes
+;
+        MOV     BH,SAttrib
+        MOV     Attrib,BH
+NOT_LAST:
+
+;
+; check name1 to see if we have a device...
+;
+        PUSH    ES                      ; Save ES:BP
+        context ES
+        invoke  DevName                 ; blast BX
+        POP     ES                      ; Restore ES:BP
+        ASSUME  ES:NOTHING
+        JC      FindFile                ; Not a device
+        OR      AL,AL                   ; Test next char again
+        JZ      GO_BDEV
+        JMP     FileInPath              ; Device name in middle of path
+
+GO_BDEV:
+        POP     SI                      ; Points to NUL at end of path
+        JMP     Build_devJ
+
+FindFile:
+        ASSUME  ES:NOTHING
+;;;; 7/28/86
+        CMP     BYTE PTR [NAME1],0E5H   ; if 1st char = E5
+        JNZ     NOE5                    ; no
+        MOV     BYTE PTR [NAME1],05H    ; change it to 05
+NOE5:
+
+;;;; 7/28/86
+        PUSH    DI                      ; Start of this element
+        PUSH    ES                      ; Save ES:BP
+        PUSH    CX                      ; CL return from NameTrans
+;DOS 3.3 FastOPen 6/12/86 F.C.
+
+        CALL    LookupPath              ; call fastopen to get dir entry
+        JNC     DIR_FOUND               ; found dir entry
+
+;DOS 3.3 FastOPen 6/12/86 F.C.
+        invoke  FINDENTRY
+DIR_FOUND:
+        POP     CX
+        POP     ES
+        POP     DI
+        JNC     LOAD_BUF
+        JMP     BADPATHPOP
+
+LOAD_BUF:
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        TEST    BYTE PTR [BX+dir_attr],attr_directory
+        JNZ     GO_NEXT                 ; DOS 3.3
+        JMP     FileInPath              ; Error or end of path
+;
+; if we are not setting the directory, then check for end of string
+;
+GO_NEXT:
+        CMP     BYTE PTR [NoSetDir],0
+        JZ      SetDir
+        MOV     DX,DI                   ; Save pointer to entry
+        MOV     CX,DS
+        context DS
+        POP     DI                      ; Start of next element
+        TEST   [FastOpenFlg],FastOpen_Set     ;only DOSOPEN can take advantage of
+        JZ     nofast                         ; the FastOpen
+        TEST   [FastOpenFlg],Lookup_Success   ; Lookup just happened
+        JZ     nofast                         ; no
+        MOV    DI,[Next_Element_Start]        ; no need to insert it again
+nofast:
+        CMP     BYTE PTR [DI],0
+        JNZ     NEXT_ONE                ; DOS 3.3
+        JMP     SetRet                  ; Got it
+NEXT_ONE:
+        PUSH    DI                      ; Put start of next element back on stack
+        MOV     DI,DX
+        MOV     DS,CX                   ; Get back pointer to entry
+ASSUME  DS:NOTHING
+
+SetDir:
+        MOV     DX,[SI]                 ; Dir_first
+
+;DOS 3.3 FastOPen 6/12/86 F.C.
+
+        PUSH    DS                    ; save [curbuf+2]
+        context DS                    ; set DS Dosgroup
+        TEST    [FastOpenFlg],Lookup_Success   ;
+        JZ      DO_NORMAL             ; fastopen not in memory or path not
+        MOV     BX,DX                 ; not found
+        MOV     DI,[CLUSNUM]          ; clusnum was set in LookupPath
+        PUSH    AX                    ; save device id (AH)
+        invoke  SETDIRSRCH
+        POP     AX                    ; restore device id (AH)
+        ADD     SP,2                  ; pop ds in stack
+        JMP     FAST_OPEN_SKIP
+
+DO_NORMAL:
+ASSUME  DS:NOTHING
+        POP     DS                      ; DS = [curbuf + 2]
+;DOS 3.3 FastOPen 6/12/86 F.C.
+
+        SUB     BX,DI                   ; Offset into sector of start of entry
+        SUB     SI,DI                   ; Offset into sector of dir_first
+        PUSH    BX
+        PUSH    AX
+        PUSH    SI
+        PUSH    CX
+        PUSH    WORD PTR [DI.buf_sector]     ;AN000;>32mb
+        PUSH    WORD PTR [DI.buf_sector+2]   ;AN000;>32mb
+        MOV     BX,DX
+        context DS
+        invoke  SETDIRSRCH              ; This uses UNPACK which might blow
+                                        ; the entry sector buffer
+        POP     [HIGH_SECTOR]
+        POP     DX
+        JC      SKIP_GETB
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL
+        XOR     AL,AL
+        invoke  GETBUFFR                ; Get the entry buffer back
+SKIP_GETB:
+        POP     CX
+        POP     SI
+        POP     AX
+        POP     BX
+        JNC     SET_THE_BUF
+        POP     DI                      ; Start of next element
+        MOV     SI,DI                   ; Point with SI
+        JMP     SHORT BADPATH
+
+SET_THE_BUF:
+        invoke  SET_BUF_AS_DIR
+        MOV     DI,WORD PTR [CURBUF]
+        ADD     SI,DI                   ; Get the offsets back
+        ADD     BX,DI
+; DOS 3.3 FasOpen 6/12/86  F.C.
+
+FAST_OPEN_SKIP:
+
+        POP     DI                      ; Start of next element
+        CALL   InsertPath            ; insert dir entry info
+
+; DOS 3.3 FasOpen 6/12/86  F.C.
+
+
+        MOV     AL,[DI]
+        OR      AL,AL
+        JZ      SETRET                  ; At end
+        INC     DI                      ; Skip over "/"
+        MOV     SI,DI                   ; Point with SI
+        invoke  PATHCHRCMP
+        JNZ     find_bad_name           ; oops
+        JMP     FINDPATH                ; Next element
+
+find_bad_name:
+        DEC     SI                      ; Undo above INC to get failure point
+BADPATH:
+        XOR     CL,CL                   ; Set zero
+        JMP     SHORT BADPRET
+
+FILEINPATH:
+        POP     DI                      ; Start of next element
+        context DS                      ; Got to from one place with DS gone
+; DOS 3.3 FastOpen
+
+        TEST    [FastOpenFlg],FastOpen_Set  ; do this here is we don't want to
+        JZ      NO_FAST                     ; device info to fastopen
+        TEST    [FastOpenFlg],Lookup_Success
+        JZ      NO_FAST
+        MOV     DI,[Next_Element_Start]  ; This takes care of one time lookup
+                                         ; success
+NO_FAST:
+
+; DOS 3.3 FastOpen
+
+        MOV     AL,[DI]
+        OR      AL,AL
+        JZ      INCRET
+        MOV     SI,DI                   ; Path too long
+        JMP     SHORT BADPRET
+
+INCRET:
+; DOS 3.3 FasOpen 6/12/86  F.C.
+
+        CALL   InsertPath            ; insert dir entry info
+
+; DOS 3.3 FasOpen 6/12/86  F.C.
+        INC     AL                      ; Reset zero
+SETRET:
+        return
+
+BADPATHPOP:
+        POP     SI                      ; Start of next element
+        MOV     AL,[SI]
+        MOV     SI,DI                   ; Start of bad element
+        OR      AL,AL                   ; zero if bad element is last, non-zero if path too long
+BADPRET:
+        MOV     AL,SAttrib
+        MOV     Attrib,AL               ; Make sure return correct
+        STC
+        return
+EndProc ROOTPATH
+
+Break   <STARTSRCH -- INITIATE DIRECTORY SEARCH>
+
+; Inputs:
+;       [THISDPB] Set
+; Function:
+;       Set up a search for GETENTRY and NEXTENTRY
+; Outputs:
+;       ES:BP = Drive parameters
+;       Sets up LASTENT, ENTFREE=ENTLAST=-1, VOLID=0
+; Destroys ES,BP,AX
+
+        procedure   StartSrch,NEAR
+        DOSAssume   CS,<DS>,"StartSrch"
+        ASSUME  ES:NOTHING
+
+        Assert  ISDPB,<<WORD PTR THISDPB+2>,<WORD PTR THISDPB>>,"StartSrch"
+        LES     BP,[THISDPB]
+        XOR     AX,AX
+        MOV     [LASTENT],AX
+        MOV     BYTE PTR [VOLID],AL     ; No volume ID found
+        DEC     AX
+        MOV     [ENTFREE],AX
+        MOV     [ENTLAST],AX
+        return
+EndProc StartSrch
+
+BREAK <MatchAttributes - the final check for attribute matching>
+
+;
+; Input:    [Attrib] = attribute to search for
+;           CH = found attribute
+; Output:   JZ <match>
+;           JNZ <nomatch>
+; Registers modified: noneski
+        procedure MatchAttributes,near
+        ASSUME  DS:NOTHING,ES:NOTHING
+        PUSH    AX
+        MOV     AL,Attrib               ; AL <- SearchSet
+        NOT     AL                      ; AL <- SearchSet'
+        AND     AL,CH                   ; AL <- SearchSet' and FoundSet
+        AND     AL,attr_all             ; AL <- SearchSet' and FoundSet and Important
+;
+; the result is non-zero if an attribute is not in the search set
+; and in the found set and in the important set. This means that we do not
+; have a match.  Do a JNZ <nomatch> or JZ <match>
+;
+        POP     AX
+        return
+EndProc MatchAttributes
+
+Break <DevName - Look for name of device>
+
+; Inputs:
+;       DS,ES:DOSGROUP
+;       Filename in NAME1
+;       ATTRIB set so that we can error out if looking for Volume IDs
+; Function:
+;       Determine if file is in list of I/O drivers
+; Outputs:
+;       Carry set if not a device
+;       ELSE
+;       Zero flag set
+;       BH = Bit 7,6 = 1, bit 5 = 0 (cooked mode)
+;            bits 0-4 set from low byte of attribute word
+;       DEVPT = DWORD pointer to Device header of device
+; BX destroyed, others preserved
+
+        procedure   DEVNAME,NEAR
+        DOSAssume   CS,<ES,DS>,"DevName"
+
+        PUSH    SI
+        PUSH    DI
+        PUSH    CX
+        PUSH    AX
+
+; E5 special code
+        PUSH    WORD PTR [NAME1]
+        CMP     [NAME1],5
+        JNZ     NOKTR
+        MOV     [NAME1],0E5H
+NOKTR:
+
+        TEST    Attrib,attr_volume_id   ; If looking for VOL id don't find devs
+        JNZ     RET31
+        MOV     SI,OFFSET DOSGROUP:NULDEV
+LOOKIO:
+ASSUME  DS:NOTHING
+        TEST    [SI.SDEVATT],DEVTYP
+        JZ      SKIPDEV                 ; Skip block devices (NET and LOCAL)
+        MOV     AX,SI
+        ADD     SI,SDEVNAME
+        MOV     DI,OFFSET DOSGROUP:NAME1
+        MOV     CX,4                    ; All devices are 8 letters
+        REPE    CMPSW                   ; Check for name in list
+        MOV     SI,AX
+        JZ      IOCHK                   ; Found it?
+SKIPDEV:
+        LDS     SI,DWORD PTR [SI]       ; Get address of next device
+        CMP     SI,-1                   ; At end of list?
+        JNZ     LOOKIO
+RET31:  STC                             ; Not found
+RETNV:  MOV     CX,SS
+        MOV     DS,CX
+        ASSUME  DS:DOSGroup
+        POP     WORD PTR [NAME1]
+        POP     AX
+        POP     CX
+        POP     DI
+        POP     SI
+        RET
+
+IOCHK:
+ASSUME  DS:NOTHING
+        MOV     WORD PTR [DEVPT+2],DS   ; Save pointer to device
+        MOV     BH,BYTE PTR [SI.SDEVATT]
+        OR      BH,0C0H
+        AND     BH,NOT 020H             ; Clears Carry
+        MOV     WORD PTR [DEVPT],SI
+        JMP     RETNV
+EndProc DevName
+
+BREAK <Build_device_ent - Make a Directory entry>
+
+; Inputs:
+;       [NAME1] has name
+;       BH is attribute field (supplied by DEVNAME)
+;       [DEVPT] points to device header (supplied by DEVNAME)
+; Function:
+;       Build a directory entry for a device at DEVFCB
+; Outputs:
+;       BX points to DEVFCB
+;       SI points to dir_first field
+;       AH = input BH
+;       AL = 0
+;       dir_first = DEVPT
+;       Zero Set, Carry Clear
+; DS,ES,BP preserved, others destroyed
+
+        procedure Build_device_ent,near
+        DOSAssume   CS,<ES,DS>,"Build_Device_Ent"
+
+        MOV     AX,"  "
+        MOV     DI,OFFSET DOSGROUP:DEVFCB+8 ; Point to extent field
+;
+; Fill dir_ext
+;
+        STOSW
+        STOSB                           ; Blank out extent field
+        MOV     AL,attr_device
+;
+; Fill Dir_attr
+;
+        STOSB                           ; Set attribute field
+        XOR     AX,AX
+        MOV     CX,10
+;
+; Fill dir_pad
+;
+        REP     STOSW                   ; Fill rest with zeros
+        invoke  DATE16
+        MOV     DI,OFFSET DOSGROUP:DEVFCB+dir_time
+        XCHG    AX,DX
+;
+; Fill dir_time
+;
+        STOSW
+        XCHG    AX,DX
+;
+; Fill dir_date
+;
+        STOSW
+        MOV     SI,DI                   ; SI points to dir_first field
+        MOV     AX,WORD PTR [DEVPT]
+;
+; Fill dir_first
+;
+        STOSW                           ; Dir_first points to device
+        MOV     AX,WORD PTR [DEVPT+2]
+;
+; Fill dir_size_l
+;
+        STOSW
+        MOV     AH,BH                   ; Put device atts in AH
+        MOV     BX,OFFSET DOSGROUP:DEVFCB
+        XOR     AL,AL                   ; Set zero, clear carry
+        return
+EndProc Build_device_ent
+
+Break   <ValidateCDS - given a CDS, validate the media and the current directory>
+
+;
+;   ValidateCDS - Get current CDS.  Splice it.  Call FatReadCDS to check
+;   media.  If media has been changed, do DOS_Chdir to validate path.  If
+;   invalid, reset original CDS to root.
+;
+;   Inputs:     ThisCDS points to CDS of interest
+;               SS:DI points to temp buffer
+;   Outputs:    The current directory string is validated on the appropriate
+;                   drive
+;               ThisDPB changed
+;               ES:DI point to CDS
+;               Carry set if error (currently user FAILed to I 24)
+;   Registers modified: all
+
+Procedure   ValidateCDS,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+Public DIR2001S,DIR2001E
+DIR2001S:
+        LocalVar    Temp,WORD
+        LocalVar    SaveCDS,DWORD
+DIR2001E:
+        Enter
+        MOV     Temp,DI
+        LDS     SI,ThisCDS
+        MOV     SaveCDSL,SI
+        MOV     SaveCDSH,DS
+        EnterCrit   critDisk
+        TEST    [SI].curdir_flags,curdir_isnet  ; Clears carry
+        JZ      DoSplice
+        JMP     FatFail
+DoSplice:
+        XOR     DL,DL
+        XCHG    DL,NoSetDir
+        Context ES
+        Invoke  FStrcpy
+        MOV     SI,Temp
+        Context DS
+        Invoke  Splice
+        ASSUME  DS:NOTHING
+        Context DS                      ;   FatReadCDS (ThisCDS);
+        MOV     NoSetDir,DL
+        LES     DI,ThisCDS
+        SaveReg <BP>
+        Invoke  FatRead_CDS
+        RestoreReg  <BP>
+        JC      FatFail
+        LDS     SI,ThisCDS              ;   if (ThisCDS->ID == -1) {
+        ASSUME  DS:NOTHING
+        CMP     [SI].curdir_ID,-1
+        JNZ     RestoreCDS
+        Context ES
+        SaveReg <wfp_Start>             ;       t = wfp_Start;
+        CMP     SI,SaveCDSL             ; if not spliced
+        JNZ     DoChdir
+        MOV     DI,Temp
+        MOV     wfp_Start,DI            ;       wfp_start = d;
+        Invoke  FStrCpy                 ;       strcpy (d, ThisCDS->Text);
+DoChdir:
+        Context DS
+        SaveReg <<WORD PTR SAttrib>,BP> ;       c = DOSChDir ();
+        Invoke  DOS_ChDir
+        RestoreReg  <BP,BX,wfp_start>   ;       wfp_Start = t;
+        MOV     SAttrib,BL
+        LDS     SI,SaveCDS
+        ASSUME  DS:NOTHING
+        JNC     SetCluster              ;       if (c == -1) {
+        MOV     WORD PTR ThisCDS,SI     ;           ThisCDS = TmpCDS;
+        MOV     WORD PTR ThisCDS+2,DS
+        XOR     CX,CX                   ;           TmpCDS->text[3] = c = 0;
+        MOV     [SI+3],CL               ;           }
+SetCluster:
+        MOV     [SI].curdir_ID,-1       ;       TmpCDS->ID = -1;
+        LDS     SI,ThisCDS              ;       ThisCDS->ID = c;
+        TEST    [SI].curdir_flags,curdir_splice      ;AN000;;MS.  for Join and Subst
+        JZ      setdirclus                           ;AN000;;MS.
+        MOV     CX,-1                                ;AN000;;MS.
+setdirclus:
+        MOV     [SI].curdir_ID,CX       ;       }
+RestoreCDS:
+        LES     DI,SaveCDS
+        MOV     WORD PTR ThisCDS,DI
+        MOV     WORD PTR ThisCDS+2,ES
+        CLC
+FatFail:
+        LeaveCrit   critDisk
+        LES     DI,SaveCDS
+        Leave
+        return
+EndProc ValidateCDS
+
+Break   <CheckThisDevice - Check for being a device>
+
+;
+;   CheckThisDevice - Examine the area at DS:SI to see if there is a valid
+;   device specified.  We will return carry if there is a device present.  The
+;   forms of devices we will recognize are:
+;
+;       [path]device
+;
+;   Note that the drive letter has *already* been removed.  All other forms
+;   are not considered to be devices.  If such a device is found we change the
+;   source pointer to point to the device component.
+;
+;   Inputs:     ES is DOSGroup
+;               DS:SI contains name
+;   Outputs:    ES is DOSGroup
+;               DS:SI point to name or device
+;               Carry flag set if device was found
+;               Carry flag reset otherwise
+;   Registers Modified: all except ES:DI, DS
+
+if FALSE
+Procedure   CheckThisDevice,NEAR
+        DOSAssume CS,<ES>,"CheckThisDevice"
+        ASSUME  DS:NOTHING
+        SaveReg <DI,SI>
+;
+; Advance to after the final path character.
+;
+        MOV     DI,SI                   ; remember first character
+PathSkip:
+        LODSB
+        OR      AL,AL
+        JZ      FoundEnd
+ IF  DBCS                       ;AN000;
+        invoke  Testkanj        ;AN000;; 2/13/KK
+        jz      Notkanje        ;AN000;; 2/13/KK
+        lodsb                   ;AN000;; 2/13/KK
+        or      al,al           ;AN000;; Skip second byte 2/13/KK  removed
+        jz      FoundEnd        ;AN000;; 2/13/KK                   removed
+        jmp     Short Pathskip  ;AN000;; Ignore missing second byte for now.
+NotKanje:                       ;AN000;
+  ENDIF                         ;AN000;
+;kanji load of next char too      2/13/KK
+IF Kanji
+ kanji load of next char too
+ENDIF
+        invoke  PathChrCmp              ; is it a path char?
+        JNZ     PathSkip
+        MOV     DI,SI
+        JMP     PathSkip
+FoundEnd:
+        MOV     SI,DI
+;
+; Parse the name
+;
+        SaveReg <DS,SI>                 ; preserve the source pointer
+        invoke  NameTrans               ; advance DS:SI
+        CMP     BYTE PTR [SI],0         ; parse entire string?
+        STC                             ; simulate a Carry return from DevName
+        JNZ     SkipSearch              ; no parse.  simulate a file return.
+        Context DS
+        Invoke  DevName
+        ASSUME  DS:NOTHING
+SkipSearch:
+        RestoreReg  <SI,DS>
+;
+; DS:SI points to the beginning of the potential device.  If we have a device
+; then we do not change SI.  If we have a file, then we reset SI back to the
+; original value.  At this point Carry set indicates FILE.
+;
+        RestoreReg  <DI>                ; get original SI
+        JNC     CheckDone               ; if device then do not reset pointer
+        MOV     SI,DI
+CheckDone:
+        RestoreReg  <DI>
+        CMC                             ; invert carry.  Carry => device
+        return
+else
+Procedure   CheckThisDevice,NEAR
+        DOSAssume CS,<ES>,"CheckThisDevice"
+        ASSUME  DS:NOTHING
+        SaveReg <DI,SI>
+        MOV     DI,SI
+;
+; Check for presence of \dev\ (Dam multiplan!)
+;
+        MOV     AL,[SI]
+        Invoke  PathChrCmp              ; is it a path char?
+        JNZ     ParseDev                ; no, go attempt to parse device
+        INC     SI                      ; simulate LODSB
+;
+; We have the leading path separator.  Look for DEV part.
+;
+        LODSW
+        OR      AX,2020h
+        CMP     AX,"e" SHL 8 + "d"
+        JNZ     NotDevice               ; not "de", assume not device
+        LODSB
+        OR      AL,20h
+        CMP     AL,"v"                  ; Not "v", assume not device
+        JNZ     NotDevice
+        LODSB
+        invoke  PathChrCmp              ; do we have the last path separator?
+        JNZ     NotDevice               ; no. go for it.
+;
+; DS:SI now points to a potential drive.  Preserve them as NameTrans advances
+; SI and DevName may destroy DS.
+;
+ParseDev:
+        SaveReg <DS,SI>                 ; preserve the source pointer
+        invoke  NameTrans               ; advance DS:SI
+        CMP     BYTE PTR [SI],0         ; parse entire string?
+        STC                             ; simulate a Carry return from DevName
+        JNZ     SkipSearch              ; no parse.  simulate a file return.
+        Context DS
+        Invoke  DevName
+        ASSUME  DS:NOTHING
+SkipSearch:
+        RestoreReg  <SI,DS>
+;
+; SI points to the beginning of the potential device.  If we have a device
+; then we do not change SI.  If we have a file, then we reset SI back to the
+; original value.  At this point Carry set indicates FILE.
+;
+CheckReturn:
+        RestoreReg  <DI>                ; get original SI
+        JNC     CheckDone               ; if device then do not reset pointer
+        MOV     SI,DI
+CheckDone:
+        RestoreReg  <DI>
+        CMC                             ; invert carry.  Carry => device
+        return
+NotDevice:
+        STC
+        JMP     CheckReturn
+endif
+
+EndProc CheckThisDevice
+
+BREAK <LookupPath - call fastopen to get dir entry info>
+
+;
+; Output  DS:SI -> path name,
+;         ES:DI -> dir entry info buffer
+;         ES:CX -> extended dir info buffer
+;
+;         carry flag clear : tables pointed by ES:DI and ES:CX are filled by
+;                            FastOpen, DS:SI points to char just one after
+;                            the last char of path name which is fully or
+;                            partially found in FastOPen
+;         carry flag set : FastOpen not in memory or path name not found
+;
+        procedure LookupPath,NEAR
+        ASSUME  ES:NOTHING
+
+;       PUSH    AX
+        TEST    [FastOpenFlg],FastOpen_Set          ; flg is set in DOSPEN
+        JNZ     FASTINST                            ; and this routine is
+NOLOOK:
+        JMP     NOLOOKUP                            ; executed once
+FASTINST:
+        TEST    [FastOpenFlg],No_Lookup             ; no more lookup?
+        JNZ     NOLOOK                              ; yes
+
+        MOV     BX,OFFSET DOSGROUP:FastOpenTable    ; get fastopen related tab
+        MOV     SI,[Wfp_Start]                      ; si points to path name
+        MOV     DI,OFFSET DOSGROUP:Dir_Info_Buff
+        MOV     CX,OFFSET DOSGROUP:FastOpen_Ext_Info
+        MOV     AL,FONC_look_up                     ; al = 1
+        PUSH    DS
+        POP     ES
+        CALL    DWORD PTR [BX.FASTOPEN_NAME_CACHING] ;call fastopen
+        JC      NOTFOUND                            ; fastopen not in memory
+
+        LEA     BX,[SI-2]
+        CMP     BX,[Wfp_Start]                      ; path found ?
+        JZ      NOTFOUND                            ; no
+                                                    ; fully or partially found
+        CMP     BYTE PTR [SI],0                     ;AN000;FO.
+        JNZ     parfnd                              ;AN000;FO.; partiallyfound
+        PUSH    CX                                  ;AN000;FO.; is attribute matched ?
+        MOV     CL,Attrib                           ;AN000;FO.;
+        MOV     CH,Sattrib                          ;AN000;FO.; attrib=sattrib
+        MOV     Attrib,CH                           ;AN000;FO.;
+        MOV     CH,ES:[DI.dir_attr]                 ;AN000;FO.;
+        invoke  Matchattributes                     ;AN000;FO.;
+;;;     MOV     Attrib,CL                           ;AN001;FO.; retore attrib
+        POP     CX                                  ;AN000;FO.;
+        JNZ     NOLOOKUP                            ;AN000;FO.; not matched
+parfnd:
+        MOV     [Next_Element_Start],SI                    ; save si
+        MOV     BX,CX
+        MOV     AX,[BX.FEI_lastent]                 ;AN000;;FO. restore lastentry
+        MOV     [LASTENT],AX                        ;AN000;;FO.
+        MOV     AX,[BX.FEI_dirstart]                ;AN001;;FO. restore dirstart
+        MOV     [DIRSTART],AX                       ;AN001;;FO.
+        MOV     AX,[BX.FEI_clusnum]                 ; restore next cluster num
+        MOV     [CLUSNUM],AX                        ;
+
+        PUSH    ES                                  ; save ES
+        LES     BX,[THISDPB]                        ; put drive id
+        MOV     AH,ES:[BX.dpb_drive]                ; in AH for DOOPEN
+        POP     ES                                  ; pop ES
+
+        MOV     WORD PTR [CURBUF+2],ES              ; [curbuf+2].bx points to
+        MOV     BX,DI                               ; start of entry
+        LEA     SI,[DI.dir_first]                   ; [curbuf+2]:si points to
+                                                    ; dir_first field in the
+                                                    ; dir entry
+        OR      [FastOpenFlg],Lookup_Success + set_for_search
+;       POP     AX
+        RET
+NOTFOUND:
+        CMP     AX,-1                               ; not in memory ?
+        JNZ     Partial_Success                     ; yes, in memory
+        MOV     [FastOpenFlg],0                     ; no more fastopen
+Partial_Success:
+        AND     [FastOpenFlg],Special_Fill_Reset
+NOLOOKUP:
+;       POP     AX
+        STC
+        RET
+EndProc LookupPath
+
+BREAK <InsertPath - call fastopen to insert dir entry info>
+
+;
+; Input:  FastOpen_Set flag set when from DOSOPEN otherwise 0
+;         Lookup_Success flag set when got dir entry info from FASTOPEN
+;         DS = DOSGROUP
+; Output: FastOPen_Ext_Info is set and path dir info is inserted
+;
+        procedure InsertPath,NEAR
+        ASSUME  ES:NOTHING
+
+        PUSHF
+        TEST   [FastOpenFlg],FastOpen_Set     ;only DOSOPEN can take advantage of
+        JZ     GET_NEXT_ELEMENT               ; the FastOpen
+        TEST   [FastOpenFlg],Lookup_Success   ; Lookup just happened
+        JZ     INSERT_DIR_INFO                ; no
+        AND    [FastOpenFlg],Lookup_Reset     ; we got dir info from fastopen so
+        MOV    DI,[Next_Element_Start]        ; no need to insert it again
+        JMP    GET_NEXT2
+INSERT_DIR_INFO:                              ; save registers
+        PUSH   DS
+        PUSH   ES
+        PUSH   BX
+        PUSH   SI
+        PUSH   DI
+        PUSH   CX
+        PUSH   AX
+;  int 3
+        LDS    DI,[CURBUF]              ; DS:DI -> buffer header
+ASSUME DS:NOTHING
+        MOV    SI,OFFSET DOSGROUP:FastOpen_Ext_Info
+        MOV    AX,WORD PTR [DI.buf_sector]  ; get directory sector
+        MOV    WORD PTR CS:[SI.FEI_dirsec],AX ;AN000; >32mb save dir sector
+        MOV    AX,WORD PTR [DI.buf_sector+2]  ;AN000; >32mb
+        context DS
+        MOV    WORD PTR [SI.FEI_dirsec+2],AX  ;AN000;>32mb save high dir sector
+        MOV    AX,[CLUSNUM]             ; save next cluster number
+        MOV    [SI.FEI_clusnum],AX
+        MOV    AX,[LASTENT]             ;AN000;FO. save lastentry for search first
+        MOV    [SI.FEI_lastent],AX      ;AN000;FO.
+        MOV    AX,[DIRSTART]            ;AN001;FO. save  for search first
+        MOV    [SI.FEI_dirstart],AX     ;AN001;FO.
+
+        MOV    AX,BX
+        ADD    DI,BUFINSIZ              ; DS:DI -> start of data in buffer
+        SUB    AX,DI                    ; AX=BX relative to start of sector
+        MOV    CL,SIZE dir_entry
+;invoke debug_DOS
+        DIV    CL
+        MOV    [SI.FEI_dirpos],AL       ; save directory entry # in buffer
+
+        PUSH   DS
+        POP    ES
+
+        MOV    DS,WORD PTR [CURBUF+2]
+        MOV    DI,BX                    ; DS:DI -> dir entry info
+ASSUME DS:NOTHING
+        CMP    DS:[DI.dir_first],0      ; never insert info when file is empty
+        JZ     SKIP_INSERT              ; e.g. newly created file
+
+        PUSH   SI                       ; ES:BX -> extended info
+        POP    BX
+
+        MOV    AL,FONC_insert           ; call fastopen insert operation
+        MOV    SI,OFFSET DOSGROUP:FastOpenTable
+        CALL   DWORD PTR ES:[SI.FASTOPEN_NAME_CACHING]
+
+        CLC
+SKIP_INSERT:
+        POP    AX
+        POP    CX                       ; restore registers
+        POP    DI
+        POP    SI
+        POP    BX
+        POP    ES
+        POP    DS
+GET_NEXT2:
+        OR     [FastOpenFlg],No_Lookup        ; we got dir info from fastopen so
+GET_NEXT_ELEMENT:
+        POPF
+        RET
+EndProc InsertPath
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/DIRCALL.ASM b/v4.0/src/DOS/DIRCALL.ASM
new file mode 100644
index 0000000..3c79fe0
--- /dev/null
+++ b/v4.0/src/DOS/DIRCALL.ASM
@@ -0,0 +1,415 @@
+;       SCCSID = @(#)dircall.asm        1.1 85/04/10
+;       SCCSID = @(#)dircall.asm        1.1 85/04/10
+TITLE DIRCALL - Directory manipulation internal calls
+NAME  DIRCALL
+; Low level directory manipulation routines for making removing and
+;   verifying local or NET directories
+;
+;   DOS_MKDIR
+;   DOS_CHDIR
+;   DOS_RMDIR
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+INCLUDE FASTOPEN.INC
+INCLUDE FASTXXXX.INC
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  THISSFT,DWORD
+        i_need  THISCDS,DWORD
+        i_need  NoSetDir,BYTE
+        i_need  CURBUF, DWORD
+        i_need  DIRSTART,WORD
+        i_need  THISDPB,DWORD
+        i_need  NAME1,BYTE
+        i_need  LASTENT,WORD
+        i_need  SATTRIB,BYTE
+        i_need  ATTRIB,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  FAILERR,BYTE
+        i_need  RenBuf,BYTE
+        i_need  FastOpenFlg,BYTE                  ; DOS 3.3
+        i_need  FastOpenTable,BYTE                ; DOS 3.3
+        i_need  WFP_START,WORD                    ; DOS 3.3
+        i_need  HIGH_SECTOR,WORD                  ; F.C. >32mb
+
+BREAK <DOS_MkDir - Make a directory entry>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+; Function:
+;       Make a new directory
+; Returns:
+;       Carry Clear
+;               No error
+;       Carry Set
+;           AX is error code
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       Already exists, device name
+; DS preserved, Others destroyed
+
+        procedure   DOS_MKDIR,NEAR
+        DOSAssume   CS,<DS>,"DOS_MkDir"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     local_mkdir
+IF NOT Installed
+        transfer NET_MKDIR
+ELSE
+        MOV     AX,(multNET SHL 8) OR 3
+        INT     2FH
+        return
+ENDIF
+
+NODEACCERRJ:
+        MOV     AX,error_access_denied
+BadRet:
+        STC
+        LeaveCrit   critDisk
+        return
+
+PATHNFJ:
+        LeaveCrit   critDisk
+        transfer SET_MKND_ERR           ; Map the MakeNode error and return
+
+LOCAL_MKDIR:
+        EnterCrit   critDisk
+;
+; MakeNode requires an SFT to fiddle with.  We Use a temp spot (RENBUF)
+;
+        MOV     WORD PTR [THISSFT+2],SS
+        MOV     WORD PTR [THISSFT],OFFSET DOSGroup:RenBuf
+;
+;  NOTE: Need WORD PTR because MASM takes type of
+;   TempSFT (byte) instead of type of sf_mft (word).
+;
+        MOV     WORD PTR RenBuf.sf_mft,0    ; make sure SHARER won't complain.
+        MOV     AL,attr_directory
+        invoke  MAKENODE
+
+        JC      PATHNFJ
+        CMP     AX,3
+        JZ      NODEACCERRJ     ; Can't make a device into a directory
+        LES     BP,[THISDPB]    ; Makenode zaps this
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        SUB     SI,DI
+        PUSH    SI              ; Pointer to dir_first
+        PUSH    WORD PTR [DI.buf_sector+2]          ;F.C. >32mb
+
+        PUSH    WORD PTR [DI.buf_sector] ; Sector of new node
+        context DS
+        PUSH    [DIRSTART]      ; Parent for .. entry
+        XOR     AX,AX
+        MOV     [DIRSTART],AX   ; Null directory
+        invoke  NEWDIR
+        JC      NODEEXISTSPOPDEL    ; No room
+        invoke  GETENT          ; First entry
+        JC      NODEEXISTSPOPDEL    ; Screw up
+        LES     DI,[CURBUF]
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI.buf_flags],buf_dirty
+yesdirty:
+        ADD     DI,BUFINSIZ     ; Point at buffer
+        MOV     AX,202EH        ; ". "
+        MOV     DX,[DIRSTART]   ; Point at itself
+        invoke  SETDOTENT
+        MOV     AX,2E2EH        ; ".."
+        POP     DX              ; Parent
+        invoke  SETDOTENT
+        LES     BP,[THISDPB]
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        POP     DX              ; Entry sector
+        POP     [HIGH_SECTOR]   ;F.C. >32mb
+
+        XOR     AL,AL           ; Pre read
+        invoke  GETBUFFR
+        JC      NODEEXISTSP
+        MOV     DX,[DIRSTART]
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        OR      [DI.buf_flags],buf_isDIR
+        POP     SI              ; dir_first pointer
+        ADD     SI,DI
+        MOV     [SI],DX
+        XOR     DX,DX
+        MOV     [SI+2],DX       ; Zero size
+        MOV     [SI+4],DX
+DIRUP:
+        TEST    [DI.buf_flags],buf_dirty  ;LB. if already dirty                 ;AN000;
+        JNZ     yesdirty2                 ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      [DI.buf_flags],buf_dirty        ; Dirty buffer
+yesdirty2:
+        context DS
+        MOV     AL,ES:[BP.dpb_drive]
+        invoke  FLUSHBUF
+        MOV     AX,error_access_denied
+        LeaveCrit   critDisk
+        return
+
+NODEEXISTSPOPDEL:
+        POP     DX              ; Parent
+        POP     DX              ; Entry sector
+        POP     [HIGH_SECTOR]   ; F.C. >32mb
+
+        LES     BP,[THISDPB]
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        XOR     AL,AL           ; Pre read
+        invoke  GETBUFFR
+        JC      NODEEXISTSP
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        OR      [DI.buf_flags],buf_isDIR
+        POP     SI              ; dir_first pointer
+        ADD     SI,DI
+        SUB     SI,dir_first    ;Point back to start of dir entry
+        MOV     BYTE PTR [SI],0E5H    ; Free the entry
+        CALL    DIRUP           ; Error doesn't matter since erroring anyway
+NODEEXISTS:
+        JMP     NODEACCERRJ
+
+NODEEXISTSP:
+        POP     SI              ; Clean stack
+        JMP     NODEEXISTS
+
+EndProc DOS_MKDIR
+
+BREAK <DOS_ChDir -- Verify a directory>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used May not be NUL
+; Function:
+;       Validate the path for potential new current directory
+; Returns:
+;       NOTE:
+;           [SATTRIB] is modified by this call
+;       Carry Clear
+;           CX is cluster number of the DIR, LOCAL CDS ONLY
+;               Caller must NOT set ID fields on a NET CDS.
+;       Carry Set
+;           AX is error code
+;               error_path_not_found
+;                       Bad path
+;               error_access_denied
+;                       device or file name
+; DS preserved, Others destroyed
+
+        procedure   DOS_CHDIR,NEAR
+        DOSAssume   CS,<DS>,"DOS_Chdir"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     LOCAL_CHDIR
+IF NOT Installed
+        transfer NET_CHDIR
+ELSE
+        MOV     AX,(multNET SHL 8) OR 5
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_CHDIR:
+        EnterCrit   critDisk
+        TEST    ES:[DI.curdir_flags],curdir_splice ;PTM.
+        JZ      nojoin                             ;PTM.
+        MOV     ES:[DI.curdir_ID],0FFFFH           ;PTM.
+nojoin:
+        MOV     [NoSetDir],FALSE
+        MOV     [SATTRIB],attr_directory+attr_system+attr_hidden
+                                ; Dir calls can find these
+; DOS 3.3  6/24/86 FastOpen
+
+        OR      [FastOpenFlg],FastOpen_Set         ; set fastopen flag
+        invoke  GetPath
+        PUSHF                                                                   ;AN000;
+        AND     [FastOpenFlg],Fast_yes             ; clear it all               ;AC000;
+        POPF                                                                    ;AN000;
+; DOS 3.3  6/24/86 FastOpen
+        MOV     AX,error_path_not_found
+        JC      ChDirDone
+        JNZ     NOTDIRPATH      ; Path not a DIR
+        MOV     CX,[DIRSTART]   ; Get cluster number
+        CLC
+ChDirDone:
+        LeaveCrit   critDisk
+        return
+
+EndProc DOS_CHDIR
+
+BREAK <DOS_RmDir -- Remove a directory>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+; Function:
+;       Remove a directory
+;       NOTE: Attempt to remove current directory must be detected by caller
+; Returns:
+;       NOTE:
+;           [SATTRIB] is modified by this call
+;       Carry Clear
+;               No error
+;       Carry Set
+;           AX is error code
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       device or file name, root directory
+;                       Bad directory ('.' '..' messed up)
+; DS preserved, Others destroyed
+
+        procedure   DOS_RMDIR,NEAR
+        DOSAssume   CS,<DS>,"DOS_RmDir"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     Local_RmDIR
+IF NOT Installed
+        transfer NET_RMDIR
+ELSE
+        MOV     AX,(multNET SHL 8) OR 1
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_RMDIR:
+        EnterCrit   critDisk
+        MOV     [NoSetDir],0
+        MOV     [SATTRIB],attr_directory+attr_system+attr_hidden
+                                ; Dir calls can find these
+        invoke  GetPath
+        JC      NOPATH          ; Path not found
+        JNZ     NOTDIRPATH      ; Path not a DIR
+        MOV     DI,[DIRSTART]
+        OR      DI,DI           ; Root ?
+        JNZ     rmdir_get_buf   ; No
+        JMP     SHORT NOTDIRPATH
+
+NOPATH:
+        MOV     AX,error_path_not_found
+        JMP     BadRet
+
+NOTDIRPATHPOP:
+        POP     AX                        ;F.C. >32mb
+        POP     AX
+NOTDIRPATHPOP2:
+        POP     AX
+NOTDIRPATH:
+        JMP     NodeAccErrJ
+
+rmdir_get_buf:
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        SUB     BX,DI           ; Compute true offset
+        PUSH    BX              ; Save entry pointer
+        PUSH    WORD PTR [DI.buf_sector+2] ;F.C. >32mb
+        PUSH    WORD PTR [DI.buf_sector] ; Save sector number
+        context DS
+        context ES
+        MOV     DI,OFFSET DOSGROUP:NAME1
+        MOV     AL,'?'
+        MOV     CX,11
+        REP     STOSB
+        XOR     AL,AL
+        STOSB                   ; Nul terminate it
+        invoke  STARTSRCH       ; Set search
+        invoke  GETENTRY        ; Get start of directory
+        JC      NOTDIRPATHPOP   ; Screw up
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+        MOV     SI,BX
+        LODSW
+        CMP     AX,(' ' SHL 8) OR '.'   ; First entry '.'?
+        JNZ     NOTDIRPATHPOP           ; Nope
+        ADD     SI,(SIZE dir_entry) - 2 ; Next entry
+        LODSW
+        CMP     AX,('.' SHL 8) OR '.'   ; Second entry '..'?
+        JNZ     NOTDIRPATHPOP           ; Nope
+        context DS
+        MOV     [LASTENT],2             ; Skip . and ..
+        invoke  GETENTRY                ; Get next entry
+        JC      NOTDIRPATHPOP           ; Screw up
+        MOV     [ATTRIB],attr_directory+attr_hidden+attr_system
+        invoke  SRCH                    ; Do a search
+        JNC     NOTDIRPATHPOP           ; Found another entry!
+        CMP     [FAILERR],0
+        JNZ     NOTDIRPATHPOP           ; Failure of search due to I 24 FAIL
+        LES     BP,[THISDPB]
+        MOV     BX,[DIRSTART]
+;; FastSeek 10/27/86
+        invoke  Delete_FSeek            ; delete the fastseek entry
+;; FastSeek 10/27/86
+        invoke  RELEASE                 ; Release data in sub dir
+        JC      NOTDIRPATHPOP           ; Screw up
+        POP     DX                      ; Sector # of entry
+        POP     [HIGH_SECTOR]           ; F.C. >32mb
+
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        XOR     AL,AL                   ; Pre read
+        invoke  GETBUFFR                ; Get sector back
+        JC      NOTDIRPATHPOP2          ; Screw up
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        OR      [DI.buf_flags],buf_isDIR
+        POP     BX                      ; Pointer to start of entry
+        ADD     BX,DI                   ; Corrected
+        MOV     BYTE PTR [BX],0E5H      ; Free the entry
+
+;DOS 3.3 FastOpen  6/16/86  F.C.
+        PUSH    DS
+        context DS
+        invoke  FastOpen_Delete         ; call fastopen to delete an entry
+        POP     DS
+;DOS 3.3 FastOpen  6/16/86  F.C.
+
+        JMP     DIRUP                   ; In MKDIR, dirty buffer and flush
+
+EndProc DOS_RMDIR
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/DISK.ASM b/v4.0/src/DOS/DISK.ASM
new file mode 100644
index 0000000..2fad68b
--- /dev/null
+++ b/v4.0/src/DOS/DISK.ASM
@@ -0,0 +1,1073 @@
+;       SCCSID = @(#)disk.asm   1.1 85/04/10
+;       SCCSID = @(#)disk.asm   1.1 85/04/10
+TITLE   DISK - Disk utility routines
+NAME    Disk
+; Low level Read and write routines for local SFT I/O on files and devs
+;
+;   SWAPCON
+;   SWAPBACK
+;   DOS_READ
+;   DOS_WRITE
+;   get_io_sft
+;   DirRead
+;   FIRSTCLUSTER
+;   SET_BUF_AS_DIR
+;   FATSecRd
+;   DREAD
+;   CHECK_WRITE_LOCK
+;   CHECK_READ_LOCK
+;
+;   Revision history:
+;
+;       A000   version 4.00  Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+include fastseek.inc                            ;AN000;
+include fastxxxx.inc                            ;AN000;
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+Installed = TRUE
+
+        I_need  DirStart,WORD
+        I_Need  CONSft,DWORD            ; SFT for swapped console In/Out
+        i_need  CONSWAP,BYTE
+        i_need  IDLEINT,BYTE
+        i_need  THISSFT,DWORD
+        i_need  DMAADD,DWORD
+        i_need  DEVCALL,BYTE
+        i_need  CALLSCNT,WORD
+        i_need  CALLXAD,DWORD
+        i_need  CONTPOS,WORD
+        i_need  NEXTADD,WORD
+        i_need  CONBUF,BYTE
+        i_need  ClusFac,BYTE
+        i_need  SecClusPos,BYTE
+        i_need  DirSec,DWORD                 ;AN000;
+        i_need  ClusNum,WORD
+        i_need  NxtClusNum,WORD
+        i_need  ReadOp,BYTE
+        i_need  CURBUF,DWORD
+        i_need  ALLOWED,BYTE
+        i_need  EXTERR_LOCUS,BYTE
+        i_need  FastSeekflg,BYTE             ;AN000;
+        i_need  HIGH_SECTOR,WORD             ;AN000;
+        I_need  JShare,DWORD                 ;AN000;
+        i_need  DOS34_FLAG,WORD              ;AN000;
+
+IF      BUFFERFLAG
+
+        i_need  BUF_EMS_MODE,BYTE
+        i_need  BUF_EMS_LAST_PAGE,BYTE
+        I_need  BUF_EMS_FIRST_PAGE,DWORD
+        I_need  BUF_EMS_SAFE_FLAG,BYTE
+        I_need  BUF_EMS_NPA640,WORD
+        I_need  BUF_EMS_PAGE_FRAME,WORD
+        I_need  BUF_EMS_PFRAME,WORD
+        I_need  LASTBUFFER,DWORD
+
+        extrn   save_user_map:near
+        extrn   restore_user_map:near
+        extrn   Setup_EMS_Buffers:near
+
+ENDIF
+
+Break   <SwapCon, Swap Back - Old-style I/O to files>
+; * * * * Drivers for file input from devices * * * *
+
+;   Indicate that ther is no more I/O occurring through another SFT outside of
+;   handles 0 and 1
+;
+;   Inputs:     DS is DOSGroup
+;   Outputs:    CONSWAP is set to false.
+;   Registers modified: none
+
+        procedure   SWAPBACK,NEAR
+        DOSAssume   CS,<DS>,"SwapBack"
+        ASSUME  ES:NOTHING
+        MOV     BYTE PTR [CONSWAP],0    ; signal no conswaps
+        return
+EndProc SWAPBACK
+
+;   Copy ThisSFT to CONSFT for use by the 1-12 primitives.
+;
+;   Inputs:     ThisSFT as the sft of the desired file
+;               DS is DOSGroup
+;   Outputs:    CONSWAP is set.  CONSFT = ThisSFT.
+;   Registers modified: none
+        procedure   SWAPCON,NEAR
+        DOSAssume   CS,<DS>,"SwapCon"
+        ASSUME  ES:NOTHING
+        SaveReg <ES,DI>
+        MOV     BYTE PTR [CONSWAP],1    ;   CONSwap = TRUE;
+        LES     DI,ThisSFT
+        Assert  ISSFT,<ES,DI>,"SwapCon"
+        MOV     WORD PTR CONSFT,DI
+        MOV     WORD PTR CONSFT+2,ES
+        RestoreReg  <DI,ES>
+        return
+EndProc SWAPCON
+
+Break   <DOS_READ -- MAIN READ ROUTINE AND DEVICE IN ROUTINES>
+
+;
+; Inputs:
+;       [THISSFT] set to the SFT for the file being used
+;       [DMAADD] contains transfer address
+;       CX = No. of bytes to read
+; Function:
+;       Perform read operation
+; Outputs:
+;    Carry clear
+;       SFT Position and cluster pointers updated
+;       CX = No. of bytes read
+;       ES:DI point to SFT
+;    Carry set
+;       AX is error code
+;       CX = 0
+;       ES:DI point to SFT
+; DS preserved, all other registers destroyed
+
+        procedure   DOS_READ,NEAR
+        DOSAssume   CS,<DS>,"DOS_Read"
+        ASSUME  ES:NOTHING
+
+IF      BUFFERFLAG
+        cmp     [BUF_EMS_MODE], -1
+        jz      dos_rd_call
+        call    choose_buf_page
+        jnc     sav_map_rd_hndl
+        return
+sav_map_rd_hndl:
+;       call    save_user_map
+dos_rd_call:
+ENDIF
+        
+
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DOS_Read"
+;
+; Verify that the sft has been opened in a mode that allows reading.
+;
+        MOV     AL,BYTE PTR ES:[DI.sf_mode]
+        AND     AL,access_mask
+        CMP     AL,open_for_write
+        JNE     READ_NO_MODE            ;Is read or both
+        transfer   SET_ACC_ERR
+
+READ_NO_MODE:
+        invoke  SETUP
+        JCXZ    NoIORet                 ; no bytes to read - fast return
+        invoke  IsSFTNet
+        JZ      LOCAL_READ
+
+;       invoke  OWN_SHARE               ;AN000;;IFS. IFS owns share ?
+;       JZ      IFS_HAS_SHARE           ;AN000;;IFS. yes
+;       EnterCrit   critDisk            ;AN000;;IFS. enter critical section
+;       CALL    CHECK_READ_LOCK         ;AN000;;IFS. check read lock
+;       JNC     READ_OK2                ;AN000;;IFS. lock check ok
+;       JMP     SHORT critexit          ;AN000;;IFS. fail
+READ_OK2:                               ;AN000;
+;       LeaveCrit   critDisk            ;AN000;;IFS. leave critical section
+IFS_HAS_SHARE:                          ;AN000;
+
+IF NOT Installed
+        transfer NET_READ
+ELSE
+        MOV     AX,(multNET SHL 8) OR 8
+        INT     2FH
+        return
+ENDIF
+
+;
+; The user ended up requesting 0 bytes of input.  We do nothing for this case
+; except return immediately.
+;
+NoIORet:
+        CLC
+        return
+
+LOCAL_READ:
+        TEST    ES:[DI.sf_flags],devid_device  ; Check for named device I/O
+        JNZ     READDEV
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        EnterCrit   critDisk
+        TEST    [FastSeekflg],Fast_yes         ; FastSeek installed ?
+        JZ      FS_no                          ; no
+        OR      [FastSeekflg],FS_begin         ; set fastseek mode
+FS_no:
+        invoke  DISKREAD
+        PUSHF                                 ; save flag
+        AND     CS:[FastSeekflg],FS_end       ; reset fastseek mode
+        POPF                                  ; retore flag
+critexit:
+        LeaveCrit   critDisk
+        return
+
+;
+; We are reading from a device.  Examine the status of the device to see if we
+; can short-circuit the I/O.  If the device in the EOF state or if it is the
+; null device, we can safely indicate no transfer.
+;
+READDEV:
+        DOSAssume   CS,<DS>,"DISK/ReadDev"
+        ASSUME  ES:NOTHING
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        MOV     BL,BYTE PTR ES:[DI.sf_flags]
+        LES     DI,[DMAADD]
+        TEST    BL,devid_device_EOF     ; End of file?
+        JZ      ENDRDDEVJ3
+        TEST    BL,devid_device_null    ; NUL device?
+        JZ      TESTRAW                 ; NO
+        XOR     AL,AL                   ; Indicate EOF by setting zero
+ENDRDDEVJ3:
+        JMP     ENDRDDEVJ2
+
+;
+; We need to hit the device.  Figure out if we do a raw read or we do the
+; bizarre std_con_string_input.
+;
+TESTRAW:
+        TEST    BL,devid_device_raw     ; Raw mode?
+        JNZ     DVRDRAW                 ; Yes, let the device do all local editing
+        TEST    BL,devid_device_con_in  ; Is it console device?
+        JZ      NOTRDCON
+        JMP     READCON
+
+DVRDRAW:
+        DOSAssume   CS,<DS>,"DISK/DvRdRaw"
+        PUSH    ES
+        POP     DS                      ; Xaddr to DS:DI
+ASSUME  DS:NOTHING
+ReadRawRetry:
+        MOV     BX,DI                   ; DS:BX transfer addr
+        XOR     AX,AX                   ; Media Byte, unit = 0
+        MOV     DX,AX                   ; Start at 0
+        invoke  SETREAD
+        PUSH    DS                      ; Save Seg part of Xaddr
+        LDS     SI,[THISSFT]
+        Assert  ISSFT,<DS,SI>,"DOS_Read/DvRdRawR"
+        invoke  DEVIOCALL
+        MOV     DX,DI                   ; DS:DX is preserved by INT 24
+        MOV     AH,86H                  ; Read error
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JZ      CRDROK                  ; No errors
+        invoke  CHARHARD
+        MOV     DI,DX                   ; DS:DI is Xaddr
+        OR      AL,AL
+        JZ      CRDROK                  ; Ignore
+        CMP     AL,3
+        JZ      CRDFERR                 ; fail.
+        POP     DS                      ; Recover saved seg part of Xaddr
+        JMP     ReadRawRetry            ; Retry
+
+;
+; We have encountered a device-driver error.  We have informed the user of it
+; and he has said for us to fail the system call.
+;
+CRDFERR:
+        POP     DI                      ; Clean stack
+DEVIOFERR:
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DOS_Read/DEVIOFERR"
+        transfer    SET_ACC_ERR_DS
+
+CRDROK:
+        POP     DI                      ; Chuck saved seg of Xaddr
+        MOV     DI,DX
+        ADD     DI,[CALLSCNT]           ; Amount transferred
+        JMP     SHORT ENDRDDEVJ3
+
+; We are going to do a cooked read on some character device.  There is a
+; problem here, what does the data look like?  Is it a terminal device, line
+; CR line CR line CR, or is it file data, line CR LF line CR LF?  Does it have
+; a ^Z at the end which is data, or is the ^Z not data?  In any event we're
+; going to do this:  Read in pieces up to CR (CRs included in data) or ^z (^z
+; included in data).  this "simulates" the way con works in cooked mode
+; reading one line at a time.  With file data, however, the lines will look
+; like, LF line CR.  This is a little weird.
+
+NOTRDCON:
+        MOV     AX,ES
+        MOV     DS,AX
+ASSUME  DS:NOTHING
+        MOV     BX,DI
+        XOR     DX,DX
+        MOV     AX,DX
+        PUSH    CX
+        MOV     CX,1
+        invoke  SETREAD
+        POP     CX
+        LDS     SI,[THISSFT]
+        Assert  ISSFT,<DS,SI>,"DOS_Read/NotRdCon"
+        LDS     SI,[SI.sf_devptr]
+DVRDLP:
+        invoke  DSKSTATCHK
+        invoke  DEVIOCALL2
+        PUSH    DI              ; Save "count" done
+        MOV     AH,86H
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JZ      CRDOK
+        invoke  CHARHARD
+        POP     DI
+        MOV     [CALLSCNT],1
+        CMP     AL,1
+        JZ      DVRDLP                  ;Retry
+        CMP     AL,3
+        JZ      DEVIOFERR               ; FAIL
+        XOR     AL,AL                   ; Ignore, Pick some random character
+        JMP     SHORT DVRDIGN
+
+CRDOK:
+        POP     DI
+        CMP     [CALLSCNT],1
+        JNZ     ENDRDDEVJ2
+        PUSH    DS
+        MOV     DS,WORD PTR [CALLXAD+2]
+        MOV     AL,BYTE PTR [DI]        ; Get the character we just read
+        POP     DS
+DVRDIGN:
+        INC     WORD PTR [CALLXAD]      ; Next character
+        MOV     [DEVCALL.REQSTAT],0
+        INC     DI                      ; Next character
+        CMP     AL,1AH                  ; ^Z?
+        JZ      ENDRDDEVJ2              ; Yes, done zero set (EOF)
+        CMP     AL,c_CR                 ; CR?
+        LOOPNZ  DVRDLP                  ; Loop if no, else done
+        INC     AX                      ; Resets zero flag so NOT EOF, unless
+                                        ;  AX=FFFF which is not likely
+ENDRDDEVJ2:
+        JMP     SHORT ENDRDDEV
+
+ASSUME  DS:NOTHING,ES:NOTHING
+
+TRANBUF:
+        LODSB
+        STOSB
+        CMP     AL,c_CR         ; Check for carriage return
+        JNZ     NORMCH
+        MOV     BYTE PTR [SI],c_LF
+NORMCH:
+        CMP     AL,c_LF
+        LOOPNZ  TRANBUF
+        JNZ     ENDRDCON
+        XOR     SI,SI           ; Cause a new buffer to be read
+        invoke  OUTT            ; Transmit linefeed
+        OR      AL,1            ; Clear zero flag--not end of file
+ENDRDCON:
+        Context DS
+        CALL    SWAPBACK
+        MOV     [CONTPOS],SI
+ENDRDDEV:
+        Context DS
+        MOV     [NEXTADD],DI
+        JNZ     SETSFTC         ; Zero set if Ctrl-Z found in input
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DOS_Read/EndRdDev"
+        AND     BYTE PTR ES:[DI.sf_flags],NOT devid_device_EOF ; Mark as no more data available
+SETSFTC:
+        invoke  SETSFT
+        return
+
+ASSUME  DS:NOTHING,ES:NOTHING
+
+READCON:
+        DOSAssume   CS,<DS>,"ReadCon"
+        CALL    SWAPCON
+        MOV     SI,[CONTPOS]
+        OR      SI,SI
+        JNZ     TRANBUF
+        CMP     BYTE PTR [CONBUF],128
+        JZ      GETBUF
+        MOV     WORD PTR [CONBUF],0FF80H        ; Set up 128-byte buffer with no template
+GETBUF:
+        PUSH    CX
+        PUSH    ES
+        PUSH    DI
+        MOV     DX,OFFSET DOSGROUP:CONBUF
+        invoke  $STD_CON_STRING_INPUT           ; Get input buffer
+        POP     DI
+        POP     ES
+        POP     CX
+        MOV     SI,2 + OFFSET DOSGROUP:CONBUF
+        CMP     BYTE PTR [SI],1AH       ; Check for Ctrl-Z in first character
+        JNZ     TRANBUF
+        MOV     AL,1AH
+        STOSB
+        DEC     DI
+        MOV     AL,c_LF
+        invoke  OUTT            ; Send linefeed
+        XOR     SI,SI
+        JMP     ENDRDCON
+
+EndProc DOS_READ
+
+Break   <DOS_WRITE -- MAIN WRITE ROUTINE AND DEVICE OUT ROUTINES>
+
+;
+; Inputs:
+;       [THISSFT] set to the SFT for the file being used
+;       [DMAADD] contains transfer address
+;       CX = No. of bytes to write
+; Function:
+;       Perform write operation
+;       NOTE: If CX = 0 on input, file is truncated or grown
+;               to current sf_position
+; Outputs:
+;    Carry clear
+;       SFT Position and cluster pointers updated
+;       CX = No. of bytes written
+;       ES:DI point to SFT
+;    Carry set
+;       AX is error code
+;       CX = 0
+;       ES:DI point to SFT
+; DS preserved, all other registers destroyed
+
+        procedure   DOS_WRITE,NEAR
+        DOSAssume   CS,<DS>,"DOS_Write"
+        ASSUME  ES:NOTHING
+
+IF      BUFFERFLAG
+        cmp     [BUF_EMS_MODE], -1
+        jz      dos_wrt_call
+        call    choose_buf_page
+        jnc     sav_map_wrt_hndl
+        return
+sav_map_wrt_hndl:
+;       call    save_user_map
+dos_wrt_call:
+ENDIF
+
+
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DosWrite"
+        MOV     AL,BYTE PTR ES:[DI.sf_mode]
+        AND     AL,access_mask
+        CMP     AL,open_for_read
+        JNE     Check_FCB_RO             ;Is write or both
+BadMode:
+        transfer    SET_ACC_ERR
+
+;
+; NOTE: The following check for writting to a Read Only File is performed
+;           ONLY on FCBs!!!!
+;       We ALLOW writes to Read Only files via handles to allow a CREATE
+;           of a read only file which can then be written to.
+;       This is OK because we are NOT ALLOWED to OPEN a RO file via handles
+;           for writting, or RE-CREATE an EXISTING RO file via handles. Thus,
+;           CREATing a NEW RO file, or RE-CREATing an existing file which
+;           is NOT RO to be RO, via handles are the only times we can write
+;           to a read-only file.
+;
+Check_FCB_RO:
+        TEST    ES:[DI.sf_mode],sf_isfcb
+        JZ      WRITE_NO_MODE           ; Not an FCB
+        TEST    ES:[DI].sf_attr,attr_read_only
+        JNZ     BadMode                 ; Can't write to Read_Only files via FCB
+WRITE_NO_MODE:
+        invoke  SETUP
+        invoke  IsSFTNet
+        JZ      LOCAL_WRITE
+
+;       invoke  OWN_SHARE               ;AN000;;IFS. IFS owns share ?
+;       JZ      IFS_HAS_SHARE2          ;AN000;;IFS. yes
+;       EnterCrit   critDisk            ;AN000;;IFS. enter critical section
+;       CALL    CHECK_WRITE_LOCK        ;AN000;;IFS. check write lock
+;       JC      nocommit                ;AN000;;IFS. lock error
+;
+;       LeaveCrit   critDisk            ;AN000;;IFS. leave critical section
+IFS_HAS_SHARE2:                         ;AN000;
+
+
+IF NOT Installed
+        transfer NET_WRITE
+ELSE
+        MOV     AX,(multNET SHL 8) OR 9
+        INT     2FH
+;       JC      nomore                 ;AN000;;IFS. error
+;       invoke  OWN_SHARE              ;AN000;;IFS. IFS owns share ?
+;       JZ      nomore                 ;AN000;;IFS. yes
+;
+;       MOV     AX,1                   ;AN000;;IFS. update all SFT for new size
+;       call    JShare + 14 * 4        ;AN000;;IFS. call ShSu
+
+nomore:                                ;AN000;
+        return
+ENDIF
+
+
+LOCAL_WRITE:
+        TEST    ES:[DI.sf_flags],devid_device  ; Check for named device I/O
+        JNZ     WRTDEV
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        EnterCrit   critDisk
+        TEST    [FastSeekflg],Fast_yes         ;AN000;FO. FastSeek installed ?
+        JZ      FS_no2                         ;AN000;FO. no
+        OR      [FastSeekflg],FS_begin         ;AN000;FO. set fastseek mode
+FS_no2:                                        ;AN000;
+        invoke  DISKWRITE
+        PUSHF                                  ;AN000;FO. save flag
+        AND     CS:[FastSeekflg],FS_end        ;AN000;FO. reset fastseek mode
+        POPF                                   ;AN000;FO. restore flag
+;; Extended Open
+        JC      nocommit                       ;AN000;EO.
+        LES     DI,[THISSFT]                   ;AN000;EO.
+        TEST    ES:[DI.sf_mode],auto_commit_write ;AN000;EO.
+        JZ      nocommit                       ;AN000;EO.
+        PUSH    CX                             ;AN000;EO.
+        invoke  DOS_COMMIT                     ;AN000;EO.
+        POP     CX                             ;AN000;EO.
+nocommit:                                      ;AN000;
+;; Extended Open
+        LeaveCrit   critDisk
+        return
+
+DVWRTRAW:
+ASSUME  DS:NOTHING
+        XOR     AX,AX                   ; Media Byte, unit = 0
+        invoke  SETWRITE
+        PUSH    DS                      ; Save seg of transfer
+        LDS     SI,[THISSFT]
+        Assert  ISSFT,<DS,SI>,"DosWrite/DvWrtRaw"
+        invoke  DEVIOCALL               ; DS:SI -> DEVICE
+        MOV     DX,DI                   ; Offset part of Xaddr saved in DX
+        MOV     AH,87H
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JZ      CWRTROK
+        invoke  CHARHARD
+        MOV     BX,DX                   ; Recall transfer addr
+        OR      AL,AL
+        JZ      CWRTROK                 ; Ignore
+        CMP     AL,3
+        JZ      CWRFERR
+        POP     DS                      ; Recover saved seg of transfer
+        JMP     DVWRTRAW                ; Try again
+
+CWRFERR:
+        POP     AX                      ; Chuck saved seg of transfer
+        JMP     CRDFERR                 ; Will pop one more stack element
+
+CWRTROK:
+        POP     AX                      ; Chuck saved seg of transfer
+        POP     DS
+        DOSAssume   CS,<DS>,"DISK/CWrtOK"
+        MOV     AX,[CALLSCNT]           ; Get actual number of bytes transferred
+ENDWRDEV:
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DosWrite/EndWrDev"
+        MOV     CX,AX
+        invoke  ADDREC
+        return
+
+WRTNUL:
+        MOV     DX,CX                   ;Entire transfer done
+WrtCookJ:
+        JMP     WRTCOOKDONE
+
+WRTDEV:
+        DOSAssume   CS,<DS>,"DISK/WrtDev"
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        OR      BYTE PTR ES:[DI.sf_flags],devid_device_EOF  ; Reset EOF for input
+        MOV     BL,BYTE PTR ES:[DI.sf_flags]
+        XOR     AX,AX
+        JCXZ    ENDWRDEV                ; problem of creating on a device.
+        PUSH    DS
+        MOV     AL,BL
+        LDS     BX,[DMAADD]             ; Xaddr to DS:BX
+ASSUME  DS:NOTHING
+        MOV     DI,BX                   ; Xaddr to DS:DI
+        XOR     DX,DX                   ; Set starting point
+        TEST    AL,devid_device_raw     ; Raw?
+        JZ      TEST_DEV_CON
+        JMP     DVWRTRAW
+
+TEST_DEV_CON:
+        TEST    AL,devid_device_con_out ; Console output device?
+        JNZ     WRITECON
+        TEST    AL,devid_device_null
+        JNZ     WRTNUL
+        MOV     AX,DX
+        CMP     BYTE PTR [BX],1AH       ; ^Z?
+        JZ      WRTCOOKJ                ; Yes, transfer nothing
+        PUSH    CX
+        MOV     CX,1
+        invoke  SETWRITE
+        POP     CX
+        LDS     SI,[THISSFT]
+        OR      CS:[DOS34_FLAG],X25_Special;AN000;;PTM. bad x25 driver
+        MOV     AH,3                    ;AN000;;PTM. prompt critical error ASAP
+        invoke  IOFUNC                  ;AN000;;PTM.
+        Assert  ISSFT,<DS,SI>,"DosWrite/TestDevCon"
+        LDS     SI,[SI.sf_devptr]
+DVWRTLP:
+        invoke  DSKSTATCHK
+        invoke  DEVIOCALL2
+        PUSH    DI
+        MOV     AH,87H
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JZ      CWROK
+        invoke  CHARHARD
+        POP     DI
+        MOV     [CALLSCNT],1
+        CMP     AL,1
+        JZ      DVWRTLP         ; Retry
+        OR      AL,AL
+        JZ      DVWRTIGN        ; Ignore
+        JMP     CRDFERR         ; Fail, pops one stack element
+
+CWROK:
+        POP     DI
+        CMP     [CALLSCNT],0
+        JZ      WRTCOOKDONE
+DVWRTIGN:
+        INC     DX
+        INC     WORD PTR [CALLXAD]
+        INC     DI
+        PUSH    DS
+        MOV     DS,WORD PTR [CALLXAD+2]
+        CMP     BYTE PTR [DI],1AH       ; ^Z?
+        POP     DS
+        JZ      WRTCOOKDONE
+        MOV     [DEVCALL.REQSTAT],0
+        LOOP    DVWRTLP
+WRTCOOKDONE:
+        MOV     AX,DX
+        POP     DS
+        JMP     ENDWRDEV
+
+WRITECON:
+        PUSH    DS
+        Context DS
+        CALL    SWAPCON
+        POP     DS
+ASSUME  DS:NOTHING
+        MOV     SI,BX
+        PUSH    CX
+WRCONLP:
+        LODSB
+        CMP     AL,1AH          ; ^Z?
+        JZ      CONEOF
+        invoke  OUTT
+        LOOP    WRCONLP
+CONEOF:
+        POP     AX                      ; Count
+        SUB     AX,CX                   ; Amount actually written
+        POP     DS
+        DOSAssume   CS,<DS>,"DISK/ConEOF"
+        CALL    SWAPBACK
+        JMP     ENDWRDEV
+EndProc DOS_WRITE
+
+;   Convert JFN number in BX to sf_entry in DS:SI We get the normal SFT if
+;   CONSWAP is FALSE or if the handle desired is 2 or more.  Otherwise, we
+;   retrieve the sft from ConSFT which is set by SwapCon.
+
+        procedure   get_io_sft,near
+ASSUME  DS:NOTHING,ES:NOTHING
+        TEST    ConSwap,-1
+        JNZ     GetRedir
+GetNormal:
+        Context DS
+        PUSH    ES
+        PUSH    DI
+        invoke  SFFromHandle
+        JC      RET44P
+        MOV     SI,ES
+        MOV     DS,SI
+ASSUME  DS:NOTHING
+        MOV     SI,DI
+RET44P:
+        POP     DI
+        POP     ES
+        return
+GetRedir:
+        CMP     BX,1
+        JA      GetNormal
+        LDS     SI,ConSFT
+        Assert  ISSFT,<DS,SI>,"GetIOSft"
+        CLC
+        return
+EndProc get_io_sft
+
+Break   <DIRREAD -- READ A DIRECTORY SECTOR>
+
+; Inputs:
+;       AX = Directory block number (relative to first block of directory)
+;       ES:BP = Base of drive parameters
+;       [DIRSEC] = First sector of first cluster of directory
+;       [CLUSNUM] = Next cluster
+;       [CLUSFAC] = Sectors/Cluster
+; Function:
+;       Read the directory block into [CURBUF].
+; Outputs:
+;       [NXTCLUSNUM] = Next cluster (after the one skipped to)
+;       [SECCLUSPOS] Set
+;       ES:BP unchanged
+;       [CURBUF] Points to Buffer with dir sector
+;       Carry set if error (user said FAIL to I 24)
+; DS preserved, all other registers destroyed.
+
+        procedure   DirRead,NEAR
+        DOSAssume   CS,<DS>,"DirRead"
+        ASSUME  ES:NOTHING
+        Assert      ISDPB,<ES,BP>,"DirRead"
+
+;
+; Note that ClusFac is is the sectors per cluster.  This is NOT necessarily
+; the same as what is in the DPB!  In the case of the root directory, we have
+; ClusFac = # sectors in the root directory.  The root directory is detected
+; by DIRStart = 0.
+;
+        XOR     DX,DX
+        CMP     DirStart,0
+        jnz     SubDir
+        XCHG    AX,DX
+        JMP     DoRead
+;
+; Convert the sector number in AX into cluster and sector-within-cluster pair
+;
+SubDir:
+        MOV     DL,AL
+        AND     DL,ES:[BP.dpb_cluster_mask]
+;
+; DX is the sector-in-cluster
+;
+        MOV     CL,ES:[BP.dpb_cluster_shift]
+        SHR     AX,CL
+;
+; DX is position in cluster
+; AX is number of clusters to skip
+;
+DoRead:
+        MOV     [SECCLUSPOS],DL
+        MOV     CX,AX
+        MOV     AH,DL
+;
+; CX is number of clusters to skip.
+; AH is remainder
+;
+        MOV     DX,WORD PTR [DIRSEC+2]       ;AN000;>32mb
+        MOV     [HIGH_SECTOR],DX             ;AN000;>32mb
+        MOV     DX,WORD PTR [DIRSEC]
+        ADD     DL,AH
+        ADC     DH,0
+        ADC     [HIGH_SECTOR],0              ;AN000;>32mb
+
+        MOV     BX,[CLUSNUM]
+        MOV     [NXTCLUSNUM],BX
+        JCXZ    FIRSTCLUSTER
+SKPCLLP:
+        invoke  UNPACK
+        retc
+        XCHG    BX,DI
+        invoke  IsEOF                   ; test for eof based on fat size
+        JAE     HAVESKIPPED
+        LOOP    SKPCLLP
+HAVESKIPPED:
+        MOV     [NXTCLUSNUM],BX
+        MOV     DX,DI
+        MOV     BL,AH
+        invoke  FIGREC
+
+        entry   FIRSTCLUSTER
+
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL
+        XOR     AL,AL           ; Indicate pre-read
+        invoke  GETBUFFR
+        retc
+
+        entry   SET_BUF_AS_DIR
+        DOSAssume   CS,<DS>,"SET_BUF_AS_DIR"
+        ASSUME  ES:NOTHING
+; Set the type of CURBUF to be a directory sector.
+; Only flags are modified.
+
+        PUSH    DS
+        PUSH    SI
+        LDS     SI,[CURBUF]
+        Assert  ISBUF,<DS,SI>,"SetBufAsDir"
+        OR      [SI.buf_flags],buf_isDIR        ; Clears carry
+        POP     SI
+        POP     DS
+        return
+EndProc DirRead
+
+Break   <FATSECRD -- READ A FAT SECTOR>
+
+; Inputs:
+;       Same as DREAD
+;       DS:BX = Transfer address
+;       CX = Number of sectors
+;       DX = Absolute record number
+;       ES:BP = Base of drive parameters
+; Function:
+;       Calls BIOS to perform FAT read.
+; Outputs:
+;       Same as DREAD
+
+        procedure   FATSecRd,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"FATSecRd"
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL
+        MOV     DI,CX
+        MOV     CL,ES:[BP.dpb_FAT_count]
+        MOV     AX,ES:[BP.dpb_FAT_size]         ;AN000;>32mb
+;       XOR     AH,AH
+        XOR     CH,CH                           ;AN000;>32mb
+        PUSH    DX
+NXTFAT:
+        MOV     [HIGH_SECTOR],0       ;AN000;>32mb FAT sectors cannot exceed
+        PUSH    CX                    ;AN000;>32mb
+        PUSH    AX
+        MOV     CX,DI
+        invoke  DSKREAD
+        POP     AX
+        POP     CX
+        JZ      RET41P          ; Carry clear
+        ADD     DX,AX
+        LOOP    NXTFAT
+        POP     DX
+        MOV     CX,DI
+
+; NOTE FALL THROUGH
+
+Break   <DREAD -- DO A DISK READ>
+
+; Inputs:
+;       DS:BX = Transfer address
+;       CX = Number of sectors
+;       DX = Absolute record number           (LOW)
+;       [HIGH_SECTOR]= Absolute record number (HIGH)
+;       ES:BP = Base of drive parameters
+;       [ALLOWED] must be set in case call to HARDERR needed
+; Function:
+;       Calls BIOS to perform disk read. If BIOS reports
+;       errors, will call HARDERRRW for further action.
+; Outputs:
+;       Carry set if error (currently user FAILED to INT 24)
+; DS,ES:BP preserved. All other registers destroyed.
+
+        entry   DREAD
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"DREAD"
+        invoke  DSKREAD
+        retz                    ; Carry clear
+        MOV     BYTE PTR [READOP],0
+        invoke  HARDERRRW
+        CMP     AL,1            ; Check for retry
+        JZ      DREAD
+        CMP     AL,3            ; Check for FAIL
+        CLC
+        JNZ     NO_CAR          ; Ignore
+        STC
+NO_CAR:
+        return
+
+RET41P: POP     DX
+        return
+EndProc FATSecRd
+
+
+Break   <CHECK_WRITE_LOCK>
+
+; Inputs:
+;       output of SETUP
+;       ES:DI -> SFT
+; Function:
+;       check write lock
+; Outputs:
+;       Carry set if error
+;       Carry clear if ok
+
+        procedure   CHECK_WRITE_LOCK,NEAR      ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                  ;AN000;
+
+        TEST    ES:[DI].sf_attr,attr_volume_id ;AN000;;MS.  volume id
+        JZ      write_cont                     ;AN000;;MS.  no
+        invoke  SET_ACC_ERR_DS                 ;AN000;;MS.
+        return                          ;AN000;;MS.
+write_cont:                             ;AN000;
+        PUSH    CX                      ;AN000;;MS. save reg
+        OR      CX,CX                   ;AN000;;MS.
+        JNZ     Not_Truncate            ;AN000;;MS.
+        MOV     CX,0FFFFH               ;AN000;;MS. check for lock on whole file
+Not_Truncate:                           ;AN000;
+        MOV     AL,80H                  ;AN000;;MS. check write access
+        invoke  LOCK_CHECK              ;AN000;;MS. check lock
+        POP     CX                      ;AN000;;MS. restore reg
+        JNC     WRITE_OK                ;AN000;;MS. lock ok
+        invoke  WRITE_LOCK_VIOLATION    ;AN000;;MS. issue I24
+        JNC     CHECK_WRITE_LOCK        ;AN000;;MS. retry
+WRITE_OK:                               ;AN000;
+        return                          ;AN000;;MS.
+EndProc CHECK_WRITE_LOCK                ;AN000;
+
+
+Break   <CHECK_READ_LOCK>
+
+; Inputs:
+;       ES:DI -> SFT
+;       output of SETUP
+; Function:
+;       check read lock
+; Outputs:
+;       Carry set if error
+;       Carry clear if ok
+
+        procedure   CHECK_READ_LOCK,NEAR       ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING                  ;AN000;
+
+        TEST    ES:[DI].sf_attr,attr_volume_id ;AN000;;MS.  volume id
+        JZ      do_retry                       ;AN000;;MS.  no
+        invoke  SET_ACC_ERR                    ;AN000;;MS.
+        return                                 ;AN000;;MS.
+do_retry:                               ;AN000;
+        MOV     AL,0                    ;AN000;;MS. check read access
+        invoke  LOCK_CHECK              ;AN000;;MS. check lock
+        JNC     READ_OK                 ;AN000;;MS. lock ok
+        invoke  READ_LOCK_VIOLATION     ;AN000;;MS. issue I24
+        JNC     CHECK_READ_LOCK         ;AN000;;MS. retry
+READ_OK:                                ;AN000; MS.
+        return                          ;AN000;;MS.
+EndProc CHECK_READ_LOCK                 ;AN000;
+
+IF BUFFERFLAG
+
+;-------------------------------------------------------------------------
+;       Function name   :       choose_buf_page
+;       Inputs          :       DMAADD = Xaddr
+;                               cx = # of bytes to transfer
+;       Outputs         :       if NC
+;
+;                               SAFE_FLAG - 0 ==> page is safe. no need to
+;                                                 detect collision between
+;                                                 user & system buffer.
+;                               SAFE_FLAG - 1 ==> page is unsafe. Must check
+;                                                 for collision
+;
+;                               CY - error
+;
+;
+;       High Level Alogrithm:
+;
+;       1. If Xaddr. is above the first physical page above 640K
+;          2. choose that page
+;          3. set safe flag
+;       4. else
+;          5. choose highest page above 640K
+;          6. If 6 or more pages above 640k
+;             7. Set safe flag                          
+;          8. else
+;             9. if Xaddr. + # of bytes to transfer does not spill into the
+;                chosen page
+;                10. set safe flag
+;             11.else
+;                12. clear safe flag
+;             13.endif
+;          14.endif
+;       15.endif
+;
+;----------------------------------------------------------------------------
+Procedure       choose_buf_page,near
+
+        assume cs:dosgroup, ds:nothing, es:nothing, ss:dosgroup
+
+        push    cx
+        push    bx
+        push    dx
+        push    si
+        push    ds
+        push    ax
+
+        mov     ax, word ptr [DMAADD+2]
+        and     ax, 0fc00h      ; page segment of transfer segment
+
+        cmp     ax, word ptr [BUF_EMS_FIRST_PAGE]
+        ja      pick_first
+        
+        cmp     [BUF_EMS_NPA640], 6
+        jae     safe_pick_last
+
+        add     cx, word ptr [DMAADD]   ; get final offset 
+        mov     bx, cx
+
+        mov     cl, 4
+        shr     bx, cl          ; get # of paragraphs
+        mov     ax, word ptr [DMAADD+2] ; get initial segment
+        add     ax, bx          ; get final segment
+
+        and     ax, 0fc00h
+        cmp     ax, word ptr [BUF_EMS_LAST_PAGE]
+        jne     safe_pick_last
+
+        mov     [BUF_EMS_SAFE_FLAG], 0
+        jmp     fin_choose_page
+
+safe_pick_last:
+        mov     [BUF_EMS_SAFE_FLAG], 1
+        jmp     fin_choose_page
+
+;pick_last:
+;       mov     ax, word ptr [BUF_EMS_LAST_PAGE]
+;       mov     [BUF_EMS_PFRAME], ax
+;       mov     ax, word ptr [BUF_EMS_LAST_PAGE+2]
+;       mov     [BUF_EMS_PAGE_FRAME], ax
+;       xor     ax, ax
+;       jmp     fin_choose_page
+
+pick_first:
+        mov     ax, word ptr [BUF_EMS_FIRST_PAGE]
+        cmp     [BUF_EMS_PFRAME], ax
+        je      fin_choose_page
+        call    restore_user_map
+        mov     word ptr [LASTBUFFER], -1
+        mov     [BUF_EMS_PFRAME], ax
+        mov     ax, word ptr [BUF_EMS_FIRST_PAGE+2]
+        mov     [BUF_EMS_PAGE_FRAME], ax
+        mov     [BUF_EMS_SAFE_FLAG], 1
+        call    Setup_EMS_Buffers
+        call    save_user_map
+        jmp     fin_choose_page
+
+err_choose_page:
+        stc
+
+fin_choose_page:
+        clc
+
+        pop     ax
+        pop     ds
+        pop     si
+        pop     dx
+        pop     bx
+        pop     cx
+        return
+
+EndProc choose_buf_page 
+
+ENDIF
+
+CODE    ENDS
+    END
+
+
diff --git a/v4.0/src/DOS/DISK2.ASM b/v4.0/src/DOS/DISK2.ASM
new file mode 100644
index 0000000..bb76e89
--- /dev/null
+++ b/v4.0/src/DOS/DISK2.ASM
@@ -0,0 +1,784 @@
+;       SCCSID = @(#)disk2.asm  1.3 85/06/19
+;       SCCSID = @(#)disk2.asm  1.3 85/06/19
+TITLE   DISK2 - Disk utility routines
+NAME    Disk2
+; Low level Read and write routines for local SFT I/O on files and devs
+;
+;   DskRead
+;   DWRITE
+;   DSKWRITE
+;   HarderrRW
+;   SETUP
+;   BREAKDOWN
+;   READ_LOCK_VIOLATION
+;   WRITE_LOCK_VIOLATION
+;   DISKREAD
+;   SET_ACC_ERR_DS
+;   SET_ACC_ERR
+;   SETSFT
+;   SETCLUS
+;   AddRec
+;
+;   Revision history:
+;
+;    AN000  version 4.00 Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  THISSFT,DWORD
+        i_need  DMAADD,DWORD
+        i_need  NEXTADD,WORD
+        i_need  ThisDrv,BYTE
+        i_need  SecClusPos,BYTE
+        i_need  ClusNum,WORD
+        i_need  ReadOp,BYTE
+        i_need  Trans,BYTE
+        i_need  BytPos,4
+        i_need  SecPos,DWORD             ; DOS 4.00 >32mb                       ;AN000;
+        i_need  BytSecPos,WORD
+        i_need  BytCnt1,WORD
+        i_need  BytCnt2,WORD
+        i_need  SecCnt,WORD
+        i_need  ThisDPB,DWORD
+        i_need  LastPos,WORD
+        i_need  EXTERRPT,DWORD
+        i_need  CALLVIDRW,DWORD
+        i_need  ALLOWED,BYTE
+        i_need  DEVCALL,BYTE
+        i_need  CALLSCNT,WORD
+        i_need  DISK_FULL,BYTE            ; disk full flag for ran blk wrt
+        i_need  FSeek_drive,BYTE          ; DOS 4.00      ;AN000;
+        i_need  FSeek_firclus,WORD        ; DOS 4.00      ;AN000;
+        i_need  HIGH_SECTOR,WORD          ; F.C. >32mb    ;AN000;
+        i_need  TEMP_VAR2,WORD            ; LB.           ;AN000;
+        i_need  TEMP_VAR,WORD             ; LB.           ;AN000;
+        i_need  IFS_DRIVER_ERR,WORD       ; LB.           ;AN000;
+        i_need  CurHashEntry,DWORD           ; DOS 4.00 current Hash entry      ;AN000;
+        i_need  BUF_HASH_PTR,DWORD           ; DOS 4.00 Hash table pointer      ;AN000;
+        i_need  BUF_HASH_COUNT,WORD          ; DOS 4.00 Hash table entries      ;AN000;
+        i_need  LastBuffer,DWORD
+        i_need  FIRST_BUFF_ADDR,WORD         ; first buffer address             ;AN000;
+
+IF      BUFFERFLAG
+        EXTRN   SAVE_MAP:NEAR
+        EXTRN   RESTORE_MAP:NEAR
+        EXTRN   SAVE_USER_MAP:NEAR
+        EXTRN   RESTORE_USER_MAP:NEAR
+        i_need  BUF_EMS_SAFE_FLAG,BYTE
+        i_need  BUF_EMS_MODE,BYTE
+        i_need  CURADD,WORD
+ENDIF
+
+
+Break   <DSKREAD -- PHYSICAL DISK READ>
+
+; Inputs:
+;       DS:BX = Transfer addr
+;       CX = Number of sectors
+;       [HIGH_SECTOR] = Absolute record number (HIGH)
+;       DX = Absolute record number            (LOW)
+;       ES:BP = Base of drive parameters
+; Function:
+;       Call BIOS to perform disk read
+; Outputs:
+;       DI = CX on entry
+;       CX = Number of sectors unsuccessfully transfered
+;       AX = Status word as returned by BIOS (error code in AL if error)
+;       Zero set if OK (from BIOS) (carry clear)
+;       Zero clear if error (carry clear)
+; SI Destroyed, others preserved
+
+        procedure   DskRead,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"DskRead"
+        PUSH    CX
+        MOV     AH,ES:[BP.dpb_media]
+        MOV     AL,ES:[BP.dpb_UNIT]
+        PUSH    BX
+        PUSH    ES
+        invoke  SETREAD
+        JMP     DODSKOP
+
+Break   <DWRITE -- SEE ABOUT WRITING>
+
+; Inputs:
+;       DS:BX = Transfer address
+;       CX = Number of sectors
+;       [HIGH_SECTOR] = Absolute record number (HIGH)
+;       DX = Absolute record number            (LOW)
+;       ES:BP = Base of drive parameters
+;       [ALLOWED] must be set in case HARDERR called
+; Function:
+;       Calls BIOS to perform disk write. If BIOS reports
+;       errors, will call HARDERRRW for further action.
+; Output:
+;       Carry set if error (currently, user FAILed to I 24)
+; BP preserved. All other registers destroyed.
+
+        entry   DWRITE
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"DWrite"
+        CALL    DSKWRITE
+        retz                    ; Carry clear
+        MOV     BYTE PTR [READOP],1
+        invoke  HARDERRRW
+        CMP     AL,1            ; Check for retry
+        JZ      DWRITE
+        CMP     AL,3            ; Check for FAIL
+        CLC
+        JNZ     NO_CAR2         ; Ignore
+        STC
+NO_CAR2:
+        return
+
+Break   <DSKWRITE -- PHYSICAL DISK WRITE>
+
+; Inputs:
+;       DS:BX = Transfer addr
+;       CX = Number of sectors
+;       DX = Absolute record number            (LOW)
+;       [HIGH_SECTOR] = Absolute record number (HIGH)
+;       ES:BP = Base of drive parameters
+; Function:
+;       Call BIOS to perform disk read
+; Outputs:
+;       DI = CX on entry
+;       CX = Number of sectors unsuccessfully transfered
+;       AX = Status word as returned by BIOS (error code in AL if error)
+;       Zero set if OK (from BIOS) (carry clear)
+;       Zero clear if error (carry clear)
+; SI Destroyed, others preserved
+
+        entry   DSKWRITE
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert  ISDPB,<ES,BP>,"DskWrite"
+        PUSH    CX
+        MOV     AH,ES:[BP.dpb_media]
+        MOV     AL,ES:[BP.dpb_UNIT]
+        PUSH    BX
+        PUSH    ES
+        invoke  SETWRITE
+DODSKOP:
+        MOV     CX,DS           ; Save DS
+        POP     DS              ; DS:BP points to DPB
+        PUSH    DS
+        LDS     SI,DS:[BP.dpb_driver_addr]
+        invoke  DEVIOCALL2
+        MOV     DS,CX           ; Restore DS
+        POP     ES              ; Restore ES
+        POP     BX
+        MOV     CX,[CALLSCNT]   ; Number of sectors transferred
+        POP     DI
+        SUB     CX,DI
+        NEG     CX              ; Number of sectors not transferred
+        MOV     AX,[DEVCALL.REQSTAT]
+        MOV     [IFS_DRIVER_ERR],AX ;IFS. save it for IFS                       ;AN000;
+        TEST    AX,STERR
+        return
+EndProc DskRead
+
+
+
+Break   <HardErrRW - map extended errors and call harderr>
+
+; Inputs:
+;       AX is error code from read or write
+;       Other registers set as per HARDERR
+; Function:
+;       Checks the error code for special extended
+;       errors and maps them if needed. Then invokes
+;       Harderr
+; Outputs:
+;       Of HARDERR
+; AX may be modified prior to call to HARDERR.
+; No other registers altered.
+
+        procedure   HARDERRRW,near
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        CMP     AL,error_I24_wrong_disk
+        JNZ     DO_ERR                          ; Nothing to do
+        PUSH    DS
+        PUSH    SI
+        LDS     SI,[CALLVIDRW]                  ; Get pointer from dev
+        MOV     WORD PTR [EXTERRPT+2],DS        ; Set ext err pointer
+        MOV     WORD PTR [EXTERRPT],SI
+        POP     SI
+        POP     DS
+DO_ERR:
+        invoke  HARDERR
+        return
+
+EndProc HARDERRRW
+
+Break   <SETUP -- SETUP A DISK READ OR WRITE FROM USER>
+
+; Inputs:
+;       ES:DI point to SFT (value also in THISSFT)
+;       [DMAADD] contains transfer address
+;       CX = Byte count
+;   WARNING Stack must be clean, two ret addrs on stack, 1st of caller,
+;               2nd of caller of caller.
+; Outputs:
+;           CX = byte count
+;           [THISDPB] = Base of drive parameters if file
+;                     = Pointer to device header if device or NET
+;           ES:DI Points to SFT
+;           [NEXTADD] = Displacement of disk transfer within segment
+;           [TRANS] = 0 (No transfers yet)
+;           [BYTPOS] = Byte position in file
+;
+;       The following fields are relevant to local files (not devices) only:
+;
+;           [SECPOS] = Position of first sector (local files only)
+;           [BYTSECPOS] = Byte position in first sector (local files only)
+;           [CLUSNUM] = First cluster (local files only)
+;           [SECCLUSPOS] = Sector within first cluster (local files only)
+;           [THISDRV] = Physical unit number (local files only)
+;
+;      RETURNS ONE LEVEL UP WITH:
+;          CX = 0
+;          CARRY = Clear
+;       IF AN ERROR IS DETECTED
+; All other registers destroyed
+
+        procedure   SETUP,NEAR
+        DOSAssume   CS,<DS>,"SetUp"
+        ASSUME  ES:NOTHING
+
+        Assert      ISSFT,<ES,DI>,"SetUp"
+        LDS     SI,ES:[DI.sf_devptr]
+ASSUME  DS:NOTHING
+        MOV     WORD PTR [THISDPB+2],DS
+        context DS
+        MOV     WORD PTR [THISDPB],SI
+        MOV     BX,WORD PTR [DMAADD]
+        MOV     [NEXTADD],BX            ;Set NEXTADD to start of Xaddr
+        MOV     BYTE PTR [TRANS],0      ;No transferes
+        MOV     AX,WORD PTR ES:[DI.sf_Position]
+        MOV     DX,WORD PTR ES:[DI.sf_Position+2]
+        MOV     WORD PTR [BYTPOS+2],DX  ;Set it
+        MOV     WORD PTR [BYTPOS],AX
+        TEST    ES:[DI.sf_flags],sf_isnet + devid_device
+        JNZ     NOSETSTUFF              ;Following not done on devs or NET
+        PUSH    ES
+        LES     BP,[THISDPB]            ;Point at the DPB
+        Assert  ISDPB,<ES,BP>,"Setup"
+        MOV     BL,ES:[BP.dpb_drive]
+        MOV     [THISDRV],BL            ;Set THISDRV
+        MOV     BX,ES:[BP.dpb_sector_size]
+;       CMP     DX,BX           ; See if divide will overflow
+;       JNC     EOFERR          ; for 16 bit sector
+;; 32 bit divide
+        invoke  DIV32                         ; F.C. >32mb   ;AN000;
+        MOV     WORD PTR [SECPOS],AX          ; F.C. >32mb   ;AN000;
+        MOV     BX,[HIGH_SECTOR]              ; F.C. >32mb   ;AN000;
+        MOV     WORD PTR [SECPOS+2],BX        ; F.C. >32mb   ;AN000;
+
+        MOV     [BYTSECPOS],DX
+        MOV     DX,AX
+        AND     AL,ES:[BP.dpb_cluster_mask]
+        MOV     [SECCLUSPOS],AL
+        MOV     AX,CX           ; Save byte count
+;       MOV     CL,ES:[BP.dpb_cluster_shift]
+        PUSH    WORD PTR [SECPOS+2]          ; F.C. >32mb          ;AN000;
+        POP     [HIGH_SECTOR]                ; F.C. >32mb          ;AN000;
+        PUSH    AX                           ; F.C. >32mb save ax  ;AN000;
+        MOV     AX,DX                        ; F.C. >32mb ax=dx    ;AN000;
+        invoke  SHR32                        ; F.C. >32mb shift ax ;AN000;
+        MOV     DX,AX                        ; F.C. >32mb dx=ax    ;AN000;
+        POP     AX                           ; F.C. >32mb restore dx ;AN000;
+
+;       SHR     DX,CL
+        CMP     DX,ES:[BP.dpb_max_cluster]   ;>32mb  if > disk size ;AN000;     ;AN000;
+        JA      EOFERR                       ;>32mb    then EOF     ;AN000;     ;AN000;
+
+        MOV     [CLUSNUM],DX
+        POP     ES              ; ES:DI point to SFT
+        MOV     CX,AX           ; Put byte count back in CX
+NOSETSTUFF:
+        MOV     AX,CX           ; Need it in AX too
+        ADD     AX,WORD PTR [DMAADD]     ; See if it will fit in one segment
+        JNC     OK              ; Must be less than 64K
+        MOV     AX,WORD PTR [DMAADD]
+        NEG     AX              ; Amount of room left in segment (know
+                                ;    less than 64K since max value of CX
+                                ;    is FFFF).
+        JNZ     NoDec
+        DEC     AX
+NoDec:
+        MOV     CX,AX           ; Can do this much
+        JCXZ    NOROOM          ; Silly user gave Xaddr of FFFF in segment
+OK:
+        return
+
+EOFERR:
+        POP     ES              ; ES:DI point to SFT
+        XOR     CX,CX           ; No bytes read
+;;;;;;;;;;; 7/18/86
+;       MOV     BYTE PTR [DISK_FULL],1      ; set disk full flag
+;;;;;;;;;;;
+NOROOM:
+        POP     BX              ; Kill return address
+        CLC
+        return                  ; RETURN TO CALLER OF CALLER
+EndProc SETUP
+
+Break   <BREAKDOWN -- CUT A USER READ OR WRITE INTO PIECES>
+
+; Inputs:
+;       CX = Length of disk transfer in bytes
+;       ES:BP = Base of drive parameters
+;       [BYTSECPOS] = Byte position witin first sector
+; Outputs:
+;       [BYTCNT1] = Bytes to transfer in first sector
+;       [SECCNT] = No. of whole sectors to transfer
+;       [BYTCNT2] = Bytes to transfer in last sector
+; AX, BX, DX destroyed. No other registers affected.
+
+        procedure   BREAKDOWN,near
+        DOSAssume   CS,<DS>,"BreakDown"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"BreakDown"
+        MOV     AX,[BYTSECPOS]
+        MOV     BX,CX
+        OR      AX,AX
+        JZ      SAVFIR          ; Partial first sector?
+        SUB     AX,ES:[BP.dpb_sector_size]
+        NEG     AX              ; Max number of bytes left in first sector
+        SUB     BX,AX           ; Subtract from total length
+        JAE     SAVFIR
+        ADD     AX,BX           ; Don't use all of the rest of the sector
+        XOR     BX,BX           ; And no bytes are left
+SAVFIR:
+        MOV     [BYTCNT1],AX
+        MOV     AX,BX
+        XOR     DX,DX
+        DIV     ES:[BP.dpb_sector_size]  ; How many whole sectors?
+        MOV     [SECCNT],AX
+        MOV     [BYTCNT2],DX    ; Bytes remaining for last sector
+        OR      DX,[BYTCNT1]
+        retnz                   ; NOT (BYTCNT1 = BYTCNT2 = 0)
+        CMP     AX,1
+        retnz
+        MOV     AX,ES:[BP.dpb_sector_size]       ; Buffer EXACT one sector I/O
+        MOV     [BYTCNT2],AX
+        MOV     [SECCNT],DX             ; DX = 0
+RET45:
+        return
+EndProc BreakDown
+
+; ES:DI points to SFT. This entry used by NET_READ
+; Carry set if to return error (CX=0,AX=error_sharing_violation).
+; Else do retrys.
+; ES:DI,DS,CX preserved
+
+        procedure READ_LOCK_VIOLATION,NEAR
+        DOSAssume   CS,<DS>,"Read_Lock_Violation"
+        ASSUME  ES:NOTHING
+
+        Assert      ISSFT,<ES,DI>,"ReadLockViolation"
+
+        MOV     [READOP],0
+ERR_ON_CHECK:
+        TEST    ES:[DI.sf_mode],sf_isfcb
+        JNZ     HARD_ERR
+        PUSH    CX
+        MOV     CL,BYTE PTR ES:[DI.sf_mode]
+        AND     CL,sharing_mask
+        CMP     CL,sharing_compat
+        POP     CX
+        JNE     NO_HARD_ERR
+HARD_ERR:
+        invoke  LOCK_VIOLATION
+        retnc                           ; User wants Retrys
+NO_HARD_ERR:
+        XOR     CX,CX                   ;No bytes transferred
+        MOV     AX,error_lock_violation
+        STC
+        return
+
+EndProc READ_LOCK_VIOLATION
+
+; Same as READ_LOCK_VIOLATION except for READOP.
+; This entry used by NET_WRITE
+        procedure WRITE_LOCK_VIOLATION,NEAR
+        DOSAssume   CS,<DS>,"Write_Lock_Violation"
+        ASSUME  ES:NOTHING
+        Assert      ISSFT,<ES,DI>,"WriteLockViolation"
+
+        MOV     [READOP],1
+        JMP     ERR_ON_CHECK
+
+EndProc WRITE_LOCK_VIOLATION
+
+
+Break   <DISKREAD -- PERFORM USER DISK READ>
+
+; Inputs:
+;       Outputs of SETUP
+; Function:
+;       Perform disk read
+; Outputs:
+;    Carry clear
+;       CX = No. of bytes read
+;       ES:DI point to SFT
+;       SFT offset and cluster pointers updated
+;    Carry set
+;       CX = 0
+;       ES:DI point to SFT
+;       AX has error code
+
+        procedure   DISKREAD,NEAR
+        DOSAssume   CS,<DS>,"DiskRead"
+        ASSUME  ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"DISKREAD"
+        PUSH    ES:[DI.sf_firclus]      ; set up 1st cluster # for FastSeek
+        POP     [FSeek_firclus]         ; 11/5/86
+
+        MOV     AX,WORD PTR ES:[DI.sf_size]
+        MOV     BX,WORD PTR ES:[DI.sf_size+2]
+        SUB     AX,WORD PTR [BYTPOS]
+        SBB     BX,WORD PTR [BYTPOS+2]
+        JB      RDERR                   ;Read starts past EOF
+        JNZ     ENUF                    ;More than 64k to EOF
+        OR      AX,AX
+        JZ      RDERR                   ;Read starts at EOF
+        CMP     AX,CX
+        JAE     ENUF                    ;I/O fits
+        MOV     CX,AX                   ;Limit read to up til EOF
+ENUF:
+        invoke  CHECK_READ_LOCK         ;IFS. check read lock                    ;AN000;
+        JNC     Read_Ok                 ; There are no locks
+        return
+
+READ_OK:
+        LES     BP,[THISDPB]
+        Assert  ISDPB,<ES,BP>,"DISKREAD/ReadOK"
+        MOV     AL,ES:[BP.dpb_drive]    ; set up drive # for FastSeek
+        MOV     [FSeek_drive],AL        ; 11/5/86  ;AN000;
+
+        CALL    BREAKDOWN
+        MOV     CX,[CLUSNUM]
+        invoke  FNDCLUS
+;------------------------------------------------------------------------
+IF      NOT IBMCOPYRIGHT
+        JC      SET_ACC_ERR_DS          ; fix to take care of I24 fail
+                                        ; migrated from 330a - HKN
+ENDIF
+;------------------------------------------------------------------------
+        OR      CX,CX
+        JZ      SKIPERR
+RDERR:
+        MOV     [DISK_FULL],1           ;MS. EOF detection  ;AN000;
+        MOV     AH,0EH                  ;MS. read/data/fail ;AN000;
+        transfer WRTERR22
+RDLASTJ:JMP     RDLAST
+SETSFTJ2: JMP   SETSFT
+
+CANOT_READ:
+        POP     CX              ; Clean stack
+        POP     CX
+        POP     BX
+
+        entry   SET_ACC_ERR_DS
+ASSUME  DS:NOTHING,ES:NOTHING
+        Context DS
+
+        entry   SET_ACC_ERR
+        DOSAssume   CS,<DS>,"SET_ACC_ERR"
+
+        XOR     CX,CX
+        MOV     AX,error_access_denied
+        STC
+        return
+
+SKIPERR:
+        MOV     [LASTPOS],DX
+        MOV     [CLUSNUM],BX
+        CMP     [BYTCNT1],0
+        JZ      RDMID
+        invoke  BUFRD
+        JC      SET_ACC_ERR_DS
+RDMID:
+        CMP     [SECCNT],0
+        JZ      RDLASTJ
+        invoke  NEXTSEC
+        JC      SETSFTJ2
+        MOV     BYTE PTR [TRANS],1      ; A transfer is taking place
+ONSEC:
+        MOV     DL,[SECCLUSPOS]
+        MOV     CX,[SECCNT]
+        MOV     BX,[CLUSNUM]
+RDLP:
+        invoke  OPTIMIZE
+        JC      SET_ACC_ERR_DS
+        PUSH    DI
+        PUSH    AX
+        PUSH    BX
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL + allowed_IGNORE
+        MOV     DS,WORD PTR [DMAADD+2]
+ASSUME  DS:NOTHING
+        PUSH    DX
+        PUSH    CX
+        invoke  SET_RQ_SC_PARMS          ;LB. do this for SC                   ;AN000;
+
+IF      BUFFERFLAG
+        pushf
+        cmp     [BUF_EMS_SAFE_FLAG], 1
+        je      safe_read
+        call    save_map
+        call    restore_user_map
+safe_read:
+        popf
+ENDIF
+
+        invoke  DREAD
+
+IF      BUFFERFLAG
+        pushf
+        cmp     [BUF_EMS_SAFE_FLAG], 1
+        je      safe_mapping
+        call    save_user_map
+        call    restore_map
+safe_mapping:
+        popf
+ENDIF
+
+        POP     BX
+        POP     DX
+        JNC     SKP_CANOT_READ
+        JMP     CANOT_READ
+SKP_CANOT_READ:
+        MOV     [TEMP_VAR],BX             ;LB. save sector count                ;AN000;
+        MOV     [TEMP_VAR2],DX            ;LB. 1st sector                       ;AN000;
+SCAN_NEXT:
+;;;;;;; invoke  GETCURHEAD                ;LB. get buffer header                ;AN000;
+        PUSH    DX                        ;LB. save regs                        ;AN000;
+        PUSH    AX                        ;LB.                                  ;AN000;
+        PUSH    BX                        ;LB.                                  ;AN000;
+        MOV     AX,DX                     ;LB.
+;       MOV     DX,[HIGH_SECTOR]          ;LB. HASH(sector#) and get entry #    ;AN000;
+        XOR     DX,DX                     ;LB. to avoid divide overflow         ;AN000;
+        DIV     [BUF_HASH_COUNT]          ;LB. get remainder                    ;AN000;
+        ADD     DX,DX                     ;LB. 8 bytes per entry                ;AN000;
+        ADD     DX,DX                     ;LB.                                  ;AN000;
+        ADD     DX,DX                     ;LB. times 8                          ;AN000;
+
+        LDS     DI,[BUF_HASH_PTR]         ;LB. get Hash Table addr              ;AN000;
+        ADD     DI,DX                     ;LB position to entry                 ;AN000;
+        CMP     [DI.Dirty_Count],0        ;LB dirty hash entry ?                ;AN000;
+        JNZ     yesdirty                  ;LB yes and map it                    ;AN000;
+        POP     BX                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB.                                  ;AN000;
+        POP     DX                        ;LB.                                  ;AN000;
+
+IF      NOT     BUFFERFLAG
+        JMP     SHORT end_scan            ;LB.                                  ;AN000;
+ELSE
+        JMP     END_SCAN
+ENDIF
+
+yesdirty:
+        MOV     WORD PTR [CurHashEntry+2],DS ;LB. update current Hash entry ptr ;AN000;
+        MOV     WORD PTR [CurHashEntry],DI ;LB.                                 ;AN000;
+        MOV     WORD PTR [LASTBUFFER],-1   ;LB. invalidate last buffer          ;AN000;
+        MOV     BX,[DI.EMS_PAGE_NUM]      ;LB. logical page                     ;AN000;
+
+IF      NOT     BUFFERFLAG
+        LDS     DI,[DI.BUFFER_BUCKET]     ;LB. ds:di is 1st buffer addr         ;AN000;
+        MOV     [FIRST_BUFF_ADDR],DI      ;LB. save first buff addr 1/19/88     ;AN000;
+        invoke  SET_MAP_PAGE              ;LB. activate handle if EMS there     ;AN000;
+ELSE
+;       int     3
+        push    ds
+        push    di              ; save hash ptr
+
+        LDS     DI,[DI.BUFFER_BUCKET]     ;ds:di is 1st buffer addr
+        POP     AX              ; Recall transfer address
+        PUSH    AX
+        PUSH    DI              ; Save search environment
+        PUSH    DX                   ; F.C. no need for high sector, <64K
+        push    cx
+
+        MOV     DX,[TEMP_VAR2]       ;LB. get 1st sector #
+        SUB     DX,WORD PTR [DI.buf_sector]   ; How far into transfer?
+        NEG     DX
+        MOV     DI,AX
+        MOV     AX,DX
+        MOV     CX,ES:[BP.dpb_sector_size]
+        MUL     CX
+        ADD     DI,AX           ; Put the buffer here
+        mov     [CURADD], di
+        
+        pop     cx
+        pop     dx
+        pop     di
+
+        invoke  SET_MAP_PAGE              ;LB. activate handle if EMS there     ;AN000;
+        pop     di                      ; restore hash ptr.
+        pop     ds
+        LDS     DI,[DI.BUFFER_BUCKET]     ;LB. ds:di is 1st buffer addr         ;AN000;
+        MOV     [FIRST_BUFF_ADDR],DI      ;LB. save first buff addr 1/19/88     ;AN000;
+ENDIF
+                                                                                ;AN000;
+        POP     BX                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB.                                  ;AN000;
+        POP     DX                        ;LB.                                  ;AN000;
+
+
+        Assert  ISDPB,<ES,BP>,"DISKREAD/RdLp"
+        MOV     AL,ES:[BP.dpb_drive]
+NXTBUF:                         ; Must see if one of these sectors is buffered
+        invoke  BUFF_RANGE_CHECK                           ;F.C. >32mb
+        JNC     inrange                    ;LB.                                 ;AN000;
+        mov     DI,[DI.buf_next]           ;LB. get next buffer 1/19/88         ;AN000;
+        JMP     DONXTBUF                   ;LB.                                 ;AN000;
+inrange:
+        TEST    [DI.buf_flags],buf_dirty
+        JZ      CLBUFF                  ; Buffer is clean, so OK
+; A sector has been read in when a dirty copy of it is in a buffer
+; The buffered sector must now be read into the right place
+        POP     AX              ; Recall transfer address
+        PUSH    AX
+        PUSH    DI              ; Save search environment
+        PUSH    DX                   ; F.C. no need for high sector, <64K
+
+        MOV     DX,[TEMP_VAR2]       ;LB. get 1st sector #
+        SUB     DX,WORD PTR [DI.buf_sector]   ; How far into transfer?
+        NEG     DX
+        MOV     SI,DI
+        MOV     DI,AX
+        MOV     AX,DX
+        MOV     CX,ES:[BP.dpb_sector_size]
+        MUL     CX
+        ADD     DI,AX           ; Put the buffer here
+        LEA     SI,[SI].BUFINSIZ
+        SHR     CX,1
+        PUSH    ES
+        MOV     ES,WORD PTR [DMAADD+2]
+        REP     MOVSW
+        JNC     EVENMOV
+        MOVSB
+EVENMOV:
+        POP     ES
+        POP     DX
+        POP     DI
+        MOV     AL,ES:[BP.dpb_drive]
+        invoke  SCANPLACE                ;LB. done with this chain              ;AN000;
+        JMP     SHORT end_scan           ;LB.                                   ;AN000;
+CLBUFF:
+        invoke  SCANPLACE
+DONXTBUF:
+        CMP     DI,[FIRST_BUFF_ADDR]     ;LB. end of buffers                    ;AN000;
+        JNZ     NXTBUF
+end_scan:
+        ADD     DX,1                     ;LB. next sector #                     ;AN000;
+        ADC     [HIGH_SECTOR],0          ;LB.                                   ;AN000;
+        DEC     [TEMP_VAR]               ;LB. decrement count                   ;AN000;
+        JZ      SCAN_DONE                ;LB. scan next sector                  ;AN000;
+        JMP     SCAN_NEXT                ;LB. scan next sector                  ;AN000;
+SCAN_DONE:
+        Context DS
+        POP     CX
+        POP     CX
+        POP     BX
+        JCXZ    RDLAST
+        invoke  IsEOF                   ; test for eof on fat size
+        JAE     SETSFT
+        MOV     DL,0
+        INC     [LASTPOS]       ; We'll be using next cluster
+        JMP     RDLP
+
+RDLAST:
+        MOV     AX,[BYTCNT2]
+        OR      AX,AX
+        JZ      SETSFT
+        MOV     [BYTCNT1],AX
+        invoke  NEXTSEC
+        JC      SETSFT
+        MOV     [BYTSECPOS],0
+        invoke  BUFRD
+        JNC     SETSFT
+        JMP     SET_ACC_ERR_DS
+
+; Inputs:
+;       [NEXTADD],[CLUSNUM],[LASTPOS] set to determine transfer size
+;               and set cluster fields
+; Function:
+;       Update [THISSFT] based on the transfer
+; Outputs:
+;       sf_position, sf_lstclus, and sf_cluspos updated
+;       ES:DI points to [THISSFT]
+;       CX No. of bytes transferred
+;       Carry clear
+
+        entry   SETSFT
+        DOSAssume   CS,<DS>,"SetSFT"
+        ASSUME  ES:NOTHING
+
+        LES     DI,[THISSFT]
+
+; Same as SETSFT except ES:DI already points to SFT
+        entry   SETCLUS
+        DOSAssume   CS,<DS>,"SetClus"
+        ASSUME  ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"SetClus"
+        MOV     CX,[NEXTADD]
+        SUB     CX,WORD PTR [DMAADD]     ; Number of bytes transfered
+        TEST    ES:[DI.sf_flags],devid_device
+        JNZ     ADDREC                   ; don't set clusters if device
+        MOV     AX,[CLUSNUM]
+        MOV     ES:[DI.sf_lstclus],AX
+        MOV     AX,[LASTPOS]
+        MOV     ES:[DI.sf_cluspos],AX
+
+; Inputs:
+;       ES:DI points to SFT
+;       CX is No. Bytes transferred
+; Function:
+;       Update the SFT offset based on the transfer
+; Outputs:
+;       sf_position updated to point to first byte after transfer
+;       ES:DI points to SFT
+;       CX No. of bytes transferred
+;       Carry clear
+
+        entry   AddRec
+        DOSAssume   CS,<DS>,"AddRec"
+        ASSUME  ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"AddRec"
+        JCXZ    RET28           ; If no records read,  don't change position
+        ADD     WORD PTR ES:[DI.sf_position],CX  ; Update current position
+        ADC     WORD PTR ES:[DI.sf_position+2],0
+RET28:  CLC
+        return
+EndProc DISKREAD
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/DISK3.ASM b/v4.0/src/DOS/DISK3.ASM
new file mode 100644
index 0000000..306b34e
--- /dev/null
+++ b/v4.0/src/DOS/DISK3.ASM
@@ -0,0 +1,662 @@
+;       SCCSID = @(#)disk3.asm  1.3 85/07/26
+;       SCCSID = @(#)disk3.asm  1.3 85/07/26
+TITLE   DISK3 - Disk utility routines
+NAME    Disk3
+; Low level Read and write routines for local SFT I/O on files and devs
+;
+;   DISKWRITE
+;   WRTERR
+;
+;   Revision history:
+;
+;    AN000 version 4.00 Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  THISSFT,DWORD
+        i_need  DMAADD,DWORD
+        i_need  SecClusPos,BYTE
+        i_need  ClusNum,WORD
+        i_need  Trans,BYTE
+        i_need  BytPos,4
+        i_need  SecPos,DWORD              ;F.C. >32mb   ;AN000;
+        i_need  BytSecPos,WORD
+        i_need  BytCnt1,WORD
+        i_need  BytCnt2,WORD
+        i_need  SecCnt,WORD
+        i_need  ThisDPB,DWORD
+        i_need  LastPos,WORD
+        i_need  ValSec,WORD               ;F.C. >32mb          ;AN000;
+        i_need  GrowCnt,DWORD
+        i_need  ALLOWED,BYTE
+        I_need  JShare,DWORD
+        I_need  FSeek_drive,BYTE          ; DOS 4.00           ;AN000;
+        I_need  FSeek_firclus,WORD        ; DOS 4.00           ;AN000;
+        I_need  FSeek_logclus,WORD        ; DOS 4.00           ;AN000;
+        I_need  HIGH_SECTOR,WORD          ;F.C. >32mb          ;AN000;
+        I_need  HIGH_SECTOR_TEMP,WORD     ;F.C. >32mb          ;AN000;
+        I_need  EXTERR,WORD                        ; DOS 4.00   ;AN000;
+        I_need  EXTERR_LOCUS,BYTE                  ; DOS 4.00   ;AN000;
+        I_need  EXTERR_ACTION,BYTE                 ; DOS 4.00   ;AN000;
+        I_need  EXTERR_CLASS,BYTE                  ; DOS 4.00   ;AN000;
+        I_need  EXITHOLD,DWORD                     ; DOS 4.00   ;AN000;
+        I_need  DISK_FULL,BYTE                     ; DOS 4.00   ;AN000;
+        I_need  SC_DRIVE,BYTE                      ; DOS 4.00   ;AN000;
+        I_need  SC_CACHE_COUNT,WORD                ; DOS 4.00   ;AN000;
+        I_need  ThisDRV,BYTE                       ; DOS 4.00   ;AN000;
+        I_need  User_In_AX,WORD                    ; DOS 4.00   ;AN000;
+        I_need  DOS34_FLAG,WORD                    ; DOS 4.00   ;AN000;
+        I_need  FIRST_BUFF_ADDR,WORD               ; DOS 4.00   ;AN000;
+
+IF      BUFFERFLAG
+        EXTRN   SAVE_MAP:NEAR
+        EXTRN   RESTORE_MAP:NEAR
+        EXTRN   SAVE_USER_MAP:NEAR
+        EXTRN   RESTORE_USER_MAP:NEAR
+        i_need  BUF_EMS_SAFE_FLAG,BYTE
+        i_need  BUF_EMS_MODE,BYTE
+ENDIF
+
+        
+
+Break   <DISKWRITE -- PERFORM USER DISK WRITE>
+
+; Inputs:
+;       Outputs of SETUP
+; Function:
+;       Perform disk write
+; Outputs:
+;    Carry clear
+;       CX = No. of bytes read
+;       ES:DI point to SFT
+;       SFT offset and cluster pointers updated
+;    Carry set
+;       CX = 0
+;       ES:DI point to SFT
+;       AX has error code
+
+        procedure   DISKWRITE,NEAR
+        DOSAssume   CS,<DS>,"DiskWrite"
+        ASSUME  ES:NOTHING
+
+        Assert  ISSFT,<ES,DI>,"DiskWrite"
+        PUSH    ES:[DI.sf_firclus]        ; set up 1st cluster # for FastSeek
+        POP     [FSeek_firclus]
+
+        invoke  CHECK_WRITE_LOCK          ;IFS. check write lock                 ;AN000;
+        JNC     WRITE_OK                  ;IFS. lock check ok                    ;AN000;
+        return
+
+WRTEOFJ:
+        JMP     WRTEOF
+
+WRITE_OK:
+        AND     ES:[DI.sf_flags],NOT (sf_close_nodate OR devid_file_clean)
+                                ; Mark file as dirty, clear no date on close
+        LES     BP,[THISDPB]
+        Assert  ISDPB,<ES,BP>,"DiskWrite/WriteOk"
+        MOV     AL,ES:[BP.dpb_drive]   ; set up drive # for FastSeek
+        MOV     [FSeek_drive],AL       ; 11/5/86 DOS 4.00
+
+        invoke  BREAKDOWN
+        MOV     AX,WORD PTR [BYTPOS]
+        MOV     DX,WORD PTR [BYTPOS+2]
+        JCXZ    WRTEOFJ                 ;Make the file length = sf_position
+        ADD     AX,CX
+        ADC     DX,0                    ; AX:DX=byte after last byte accessed
+;
+; Make sure divide won't overflow
+;
+        MOV     BX,ES:[BP.dpb_sector_size]
+;       CMP     DX,BX                   ;F.C. >32mb  16 bit sector check        ;AN000;
+;       JAE     WrtErr                  ;F.C. >32mb                             ;AN000;
+
+        CALL    DIV32                   ;F.C. perform 32 bit divide             ;AN000;
+        MOV     BX,AX                   ; Save last full sector
+        OR      DX,DX
+        JNZ     CALCLUS
+        SUB     AX,1                    ; AX must be zero base indexed          ;AC000;
+        SBB     [HIGH_SECTOR],0         ;F.C. >32mb                             ;AN000;
+CALCLUS:
+        PUSH    [HIGH_SECTOR]           ;F.C. >32mb                             ;AN000;
+        CALL    SHR32                   ;F.C. >32mb                             ;AN000;
+        POP     [HIGH_SECTOR]           ;F.C. >32mb                             ;AN000;
+
+;       SHR     AX,CL                   ; Last cluster to be accessed
+        PUSH    AX
+        PUSH    DX                      ; Save the size of the "tail"
+        PUSH    ES
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DiskWrite/CalClus"
+        MOV     AX,WORD PTR ES:[DI.sf_size]
+        MOV     DX,WORD PTR ES:[DI.sf_size+2]
+        POP     ES
+
+
+
+        PUSH    AX                      ;F.C. >32mb                             ;AN000;
+        MOV     AX,DX                   ;F.C. >32mb                             ;AN000;
+        XOR     DX,DX                   ;F.C. >32mb                             ;AN000;
+        DIV     ES:[BP.dpb_sector_size] ;F.C. >32mb                             ;AN000;
+        MOV     [HIGH_SECTOR_TEMP],AX   ;F.C. >32mb                             ;AN000;
+        POP     AX                      ;F.C. >32mb                             ;AN000;
+
+        DIV     ES:[BP.dpb_sector_size]
+        MOV     CX,AX           ; Save last full sector of current file
+        OR      DX,DX
+        JZ      NORNDUP
+        ADD     AX,1            ; Round up if any remainder                     ;AC000;
+        ADC     [HIGH_SECTOR_TEMP],0    ;F.C. >32mb                             ;AN000;
+NORNDUP:
+        PUSH    [HIGH_SECTOR_TEMP]      ;F.C. >32mb                             ;AN000;
+        POP     WORD PTR [VALSEC+2]     ;F.C. >32mb                             ;AN000;
+        MOV     WORD PTR [VALSEC],AX  ;Number of sectors that have been written
+        XOR     AX,AX
+        MOV     WORD PTR [GROWCNT],AX
+        MOV     WORD PTR [GROWCNT+2],AX
+        POP     AX
+
+        MOV     DI,[HIGH_SECTOR]        ;F.C. >32mb                             ;AN000;
+        CMP     DI,[HIGH_SECTOR_TEMP]   ;F.C. >32mb                             ;AN000;
+        JB      NOGROW                  ;F.C. >32mb                             ;AN000;
+        JZ      lowsec                  ;F.C. >32mb                             ;AN000;
+        SUB     BX,CX                   ;F.C. >32mb                             ;AN000;
+        SBB     DI,[HIGH_SECTOR_TEMP]   ;F.C. >32mb di:bx no. of sectors        ;AN000;
+        JMP     yesgrow                 ;F.C. >32mb                             ;AN000;
+lowsec:
+        MOV     DI,0            ;F.C. >32mb
+        SUB     BX,CX           ; Number of full sectors
+        JB      NOGROW
+        JZ      TESTTAIL
+yesgrow:
+        MOV     CX,DX
+        XCHG    AX,BX
+        MUL     ES:[BP.dpb_sector_size]  ; Bytes of full sector growth
+        MOV     [HIGH_SECTOR],DX         ;F.C. >32mb save dx                    ;AN000;
+        MOV     [HIGH_SECTOR_TEMP],AX    ;F.C. >32mb save ax                    ;AN000;
+        MOV     AX,DI                    ;F.C. >32mb                            ;AN000;
+        MUL     ES:[BP.dpb_sector_size]  ;F.C. >32mb do higher word multiply    ;AN000;
+        ADD     AX,[HIGH_SECTOR]         ;F.C. >32mb add lower value            ;AN000;
+        MOV     DX,AX                    ;F.C. >32mb DX:AX is the result of     ;AN000;
+        MOV     AX,[HIGH_SECTOR_TEMP]    ;F.C. >32mb a 32 bit multiply          ;AN000;
+
+        SUB     AX,CX           ; Take off current "tail"
+        SBB     DX,0            ; 32-bit extension
+        ADD     AX,BX           ; Add on new "tail"
+        ADC     DX,0            ; ripple tim's head off
+        JMP     SHORT SETGRW
+HAVSTART:
+;int 3
+        MOV     CX,AX
+        invoke  SKPCLP
+        JCXZ    DOWRTJ
+;;; 11/5/86 FastSeek
+        MOV     [FSeek_logclus],DX   ; delete EOF (FFFFH)
+        INC     [FSeek_logclus]
+        invoke  FastSeek_Truncate    ;
+;;; 11/5/86 FastSeek
+        invoke  ALLOCATE
+        JNC     DOWRTJ
+
+        entry   WRTERR
+        DOSAssume   CS,<DS>,"DiskWrite/WrtErr"
+        ASSUME  ES:NOTHING
+
+        MOV     AH,0FH                          ;MS. write/data/fail/abort      ;AN000;
+ entry WRTERR22
+        MOV     AL,[THISDRV]                    ;MS.                            ;AN000;
+        CALL    File_Handle_Fail_Error  ;MS. issue disk full I24
+        MOV     CX,0                    ;No bytes transferred
+;       XOR     CX,CX                   ; will be deleted
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DiskWrite/WrtErr"
+;       CLC
+        return
+
+DOWRTJ: JMP     DOWRT
+
+ACC_ERRWJ:
+        JMP     SET_ACC_ERRW
+
+TESTTAIL:
+        SUB     AX,DX
+        JBE     NOGROW
+        XOR     DX,DX
+SETGRW:
+        MOV     WORD PTR [GROWCNT],AX
+        MOV     WORD PTR [GROWCNT+2],DX
+NOGROW:
+        POP     AX
+        MOV     CX,[CLUSNUM]    ; First cluster accessed
+        invoke  FNDCLUS
+        JC      ACC_ERRWJ
+        MOV     [CLUSNUM],BX
+        MOV     [LASTPOS],DX
+;;; 11/5/86 FastSeek
+        MOV     [FSeek_logclus],AX    ; set up last position
+        SUB     AX,DX           ; Last cluster minus current cluster
+        JZ      DOWRT           ; If we have last clus, we must have first
+        JCXZ    HAVSTART        ; See if no more data
+        PUSH    CX              ; No. of clusters short of first
+        MOV     CX,AX
+
+;;; 11/5/86 FastSeek
+        CMP     [CLUSNUM],0           ;FS. null file                            ;AN000;
+        JZ      NULL_FILE             ;FS. yes                                  ;AN000;
+        MOV     [FSeek_logclus],DX    ;FS. delete EOF (FFFFH)                   ;AN000;
+        INC     [FSeek_logclus]       ;FS.                                      ;AN000;
+        invoke  FastSeek_Truncate     ;FS.                                      ;AN000;
+NULL_FILE:
+;;; 11/5/86 FastSeek
+        invoke  ALLOCATE
+        POP     AX
+        JC      WRTERR
+        MOV     CX,AX
+        MOV     DX,[LASTPOS]
+        INC     DX
+        DEC     CX
+        JZ      NOSKIP
+;;; 11/5/86 FastSeek
+        MOV     [FSeek_logclus],DX    ;
+        ADD     [FSeek_logclus],CX    ; set up last position
+        invoke  SKPCLP
+        JC      ACC_ERRWJ
+NOSKIP:
+        MOV     [CLUSNUM],BX
+        MOV     [LASTPOS],DX
+DOWRT:
+        CMP     [BYTCNT1],0
+        JZ      WRTMID
+        MOV     BX,[CLUSNUM]
+        invoke  BUFWRT
+        JC      ACC_ERRWJ
+WRTMID:
+        MOV     AX,[SECCNT]
+        OR      AX,AX
+        JNZ     havemid
+        JMP     WRTLAST
+havemid:
+        ADD     WORD PTR [SECPOS],AX
+        ADC     WORD PTR [SECPOS+2],0    ;F.C. >32mb                            ;AN000;
+        invoke  NEXTSEC
+        JNC     gotok
+        JMP     ACC_ERRWJ
+gotok:
+        MOV     BYTE PTR [TRANS],1       ; A transfer is taking place
+        MOV     DL,[SECCLUSPOS]
+        MOV     BX,[CLUSNUM]
+        MOV     CX,[SECCNT]
+WRTLP:
+        invoke  OPTIMIZE
+        JNC     wokok
+        JMP     ACC_ERRWJ
+wokok:
+        PUSH    DI
+        PUSH    AX
+        PUSH    DX
+        PUSH    BX
+        Assert  ISDPB,<ES,BP>,"DiskWrite/WrtLp"
+        MOV     AL,ES:[BP.dpb_drive]
+        MOV     [SC_DRIVE],AL             ;LB. save it for INVALIDATE_SC        ;AN000;
+        PUSH    CX                        ;LB.                                  ;AN000;
+        PUSH    [HIGH_SECTOR]             ;LB.                                  ;AN000;
+SCANNEXT:                                 ;LB.                                  ;AN000;
+        invoke  GETCURHEAD                ;LB.                                  ;AN000;
+ASSUME  DS:NOTHING
+NEXTBUFF:                       ; Search for buffers
+        CMP     [SC_CACHE_COUNT],0          ;LB. SC support ?                   ;AN000;
+        JZ      nosc                        ;LB. no                             ;AN000;
+        PUSH    AX                          ;LB. save reg                       ;AN000;
+        PUSH    CX                          ;LB. save reg                       ;AN000;
+        PUSH    DX                          ;LB. save reg                       ;AN000;
+        invoke  INVALIDATE_SC               ;LB. invalidate SC                  ;AN000;
+        POP     DX                          ;LB. save reg                       ;AN000;
+        POP     CX                          ;LB. save reg                       ;AN000;
+        POP     AX                          ;LB. save reg                       ;AN000;
+nosc:
+        CALL    BUFF_RANGE_CHECK            ;F.C. >32mb                         ;AN000;
+        JNC     inrange2                    ;F.C. >32mb                         ;AN000;
+        mov     DI,[DI.buf_next]            ;LB. get next buffer 1/19/88        ;AN000;
+        JMP     DONEXTBUFF                  ;LB.                                ;AN000;
+inrange2:
+        TEST    [DI.buf_flags],buf_dirty    ;LB. if dirty                       ;AN000;
+        JZ      not_dirty                   ;LB.                                ;AN000;
+        invoke  DEC_DIRTY_COUNT             ;LB. then decrement dirty count     ;AN000;
+not_dirty:
+        MOV     WORD PTR [DI.buf_ID],(buf_visit SHL 8) OR 0FFH    ; Free the buffer, it is being over written
+        invoke  SCANPLACE
+DONEXTBUFF:
+        CMP     DI,[FIRST_BUFF_ADDR]      ;LB. end of chain                     ;AN000;
+        JNZ     NEXTBUFF                  ;LB. no                               ;AN000;
+        ADD     DX,1                      ;LB. next sector number               ;AN000;
+        ADC     [HIGH_SECTOR],0           ;LB.                                  ;AN000;
+        LOOP    SCANNEXT                  ;LB. check again                      ;AN000;
+        POP     [HIGH_SECTOR]             ;LB.                                  ;AN000;
+        POP     CX                        ;LB. get count back                   ;AN000;
+
+        POP     BX
+        POP     DX
+        MOV     DS,WORD PTR [DMAADD+2]
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL + allowed_IGNORE
+
+IF      BUFFERFLAG
+        pushf
+        cmp     [BUF_EMS_MODE], -1
+        je      safe_write      
+        call    save_map
+        call    restore_user_map
+safe_write:
+        popf
+ENDIF   
+
+        invoke  DWRITE
+
+IF      BUFFERFLAG
+        pushf
+        cmp     [BUF_EMS_MODE], -1
+        je      safe_map        
+        call    save_user_map
+        call    restore_map
+safe_map:
+        popf
+ENDIF
+
+        POP     CX
+        POP     BX
+        Context DS
+        JC      SET_ACC_ERRW
+        JCXZ    WRTLAST
+        MOV     DL,0
+        INC     [LASTPOS]       ; We'll be using next cluster
+        JMP     WRTLP
+
+WRTLAST:
+        MOV     AX,[BYTCNT2]
+        OR      AX,AX
+        JZ      FINWRT
+        MOV     [BYTCNT1],AX
+        invoke  NEXTSEC
+        JC      SET_ACC_ERRW
+        MOV     [BYTSECPOS],0
+        invoke  BUFWRT
+        JC      SET_ACC_ERRW
+FINWRT:
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DiskWrite/FinWrt"
+        MOV     AX,WORD PTR [GROWCNT]
+        MOV     CX,WORD PTR [GROWCNT+2]
+        OR      AX,AX
+        JNZ     UPDATE_size
+        JCXZ    SAMSIZ
+Update_size:
+        ADD     WORD PTR ES:[DI.sf_size],AX
+        ADC     WORD PTR ES:[DI.sf_size+2],CX
+;
+; Make sure that all other SFT's see this growth also.
+;
+        MOV     AX,1
+if installed
+        call    JShare + 14 * 4
+else
+        Call    ShSU
+endif
+SAMSIZ:
+        transfer SETCLUS                  ; ES:DI already points to SFT
+
+SET_ACC_ERRW:
+        transfer SET_ACC_ERR_DS
+
+WRTEOF:
+        MOV     CX,AX
+        OR      CX,DX
+        JZ      KILLFIL
+        SUB     AX,1
+        SBB     DX,0
+
+        PUSH    BX
+        MOV     BX,ES:[BP.dpb_sector_size]    ;F.C. >32mb                       ;AN000;
+        CALL    DIV32                         ;F.C. >32mb                       ;AN000;
+        POP     BX                            ;F.C. >32mb                       ;AN000;
+        CALL    SHR32                         ;F.C. >32mb                       ;AN000;
+
+
+;       SHR     AX,CL
+        MOV     CX,AX
+        invoke  FNDCLUS
+SET_ACC_ERRWJ2:
+        JC      SET_ACC_ERRW
+;;; 11/5/86 FastSeek
+        MOV     [FSeek_logclus],DX    ; truncate clusters starting from DX
+        invoke  FastSeek_Truncate
+;;; 11/5/86 FastSeek
+        JCXZ    RELFILE
+        invoke  ALLOCATE
+        JC      WRTERRJ              ;;;;;;;;; disk full
+UPDATE:
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DiskWrite/update"
+        MOV     AX,WORD PTR [BYTPOS]
+        MOV     WORD PTR ES:[DI.sf_size],AX
+        MOV     AX,WORD PTR [BYTPOS+2]
+        MOV     WORD PTR ES:[DI.sf_size+2],AX
+;
+; Make sure that all other SFT's see this growth also.
+;
+        MOV     AX,2
+if installed
+        Call    JShare + 14 * 4
+else
+        Call    ShSU
+endif
+        XOR     CX,CX
+        transfer ADDREC
+
+WRTERRJ: JMP     WRTERR
+;;;;;;;;;;;;;;;; 7/18/86
+;;;;;;;;;;;;;;;;;
+RELFILE:
+        MOV     DX,0FFFFH
+        invoke  RELBLKS
+Set_Acc_ERRWJJ:
+        JC      SET_ACC_ERRWJ2
+        JMP     SHORT UPDATE
+
+KILLFIL:
+        XOR     BX,BX
+        PUSH    ES
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"DiskWrite/KillFil"
+        MOV     ES:[DI.sf_cluspos],BX
+        MOV     ES:[DI.sf_lstclus],BX
+        XCHG    BX,ES:[DI.sf_firclus]
+        POP     ES
+;; 11/5/86 FastSeek
+        invoke  Delete_FSeek   ; delete fastseek entry
+
+        OR      BX,BX
+        JZ      UPDATEJ
+;; 10/23/86 FastOpen update
+        PUSH    ES              ; since first cluster # is 0
+        PUSH    BP              ; we must delete the old cache entry
+        PUSH    AX
+        PUSH    CX
+        PUSH    DX
+        LES     BP,[THISDPB]             ; get current DPB
+        MOV     DL,ES:[BP.dpb_drive]     ; get current drive
+        MOV     CX,BX                    ; first cluster #
+        MOV     AH,2                     ; delete cache entry by drive:firclus
+        invoke  FastOpen_Update          ; call fastopen
+        POP     DX
+        POP     CX
+        POP     AX
+        POP     BP
+        POP     ES
+;; 10/23/86 FastOpen update
+
+        invoke  RELEASE
+        JC      SET_ACC_ERRWJJ
+UpDateJ:
+        JMP     UPDATE
+EndProc DISKWRITE
+
+
+
+Break   <DIV32 -- PERFORM 32 BIT DIVIDE>
+
+; Inputs:
+;       DX:AX = 32 bit dividend   BX= divisor
+; Function:
+;       Perform 32 bit division
+; Outputs:
+;       [HIGH_SECTOR]:AX = quotiend , DX= remainder
+
+        procedure   DIV32,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+
+        PUSH    AX                      ;F.C. >32mb                             ;AN000;
+        MOV     AX,DX                   ;F.C. >32mb                             ;AN000;
+        XOR     DX,DX                   ;F.C. >32mb                             ;AN000;
+        DIV     BX                      ;F.C. >32mb                             ;AN000;
+        MOV     [HIGH_SECTOR],AX        ;F.C. >32mb                             ;AN000;
+        POP     AX                      ;F.C. >32mb                             ;AN000;
+
+
+        DIV     BX                      ; AX=last sector accessed
+        return
+
+EndProc DIV32
+
+Break   <SHR32 -- PERFORM 32 BIT SHIFT RIGHT>
+
+; Inputs:
+;       [HIGH_SECTOR]:AX = 32 bit sector number
+; Function:
+;       Perform 32 bit shift right
+; Outputs:
+;       AX= cluster number
+
+        procedure   SHR32,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+
+        MOV     CL,ES:[BP.dpb_cluster_shift]
+        XOR     CH,CH
+entry ROTASHFT                          ;F.C. >32mb                             ;AN000;
+        OR      CX,CX                   ;F.C. >32mb                             ;AN000;
+        JZ      norota                  ;F.C. >32mb                             ;AN000;
+ROTASHFT2:
+        CLC                             ;F.C. >32mb                             ;AN000;
+        RCR     [HIGH_SECTOR],1         ;F.C. >32mb                             ;AN000;
+        RCR     AX,1                    ;F.C. >32mb                             ;AN000;
+        LOOP    ROTASHFT2               ;F.C. >32mb:                            ;AN000;
+norota:
+        return
+
+EndProc SHR32
+
+
+; Issue File Handle Fail INT 24 Critical Error
+; Input: Disk_Full=0  ok
+;                  1  disk full or EOF
+; Function: issue critical error for disk full or EOF error
+;
+; OutPut: carry clear , no I24
+;         carry set, fail from I24
+
+procedure File_Handle_Fail_Error,NEAR                                           ;AN000;
+        ASSUME  ES:NOTHING,DS:NOTHING                                           ;AN000;
+                                                                                ;AN000;
+        CMP     [DISK_FULL],0    ;MS. disk full or EOF                          ;AN000;
+        JZ      Fexit            ;MS. no                                        ;AN000;
+        TEST    [DOS34_FLAG],Disable_EOF_I24   ;MS. check input status ?        ;AN000;
+        JNZ     Fexit            ;MS. yes                                       ;AN000;
+                                                                                ;AN000;
+        LES     DI,[THISSFT]     ;MS. get current SFT                           ;AN000;
+;       LES     DI,ES:[DI.sf_DEVPTR];MS. get device header                      ;AN000;
+        TEST    ES:[DI.sf_flags],Handle_Fail_I24  ;MS. gen I24 ?                ;AN000;
+        JZ      Fexit            ;MS. no                                        ;AN000;
+        PUSH    DS               ;MS. save DS                                   ;AN000;
+        TEST    AH,1                            ;MS. READ ?                     ;AN000;
+        JZ      readeof                         ;MS. yes                        ;AN000;
+        MOV     [EXTERR],error_Handle_Disk_Full ;MS. set extended error         ;AN000;
+        JMP     SHORT errset                    ;MS. set extended error         ;AN000;
+readeof:
+        MOV     [EXTERR],error_Handle_EOF       ;MS. set extended error         ;AN000;
+errset:
+        MOV     [EXTERR_CLASS],errCLASS_OutRes  ;MS. set class                  ;AN000;
+        MOV     [EXTERR_ACTION],errACT_Abort    ;MS. set action                 ;AN000;
+        MOV     [EXTERR_LOCUS],errLOC_Unk       ;MS. set locus                  ;AN000;
+        MOV     word ptr [EXITHOLD + 2],ES      ;MS. save es:bp in exithold     ;AN000;
+        MOV     word ptr [EXITHOLD],BP          ;MS.                            ;AN000;
+        TEST    ES:[DI.sf_flags],devid_device     ;MS. device  ?                ;AN000;
+        JNZ     chardev2                          ;MS. yes                      ;AN000;
+        LDS     SI,ES:[DI.sf_DEVPTR]              ;MS. get dpb                  ;AN000;
+        LDS     SI,[SI.dpb_driver_addr]           ;MS. get drive device haeder  ;AN000;
+        JMP     SHORT doi24                       ;MS. gen I24 ?                ;AN000;
+chardev2:
+        LDS     SI,ES:[DI.sf_DEVPTR]              ;MS. get chr dev header       ;AN000;
+doi24:
+        MOV     BP,DS                             ;MS. bp:si -> device header   ;AN000;
+        MOV     DI,error_I24_gen_failure        ;MS. general error              ;AN000;
+        invoke  NET_I24_ENTRY                   ;MS. issue I24                  ;AN000;
+        STC                                     ;MS. must be fail               ;AN000;
+        POP     DS                              ;MS. restore DS                 ;AN000;
+        MOV     AX,[EXTERR]                     ;MS. set error                  ;AN000;
+        JMP     SHORT Fend                      ;MS. exit                       ;AN000;
+Fexit:                                                                          ;AN000;
+        CLC                                     ;MS. clear carry                ;AN000;
+Fend:                                                                           ;AN000;
+        return                                  ;MS.                            ;AN000;
+                                                                                ;AN000;
+EndProc File_Handle_Fail_Error                                                  ;AN000;
+
+
+Break   <BUFF_RANGE_CHECK- buffer range checkink>
+
+; Inputs:
+;       DS:DI -> buffer. AL= drive #
+;       [HIGH_SECTOR]:DX = sector #
+; Function:
+;       check if sector is in the buffer
+; Outputs:
+;       carry clear= in the range
+;             set  = not in the range
+
+        procedure   BUFF_RANGE_CHECK,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        CMP     WORD PTR [DI.buf_sector],DX                                     ;AN000;
+        JNZ     DONEXTBUFF2     ; not this sector          ;F.C. >32mb          ;AN000;
+        MOV     SI,[HIGH_SECTOR]                           ;F.C. >32mb          ;AN000;
+        CMP     WORD PTR [DI.buf_sector+2],SI              ;F.C. >32mb          ;AN000;
+        JNZ     DONEXTBUFF2     ; Not for this drive
+        CMP     AL,[DI.buf_ID]
+        JZ      secfound        ; Buffer has the sector                         ;AN000;
+DONEXTBUFF2:
+        STC
+secfound:
+        return
+
+EndProc BUFF_RANGE_CHECK
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/DISP.ASM b/v4.0/src/DOS/DISP.ASM
new file mode 100644
index 0000000..fba9764
--- /dev/null
+++ b/v4.0/src/DOS/DISP.ASM
@@ -0,0 +1,579 @@
+;       SCCSID = @(#)disp.asm   1.1 85/04/10
+;       SCCSID = @(#)disp.asm   1.1 85/04/10
+;
+; Dispatcher code
+;
+
+.xlist
+.xcref
+INCLUDE DOSSYM.INC
+include dosseg.asm
+.cref
+.list
+
+AsmVars <Kanji, Debug>
+
+BREAK   <Copyright notice and version>
+CODE    SEGMENT BYTE PUBLIC 'CODE'
+
+
+        I_need  CurrentPDB,WORD
+        I_need  CntCFlag,BYTE
+        I_need  User_SS,WORD
+        I_need  User_SP,WORD
+        I_need  NSS,WORD
+        I_need  NSP,WORD
+        I_need  MaxCall,BYTE
+        I_need  MaxCom,BYTE
+        I_need  SaveDS,WORD
+        I_need  SaveBX,WORD
+        I_need  INDOS,BYTE
+        I_need  User_ID,WORD
+        I_need  Proc_ID,WORD
+        I_need  AuxStack,BYTE
+        I_need  IOSTACK,BYTE
+        I_need  DSKSTACK,BYTE
+        I_need  fsharing,BYTE
+        I_need  NoSetDir,BYTE
+        I_need  FailERR,BYTE
+        I_need  Errormode,BYTE
+        I_need  restore_tmp,WORD
+        I_need  WPERR,BYTE
+        I_need  Dispatch,WORD
+        I_need  ConSwap,BYTE
+        I_need  User_In_AX,WORD
+        I_need  EXTERR_LOCUS,BYTE
+        I_need  IdleInt,BYTE
+        I_need  Printer_Flag,BYTE
+        I_need  CPSWFLAG,BYTE              ;AN000;
+        I_need  CPSWSAVE,BYTE              ;AN000;
+        I_need  DISK_FULL,BYTE             ;AN000;
+        I_need  InterCon,BYTE              ;AN000;
+        I_need  BOOTDRIVE,BYTE             ;AN000;
+        I_need  EXTOPEN_ON,BYTE            ;AN000;
+        I_need  DOS34_FLAG,WORD            ;AN000;
+        I_need  ACT_PAGE,WORD              ;AN000;
+
+        IF      NOT IBM
+        I_need  OEM_HANDLER,DWORD
+        ENDIF
+
+        IF      BUFFERFLAG
+        I_am    SETVECTFLAG,BYTE,<0>
+        i_need  BUF_EMS_SEG_CNT,WORD         ; DOS 4.00 EMS seg count           ;AN000;
+        i_need  BUF_EMS_MODE,BYTE            ; DOS 4.00 EMS mode                ;AN000;
+        i_am    BUF_EMS_MAP_USER,12,<0,0,0,0,0,0,0,0,0,0,0,0>
+        ENDIF
+
+ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+BREAK   <System call entry points and dispatcher>
+ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+BREAK <$Set_CTRL_C_Trapping -- En/Disable ^C check in dispatcher>
+
+; Inputs:
+;       AL = 0 read ^C status
+;       AL = 1 Set ^C status, DL = 0/1 for ^C off/on
+;       AL = 2 Set ^C status to contents of DL.  Output is old state.
+;       AL = 3 Get CPSW state to DL        DOS 3.4
+;       AL = 4 Set CPSW state from DL      DOS 3.4
+;       AL = 5 get DOS boot drive
+; Function:
+;       Enable disable ^C checking in dispatcher
+; Outputs:
+;       If AL = 0 then DL = 0/1 for ^C off/on
+
+        procedure   $SET_CTRL_C_TRAPPING,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        OR      AL,AL
+        JNZ     Check1
+        MOV     DL,CntCFlag
+        IRET
+Check1:
+        CMP     AL,2
+        JA      CPSWchk                        ;AN000;
+        JZ      SetAndRet
+        PUSH    DX
+        AND     DL,01h
+        MOV     [CNTCFLAG],DL
+        POP     DX
+        IRET
+SetAndRet:
+        AND     DL,01h
+        XCHG    CntCFlag,DL
+        IRET
+BadVal:
+        MOV     AL,0FFH
+        IRET
+;; DOS 4.00 File Tagging
+
+CPSWchk:                                ;AN000;
+;       PUSH    AX                      ;AN000;;FT.
+;       MOV     AL,[CPSWSAVE]           ;AN000;;FT. DOS 3.4
+;       MOV     [CPSWFLAG],AL           ;AN000;;FT. DOS 3.4 in case ABORT
+;       POP     AX                      ;AN000;;FT.
+        CMP     AL,3                    ;AN000;;FT get CPSW state ?
+        JNZ     CPSWset                 ;AN000;;FT. no
+;       MOV     DL,CPSWFLAG             ;AN000;;FT. return CPSW state
+        IRET                            ;AN000;
+CPSWset:                                ;AN000;
+        CMP     AL,4                     ;AN000;;FT. set CPSW state ?
+        JA      QueryDOSboot             ;AN000;;FT. check query dos boot drive
+;       PUSH    AX                       ;AN000;;FT.
+;       CallInstall NLSInstall,NLSFUNC,0 ;AN000;;FT. NLSFUNC installed ?
+;       CMP     AL,0FFH                  ;AN000;;FT.
+;       POP     AX                       ;AN000;;FT.
+;       JNZ     BadVal                   ;AN000;;FT. not loaded, therefore ignore
+;;;;    AND     DL,01H                   ;AN000;;FT. only 0 or 1
+;;;;    MOV     [CPSWFLAG],DL            ;AN000;;FT. set the flag
+;;;;    MOV     [CPSWSAVE],DL            ;AN000;;FT. save one copy
+        IRET                             ;AN000;;FT.
+QueryDOSboot:                            ;AN000;
+        CMP     AL,5                ;AN000;MS.
+        JA      BadVal              ;AN000;MS.
+        MOV     DL,[BOOTDRIVE]      ;AN000;;MS. put boot drive in DL
+        IRET                        ;AN000;;MS.
+
+
+;; DOS 4.00 File Tagging
+
+EndProc $SET_CTRL_C_TRAPPING
+
+BREAK <$Get_current_PDB -- Set/Get PDB value>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+; The following two routines are dispatched to directly with ints disabled
+; immediately after the int 21h entry.  no DIS state is set.
+;
+; $Set_current_PDB takes BX and sets it to be the current process
+;   *** THIS FUNCTION CALL IS SUBJECT TO CHANGE!!! ***
+;
+        procedure   $SET_CURRENT_PDB,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     [CurrentPDB],BX
+        IRET
+EndProc $SET_CURRENT_PDB
+
+;
+; $get_current_PDB returns in BX the current process
+;   *** THIS FUNCTION CALL IS SUBJECT TO CHANGE!!! ***
+;
+procedure   $GET_CURRENT_PDB,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     BX,[CurrentPDB]
+        IRET
+EndProc $GET_CURRENT_PDB
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+;
+; Sets the Printer Flag to whatever is in AL.
+; NOTE: THIS PROCEDURE IS SUBJECT TO CHANGE!!!
+;
+Procedure $Set_Printer_Flag
+ASSUME DS:NOTHING, ES:NOTHING, SS:NOTHING
+        mov     [Printer_Flag],al
+        IRET
+EndProc $Set_Printer_Flag
+
+        procedure   SYSTEM_CALL,NEAR
+;
+; The Quit entry point is where all INT 20h's come from.  These are old- style
+; exit system calls.  The CS of the caller indicates which Process is dying.
+; The error code is presumed to be 0.  We simulate an ABORT system call.
+;
+        entry   QUIT
+        MOV     AH,0
+        JMP     SHORT SAVREGS
+;
+; The system call in AH is out of the range that we know how to handle.  We
+; arbitrarily set the contents of AL to 0 and IRET.  Note that we CANNOT set
+; the carry flag to indicate an error as this may break some programs
+; compatability.
+;
+BADCALL:
+        MOV     AL,0
+        entry   IRETT
+        IRET
+;
+; An alternative method of entering the system is to perform a CALL 5 in the
+; program segment prefix with the contents of CL indicating what system call
+; the user would like.  A subset of the possible system calls is allowed here;
+; only the CPM-compatible calls may get dispatched.
+;
+        entry   CALL_ENTRY              ; System call entry point and dispatcher
+        POP     AX                      ; IP from the long call at 5
+        POP     AX                      ; Segment from the long call at 5
+        POP     [User_SP]               ; IP from the CALL 5
+;
+; Re order the stack to simulate an interrupt 21.
+;
+        PUSHF                           ; Start re-ordering the stack
+        CLI
+        PUSH    AX                      ; Save segment
+        PUSH    [User_SP]               ; Stack now ordered as if INT had been used
+        CMP     CL,MAXCALL              ; This entry point doesn't get as many calls
+        JA      BADCALL
+        MOV     AH,CL
+        JMP     SHORT SavRegs
+;
+; This is the normal INT 21 entry point.  We first perform a quick test to see
+; if we need to perform expensive DOS-entry functions.  Certain system calls
+; are done without interrupts being enabled.
+;
+
+entry   COMMAND                         ; Interrupt call entry point (INT 21H)
+
+        IF      NOT IBM
+        CMP     AH,SET_OEM_HANDLER
+        JB      NOTOEM
+        JMP     $SET_OEM_HANDLER
+NOTOEM:
+        ENDIF
+
+        CMP     AH,MAXCOM
+        JA      BadCall
+
+;
+; The following set of calls are issued by the server at *arbitrary* times
+; and, therefore, must be executed on the user's entry stack and executed with
+; interrupts off.
+;
+SAVREGS:
+        CMP     AH,GET_CURRENT_PDB
+        JZ      $GET_CURRENT_PDB
+        CMP     AH,GetCurrentPSP
+        JZ      $GET_CURRENT_PDB
+        CMP     AH,SET_CURRENT_PDB
+        JZ      $SET_CURRENT_PDB
+        CMP     AH,Set_CTRL_C_Trapping
+        JNZ     chkprt
+        JMP     $Set_CTRL_C_Trapping
+chkprt:
+        CMP     AH,SET_PRINTER_FLAG
+        JZ      $Set_Printer_Flag
+;
+; Preserve all user's registers on his own stack.
+;
+        CALL    save_world
+        MOV     [SaveDS],DS
+        MOV     [SaveBX],BX
+        MOV     BX,CS
+        MOV     DS,BX
+        ASSUME  DS:DOSGROUP
+        INC     [INDOS]                 ; Flag that we're in the DOS
+        XOR     AX,AX
+        MOV     [USER_ID],AX
+        MOV     AX,CurrentPDB           ; current process
+        MOV     [PROC_ID],AX            ; Assume local machine for the moment
+;
+; Provide one level of reentrancy for INT 24 recallability.
+;
+        MOV     AX,[user_SP]
+        MOV     [NSP],AX
+        MOV     AX,[user_SS]
+        MOV     [NSS],AX
+        POP     AX
+        PUSH    AX
+        MOV     [user_SP],SP
+        MOV     [user_SS],SS
+;
+; save user stack in his area for later returns (possibly from EXEC)
+;
+        MOV     DS,[CurrentPDB]
+ASSUME  DS:NOTHING
+        MOV     WORD PTR DS:[PDB_User_stack],SP
+        MOV     WORD PTR DS:[PDB_User_stack+2],SS
+
+        MOV     fSharing,0              ; allow redirection
+
+        MOV     BX,CS                   ; no holes here.
+        MOV     SS,BX
+ASSUME  SS:DOSGROUP
+
+entry   REDISP
+        MOV     SP,OFFSET DOSGROUP:AUXSTACK ; Enough stack for interrupts
+        STI                             ; stack is in our space now...
+ IF  DBCS                                       ;AN000;
+        MOV     BH, BYTE PTR DS:[PDB_InterCon]  ;AN000;; get interim mode  2/13/KK
+        MOV     SS:[InterCon], BH               ;AN000;; 2/13/KK
+ ENDIF                                          ;AN000;
+        MOV     BX,CS
+        MOV     DS,BX
+        DOSAssume   CS,<DS>,"MSCODE/ReDisp"
+;; DOS 3.4 INIT
+;       MOV     BL,[CPSWSAVE]           ;AN000;;FT. DOS 3.4
+;       MOV     [CPSWFLAG],BL           ;AN000;;FT. DOS 3.4 in case ABORT
+        MOV     [DISK_FULL],0           ;AN000;;MS. no disk full
+        MOV     [EXTOPEN_ON],0          ;AN000;;EO. clear extended open flag
+        MOV     [DOS34_FLAG],0          ;AN000;;MS. clear common flag
+        MOV     [ACT_PAGE],-1           ;BN000;BL;AN000;;LB. invalidate active page
+;; DOS 4.00 INIT
+        XOR     BH,BH
+        MOV     [CONSWAP],BH            ; random clean up of possibly mis-set flags
+        MOV     [IDLEINT],1             ; presume that we can issue INT 28
+        MOV     BYTE PTR [NoSetDir],BH  ; set directories on search
+        MOV     BYTE PTR [FAILERR],BH   ; FAIL not in progress
+        MOV     BL,AH
+        SHL     BX,1                    ; 2 bytes per call in table
+        CLD
+;
+; Since the DOS maintains mucho state information across system calls, we
+; must be very careful about which stack we use.
+;
+; First, all abort operations must be on the disk stack.  THis is due to the
+; fact that we may be hitting the disk (close operations, flushing) and may
+; need to report an INT 24.
+;
+        OR      AH,AH
+        JZ      DSKROUT                 ; ABORT
+;
+; Second, PRINT and PSPRINT and the server issue GetExtendedError calls at
+; INT 28 and INT 24 time.  This call MUST, therefore, use the AUXSTACK.
+;
+        CMP     AH,GetExtendedError
+        JZ      DISPCALL
+;
+; Old 1-12 system calls may be either on the IOSTACK (normal operation) or
+; on the AUXSTACK (at INT 24 time).
+;
+        CMP     AH,12
+        JA      DSKROUT
+        CMP     [ERRORMODE],0           ; Are we in an INT 24?
+        JNZ     DISPCALL                ; Stay on AUXSTACK if INT 24.
+        MOV     SP,OFFSET DOSGROUP:IOSTACK
+        JMP     SHORT DISPCALL
+;
+; We are on a system call that is classified as "the rest".  We place
+; ourselves onto the DSKSTACK and away we go.  We know at this point:
+;
+;   o   An INT 24 cannot be in progress.  Therefore we reset errormode and
+;       wperr
+;   o   That there can be no critical sections in effect.  We signal the
+;       server to remove all the resources.
+;
+DSKROUT:
+        MOV     [USER_IN_AX],AX         ; Remember what user is doing
+        MOV     [EXTERR_LOCUS],errLOC_Unk ; Default
+        MOV     [ERRORMODE],0           ; Cannot make non 1-12 calls in
+        MOV     [WPERR],-1              ; error mode, so good place to make
+;
+; Release all resource information
+;
+        PUSH    AX
+        MOV     AH,82h
+        INT     int_IBM
+        POP     AX
+
+;
+; Since we are going to be running on the DSKStack and since INT 28 people
+; will use the DSKStack, we must turn OFF the generation of INT 28's.
+;
+        MOV     IdleInt,0
+        MOV     SP,OFFSET DOSGROUP:DSKSTACK
+        TEST    [CNTCFLAG],-1
+        JZ      DISPCALL                ; Extra ^C checking is disabled
+        PUSH    AX
+        invoke  DSKSTATCHK
+        POP     AX
+DISPCALL:
+        MOV     BX,CS:Dispatch[BX]
+        XCHG    BX,SaveBX
+        MOV     DS,SaveDS
+
+IF      BUFFERFLAG
+        mov     cs:[SETVECTFLAG], 0
+        cmp     ah, 25h
+        jne     saveuser
+        cmp     ah, 35h
+        jne     saveuser
+        mov     cs:[SETVECTFLAG], 1
+saveuser:
+        invoke  SAVE_USER_MAP               ;AN000;LB.  save EMS map
+ENDIF
+
+        ASSUME  DS:NOTHING
+        CALL    SaveBX
+
+IF      BUFFERFLAG
+      invoke  RESTORE_USER_MAP            ;AN000;LB.  retsore EMS map
+ENDIF
+
+        entry   LEAVEDOS
+ASSUME  SS:NOTHING                      ; User routines may misbehave
+        CLI
+        DEC     [INDOS]
+        MOV     SS,[user_SS]
+        MOV     SP,[user_SP]
+        MOV     BP,SP
+        MOV     BYTE PTR [BP.user_AX],AL
+        MOV     AX,[NSP]
+        MOV     [user_SP],AX
+        MOV     AX,[NSS]
+        MOV     [user_SS],AX
+        CALL    restore_world
+        IRET
+EndProc SYSTEM_CALL
+
+;
+; restore_world restores all registers ('cept SS:SP, CS:IP, flags) from
+; the stack prior to giving the user control
+;
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        procedure   restore_world,NEAR
+        POP     restore_tmp             ; POP     restore_tmp
+        POP     AX                      ; PUSH    ES
+        POP     BX                      ; PUSH    DS
+        POP     CX                      ; PUSH    BP
+        POP     DX                      ; PUSH    DI
+        POP     SI                      ; PUSH    SI
+        POP     DI                      ; PUSH    DX
+        POP     BP                      ; PUSH    CX
+        POP     DS                      ; PUSH    BX
+        POP     ES                      ; PUSH    AX
+        JMP     restore_tmp             ; PUSH    restore_tmp
+EndProc restore_world
+
+;
+; save_world saves complete registers on the stack
+;
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        procedure   save_world,NEAR
+        POP     restore_tmp
+        PUSH    ES
+        PUSH    DS
+        PUSH    BP
+        PUSH    DI
+        PUSH    SI
+        PUSH    DX
+        PUSH    CX
+        PUSH    BX
+        PUSH    AX
+        JMP     restore_tmp             ; PUSH    restore_tmp
+EndProc save_world
+
+IF BUFFERFLAG
+
+Break   <SAVE_USER_MAP - save map >                                                     ;AN000;
+; Inputs:                                                                       ;AN000;
+;       none                                                                    ;AN000;
+; Function:                                                                     ;AN000;
+;       save map                                                                ;AN000;
+; Outputs:                                                                      ;AN000;
+;       none                                                                    ;AN000;
+; No other registers altered                                                    ;AN000;
+                                                                                ;AN000;
+Procedure   SAVE_USER_MAP,NEAR                                                   ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+                                                                                ;AN000;
+        CMP     cs:[BUF_EMS_MODE],-1      ;LB. EMS support                      ;AN000;
+        JZ      No_user_save              ;LB. no                               ;AN000;
+        CMP     cs:[SETVECTFLAG], 1
+        jz      No_user_save
+;       MOV     [ACT_PAGE],-1             ;LB. invalidate active page           ;AN000;
+;       MOV     WORD PTR [LASTBUFFER],-1  ;LB.  and last buffer pointer         ;AN000;
+        PUSH    AX                        ;LB. save regs                        ;AN000;
+        PUSH    DS                        ;LB. save regs                        ;AN000;
+        PUSH    ES                        ;LB.                                  ;AN000;
+        PUSH    SI                        ;LB.                                  ;AN000;
+        PUSH    DI                        ;LB.                                  ;AN000;
+        MOV     SI,OFFSET DOSGROUP:BUF_EMS_SEG_CNT     ;LB.                     ;AN000;
+        MOV     DI,OFFSET DOSGROUP:BUF_EMS_MAP_USER     ;LB.                    ;AN000;
+
+        PUSH    CS
+        POP     ES
+        PUSH    CS                        ;LB. ds:si -> ems seg cnt             ;AN000;
+        POP     DS                        ;LB.                                  ;AN000;
+
+        MOV     AX,4F00H                  ;LB. save map                         ;AN000;
+        EnterCrit  critDisk               ;LB. enter critical section           ;AN000;
+        INT     67H                       ;LB.                                  ;AN000;
+        LeaveCrit  critDisk               ;LB. leave critical section           ;AN000;
+        POP     DI                        ;LB.                                  ;AN000;
+        POP     SI                        ;LB. restore regs                     ;AN000;
+        POP     ES                        ;LB.                                  ;AN000;
+        POP     DS                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB. restore                          ;AN000;
+No_user_save:                                                                    ;AN000;
+        return                                                                  ;AN000;
+EndProc SAVE_USER_MAP                                                            ;AN000;
+                                                                                ;AN000;
+
+Break   <RESTORE_USER_MAP- retore map >                                         ;AN000;
+; Inputs:                                                                       ;AN000;
+;       none                                                                    ;AN000;
+; Function:                                                                     ;AN000;
+;       restore_map                                                             ;AN000;
+; Outputs:                                                                      ;AN000;
+;       none                                                                    ;AN000;
+; No other registers altered                                                    ;AN000;
+                                                                                ;AN000;
+Procedure   RESTORE_USER_MAP,NEAR                                                        ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING                                           ;AN000;
+        
+        CMP     cs:[BUF_EMS_MODE],-1      ;LB. EMS support                      ;AN000;
+        JZ      No_user_restore           ;LB. no                               ;AN000;
+        CMP     cs:[SETVECTFLAG], 1
+        jz      No_user_restore
+        PUSH    AX                        ;LB. save regs                        ;AN000;
+        PUSH    DS                        ;LB. save regs                        ;AN000;
+        PUSH    SI                        ;LB.                                  ;AN000;
+        MOV     SI,OFFSET DOSGROUP:BUF_EMS_MAP_USER     ;LB.                    ;AN000;
+
+        PUSH    CS
+        POP     DS
+
+        MOV     AX,4F01H                  ;LB. restore map                      ;AN000;
+        EnterCrit  critDisk               ;LB. enter critical section           ;AN000;
+        INT     67H                       ;LB.                                  ;AN000;
+        LeaveCrit  critDisk               ;LB. leave critical section           ;AN000;
+        POP     SI                        ;LB. restore regs                     ;AN000;
+        POP     DS                        ;LB.                                  ;AN000;
+        POP     AX                        ;LB.                                  ;AN000;
+No_user_restore:                                                                         ;AN000;
+        return                                                                  ;AN000;
+EndProc RESTORE_USER_MAP
+
+ENDIF
+
+;
+; get_user_stack returns the user's stack (and hence registers) in DS:SI
+;
+        procedure   get_user_stack,NEAR
+        LDS     SI,DWORD PTR [user_SP]
+        return
+EndProc get_user_stack
+
+        IF      NOT IBM
+BREAK <Set_OEM_Handler -- Set OEM sys call address and handle OEM Calls
+
+$SET_OEM_HANDLER:
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+; Inputs:
+;       User registers, User Stack, INTS disabled
+;       If CALL F8, DS:DX is new handler address
+; Function:
+;       Process OEM INT 21 extensions
+; Outputs:
+;       Jumps to OEM_HANDLER if appropriate
+
+        JNE     DO_OEM_FUNC             ; If above F8 try to jump to handler
+        MOV     WORD PTR [OEM_HANDLER],DX   ; Set Handler
+        MOV     WORD PTR [OEM_HANDLER+2],DS
+        IRET                            ; Quick return, Have altered no registers
+
+DO_OEM_FUNC:
+        CMP     WORD PTR [OEM_HANDLER],-1
+        JNZ     OEM_JMP
+        JMP     BADCALL                 ; Handler not initialized
+
+OEM_JMP:
+        JMP     [OEM_HANDLER]
+        ENDIF
+
+
+CODE    ENDS
diff --git a/v4.0/src/DOS/DISPATCH.ASM b/v4.0/src/DOS/DISPATCH.ASM
new file mode 100644
index 0000000..0f50ef0
--- /dev/null
+++ b/v4.0/src/DOS/DISPATCH.ASM
@@ -0,0 +1,214 @@
+;       SCCSID = @(#)dispatch.asm       1.1 85/04/10
+;       SCCSID = @(#)dispatch.asm       1.1 85/04/10
+;
+; Major dispatch code and table for MSDOS 2.X and above.
+;
+;   Modification history:
+;
+;       Created: MZ 30 March 1983
+;
+; The system calls are dispatched to in such a fashion as to have their entire
+; register set passed to them except for CS:IP and SS:SP.  This reduces the
+; need for retreiving information from the user's stack.
+;
+; There are also critical sections that need to be observed when running in a
+; multitasking environment.  These sections are:
+;
+;   1   critDisk    any of the disk code that will twiddle the buffer cache
+;   2   critDevice  all device drivers
+;
+;   4   critMem     memory allocation stuff
+;   5   critNet     network critical section
+;
+; The system calls below are noted as to which of these critical sections they
+; belong.  The critical sections are noted in the source files by the macros
+; EnterCrit and LeaveCrit.
+;
+; The break-down of the individual system calls into source files is as
+; follows (* means done):
+;
+;   *   handle.asm:     Close, Read, Write, LSeek, XDup, XDup2, FileTimes
+;       IOCTL.INC:      IOCTL
+;   *   file.asm:       Open, Creat, ChMod, Unlink, Rename, CreateTemp,
+;                       CreateNew
+;   *   srvcall.asm:    $ServerCall
+;   *   path.asm:       MkDir, RmDir, ChDir, CurrentDir
+;   *   alloc.asm:      $Alloc, $Dealloc, $SetBlock, $AllocOper
+;                       arena_free_process, arena_next -> LOW LEVEL <-
+;                       check_signature, Coalesce
+;   *   search.asm:     DirSearchFirst, DirSearchNext, FindFirst, FindNext,
+;                       PackName                 -> LOW LEVEL <-
+;   *   proc.asm:       Exec, Exit, Abort, Wait, KeepProcess
+;   *   cpmio.asm:      StdConInput, StdConOutput, StdAuxInput, StdAuxOutput,
+;                       StdPrinterOutput, RawConIO, RawConInput,
+;                       StdConInputNoEcho, StdConStringInput,
+;                       StdConStringOutput, StdConInputStatus,
+;                       StdConInputFlush
+;                       OUT, BUFOUT, RAWOUT, RAWOUT2    -> LOW LEVEL <-
+;   *   fcbio.asm:      FCBOpen, FCBClose, FCBDelete, FCBSeqRead, FCBSeqWrite,
+;                       FCBCreate, FCBRename, FCBRandomRead, FCBRandomWrite,
+;                       GetFCBFileLength, GetFCBPosition, FCBRandomReadBlock,
+;                       FCBRandomWriteBlock
+;   *   Time.asm:       GetDate, SetDate, GetTime, SetTime
+;   *   Parse.asm:      Parse_file_descriptor, PathParse
+;   *   GetSet.asm:     GetInterruptVector, SetInterruptVector,
+;                       GetVerifyOnWrite, SetVerifyOnWrite, GetDMA, SetDMA,
+;                       GetVersion, SetCTRLCTrapping, GetDriveFreespace,
+;                       CharOper, International, SetDefaultDrive,
+;                       GetDefaultDrive
+;   *   Misc.asm:       Sleazefunc, SleazefuncDL, GetDefaultDPB, GetDPB,
+;                       CreateProcessDataBlock, GetINDOSFlag, GetInVars,
+;                       SetDPB, DupPDB, DiskReset
+;                       StrCmp, StrCpy, Ucase            -> LOW LEVEL <-
+;
+; STUB MODULES
+;       Net.asm         **** This will get broken down more???
+;   *   Share.asm       Share_Check, Share_Violation
+;   *   Lock.asm        $LockOper
+;                       DOS_LOCK,DOS_UNLOCK,Lock_Check, Lock_Violation
+
+; INTERNAL INTERFACE MODULES
+;   *   Lock.asm        DOS_LOCK, DOS_UNLOCK   -->> STUBS <<--
+;   *   Dinfo.asm       DISK_INFO
+;   *   Finfo.asm       GET_FILE_INFO, SET_FILE_ATTRIBUTE
+;   *   Create.asm      DOS_CREATE, DOS_CREATE_NEW,
+;                       Set_Mknd_Err           --> Low level routine <--
+;   *   Dup.asm         DOS_DUP
+;   *   Open.asm        DOS_OPEN,
+;                       SetBadPathError,       --> Low level routines <--
+;                       Check_Access_AX, Share_Error, Set_SFT_Mode
+;   *   Close.asm       DOS_CLOSE, DOS_COMMIT, DOS_CLOSE_GOT_SFT,
+;                       Free_SFT               --> Low level routine <--
+;   *   Abort.asm       DOS_ABORT
+;   *   ISearch.asm     DOS_SEARCH_FIRST, DOS_SEARCH_NEXT,
+;                       RENAME_NEXT            --> Low level routine <--
+;   *   Dircall.asm     DOS_MKDIR, DOS_CHDIR, DOS_RMDIR
+;   *   Rename.asm      DOS_RENAME
+;   *   Delete.asm      DOS_DELETE,
+;                       REN_DEL_Check          --> Low level routine <--
+;   *   Disk.asm        DOS_READ, DOS_WRITE
+
+; LOW LEVEL MODULES
+;   *   Fat.asm         UNPACK, PACK, MAPCLUSTER, FATREAD_SFT,
+;                       FATREAD_CDS, FAT_operation
+;   *   Ctrlc.asm       --> STD/IBM versions <--
+;                       FATAL, FATAL1, reset_environment, DSKSTATCHK,
+;                       SPOOLINT, STATCHK, CNTCHAND, DIVOV, RealDivOv,
+;                       CHARHARD, HardErr
+;   *   Buf.asm         SETVISIT, ScanPlace, PLACEBUF, PLACEHEAD, PointComp,
+;                       GETBUFFR, GETBUFFRB, FlushBuf, BufWrite,
+;                       SKIPVISIT
+;   *   Disk.asm        SWAPBACK, SWAPCON, get_io_sft, DirRead, FATSecRd,
+;                       DskRead, SETUP, BREAKDOWN, DISKREAD, DISKWRITE,
+;                       FIRSTCLUSTER, DREAD, DWRITE, DSKWRITE,
+;                       READ_LOCK_VIOLATION, WRITE_LOCK_VIOLATION,
+;                       SETSFT, SETCLUS, AddRec
+;   *   Mknode.asm      BUILDDIR, SETDOTENT, MakeNode, NEWENTRY, FREEENT,
+;                       NEWDIR, DOOPEN,RENAME_MAKE
+;   *   FCB.asm         MakeFcb, NameTrans, PATHCHRCMP, GetLet, TESTKANJ,
+;                       NORMSCAN, CHK, DELIM
+;   *   Rom.asm         GET_random_record, GETRRPOS1, GetRRPos, SKPCLP,
+;                       FNDCLUS, BUFSEC, BUFRD, BUFWRT, NEXTSEC,
+;                       OPTIMIZE, FIGREC, GETREC, ALLOCATE, RESTFATBYT,
+;                       RELEASE, RELBLKS, GETEOF
+;   *   Dev.asm         IOFUNC, DEVIOCALL, SETREAD, SETWRITE, GOTDPB,
+;                       DEVIOCALL2, DEV_CLOSE_SFT, DEV_OPEN_SFT
+;   *   Dir.asm         SEARCH, SETDIRSRCH, GETPATH, ROOTPATH, StartSrch,
+;                       MatchAttributes, DEVNAME, Build_device_ent,
+;                       FindEntry, Srch, NEXTENT, GETENTRY, GETENT,
+;                       NEXTENTRY, GetPathNoSet, FINDPATH
+;
+
+; critical section information for the system calls
+
+;   System Call                       Who takes care of the reentrancy
+;   Abort                          0    (flushbuf) DOS_Close
+;   Std_Con_Input                  1    DOS_Read
+;   Std_Con_Output                 2    DOS_Write
+;   Std_Aux_Input                  3    DOS_Read
+;   Std_Aux_Output                 4    DOS_Write
+;   Std_Printer_Output             5    DOS_Write
+;   Raw_Con_IO                     6    DOS_Read/DOS_Write
+;   Raw_Con_Input                  7    DOS_Read
+;   Std_Con_Input_No_Echo          8    DOS_Read
+;   Std_Con_String_Output          9    DOS_Write
+;   Std_Con_String_Input           A    DOS_Read
+;   Std_Con_Input_Status           B    DOS_Read
+;   Std_Con_Input_Flush            C    DOS_Read
+;   Disk_Reset                     D    (FlushBuf, ScanPlace, SkipVisit)
+;   Set_Default_Drive              E    *none*
+;   FCB_Open                       F    DOS_Open
+;   FCB_Close                     10    DOS_Close
+;   Dir_Search_First              11    DOS_Search_First
+;   Dir_Search_Next               12    DOS_Search_Next
+;   FCB_Delete                    13    DOS_Delete
+;   FCB_Seq_Read                  14    DOS_Read/DOS_Write
+;   FCB_Seq_Write                 15    DOS_Read/DOS_Write
+;   FCB_Create                    16    DOS_Create
+;   FCB_Rename                    17    DOS_rename
+;   Get_Default_Drive             19    *none*
+;   Set_DMA                       1A    *none*
+;   Get_Default_DPB               1F    *none*
+;   FCB_Random_Read               21    DOS_Read/DOS_Write
+;   FCB_Random_Write              22    DOS_Read/DOS_Write
+;   Get_FCB_File_Length           23    Get_file_info
+;   Get_FCB_Position              24    *none*
+;   Set_Interrupt_Vector          25    *none*
+;   Create_Process_Data_Block     26    *none*
+;   FCB_Random_Read_Block         27    DOS_Read/DOS_Write
+;   FCB_Random_Write_Block        28    DOS_Read/DOS_Write
+;   Parse_File_Descriptor         29    *none*
+;   Get_Date                      2A    DEVIOCALL
+;   Set_Date                      2B    DEVIOCALL
+;   Get_Time                      2C    DEVIOCALL
+;   Set_Time                      2D    DEVIOCALL
+;   Set_Verify_On_Write           2E    *none*
+;   Get_DMA                       2F    *none*
+;   Get_Version                   30    *none*
+;   Keep_Process                  31    $abort...
+;   Get_DPB                       32    *none*
+;   Set_CTRL_C_Trapping           33    *none*
+;   Get_InDOS_Flag                34    *none*
+;   Get_Interrupt_Vector          35    *none*
+;   Get_Drive_Freespace           36    Disk_Info
+;   Char_Oper                     37    *none*
+;   International                 38    *none*
+;   MKDir                         39    DOS_MkDir
+;   RMDir                         3A    DOS_RmDir
+;   CHDir                         3B    DOS_ChDir
+;   Creat                         3C    DOS_Create
+;   Open                          3D    DOS_Open
+;   Close                         3E    DOS_Close
+;   Read                          3F    DOS_Read
+;   Write                         40    DOS_Write
+;   Unlink                        41    DOS_Delete
+;   LSeek                         42    *none*
+;   CHMod                         43    Get_file_info, Set_File_Attribute
+;   IOCtl                         44    DEVIOCALL
+;   XDup                          45    *none*
+;   XDup2                         46    *none*
+;   Current_Dir                   47    $Current_Dir
+;   Alloc                         48    $Alloc
+;   Dealloc                       49    $Dealloc
+;   Setblock                      4A    $SetBlock
+;   Exec                          4B
+;   Exit                          4C    $abort...
+;   Wait                          4D    *none*
+;   Find_First                    4E    DOS_Search_First
+;   Find_Next                     4F    DOS_Search_Next
+;   Set_Current_PDB               50    *none*
+;   Get_Current_PDB               51    *none*
+;   Get_In_Vars                   52    *none*
+;   SetDPB                        53    *none*
+;   Get_Verify_On_Write           54    *none*
+;   Dup_PDB                       55
+;   Rename                        56    DOS_Rename
+;   File_Times                    57    *none*
+;   AllocOper                     58    *none*
+;   GetExtendedError              59    *none*
+;   CreateTempFile                5A    DOS_Create_New
+;   CreateNewFile                 5B    DOS_Create_New
+;   LockOper                      5C
+;   ServerCall                    5D
+;   UserOper                      5E
+;   AssignOper                    5F
diff --git a/v4.0/src/DOS/DOSMES.ASM b/v4.0/src/DOS/DOSMES.ASM
new file mode 100644
index 0000000..3770c5d
--- /dev/null
+++ b/v4.0/src/DOS/DOSMES.ASM
@@ -0,0 +1,442 @@
+;       SCCSID = @(#)dosmes.asm 1.7 85/10/23
+;       SCCSID = @(#)dosmes.asm 1.7 85/10/23
+;
+; Message file for Internationalized messages.  There is
+; only one message here available for translation.
+;
+;
+;    Revision history
+;         A000    version 4.00  Jan. 1988
+;
+
+IFNDEF  KANJI
+KANJI   EQU     FALSE
+ENDIF
+
+IFNDEF  Rainbow
+Rainbow EQU FALSE
+ENDIF
+
+include dossym.inc
+include dosmac.inc
+include doscntry.inc
+
+CONSTANTS       SEGMENT WORD PUBLIC 'CONST'
+
+    PUBLIC  UserNum, OEMNum
+    Public DMES001S,DMES001E
+DMES001S Label byte
+USERNUM DW      ?                       ; 24 bit user number
+        DB      ?
+IF      IBM
+        IF      IBMCOPYRIGHT
+        OEMNUM  DB      0                       ; 8 bit OEM number
+        ELSE
+        OEMNUM  DB      0FFH                    ; 8 bit OEM number
+        ENDIF
+ELSE
+OEMNUM  DB      0FFH
+ENDIF
+
+
+DMES001E label byte
+CONSTANTS       ENDS
+
+TABLE           SEGMENT BYTE PUBLIC 'TABLE'
+Public DMES002S
+DMES002S  label byte
+
+
+; The following table is used for DOS 3.3
+;DOS country and code page information is defined here for DOS 3.3.
+;The initial value for ccDosCountry is 1 (USA).
+;The initial value for ccDosCodepage is 850.
+;
+;
+                   PUBLIC  COUNTRY_CDPG,UCASE_TAB,FILE_UCASE_TAB
+                   PUBLIC  FILE_CHAR_TAB
+;
+; country and code page infomation
+;
+COUNTRY_CDPG  label  byte
+
+         db   0,0,0,0,0,0,0,0         ; reserved words
+         db   '\COUNTRY.SYS',0        ; path name of country.sys
+         db   51 dup (?)
+         dw   437                     ; system code page id
+         dw   6                       ; number of entries
+         db   SetUcase                ; Ucase type
+         dw   OFFSET DOSGROUP:UCASE_TAB    ;pointer to upper case table
+         dw   0                            ; segment of poiter
+         db   SetUcaseFile            ; Ucase file char type
+         dw   OFFSET DOSGROUP:FILE_UCASE_TAB    ;pointer to file upper case table
+         dw   0                            ; segment of poiter
+         db   SetFileList             ; valid file chars type
+         dw   OFFSET DOSGROUP:FILE_CHAR_TAB   ;pointer to valid file char tab
+         dw   0                            ; segment of poiter
+         db   SetCollate              ; collate type
+         dw   OFFSET DOSGROUP:COLLATE_TAB  ;pointer to collate table
+         dw   0                            ; segment of poiter
+         db   SetDBCS                 ;AN000; DBCS Ev                     2/12/KK
+         dw   OFFSET DOSGROUP:DBCS_TAB ;AN000;;pointer to DBCS Ev table   2/12/KK
+         dw   0                        ;AN000; segment of poiter         2/12/KK
+         db   SetCountryInfo          ; country info type
+         dw   NEW_COUNTRY_SIZE        ; extended country info size
+         dw   1                       ; USA country id
+         dw   437                     ; USA system code page id
+         dw   0                       ; date format
+         db   '$',0,0,0,0             ; currency symbol
+         db   ',',0                   ; thousand separator
+         db   '.',0                   ; decimal separator
+         db   '-',0                   ; date separator
+         db   ':',0                   ; time separator
+         db   0                       ; currency format flag
+         db   2                       ; # of disgit in currency
+         db   0                       ; time format
+         dw   OFFSET DOSGROUP:MAP_CASE  ;mono case routine entry point
+         dw   0                         ; segment of entry point
+         db   ',',0                    ; data list separator
+         dw   0,0,0,0,0                ; reserved
+
+
+
+;
+;
+;
+;
+;
+; upper case table
+;
+UCASE_TAB    label   byte
+                    dw  128
+                    db  128,154,069,065,142,065,143,128
+                    db  069,069,069,073,073,073,142,143
+                    db  144,146,146,079,153,079,085,085
+                    db  089,153,154,155,156,157,158,159
+                    db  065,073,079,085,165,165,166,167
+                    db  168,169,170,171,172,173,174,175
+                    db  176,177,178,179,180,181,182,183
+                    db  184,185,186,187,188,189,190,191
+                    db  192,193,194,195,196,197,198,199
+                    db  200,201,202,203,204,205,206,207
+                    db  208,209,210,211,212,213,214,215
+                    db  216,217,218,219,220,221,222,223
+                    db  224,225,226,227,228,229,230,231
+                    db  232,233,234,235,236,237,238,239
+                    db  240,241,242,243,244,245,246,247
+                    db  248,249,250,251,252,253,254,255
+
+;
+; file upper case table
+;
+FILE_UCASE_TAB  label  byte
+                    dw  128
+                    db  128,154,069,065,142,065,143,128
+                    db  069,069,069,073,073,073,142,143
+                    db  144,146,146,079,153,079,085,085
+                    db  089,153,154,155,156,157,158,159
+                    db  065,073,079,085,165,165,166,167
+                    db  168,169,170,171,172,173,174,175
+                    db  176,177,178,179,180,181,182,183
+                    db  184,185,186,187,188,189,190,191
+                    db  192,193,194,195,196,197,198,199
+                    db  200,201,202,203,204,205,206,207
+                    db  208,209,210,211,212,213,214,215
+                    db  216,217,218,219,220,221,222,223
+                    db  224,225,226,227,228,229,230,231
+                    db  232,233,234,235,236,237,238,239
+                    db  240,241,242,243,244,245,246,247
+                    db  248,249,250,251,252,253,254,255
+
+;
+; file char list
+;
+FILE_CHAR_TAB  label  byte
+                dw      22                              ; length
+                db      1,0,255                         ; include all
+                db      0,0,20h                         ; exclude 0 - 20h
+                db      2,14,'."/\[]:|<>+=;,'           ; exclude 14 special
+                db      24 dup (?)                      ; reserved
+;
+; collate table
+;
+COLLATE_TAB    label   byte
+                dw      256
+        db      0,1,2,3,4,5,6,7
+        db      8,9,10,11,12,13,14,15
+        db      16,17,18,19,20,21,22,23
+        db      24,25,26,27,28,29,30,31
+        db      " ","!",'"',"#","$","%","&","'"
+        db      "(",")","*","+",",","-",".","/"
+        db      "0","1","2","3","4","5","6","7"
+        db      "8","9",":",";","<","=",">","?"
+        db      "@","A","B","C","D","E","F","G"
+        db      "H","I","J","K","L","M","N","O"
+        db      "P","Q","R","S","T","U","V","W"
+        db      "X","Y","Z","[","\","]","^","_"
+        db      "`","A","B","C","D","E","F","G"
+        db      "H","I","J","K","L","M","N","O"
+        db      "P","Q","R","S","T","U","V","W"
+        db      "X","Y","Z","{","|","}","~",127
+        db      "C","U","E","A","A","A","A","C"
+        db      "E","E","E","I","I","I","A","A"
+        db      "E","A","A","O","O","O","U","U"
+        db      "Y","O","U","$","$","$","$","$"
+        db      "A","I","O","U","N","N",166,167
+        db      "?",169,170,171,172,"!",'"','"'
+        db      176,177,178,179,180,181,182,183
+        db      184,185,186,187,188,189,190,191
+        db      192,193,194,195,196,197,198,199
+        db      200,201,202,203,204,205,206,207
+        db      208,209,210,211,212,213,214,215
+        db      216,217,218,219,220,221,222,223
+        db      224,"S"
+        db      226,227,228,229,230,231
+        db      232,233,234,235,236,237,238,239
+        db      240,241,242,243,244,245,246,247
+        db      248,249,250,251,252,253,254,255
+;
+; dbcs is not supported in DOS 3.3
+;                  DBCS_TAB         CC_DBCS <>
+;
+; DBCS for DOS 4.00                        2/12/KK
+   PUBLIC    DBCS_TAB
+DBCS_TAB        label byte              ;AN000;  2/12/KK
+                dw      0               ;AN000;  2/12/KK      max number
+                db      16 dup(0)       ;AN000;  2/12/KK
+
+;               dw      6               ;  2/12/KK
+;               db      081h,09fh       ;  2/12/KK
+;               db      0e0h,0fch       ;  2/12/KK
+;               db      0,0             ;  2/12/KK
+;
+;
+include divmes.asm
+include yesno.asm
+
+TABLE           ENDS
+
+CODE            SEGMENT BYTE PUBLIC 'CODE'
+ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+;CASE MAPPER ROUTINE FOR 80H-FFH character range, DOS 3.3
+;     ENTRY: AL = Character to map
+;     EXIT:  AL = The converted character
+; Alters no registers except AL and flags.
+; The routine should do nothing to chars below 80H.
+;
+; Example:
+
+Procedure   MAP_CASE,FAR
+        CMP     AL,80H
+        JAE     Map1            ;Map no chars below 80H ever
+        RET
+Map1:
+        SUB     AL,80H          ;Turn into index value
+        PUSH    DS
+        PUSH    BX
+        MOV     BX,OFFSET DOSGROUP:UCASE_TAB + 2
+FINISH:
+        PUSH    CS              ;Move to DS
+        POP     DS
+        XLAT    ds:[bx]         ;Get upper case character
+        POP     BX
+        POP     DS
+L_RET:  RET
+EndProc MAP_CASE
+
+SUBTTL EDIT FUNCTION ASSIGNMENTS AND HEADERS
+PAGE
+; The following two tables implement the current buffered input editing
+; routines.  The tables are pairwise associated in reverse order for ease
+; in indexing.  That is; The first entry in ESCTAB corresponds to the last
+; entry in ESCFUNC, and the last entry in ESCTAB to the first entry in ESCFUNC.
+
+
+TABLE   SEGMENT
+        PUBLIC  CANCHAR
+CANCHAR DB      CANCEL                  ;Cancel line character
+        PUBLIC  ESCCHAR
+ESCCHAR DB      ESCCH                   ;Lead-in character for escape sequences
+        IF      NOT Rainbow
+ESCTAB  LABEL BYTE
+        IF      NOT IBM
+        IF      WANG
+        DB      0C0h                    ; ^Z inserter
+        DB      0C1H                    ; Copy one char
+        DB      0C1H                    ; Copy one char
+        DB      0C7H                    ; Skip one char
+        DB      08AH                    ; Copy to char
+        DB      088H                    ; Skip to char
+        DB      09AH                    ; Copy line
+        DB      0CBH                    ; Kill line (no change in template)
+        DB      08BH                    ; Reedit line (new template)
+        DB      0C3H                    ; Backspace
+        DB      0C6H                    ; Enter insert mode
+        DB      0D6H                    ; Exit insert mode
+        DB      0C6H                    ; Escape character
+        DB      0C6H                    ; End of table
+        ELSE
+                                        ; VT52 equivalences
+        DB      "Z"                     ; ^Z inserter
+        DB      "S"                     ; F1 Copy one char
+        DB      "S"                     ; F1 Copy one char
+        DB      "V"                     ; F4 Skip one char
+        DB      "T"                     ; F2 Copy to char
+        DB      "W"                     ; F5 Skip to char
+        DB      "U"                     ; F3 Copy line
+        DB      "E"                     ; SHIFT ERASE Kill line (no change in template)
+        DB      "J"                     ; ERASE Reedit line (new template)
+        DB      "D"                     ; LEFT Backspace
+        DB      "P"                     ; BLUE Enter insert mode
+        DB      "Q"                     ; RED Exit insert mode
+        DB      "R"                     ; GRAY Escape character
+        DB      "R"                     ; End of table
+        ENDIF
+        ENDIF
+        IF      IBM
+        DB      64                      ; Ctrl-Z - F6
+        DB      77                      ; Copy one char - -->
+        DB      59                      ; Copy one char - F1
+        DB      83                      ; Skip one char - DEL
+        DB      60                      ; Copy to char - F2
+        DB      62                      ; Skip to char - F4
+        DB      61                      ; Copy line - F3
+        DB      61                      ; Kill line (no change to template ) - Not used
+        DB      63                      ; Reedit line (new template) - F5
+        DB      75                      ; Backspace - <--
+        DB      82                      ; Enter insert mode - INS (toggle)
+        DB      82                      ; Exit insert mode - INS (toggle)
+        DB      65                      ; Escape character - F7
+        DB      65                      ; End of table
+        ENDIF
+ESCEND LABEL BYTE
+ESCTABLEN EQU   ESCEND-ESCTAB
+
+ESCFUNC LABEL   WORD
+        short_addr  GETCH               ; Ignore the escape sequence
+        short_addr  TWOESC
+        short_addr  EXITINS
+        short_addr  ENTERINS
+        short_addr  BACKSP
+        short_addr  REEDIT
+        short_addr  KILNEW
+        short_addr  COPYLIN
+        short_addr  SKIPSTR
+        short_addr  COPYSTR
+        short_addr  SKIPONE
+        short_addr  COPYONE
+        short_addr  COPYONE
+        short_addr  CTRLZ
+        ENDIF
+TABLE   ENDS
+
+;
+; OEMFunction key is expected to process a single function
+;   key input from a device and dispatch to the proper
+;   routines leaving all registers UNTOUCHED.
+;
+; Inputs:   CS, SS are DOSGROUP
+; Outputs:  None. This function is expected to JMP to one of
+;           the following labels:
+;
+;           GetCh       - ignore the sequence
+;           TwoEsc      - insert an ESCChar in the buffer
+;           ExitIns     - toggle insert mode
+;           EnterIns    - toggle insert mode
+;           BackSp      - move backwards one space
+;           ReEdit      - reedit the line with a new template
+;           KilNew      - discard the current line and start from scratch
+;           CopyLin     - copy the rest of the template into the line
+;           SkipStr     - read the next character and skip to it in the template
+;           CopyStr     - read next char and copy from template to line until char
+;           SkipOne     - advance position in template one character
+;           CopyOne     - copy next character in template into line
+;           CtrlZ       - place a ^Z into the template
+; Registers that are allowed to be modified by this function are:
+;           AX, CX, BP
+
+Procedure   OEMFunctionKey,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+ IF  DBCS                               ;AN000;
+extrn   intCNE0:near                    ;AN000; 2/17/KK
+        CALL    intCNE0                 ;AN000; 2/17/KK
+ ELSE                                   ;AN000;
+        invoke  $std_con_input_no_echo  ; Get the second byte of the sequence
+ ENDIF                                  ;AN000;
+        IF NOT Rainbow
+        MOV     CL,ESCTABLEN            ; length of table for scan
+        PUSH    DI                      ; save DI (cannot change it!)
+        MOV     DI,OFFSET DOSGROUP:ESCTAB   ; offset of second byte table
+        REPNE   SCASB                   ; Look it up in the table
+        POP     DI                      ; restore DI
+        SHL     CX,1                    ; convert byte offset to word
+        MOV     BP,CX                   ; move to indexable register
+        JMP     [BP+OFFSET DOSGROUP:ESCFUNC]    ; Go to the right routine
+        ENDIF
+        IF Rainbow
+
+TransferIf  MACRO   value,address
+        local   a
+        CMP     AL,value
+        JNZ     a
+        transfer    address
+a:
+ENDM
+
+        CMP     AL,'['                  ; is it second lead char
+        JZ      EatParm                 ; yes, go walk tree
+GoGetCh:
+        transfer    GetCh               ; no, ignore sequence
+EatParm:
+        invoke  $std_con_input_no_echo  ; get argument
+        CMP     AL,'A'                  ; is it alphabetic arg?
+        JAE     EatAlpha                ; yes, go snarf one up
+        XOR     BP,BP                   ; init digit counter
+        JMP     InDigit                 ; jump into internal eat digit routine
+EatNum:
+        invoke  $std_con_input_no_echo  ; get next digit
+InDigit:
+        CMP     AL,'9'                  ; still a digit?
+        JA      CheckNumEnd             ; no, go check for end char
+        SUB     AL,'0'                  ; turn into potential digit
+        JL      GoGetCh                 ; oops, not a digit, ignore
+        MOV     CX,BP                   ; save BP for 10 multiply
+        CBW                             ; make AL into AX
+        SHL     BP,1                    ; 2*BP
+        SHL     BP,1                    ; 4*BP
+        ADD     BP,CX                   ; 5*BP
+        SHL     BP,1                    ; 10*BP
+        ADD     BP,AX                   ; 10*BP + digit
+        JMP     EatNum                  ; continue with number
+CheckNumEnd:
+        CMP     AL,7Eh                  ; is it end char ~
+        JNZ     GoGetCh                 ; nope, ignore key sequence
+        MOV     AX,BP
+        transferIf  1,SkipStr           ; FIND key
+        transferIf  2,EnterIns          ; INSERT HERE key
+        transferIf  3,SkipOne           ; REMOVE
+        transferIf  4,CopyStr           ; SELECT
+        transferIf  17,TwoEsc           ; INTERRUPT
+        transferIf  18,ReEdit           ; RESUME
+        transferIf  19,KilNew           ; CANCEL
+        transferIf  21,CtrlZ            ; EXIT
+        transferIf  29,CopyLin          ; DO
+        JMP     GoGetCh
+EatAlpha:
+        CMP     AL,'O'                  ; is it O?
+        JA      GoGetCh                 ; no, after assume bogus
+        JZ      EatPQRS                 ; eat the rest of the bogus key
+        transferIf  'C',CopyOne         ; RIGHT
+        transferIf  'D',BackSp          ; LEFT
+        JMP     GoGetCh
+EatPQRS:
+        invoke  $std_con_input_no_echo  ; eat char after O
+        JMP     GoGetCh
+        ENDIF
+
+EndProc OEMFunctionKey
+
+CODE            ENDS
+
+        END
diff --git a/v4.0/src/DOS/DOSPRINT.ASM b/v4.0/src/DOS/DOSPRINT.ASM
new file mode 100644
index 0000000..92789cf
--- /dev/null
+++ b/v4.0/src/DOS/DOSPRINT.ASM
@@ -0,0 +1,36 @@
+;       SCCSID = @(#)dosprint.asm       1.1 85/04/10
+;       SCCSID = @(#)dosprint.asm       1.1 85/04/10
+TITLE   DOSPRINT - PRINTF at DOS level
+NAME    DOSPRINT
+;
+;
+;   Modification history:
+;
+;       Created: MZ 16 June 1984
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+.sall
+
+        I_Need  Proc_ID,WORD
+        I_Need  User_ID,WORD
+
+BREAK   <debugging output>
+
+include print.asm
+
+CODE ENDS
+END
diff --git a/v4.0/src/DOS/DUP.ASM b/v4.0/src/DOS/DUP.ASM
new file mode 100644
index 0000000..0f8c768
--- /dev/null
+++ b/v4.0/src/DOS/DUP.ASM
@@ -0,0 +1,68 @@
+;       SCCSID = @(#)dup.asm    1.1 85/04/10
+;       SCCSID = @(#)dup.asm    1.1 85/04/10
+TITLE   DOS_DUP - Internal SFT DUP (for network SFTs)
+NAME    DOS_DUP
+; Low level DUP routine for use by EXEC when creating a new process. Exports
+;   the DUP to the server machine and increments the SFT ref count
+;
+; DOS_DUP
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+        i_need  THISSFT,DWORD
+
+BREAK <DOS_DUP -- DUP SFT across network>
+
+; Inputs:
+;       [THISSFT] set to the SFT for the file being DUPed
+;               (a non net SFT is OK, in this case the ref
+;                count is simply incremented)
+; Function:
+;       Signal to the devices that alogical open is occurring
+; Returns:
+;       ES:DI point to SFT
+;    Carry clear
+;       SFT ref_count is incremented
+; Registers modified: None.
+; NOTE:
+;       This routine is called from $CREATE_PROCESS_DATA_BLOCK at DOSINIT
+;       time with SS NOT DOSGROUP. There will be no Network handles at
+;       that time.
+
+        procedure   DOS_DUP,NEAR
+        ASSUME  ES:NOTHING,SS:NOTHING
+
+        LES     DI,ThisSFT
+        Entry   Dos_Dup_Direct
+        Assert  ISSFT,<ES,DI>,"DOSDup"
+        invoke  IsSFTNet
+        JNZ     DO_INC
+        invoke  DEV_OPEN_SFT
+DO_INC:
+        Assert  ISSFT,<ES,DI>,"DOSDup/DoInc"
+        INC     ES:[DI.sf_ref_count]    ; Clears carry (if this ever wraps
+                                        ;   we're in big trouble anyway)
+        return
+
+EndProc DOS_DUP
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/EXEC.ASM b/v4.0/src/DOS/EXEC.ASM
new file mode 100644
index 0000000..aa120c2
--- /dev/null
+++ b/v4.0/src/DOS/EXEC.ASM
@@ -0,0 +1,931 @@
+;       SCCSID = @(#)exec.asm   1.3 85/08/13
+;       SCCSID = @(#)exec.asm   1.3 85/08/13
+;    AN000 version 4.0 jan. 1988
+;    A007  PTM 3957 - fake vesrion for IBMCACHE.COM
+;    A008  PTM 4070 - fake version for MS WINDOWS
+
+SUBTTL $exec - load/go a program
+PAGE
+;
+; Assembler usage:
+;           LDS     DX, name
+;           LES     BX, blk
+;           MOV     AH, Exec
+;           MOV     AL, func
+;           INT     int_command
+;
+;       AL  Function
+;       --  --------
+;        0  Load and execute the program.
+;        1  Load, create  the  program  header  but  do  not
+;           begin execution.
+;        3  Load overlay. No header created.
+;
+;           AL = 0 -> load/execute program
+;
+;           +---------------------------+
+;           | WORD segment address of   |
+;           | environment.              |
+;           +---------------------------+
+;           | DWORD pointer to ASCIZ    |
+;           | command line at 80h       |
+;           +---------------------------+
+;           | DWORD pointer to default  |
+;           | FCB to be passed at 5Ch   |
+;           +---------------------------+
+;           | DWORD pointer to default  |
+;           | FCB to be passed at 6Ch   |
+;           +---------------------------+
+;
+;           AL = 1 -> load program
+;
+;           +---------------------------+
+;           | WORD segment address of   |
+;           | environment.              |
+;           +---------------------------+
+;           | DWORD pointer to ASCIZ    |
+;           | command line at 80h       |
+;           +---------------------------+
+;           | DWORD pointer to default  |
+;           | FCB to be passed at 5Ch   |
+;           +---------------------------+
+;           | DWORD pointer to default  |
+;           | FCB to be passed at 6Ch   |
+;           +---------------------------+
+;           | DWORD returned value of   |
+;           | CS:IP                     |
+;           +---------------------------+
+;           | DWORD returned value of   |
+;           | SS:IP                     |
+;           +---------------------------+
+;
+;           AL = 3 -> load overlay
+;
+;           +---------------------------+
+;           | WORD segment address where|
+;           | file will be loaded.      |
+;           +---------------------------+
+;           | WORD relocation factor to |
+;           | be applied to the image.  |
+;           +---------------------------+
+;
+; Returns:
+;           AX = error_invalid_function
+;              = error_bad_format
+;              = error_bad_environment
+;              = error_not_enough_memory
+;              = error_file_not_found
+;
+;   Revision history:
+;
+;        A000   version 4.00  Jan. 1988
+;
+include EA.INC
+include version.inc
+
+        I_Need     Temp_Var2,WORD            ;AN000;file type from $open
+        I_Need     Special_Entries,WORD      ;AN007;address of special entries
+        I_Need     Special_Version,WORD      ;AN007;special version number
+        I_Need     Fake_Count,BYTE           ;AN008;fake version count
+
+IF      BUFFERFLAG
+        extrn   restore_user_map:near
+ENDIF
+
+TABLE   SEGMENT
+
+exec_init_SP        DW  ?
+exec_init_SS        DW  ?
+exec_init_IP        DW  ?
+exec_init_CS        DW  ?
+
+exec_internal_buffer    EQU OpenBuf
+
+exec_signature      DW  ?               ; must contain 4D5A  (yay zibo!)
+exec_len_mod_512    DW  ?               ; low 9 bits of length
+exec_pages          DW  ?               ; number of 512b pages in file
+exec_rle_count      DW  ?               ; count of reloc entries
+exec_par_dir        DW  ?               ; number of paragraphs before image
+exec_min_BSS        DW  ?               ; minimum number of para of BSS
+exec_max_BSS        DW  ?               ; max number of para of BSS
+exec_SS             DW  ?               ; stack of image
+exec_SP             DW  ?               ; SP of image
+exec_chksum         DW  ?               ; checksum  of file (ignored)
+exec_IP             DW  ?               ; IP of entry
+exec_CS             DW  ?               ; CS of entry
+exec_rle_table      DW  ?               ; byte offset of reloc table
+Exec_header_len     EQU $-Exec_Signature
+
+exec_internal_buffer_size   EQU (128+128+53+curdirLEN)
+%out    Please make sure that the following are contiguous and of the
+%out    following sizes:
+%out
+%out    OpenBuf     128
+%out    RenBuf      128
+%out    SearchBuf    53
+%out    DummyCDS    CurDirLen
+
+TABLE   ENDS
+
+.sall
+
+procedure   $Exec,NEAR
+        ASSUME  DS:NOTHING, ES:NOTHING
+PUBLIC EXEC001S,EXEC001E
+EXEC001S:
+        LocalVar    exec_blk,DWORD
+        LocalVar    exec_func,BYTE
+        LocalVar    exec_load_high,BYTE
+        LocalVar    exec_fh,WORD
+        LocalVar    exec_rel_fac,WORD
+        LocalVar    exec_res_len_para,WORD
+        LocalVar    exec_environ,WORD
+        LocalVar    exec_size,WORD
+        LocalVar    exec_load_block,WORD
+        LocalVar    exec_dma,WORD
+        LocalVar    execNameLen,WORD
+        LocalVar    execName,DWORD
+EXEC001E:
+        Enter
+;
+; validate function
+;
+
+        CMP     AL,3                    ; only 0, 1 or 3 are allowed
+        JNA     exec_check_2
+
+exec_bad_fun:
+        MOV     EXTERR_LOCUS,errLOC_Unk ; Extended Error Locus
+        mov     al,error_invalid_function
+
+exec_ret_err:
+        Leave
+        transfer    SYS_RET_ERR
+
+exec_check_2:
+        CMP     AL,2
+        JZ      exec_bad_fun
+
+        MOV     exec_blkL,BX            ; stash args
+        MOV     exec_blkH,ES
+        MOV     exec_func,AL
+        MOV     exec_load_high,0
+;
+; set up length of exec name
+;
+        MOV     execNameL,DX
+        MOV     execNameH,DS
+        MOV     SI,DX                   ; move pointer to convenient place
+        invoke  DStrLen
+        MOV     ExecNameLen,CX          ; save length
+
+        XOR     AL,AL                   ; open for reading
+        PUSH    BP
+        invoke  $OPEN                   ; is the file there?
+        POP     BP
+        JC      exec_ret_err
+;File Type Checking
+;       CMP     BYTE PTR [Temp_Var2],EAEXISTING      ;AN000;;FT.  old file ?
+;       JZ      oldexf                               ;AN000;;FT.  yes
+;       TEST    BYTE PTR EXEC_FUNC,EXEC_FUNC_OVERLAY ;AN000;;FT.  exec overlay?
+;       JNZ     exovrly                              ;AN000;;FT.  yes
+;       CMP     BYTE PTR [Temp_Var2],EAEXECUTABLE    ;AN000;;FT.  only file type
+;       JZ      oldexf                               ;AN000;;FT.  3 & 4 will pass
+;       CMP     BYTE PTR [Temp_Var2],EAINSTALLABLE   ;AN000;;FT.
+;       JZ      oldexf                               ;AN000;;FT.
+;exerr:                                               ;AN000;;FT.
+;       MOV     AL,error_access_denied               ;AN000;;FT.  error
+;       JMP     exec_ret_err                         ;AN000;;FT.
+;exovrly:                                             ;AN000;;FT.
+;       CMP     BYTE PTR [Temp_Var2],EAOVERLAY       ;AN000;;FT.  only 5,6,7  pass
+;       JZ      oldexf                               ;AN000;;FT.
+;       CMP     BYTE PTR [Temp_Var2],EADEV_DRIVER    ;AN000;;FT.
+;       JZ      oldexf                               ;AN000;;FT.
+;       CMP     BYTE PTR [Temp_Var2],EAIFS_DRIVER    ;AN000;;FT.
+;       JNZ     exerr                                ;AN000;;FT.
+;
+;oldexf:                                              ;AN000;
+;File Type Checking
+
+        MOV     exec_fh,AX
+        MOV     BX,AX
+        XOR     AL,AL
+        invoke  $IOCTL
+        JC      Exec_bombJ
+        TEST    DL,devid_ISDEV
+        JZ      exec_check_environ
+        MOV     AL,error_file_not_found
+Exec_bombJ:
+        JMP     Exec_Bomb
+
+BadEnv:
+        MOV     AL,error_bad_environment
+        JMP     exec_bomb
+
+exec_check_environ:
+        MOV     exec_load_block,0
+        MOV     exec_environ,0
+
+        TEST    BYTE PTR exec_func,exec_func_overlay    ; overlays... no environment
+        JNZ     exec_read_header
+        LDS     SI,exec_blk             ; get block
+        MOV     AX,[SI].Exec1_environ   ; address of environ
+        OR      AX,AX
+        JNZ     exec_scan_env
+        MOV     DS,CurrentPDB
+        MOV     AX,DS:[PDB_environ]
+        MOV     exec_environ,AX
+        OR      AX,AX
+        JZ      exec_read_header
+
+exec_scan_env:
+        MOV     ES,AX
+        XOR     DI,DI
+        MOV     CX,07FFFh               ; at most 32k of environment
+        XOR     AL,AL
+
+exec_get_environ_len:
+        REPNZ   SCASB                   ; find that nul byte
+        JNZ     BadEnv
+        DEC     CX                      ; Dec CX for the next nul byte test
+        JB      BadEnv                  ; gone beyond the end of the environment
+        SCASB                           ; is there another nul byte?
+        JNZ     exec_get_environ_len    ; no, scan some more
+        PUSH    DI
+        LEA     BX,[DI+0Fh+2]
+        ADD     BX,ExecNameLen          ; BX <- length of environment
+                                        ; remember argv[0] length
+                                        ; round up and remember argc
+        MOV     CL,4
+        SHR     BX,CL                   ; number of paragraphs needed
+        PUSH    ES
+        invoke  $ALLOC                  ; can we get the space?
+        POP     DS
+        POP     CX
+        JNC     exec_save_environ
+        JMP     exec_no_mem             ; nope... cry and sob
+
+exec_save_environ:
+        MOV     ES,AX
+        MOV     exec_environ,AX         ; save him for a rainy day
+        XOR     SI,SI
+        MOV     DI,SI
+        REP     MOVSB                   ; copy the environment
+        MOV     AX,1
+        STOSW
+        LDS     SI,execName
+        MOV     CX,execNameLen
+        REP     MOVSB
+
+exec_read_header:
+;
+; We read in the program header into the above data area and determine
+; where in this memory the image will be located.
+;
+        Context DS
+        MOV     CX,exec_header_len      ; header size
+        MOV     DX,OFFSET DOSGROUP:exec_signature
+        PUSH    ES
+        PUSH    DS
+        CALL    ExecRead
+        POP     DS
+        POP     ES
+        JC      exec_bad_file
+        OR      AX,AX
+        JZ      exec_bad_file
+        CMP     AX,exec_header_len      ; did we read the right number?
+        JNZ     exec_com_filej          ; yep... continue
+        TEST    exec_max_BSS,-1         ; indicate load high?
+        JNZ     exec_check_sig
+        MOV     exec_load_high,-1
+exec_check_sig:
+        MOV     AX,exec_signature
+        CMP     AX,exe_valid_signature  ; zibo arises!
+        JZ      exec_save_start         ; assume com file if no signature
+        CMP     AX,exe_valid_old_signature  ; zibo arises!
+        JZ      exec_save_start         ; assume com file if no signature
+
+exec_com_filej:
+        JMP     exec_com_file
+
+;
+; We have the program header... determine memory requirements
+;
+exec_save_start:
+        MOV     AX,exec_pages           ; get 512-byte pages
+        MOV     CL,5                    ; convert to paragraphs
+        SHL     AX,CL
+        SUB     AX,exec_par_dir         ; AX = size in paragraphs
+        MOV     exec_res_len_para,AX
+
+;
+; Do we need to allocate memory?  Yes if function is not load-overlay
+;
+        TEST    BYTE PTR exec_func,exec_func_overlay
+        JZ      exec_allocate           ; allocation of space
+;
+; get load address from block
+;
+        LES     DI,exec_blk
+        MOV     AX,ES:[DI].exec3_load_addr
+        MOV     exec_dma,AX
+        MOV     AX,ES:[DI].exec3_reloc_fac
+        MOV     exec_rel_fac,AX
+IF DEBUG
+        JMP     exec_find_res
+ELSE
+        JMP     SHORT exec_find_res
+ENDIF
+
+exec_no_mem:
+        MOV     AL,error_not_enough_memory
+        JMP     SHORT exec_bomb
+
+exec_bad_file:
+        MOV     AL,error_bad_format
+
+exec_bomb:
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     BX,exec_fh
+        CALL    exec_dealloc
+        LeaveCrit   CritMem
+        SaveReg <AX,BP>
+        invoke  $CLOSE
+        RestoreReg  <BP,AX>
+        JMP     Exec_Ret_Err
+
+exec_allocate:
+        DOSAssume   CS,<DS>,"EXEC/exec_allocate"
+        PUSH    AX
+        MOV     BX,0FFFFh               ; see how much room in arena
+        PUSH    DS
+        invoke  $ALLOC                  ; should have carry set and BX has max
+        POP     DS
+        POP     AX
+        ADD     AX,10h                  ; room for header
+        CMP     BX,11h                  ; enough room for a header
+        JB      exec_no_mem
+        CMP     AX,BX                   ; is there enough for bare image?
+        JA      exec_no_mem
+        TEST    exec_load_high,-1       ; if load high, use max
+        JNZ     exec_BX_max             ; use max
+        ADD     AX,exec_min_BSS         ; go for min allocation
+        JC      exec_no_mem             ; oops! carry
+        CMP     AX,BX                   ; enough space?
+        JA      exec_no_mem             ; nope...
+        SUB     AX,exec_min_BSS
+        ADD     AX,exec_max_BSS         ; go for the MAX
+        JC      exec_BX_max
+        CMP     AX,BX
+        JBE     exec_got_block
+
+exec_BX_max:
+        MOV     AX,BX
+
+exec_got_block:
+        PUSH    DS
+        MOV     BX,AX
+        MOV     exec_size,BX
+        invoke  $ALLOC                  ; get the space
+        POP     DS
+        JC      exec_no_mem
+        MOV     exec_load_block,AX
+        ADD     AX,10h
+        TEST    exec_load_high,-1
+        JZ      exec_use_ax             ; use ax for load info
+        ADD     AX,exec_size            ; go to end
+        SUB     AX,exec_res_len_para    ; drop off header
+        SUB     AX,10h                  ; drop off pdb
+exec_use_ax:
+        MOV     exec_rel_fac,AX         ; new segment
+        MOV     exec_dma,AX             ; beginning of dma
+
+;
+; Determine the location in the file of the beginning of the resident
+;
+exec_find_res:
+        MOV     DX,exec_par_dir
+        PUSH    DX
+        MOV     CL,4
+        SHL     DX,CL                   ; low word of location
+        POP     AX
+        MOV     CL,12
+        SHR     AX,CL                   ; high word of location
+        MOV     CX,AX                   ; CX <- high
+
+;
+; Read in the resident image (first, seek to it)
+;
+        MOV     BX,exec_fh
+        PUSH    DS
+        XOR     AL,AL
+        invoke  $LSEEK                  ; seek to resident
+        POP     DS
+        jnc     exec_big_read
+        jmp     exec_bomb
+
+exec_big_read:                          ; Read resident into memory
+        MOV     BX,exec_res_len_para
+        CMP     BX,1000h                ; too many bytes to read?
+        JB      exec_read_ok
+        MOV     BX,0FE0h                ; max in one chunk FE00 bytes
+
+exec_read_ok:
+        SUB     exec_res_len_para,BX    ; we read (soon) this many
+        PUSH    BX
+        MOV     CL,4
+        SHL     BX,CL                   ; get count in bytes from paras
+        MOV     CX,BX                   ; count in correct register
+        PUSH    DS
+        MOV     DS,exec_dma             ; Set up read buffer
+        ASSUME  DS:NOTHING
+        XOR     DX,DX
+        PUSH    CX                      ; save our count
+        CALL    ExecRead
+        POP     CX                      ; get old count to verify
+        POP     DS
+        JC      exec_bad_fileJ
+        DOSAssume   CS,<DS>,"EXEC/exec_read_ok"
+        CMP     CX,AX                   ; did we read enough?
+        POP     BX                      ; get paragraph count back
+        JZ      execCheckEnd            ; and do reloc if no more to read
+;
+; The read did not match the request.  If we are off by 512 bytes or more
+; then the header lied and we have an error.
+;
+        SUB     CX,AX
+        CMP     CX,512
+        JAE     Exec_Bad_fileJ
+;
+; We've read in CX bytes... bump DTA location
+;
+ExecCheckEnd:
+        ADD     exec_dma,BX             ; bump dma address
+        TEST    exec_res_len_para,-1
+        JNZ     exec_big_read
+;
+; The image has now been read in.  We must perform relocation to
+; the current location.
+;
+exec_do_reloc:
+        MOV     CX,exec_rel_fac
+        MOV     AX,exec_SS              ; get initial SS
+        ADD     AX,CX                   ; and relocate him
+        MOV     exec_init_SS,AX
+
+        MOV     AX,exec_SP              ; initial SP
+        MOV     exec_init_SP,AX
+
+        LES     AX,DWORD PTR exec_IP
+        MOV     exec_init_IP,AX
+        MOV     AX,ES
+        ADD     AX,CX                   ; relocated...
+        MOV     exec_init_CS,AX
+
+        XOR     CX,CX
+        MOV     DX,exec_rle_table
+        MOV     BX,exec_fh
+        PUSH    DS
+        XOR     AX,AX
+        invoke  $LSEEK
+        POP     DS
+
+        JNC     exec_get_entries
+exec_bad_filej:
+        JMP     exec_bad_file
+
+exec_get_entries:
+        MOV     DX,exec_rle_count       ; Number of entries left
+
+exec_read_reloc:
+        ASSUME  DS:NOTHING
+        PUSH    DX
+        MOV     DX,OFFSET DOSGROUP:exec_internal_buffer
+        MOV     CX,((exec_internal_buffer_size)/4)*4
+        PUSH    DS
+        CALL    ExecRead
+        POP     ES
+        POP     DX
+        JC      exec_bad_filej
+        MOV     CX,(exec_internal_buffer_size)/4
+        MOV     DI,OFFSET DOSGROUP:exec_internal_buffer ; Pointer to byte location in header
+;
+; Relocate a single address
+;
+        MOV     SI,exec_rel_fac
+
+exec_reloc_one:
+        OR      DX,DX                   ; Any more entries?
+        JE      exec_set_PDBJ
+
+exec_get_addr:
+        LDS     BX,DWORD PTR ES:[DI]    ; Get ra/sa of entry
+        MOV     AX,DS                   ; Relocate address of item
+        ADD     AX,SI
+        MOV     DS,AX
+        ADD     [BX],SI
+        ADD     DI,4
+        DEC     DX
+        LOOP    exec_reloc_one          ; End of internal buffer?
+
+;
+; We've exhausted a single buffer's worth.  Read in the next piece
+; of the relocation table.
+;
+
+        PUSH    ES
+        POP     DS
+        JMP     exec_read_reloc
+
+exec_set_PDBJ:
+        JMP     exec_set_PDB
+
+exec_no_memj:
+        JMP     exec_no_mem
+
+;
+; we have a .COM file.  First, determine if we are merely loading an overlay.
+;
+exec_com_file:
+        TEST    BYTE PTR exec_func,exec_func_overlay
+        JZ      exec_alloc_com_file
+        LDS     SI,exec_blk             ; get arg block
+        LODSW                           ; get load address
+        MOV     exec_dma,AX
+        MOV     AX,0FFFFh
+        JMP     SHORT exec_read_block   ; read it all!
+
+; We must allocate the max possible size block (ick!)  and set up
+; CS=DS=ES=SS=PDB pointer, IP=100, SP=max size of block.
+;
+exec_alloc_com_file:
+        MOV     BX,0FFFFh
+        invoke  $ALLOC                  ; largest piece available as error
+        OR      BX,BX
+        JZ      exec_no_memj
+        MOV     exec_size,BX            ; save size of allocation block
+        PUSH    BX
+        invoke  $ALLOC                  ; largest piece available as error
+        POP     BX                      ; get size of block...
+        MOV     exec_load_block,AX
+        ADD     AX,10h                  ; increment for header
+        MOV     exec_dma,AX
+        XOR     AX,AX                   ; presume 64K read...
+        CMP     BX,1000h                ; 64k or more in block?
+        JAE     exec_read_com           ; yes, read only 64k
+        MOV     AX,BX                   ; convert size to bytes
+        MOV     CL,4
+        SHL     AX,CL
+exec_read_com:
+        SUB     AX,100h                 ; remember size of psp
+exec_read_block:
+        PUSH    AX                      ; save number to read
+        MOV     BX,exec_fh              ; of com file
+        XOR     CX,CX                   ; but seek to 0:0
+        MOV     DX,CX
+        XOR     AX,AX                   ; seek relative to beginning
+        invoke  $LSEEK                  ; back to beginning of file
+        POP     CX                      ; number to read
+        MOV     DS,exec_dma
+        XOR     DX,DX
+        PUSH    CX
+        CALL    ExecRead
+        POP     SI                      ; get number of bytes to read
+        jnc     OkRead
+        jmp     exec_bad_file
+OkRead:
+        CMP     AX,SI                   ; did we read them all?
+        JZ      exec_no_memj            ; exactly the wrong number... no memory
+        TEST    BYTE PTR exec_func,exec_func_overlay
+        JNZ     exec_set_PDB            ; no starto, chumo!
+        MOV     AX,exec_DMA
+        SUB     AX,10h
+        MOV     exec_init_CS,AX
+        MOV     exec_init_IP,100h       ; initial IP is 100
+;
+; SI is at most FF00h.  Add FE to account for PSP - word of 0 on stack.
+;
+        ADD     SI,0FEh                 ; make room for stack
+        MOV     exec_init_SP,SI         ; max value for read is also SP!
+        MOV     exec_init_SS,AX
+        MOV     DS,AX
+        MOV     WORD PTR [SI],0         ; 0 for return
+
+exec_set_PDB:
+        MOV     BX,exec_fh              ; we are finished with the file.
+        CALL    exec_dealloc
+        PUSH    BP
+        invoke  $CLOSE                  ; release the jfn
+        POP     BP
+        CALL    exec_alloc
+        TEST    BYTE PTR exec_func,exec_func_overlay
+        JZ      exec_build_header
+        CALL    Scan_Execname           ;MS.;AN007;
+        CALL    Scan_Special_Entries    ;MS.;AN007;
+        Leave
+        transfer    SYS_RET_OK          ; overlay load -> done
+
+exec_build_header:
+        MOV     DX,exec_load_block
+;
+; assign the space to the process
+;
+
+        MOV     SI,arena_owner          ; pointer to owner field
+
+        MOV     AX,exec_environ         ; get environ pointer
+        OR      AX,AX
+        JZ      NO_OWNER                ; no environment
+        DEC     AX                      ; point to header
+        MOV     DS,AX
+        MOV     [SI],DX                 ; assign ownership
+NO_OWNER:
+        MOV     AX,exec_load_block      ; get load block pointer
+        DEC     AX
+        MOV     DS,AX                   ; point to header
+        MOV     [SI],DX                 ; assign ownership
+
+        PUSH    DS                      ;AN000;MS. make ES=DS
+        POP     ES                      ;AN000;MS.
+        MOV     DI,ARENA_NAME           ;AN000;MS. ES:DI points to destination
+        CALL    Scan_Execname           ;AN007;MS. parse execname
+                                        ;          ds:si->name, cx=name length
+        PUSH    CX                      ;AN007;;MS. save for fake version
+        PUSH    SI                      ;AN007;;MS. save for fake version
+
+movename:                               ;AN000;
+        LODSB                           ;AN000;;MS. get char
+        CMP     AL,'.'                  ;AN000;;MS. is '.' ,may be name.exe
+        JZ      mem_done                ;AN000;;MS. no, move to header
+                                        ;AN000;
+        STOSB                           ;AN000;;MS. move char
+        LOOP    movename                ;AN000;;MS. continue
+mem_done:                               ;AN000;
+        XOR     AL,AL                   ;AN000;;MS. make ASCIIZ
+        CMP     DI,SIZE ARENA           ;AN000;MS. if not all filled
+        JAE     fill8                   ;AN000;MS.
+        STOSB                           ;AN000;MS.
+fill8:                                  ;AN000;
+        POP    SI                       ;AN007;MS. ds:si -> file name
+        POP    CX                       ;AN007;MS.
+
+        CALL   Scan_Special_Entries     ;AN007;MS.
+
+        PUSH    DX
+        MOV     SI,exec_size
+        ADD     SI,DX
+        invoke  $Dup_PDB                ; ES is now PDB
+        POP     DX
+
+        PUSH    exec_environ
+        POP     ES:[PDB_environ]
+;
+; set up proper command line stuff
+;
+        LDS     SI,exec_blk             ; get the block
+        PUSH    DS                      ; save its location
+        PUSH    SI
+        LDS     SI,[SI.exec0_5C_FCB]    ; get the 5c fcb
+;
+; DS points to user space 5C FCB
+;
+        MOV     CX,12                   ; copy drive, name and ext
+        PUSH    CX
+        MOV     DI,5Ch
+        MOV     BL,[SI]
+        REP     MOVSB
+;
+; DI = 5Ch + 12 = 5Ch + 0Ch = 68h
+;
+        XOR     AX,AX                   ; zero extent, etc for CPM
+        STOSW
+        STOSW
+;
+; DI = 5Ch + 12 + 4 = 5Ch + 10h = 6Ch
+;
+        POP     CX
+        POP     SI                      ; get block
+        POP     DS
+        PUSH    DS                      ; save (again)
+        PUSH    SI
+        LDS     SI,[SI.exec0_6C_FCB]    ; get 6C FCB
+;
+; DS points to user space 6C FCB
+;
+        MOV     BH,[SI]                 ; do same as above
+        REP     MOVSB
+        STOSW
+        STOSW
+        POP     SI                      ; get block (last time)
+        POP     DS
+        LDS     SI,[SI.exec0_com_line]  ; command line
+;
+; DS points to user space 80 command line
+;
+        OR      CL,80h
+        MOV     DI,CX
+        REP     MOVSB                   ; Wham!
+;
+; Process BX into default AX (validity of drive specs on args).  We no longer
+; care about DS:SI.
+;
+        DEC     CL                      ; get 0FFh in CL
+        MOV     AL,BH
+        XOR     BH,BH
+        invoke  GetVisDrv
+        JNC     exec_BL
+        MOV     BH,CL
+exec_BL:
+        MOV     AL,BL
+        XOR     BL,BL
+        invoke  GetVisDrv
+        JNC     exec_Set_Return
+        MOV     BL,CL
+exec_set_return:
+        invoke  get_user_stack          ; get his return address
+        PUSH    [SI.user_CS]            ; suck out the CS and IP
+        PUSH    [SI.user_IP]
+        PUSH    [SI.user_CS]            ; suck out the CS and IP
+        PUSH    [SI.user_IP]
+        POP     WORD PTR ES:[PDB_Exit]
+        POP     WORD PTR ES:[PDB_Exit+2]
+        XOR     AX,AX
+        MOV     DS,AX
+        POP     DS:[addr_int_terminate] ; save them where we can get them later
+        POP     DS:[addr_int_terminate+2]   ; when the child exits.
+        MOV     WORD PTR DMAADD,80h
+        MOV     DS,CurrentPDB
+        MOV     WORD PTR DMAADD+2,DS
+        TEST    BYTE PTR exec_func,exec_func_no_execute
+        JZ      exec_go
+
+        LDS     SI,DWORD PTR exec_init_SP   ; get stack
+        LES     DI,exec_blk             ; and block for return
+        MOV     ES:[DI].exec1_SS,DS     ; return SS
+
+        DEC     SI                      ; 'push' default AX
+        DEC     SI
+        MOV     [SI],BX                 ; save default AX reg
+        MOV     ES:[DI].exec1_SP,SI     ; return 'SP'
+
+        LDS     AX,DWORD PTR exec_init_IP
+        MOV     ES:[DI].exec1_CS,DS     ; initial entry stuff
+
+        MOV     ES:[DI].exec1_IP,AX
+        Leave
+        transfer    SYS_RET_OK
+
+exec_go:
+        LDS     SI,DWORD PTR exec_init_IP   ; get entry point
+        LES     DI,DWORD PTR exec_init_SP   ; new stack
+        MOV     AX,ES
+;
+; DS:SI points to entry point
+; AX:DI points to initial stack
+; DX has PDB pointer
+; BX has initial AX value
+;
+        CLI
+        MOV     BYTE PTR INDOS,0
+        ASSUME  SS:NOTHING
+        MOV     SS,AX                   ; set up user's stack
+        MOV     SP,DI                   ; and SP
+        STI
+        PUSH    DS                      ; fake long call to entry
+        PUSH    SI
+        MOV     ES,DX                   ; set up proper seg registers
+        MOV     DS,DX
+        MOV     AX,BX                   ; set up proper AX
+procedure   exec_long_ret,FAR
+
+IF      BUFFERFLAG
+        invoke  restore_user_map
+ENDIF
+
+        RET
+EndProc exec_long_ret
+
+EndProc $Exec
+
+Procedure   ExecRead,NEAR
+        CALL    exec_dealloc
+        MOV     bx,exec_fh
+        PUSH    BP
+        invoke  $READ
+        POP     BP
+        CALL    exec_alloc
+        return
+EndProc ExecRead
+
+procedure   exec_dealloc,near
+        ASSUME      DS:NOTHING,ES:NOTHING
+        PUSH        BX
+        MOV         BX,arena_owner_system
+        EnterCrit   CritMEM
+        CALL        ChangeOwners
+        POP         BX
+        return
+EndProc exec_dealloc
+
+procedure   exec_alloc,near
+        PUSH        BX
+        MOV         BX,CurrentPDB
+        CALL        ChangeOwners
+        LeaveCrit   CritMEM
+        POP         BX
+        return
+EndProc exec_alloc
+
+procedure   ChangeOwners,NEAR
+        pushf
+        PUSH    AX
+        MOV     AX,exec_environ
+        CALL    ChangeOwner
+        MOV     AX,exec_load_block
+        Call    ChangeOwner
+        POP     AX
+        popf
+        return
+EndProc ChangeOwners
+
+Procedure   ChangeOwner,near
+        OR      AX,AX                   ; is area allocated?
+        retz                            ; no, do nothing
+        DEC     AX
+        PUSH    DS
+        MOV     DS,AX
+        MOV     DS:[arena_owner],BX
+        POP     DS
+        return
+EndProc ChangeOwner
+
+Procedure    Scan_Execname,near         ;AN000;MS.
+
+        LDS     SI,execName             ;AN000;MS. DS:SI points to name
+save_begin:                             ;AN000;
+        MOV     CX,SI                   ;AN000;MS. CX= starting addr
+scan0:                                  ;AN000;
+        LODSB                           ;AN000;MS. get char
+        CMP     AL,':'                  ;AN000;;MS. is ':' , may be A:name
+        JZ      save_begin              ;AN000;;MS. yes, save si
+        CMP     AL,'\'                  ;AN000;;MS. is '\', may be A:\name
+        JZ      save_begin              ;AN000;;MS. yes, save si
+        CMP     AL,0                    ;AN000;;MS. is end of name
+        JNZ     scan0                   ;AN000;;MS. no, continue scanning
+        SUB     SI,CX                   ;AN000;;MS. get name's length
+        XCHG    SI,CX                   ;AN000;;MS. cx= length, si= starting addr
+
+        return                          ;AN000;;MS.
+EndProc Scan_Execname                   ;AN000;;MS.
+
+
+Procedure    Scan_Special_Entries,near  ;AN000;MS.
+
+        DEC    CX                       ;AN007;MS. cx= name length
+        MOV    DI,CS:[Special_Entries]  ;AN007;MS. es:di -> addr of special entries
+        CALL   Reset_Version            ;AN008;MS.
+        PUSH   CS                       ;AN007;MS.
+        POP    ES                       ;AN007;MS.
+Getentries:                             ;AN007;MS.
+        MOV    AL,ES:[DI]               ;AN007;MS. end of list
+        OR     AL,AL                    ;AN007;MS.
+        JZ     end_list                 ;AN007;MS. yes
+        MOV    CS:[Temp_Var2],DI        ;AN007;MS. save di
+        CMP    AL,CL                    ;AN007;MS. same length ?
+        JNZ    skipone                  ;AN007;MS. no
+        INC    DI                       ;AN007;MS. es:di -> special name
+        PUSH   CX                       ;AN007;MS. save length and name addr
+        PUSH   SI                       ;AN007;MS.
+        REPZ   CMPSB                    ;AN007;MS. same name ?
+        JNZ    not_matched              ;AN007;MS. no
+        MOV    AX,ES:[DI]               ;AN007;MS. get special version
+        MOV    CS:[Special_Version],AX  ;AN007;MS. save it
+        MOV    AL,ES:[DI+2]             ;AN008;MS. get fake count
+        MOV    CS:[Fake_Count],AL       ;AN007;MS. save it
+        POP    SI                       ;AN007;MS.
+        POP    CX                       ;AN007;MS.
+        JMP    SHORT end_list           ;AN007;MS.
+not_matched:                            ;AN007;MS.
+        POP    SI                       ;AN007;MS. restore si,cx
+        POP    CX                       ;AN007;MS.
+skipone:                                ;AN007;MS.
+        MOV    DI,CS:[Temp_Var2]        ;AN007;MS. restore old di
+        XOR    AH,AH                    ;AN007;MS. position to next entry
+        ADD    DI,AX                    ;AN007;MS.
+        ADD    DI,4                     ;AN007;MS.
+        JMP    Getentries               ;AN007;MS.
+
+
+end_list:                               ;AN007;MS.
+        return
+EndProc Scan_Special_Entries            ;AN000;;MS.
+
+Procedure    Reset_Version,near         ;AN008;MS.
+
+        CMP    CS:[Fake_Count],0FFH     ;AN008;MS.
+        JNZ    dont_reset               ;AN008;MS.
+        MOV    CS:[Special_Version],0   ;AN008;MS. reset to current version
+dont_reset:
+        return
+EndProc Reset_Version,near              ;AN008;;MS.
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/EXTATTR.ASM b/v4.0/src/DOS/EXTATTR.ASM
new file mode 100644
index 0000000..1cc1d32
--- /dev/null
+++ b/v4.0/src/DOS/EXTATTR.ASM
@@ -0,0 +1,679 @@
+TITLE   EXTATTR- Extended Attributes
+NAME    EXTATTR
+;
+; Get or Set Extended Attributes by handle
+;
+;
+;   GetSetEA
+;   Set_Output
+;   Search_EA
+;   Copy_QEA
+;   Set_one_EA
+;   Get_one_EA
+;   Get_Value
+;   GSetDevCdpg
+;   Get_max_EA_size
+;
+;   Revision history
+;
+;          A000   version 4.00  Jan. 1988
+;
+;
+;
+;
+;
+;
+;
+
+.xlist
+;
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm                           ;AN000;
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'          ;AN000;
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP      ;AN000;
+
+.xcref
+INCLUDE DOSSYM.INC                           ;AN000;
+INCLUDE DEVSYM.INC                           ;AN000;
+include EA.inc                               ;AN000;
+.cref
+.list
+.sall
+
+
+;       I_need  XA_from,BYTE            ;AN000;
+
+;       I_need  XA_TABLE,BYTE           ;AN000;
+;       I_need  XA_TEMP,WORD            ;AN000;
+;       I_need  XA_COUNT,WORD           ;AN000;
+;       I_need  XA_DEVICE,BYTE          ;AN000;
+        I_need  XA_TYPE,BYTE            ;AN000;
+        I_need  SAVE_ES,WORD            ;AN000;
+        I_need  SAVE_DI,WORD            ;AN000;
+        I_need  SAVE_DS,WORD            ;AN000;
+        I_need  SAVE_SI,WORD            ;AN000;
+        I_need  SAVE_CX,WORD            ;AN000;
+        I_need  SAVE_BX,WORD            ;AN000;
+;       I_need  XA_handle,WORD          ;AN000;
+;       I_need  CPSWFLAG,BYTE           ;AN000;
+;       I_need  XA_PACKET,BYTE          ;AN000;
+;       I_need  MAX_EA_SIZE,WORD        ;AN000;
+;       I_need  MAX_EANAME_SIZE,WORD    ;AN000;
+;       I_need  THISSFT,DWORD           ;AN000;
+;IF DBCS                                ;AN000;
+;       I_need  DBCS_PACKET,BYTE        ;AN000;                                 ;AN000;
+;ENDIF                                  ;AN000;                                 ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+BREAK <GetSet_EA get or set extended attributes by handle>                      ;AN000;
+                                                                                ;AN000;
+;      Input: [XA_type] = function code, (e.g., get,set)                        ;AN000;
+;             [ThisSFT] points to SFT                                           ;AN000;
+;             ES:BP points to drive parameter block                             ;AN000;
+;             [XA_from] = By_Create or By_EA                                    ;AN000;
+;             [SAVE_ES]:[SAVE_DI]  points to get/set list                       ;AN000;
+;             [SAVE_DS]:[SAVE_SI]  points to get query list                     ;AN000;
+;             [SAVE_CX] = size of buffer
+;             [XA_device]= 1 device, 0 file                                     ;AN000;
+;             [XA_handle] for device                                            ;AN000;
+;       Function: Get or Set extended attributes by handle                      ;AN000;
+;       Output: carry set: error                                                ;AN000;
+;               carry clear: extended attributes are successfully get/set       ;AN000;
+;                            extended attribute cluster may be created          ;AN000;
+;                                                                               ;AN000;
+;                                                                               ;AN000;
+;                                                                               ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+procedure   GetSet_XA,near                                         ;AN000;
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP      ;AN000;
+
+
+        LES    DI,DWORD PTR [SAVE_DI]  ;AN000;;FT. ES:DI -> query list
+;;      MOV    [SAVE_BX],2             ;AN000;;FT. size returned
+;;      XOR    DX,DX                   ;AN000;;FT. dx=0, codepage id
+
+        CMP    [XA_type],2             ;AN000;;FT. get EA  ?
+        JNZ    eaname                  ;AN000;;FT. no
+getEAs:                                ;AN000;
+        CMP    [SAVE_CX],0             ;AN000;;FT. get max data size
+        JNZ    notmax                  ;AN000;;FT. no
+;;      CALL   Get_max_EA_size         ;AN000;;FT.
+
+        MOV    CX,2                    ;AN000;;FT. FAKE FAKE..............
+        JNC    set_user_cx             ;AN000;;FT.
+        JMP    OKexit                  ;AN000;;FT. error
+notmax:
+        CMP    [SAVE_CX],1             ;AN000;;FT. buffer size =1   ?
+        JNZ    goodsiz                 ;AN000;;FT. no
+errout:                                ;AN000;
+        JMP    insuff_space            ;AN000;;FT. no error
+goodsiz:                               ;AN000;
+        MOV    WORD PTR ES:[DI],0      ;AN000;FT. FAKE FAKE ...............
+        MOV    CX,2                    ;AN000;FT. FAKE FAKE ...............
+        JMP    set_user_cx             ;AN000;FT. FAKE FAKE ...............
+
+;       SUB    [SAVE_CX],2             ;AN000;;FT. minus count size
+;       CMP    [SAVE_SI],-1            ;AN000;;FT. get all ?
+;       JNZ    getsome                 ;AN000;;FT. no
+;       PUSH   CS                      ;AN000;;FT. ds:si-> EA entry addr
+;       POP    DS                      ;AN000;;FT.
+;       INC    DI                      ;AN000;;FT.
+;       INC    DI                      ;AN000;;FT. es:di -> address after count
+;       MOV    SI,OFFSET DOSGROUP:XA_TABLE  ;AN000;FT.
+;       MOV    CX,XA_COUNT             ;AN000;;FT. cx= number of EA entries
+;;;;;;
+;getone:
+;       CALL   GET_ONE_EA              ;AN000;;FT. get EA
+;       JC     setout                  ;AN000;;FT. insufficient memory
+;       INC    DX                      ;AN000;;FT. next EA ID
+;       LOOP   getone                  ;AN000;;FT. next one
+;setout:                               ;AN000;
+;       CALL   Set_Output              ;AN000;;FT.
+;       OR     CX,CX                   ;AN000;;FT.
+;       JNZ    errout                  ;AN000;;FT.
+;
+;       JMP    OKexit                  ;AN000;;FT.
+eaname:
+        CMP    [XA_type],3             ;AN000;;FT. get EA name?`
+        JZ     geteaname               ;AN000;;FT. yes
+        JMP    setea                   ;AN000;;FT.
+geteaname:
+;       MOV    [SAVE_SI],-1            ;AN000;;FT. make get all
+        CMP    [SAVE_CX],0             ;AN000;;FT. get max data size
+        JNZ    notmax                  ;AN000;;FT. no
+        MOV    CX,2                    ;AN000;;FT. FAKE FAKE ......................
+;;      MOV    CX,[MAX_EANAME_SIZE]    ;AN000;;FT. get name size
+set_user_cx:                           ;AN000;
+        invoke get_user_stack          ;AN000;;FT. get user stack
+        MOV    [SI.user_CX],CX         ;AN000;;FT.
+        JMP    OKexit                  ;AN000;;FT. exit
+
+getsome:                               ;AN000;
+;       LDS    SI,DWORD PTR [SAVE_SI]  ;AN000;;FT.
+;       LODSW                          ;AN000;;FT.
+;       MOV    CX,AX                   ;AN000;;FT. cx=number of query entries
+;       JCXZ   setout                  ;AN000;;FT. yes
+;       STOSW                          ;AN000;;FT. es:di -> EA
+;get_next_EA:                          ;AN000;
+;       PUSH   DS                      ;AN000;;FT. save ds:si
+;       PUSH   SI                      ;AN000;;FT.      es:di
+;       PUSH   ES                      ;AN000;;FT.
+;       PUSH   DI                      ;AN000;;FT.
+;       CALL   Search_EA               ;AN000;;FT. search query EA from table
+;       JC     EAnotFound              ;AN000;;FT. EA not found
+;       PUSH   ES                      ;AN000;;FT.
+;       POP    DS                      ;AN000;;FT.
+;       MOV    SI,DI                   ;AN000;;FT. ds:si -> found EA
+;       POP    DI                      ;AN000;;FT. es:di -> buffer
+;       POP    ES                      ;AN000;;FT.
+;       CALL   GET_ONE_EA              ;AN000;;FT. copy to buffer
+;       POP    SI                      ;AN000;;FT.
+;       POP    DS                      ;AN000;;FT.
+;       JC     setfinal                ;AN000;;FT. memory not enough
+;       MOV    AL,[SI.QEA_NAMELEN]     ;AN000;;FT.
+;       XOR    AH,AH                   ;AN000;;FT.
+;       ADD    AX,QEA_NAME             ;AN000;;FT.
+;       ADD    SI,AX                   ;AN000;;FT. ds:si -> next query entry
+;testend:                              ;AN000;
+;       LOOP   get_next_EA             ;AN000;;FT. do next
+;setfinal:                             ;AN000;
+;       LDS    SI,DWORD PTR [SAVE_SI]  ;AN000;;FT.
+;       MOV    DX,[SI]                 ;AN000;;FT.
+;       SUB    DX,CX                   ;AN000;;FT. dx= returned count
+;       JMP    setout                  ;AN000;;FT.
+;EAnotFound:                           ;AN000;
+;       POP    DI                      ;AN000;;FT. restore regs
+;       POP    ES                      ;AN000;;FT.
+;       POP    SI                      ;AN000;;FT.
+;       POP    DS                      ;AN000;;FT.
+;
+;       CALL   COPY_QEA                ;AN000;;FT. copy query EA to buffer
+;       JC     setfinal                ;AN000;;FT. not enough memory
+;       JMP    testend                 ;AN000;;FT.
+setea:                                 ;AN000;
+        JMP    OKexit                  ;AN000;;FT. FAKE FAKE ..........
+;       LDS    SI,DWORD PTR [SAVE_DI]  ;AN000;;FT.
+;       LODSW                          ;AN000;;FT.
+;       MOV    CX,AX                   ;AN000;;FT. cx=number of query entries
+;       OR     CX,CX                   ;AN000;;FT. cx=0 ?
+;       JZ     OKexit                  ;AN000;;FT. yes
+;set_next:                             ;AN000;
+;       CALL   Search_EA               ;AN000;;FT.
+;       JNC    toset                   ;AN000;;FT.
+;set_reason:                           ;AN000;
+;       CLC                            ;AN000;;FT. clear acrry
+;       MOV    [SI.EA_RC],AL           ;AN000;;FT. set reason code
+;       DEC    CX                      ;AN000;;FT. end of set ?
+;       JZ     OKexit                  ;AN000;;FT. yes
+
+;       MOV    AL,[SI.EA_NAMELEN]      ;AN000;;FT.
+;       XOR    AH,AH                   ;AN000;;FT.
+;       ADD    AX,[SI.EA_VALLEN]       ;AN000;;FT.
+;       ADD    SI,EA_NAME              ;AN000;;FT.
+;       ADD    SI,AX                   ;AN000;;FT. es:di -> next EA entry
+;       JMP    set_next                ;AN000;;FT.
+;toset:                                ;AN000;
+;       CALL   SET_ONE_EA              ;AN000;;FT. set it
+;       JMP    set_reason              ;AN000;;FT.
+ insuff_space:                         ;AN000;;FT.
+;       MOV    AX,error_not_enough_memory        ;AN000;FT. insufficient memory err
+;       STC                                      ;AN000;
+OKexit:                                          ;AN000;
+        return                                   ;AN000;
+
+EndProc GetSet_XA                                ;AN000;
+
+
+; Input: [SAVE_ES]:[SAVE_DI] points to buffer
+;        [SAVE_BX]= returned size
+;        DX= returned count
+; Function: set returned size and count                                         ;AN000;
+; Output: none
+                                                                                ;AN000;
+;procedure   Set_Output,NEAR                                                     ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       LES    DI,DWORD PTR [SAVE_DI]  ;FT. es:di -> count                      ;AN000;
+;       MOV    ES:[DI],DX              ;FT.                                     ;AN000;
+;       MOV    BX,[SAVE_BX]            ;FT. cx=size returned                    ;AN000;
+;       invoke get_user_stack          ;FT. get user stack                      ;AN000;
+;       MOV    [SI.user_CX],BX         ;FT.                                     ;AN000;
+;       return                         ;FT.                                     ;AN000;
+;                                                                               ;AN000;
+;EndProc Set_Output                                                              ;AN000;
+
+
+; Input: DS:SI= query EA addr                                                   ;AN000;
+; Function: search the EA                                                       ;AN000;
+; Output: carry clear
+;        DX= EA ID (0 codpage, 1  Filetype, etc.)
+;        ES:DI points to found entry
+;         carry set, not found, AL= reason code                                 ;AN000;
+                                                                                ;AN000;
+;procedure   Search_EA,NEAR                                                      ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       PUSH   CX                                ;FT. save entry count          ;AN000;
+;       MOV    AL,EARCNOTFOUND                   ;FT. preset error code         ;AN000;
+;       MOV    BL,[SI.QEA_NAMELEN]               ;FT.        ?                  ;AN000;
+;       CMP    [XA_TYPE],4                       ;FT. set    ?                  ;AN000;
+;       JNZ    gettyp                            ;FT. no                        ;AN000;
+;       MOV    BL,[SI.EA_NAMELEN]                ;FT.        ?                  ;AN000;
+;gettyp:
+;       OR     BL,BL                             ;FT.                           ;AN000;
+;       JZ     not_found                         ;FT.                           ;AN000;
+;       PUSH   CS                                ;FT. ds:si-> EA entry addr     ;AN000;
+;       POP    ES                                ;FT.                           ;AN000;
+;       MOV    DI,OFFSET DOSGROUP:XA_TABLE       ;FT.                           ;AN000;
+;       MOV    CX,XA_COUNT                       ;FT. cx= number of EA entries  ;AN000;
+;       XOR    DX,DX                             ;FT. dx=0, codepage id         ;AN000;
+;
+;start_find:
+;       PUSH   CX                                ;FT. save entry count          ;AN000;
+;       MOV    CL,BL                             ;FT.                           ;AN000;
+;       XOR    CH,CH                             ;FT. get name len              ;AN000;
+;       PUSH   SI                                ;FT.                           ;AN000;
+;       PUSH   DI                                ;FT.                           ;AN000;
+;       CMP    [XA_TYPE],4                       ;FT. set    ?                  ;AN000;
+;       JNZ    gettyp2                           ;FT. no                        ;AN000;
+;       ADD    SI,EA_NAME                        ;FT.                           ;AN000;
+;       JMP    short updi                        ;FT.                           ;AN000;
+;gettyp2:
+;       ADD    SI,QEA_NAME                       ;FT. compare EA names          ;AN000;
+;updi:
+;       ADD    DI,EA_NAME                        ;FT.                           ;AN000;
+;       REP    CMPSB                             ;FT.                           ;AN000;
+;       POP    DI                                ;FT.                           ;AN000;
+;       POP    SI                                ;FT.                           ;AN000;
+;       POP    CX                                ;FT.                           ;AN000;
+;       JNZ    not_matched                       ;FT. name not matched          ;AN000;
+;       MOV    AL,EARCDEFBAD                     ;FT. preset error code         ;AN000;
+;       PUSH   SI                                ;FT.                           ;AN000;
+;       PUSH   DI                                ;FT.                           ;AN000;
+;       CMPSB                                    ;FT. compare type              ;AN000;
+;       JNZ    not_matched2                      ;FT. type not matched          ;AN000;
+;       CMPSW                                    ;FT. compare flags             ;AN000;
+;       JNZ    not_matched2                      ;FT. flag not matched          ;AN000;
+;       POP    DI                                ;FT.                           ;AN000;
+;       POP    SI                                ;FT. found one                 ;AN000;
+;       JMP    SHORT found_one                   ;FT.                           ;AN000;
+;not_matched:
+;       DEC    CX                                ;FT. end of table              ;AN000;
+;       JZ     not_found                         ;FT. yes                       ;AN000;
+;       MOV    AL,ES:[DI.EA_NAMELEN]             ;FT.                           ;AN000;
+;       XOR    AH,AH                             ;FT.                           ;AN000;
+;
+;       ADD    DI,EA_NAME                        ;FT.                           ;AN000;
+;       ADD    DI,AX                             ;FT. es:di -> next EA entry    ;AN000;
+;       INC    DX                                ;FT. increment EA ID           ;AN000;
+;       JMP    start_find                        ;FT.                           ;AN000;
+;not_matched2:
+;       POP    DI                                ;FT.                           ;AN000;
+;       POP    SI                                ;FT.                           ;AN000;
+;       JMP    not_matched                       ;FT.                           ;AN000;
+;not_found:
+;       STC                                      ;FT.                           ;AN000;
+;found_one:
+;       POP    CX                                ;FT.                           ;AN000;
+;       return                                   ;FT.                           ;AN000;
+                                                                                ;AN000;
+;EndProc Search_EA                                                               ;AN000;
+                                                                                ;AN000;
+; Input: ES:DI= buffer address                                                  ;AN000;
+;        DS:SI= EA entry address
+;        [SAVE_CX]= buffer size
+;        AL = reason code
+; Function: move one query entry to buffer                                      ;AN000;
+; Output: carry clear
+;           DS:SI points to next entry
+;           ES:DI points to next entry
+;           [SAVE_CX],[SAVE_BX], updated                                               ;AN000;
+;         carry set, insufficient memory error                                  ;AN000;
+                                                                                ;AN000;
+;procedure   COPY_QEA,NEAR                                                       ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       PUSH   CX                                ;FT.                           ;AN000;
+;       MOV    DL,AL                             ;FT.                           ;AN000;
+;       MOV    CX,EA_NAME -EA_TYPE               ;FT.                           ;AN000;
+;
+;       MOV    BL,[SI.QEA_NAMELEN]               ;FT.                           ;AN000;
+;       XOR    BH,BH                             ;FT.                           ;AN000;
+;       ADD    CX,BX                             ;FT. cx= query EA size         ;AN000;
+;       CMP    CX,[SAVE_CX]                      ;FT. > buffer size             ;AN000;
+;       JA     sizeshort2                        ;FT. yes                       ;AN000;
+;       PUSH   CX                                ;FT.                           ;AN000;
+;       LODSB                                    ;FT. move type                 ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;       LODSW                                    ;FT.                           ;AN000;
+;       STOSW                                    ;FT. move flag                 ;AN000;
+;       MOV    AL,DL                             ;FT. move RC                   ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;
+;       LODSB                                    ;FT. move name len             ;AN000;
+;       MOV    CL,AL                             ;FT.                           ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;       XOR    AX,AX                             ;FT. zero value length         ;AN000;
+;       STOSW                                    ;FT.                           ;AN000;
+;       OR     CL,CL                             ;FT.                           ;AN000;
+;       JZ     zeroname                          ;FT.                           ;AN000;
+;       XOR    CH,CH                             ;FT.                           ;AN000;
+;
+;       REP    MOVSB                             ;FT. move EA to buffer         ;AN000;
+;zeroname:
+;       POP    CX                                ;FT.                           ;AN000;
+;       ADD    [SAVE_BX],CX                      ;FT. bx=bx+entry size          ;AN000;
+;       SUB    [SAVE_CX],CX                      ;FT. update buffer size        ;AN000;
+;       CLC                                      ;FT.                           ;AN000;
+;       JMP    SHORT okget2                      ;FT.                           ;AN000;
+;
+;sizeshort2:
+;       MOV    AX,error_not_enough_memory        ;FT.  error                    ;AN000;
+;       STC                                      ;FT.                           ;AN000;
+;okget2:
+;       POP    CX                                ;FT.                           ;AN000;
+;       return                              ;FT.                                ;AN000;
+;                                                                               ;AN000;
+;EndProc COPY_QEA                                                                ;AN000;
+                                                                                ;AN000;
+; Input: ES:DI= found EA entry addr                                             ;AN000;
+;        DS:SI= source EA entry address
+;        DX= EA ID (0 codpage, 1  Filetype, etc.)
+; Function: set one EA                                                          ;AN000;
+; Output: carry clear
+;           EA set
+;         carry set, AL= reason code                                            ;AN000;
+                                                                                ;AN000;
+;procedure   SET_ONE_EA,NEAR                                                     ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       PUSH   CX                                ;FT.                           ;AN000;
+;       MOV    AL,EARCDEFBAD                     ;FT.  prseet error code        ;AN000;
+;       MOV    BX,[SI.EA_VALLEN]                 ;FT.                           ;AN000;
+;       CMP    BX,ES:[DI.EA_VALLEN]              ;FT.  length equal ?           ;AN000;
+;       JNZ    notset                            ;FT.  no                       ;AN000;
+;       PUSH   DS                                ;FT.                           ;AN000;
+;       PUSH   SI                                ;FT.                           ;AN000;
+;       MOV    AL,[SI.EA_NAMELEN]                ;FT.                           ;AN000;
+;       XOR    AH,AH                             ;FT.                           ;AN000;
+;       ADD    SI,EA_NAME                        ;FT.                           ;AN000;
+;       ADD    SI,AX                             ;FT.                           ;AN000;
+;       CMP    DX,0                              ;FT.                           ;AN000;
+;       JNZ    set_filetyp                       ;FT.                           ;AN000;
+;       LODSW                                    ;FT.                           ;AN000;
+;       CMP    [XA_DEVICE],0                     ;FT. device ?                  ;AN000;
+;       JZ     notdevice                         ;FT. no                        ;AN000;
+;       OR     AX,AX                             ;FT. code page 0 ?             ;AN000;
+;       JZ     NORM0                             ;FT. yes                       ;AN000;
+;
+;       CALL   GSetDevCdPg                       ;FT.                           ;AN000;
+;       JNC    welldone                          ;FT.                           ;AN000;
+;       CMP    [CPSWFLAG],0                      ;FT. code page matching on     ;AN000;
+;       JZ     NORM0                             ;FT. no                        ;AN000;
+;       invoke SAVE_WORLD                        ;FT. save all regs             ;AN000;
+;       LDS    SI,[THISSFT]                      ;FT. ds:si -> sft              ;AN000;
+;       LDS    SI,[SI.sf_devptr]                 ;FT. ds:si -> device header    ;AN000;
+;       MOV    BP,DS                             ;FT. save all regs             ;AN000;
+;       invoke Code_Page_Mismatched_Error        ;FT.                           ;AN000;
+;       CMP    AL,0                              ;FT. ignore ?                  ;AN000;
+;       JZ     NORM1                             ;FT.                           ;AN000;
+;       invoke RESTORE_WORLD                     ;FT. save all regs             ;AN000;
+;NORM0:
+;       MOV    AL,EARCDEVERROR                   ;FT.                           ;AN000;
+;       STC                                      ;FT.                           ;AN000;
+;       JMP    SHORT sdone                       ;FT.                           ;AN000;
+;NORM1:
+;       invoke RESTORE_WORLD                     ;FT. save all regs             ;AN000;
+;       JMP    SHORT welldone                    ;FT.                           ;AN000;
+;notdevice:
+;       LDS    SI,[THISSFT]                      ;FT.                           ;AN000;
+;       MOV    [SI.sf_CodePage],AX               ;FT. set codepege              ;AN000;
+;       JMP    SHORT welldone                    ;FT.
+;set_filetyp:
+;       LODSB                                    ;FT.                           ;AN000;
+;       LDS    SI,[THISSFT]                      ;FT. set filtype               ;AN000;
+;       MOV    [SI.sf_ATTR_HI],AL                ;FT.                           ;AN000;
+;
+;welldone:
+;       XOR    AL,AL                             ;FT.  success                  ;AN000;
+;sdone:
+;       POP    SI                                ;FT.                           ;AN000;
+;       POP    DS                                ;FT.                           ;AN000;
+;notset:
+;       POP    CX                                ;FT.                           ;AN000;
+;        return                                   ;FT.                           ;AN000;
+                                                                                ;AN000;
+;EndProc SET_ONE_EA                                                              ;AN000;
+                                                                                ;AN000;
+; Input: ES:DI= buffer address                                                  ;AN000;
+;        DS:SI= EA entry address
+;        [SAVE_CX]= buffer size available
+;        [SAVE_BX]= size returned
+;        DX= EA ID (0 codpage, 1  Filetype, etc.)
+; Function: move one EA entry to the buffer                                     ;AN000;
+; Output: carry clear
+;           DS:SI points to next entry
+;           ES:DI points to next entry
+;           [SAVE_CX],BX, updated                                               ;AN000;
+;         carry set, insufficient memory error                                  ;AN000;
+                                                                                ;AN000;
+;procedure   GET_ONE_EA,NEAR                                                     ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       PUSH   CX                                ;FT.                           ;AN000;
+;       CMP    [XA_TYPE],2                       ;FT. type 2 ?                  ;AN000;
+;       JZ     gtyp2                             ;FT. yes                       ;AN000;
+;       MOV    CX,QEA_NAME - QEA_TYPE            ;FT.                           ;AN000;
+;       JMP    SHORT addnmlen                    ;FT.
+;gtyp2:
+;       MOV    CX,EA_NAME - EA_TYPE              ;FT. cx = EA entry size        ;AN000;
+;       ADD    CX,[SI.EA_VALLEN]                 ;FT.                           ;AN000;
+;addnmlen:
+;       MOV    AL,[SI.EA_NAMELEN]                ;FT.
+;       XOR    AH,AH                             ;FT.                           ;AN000;
+;       ADD    CX,AX                             ;FT.                           ;AN000;
+;       CMP    CX,[SAVE_CX]                      ;FT. > buffer size             ;AN000;
+;       JA     sizeshort                         ;FT. yes                       ;AN000;
+;       PUSH   CX                                ;FT.                           ;AN000;
+;       LODSB                                    ;FT. move type                 ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;       LODSW                                    ;FT.                           ;AN000;
+;       STOSW                                    ;FT. move flag                 ;AN000;
+;       LODSB                                    ;FT. EA list need RC           ;AN000;
+;       CMP    [XA_TYPE],2                       ;FT.                           ;AN000;
+;       JNZ    norc                              ;FT.                           ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;norc:
+;       LODSB                                    ;FT. move name len             ;AN000;
+;       STOSB                                    ;FT.                           ;AN000;
+;       MOV    CL,AL                             ;FT.                           ;AN000;
+;       XOR    CH,CH                             ;FT.                           ;AN000;
+;       LODSW                                    ;FT. EA list need value len    ;AN000;
+;       CMP    [XA_TYPE],2                       ;FT.                           ;AN000;
+;       JNZ    novalen                           ;FT.                           ;AN000;
+;       STOSW                                    ;FT.                           ;AN000;
+;novalen:
+;
+;       REP    MOVSB                             ;FT. move EA to buffer         ;AN000;
+;       CMP    [XA_TYPE],2                       ;FT.                           ;AN000;
+;       JNZ    novalue                           ;FT.                           ;AN000;
+;       CALL   GET_VALUE                         ;FT. get value for type 2      ;AN000;
+;novalue:
+;       POP    CX                                ;FT.                           ;AN000;
+;       ADD    [SAVE_BX],CX                      ;FT. add entry size            ;AN000;
+;       LES    DI,DWORD PTR [SAVE_DI]            ;FT.                           ;AN000;
+;       ADD    DI,[SAVE_BX]                      ;FT. es:di -> next entry       ;AN000;
+;       SUB    [SAVE_CX],CX                      ;FT. update buffer size        ;AN000;
+;       CLC                                      ;FT.                           ;AN000;
+;       JMP    SHORT okget                       ;FT.                           ;AN000;
+;
+;sizeshort:
+;       MOV    AX,error_not_enough_memory        ;FT.  error                    ;AN000;
+;       STC                                      ;FT.                           ;AN000;
+;okget:
+;       POP    CX                                ;FT.                           ;AN000;
+;       return                              ;FT.                                ;AN000;
+;                                                                               ;AN000;
+;EndProc GET_ONE_EA                                                              ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+; Input: DX= EA ID (0 codpage, 1 Filetype, etc.)
+;        [THISSFT]= points to SFT
+;        ES:DI= buffer address of EA value
+;        [XA_DEVICE]=0 file, 1 device
+; Function: get attribute                                                       ;AN000;
+; Output: none                                                                  ;AN000;
+;                                                                               ;AN000;
+                                                                                ;AN000;
+;procedure   GET_VALUE,NEAR                                                      ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       PUSH   DS                            ;FT. save ds:si                    ;AN000;
+;       PUSH   SI                            ;FT.                               ;AN000;
+;       LDS    SI,[ThisSFT]                  ;FT. ds:si -> SFT                  ;AN000;
+;
+;       CMP    DX,0                          ;FT. code page ?                   ;AN000;
+;       JNZ    eafiltyp                      ;FT. no                            ;AN000;
+;       CMP    [XA_DEVICE],0                 ;FT. device ?                      ;AN000;
+;       JZ     notdev                        ;FT. no                            ;AN000;
+;       CALL   GSetDevCdPg                   ;FT. do ioctl invoke               ;AN000;
+;       JNC    okcdpg                        ;FT. error ?                       ;AN000;
+;       PUSH   DI                            ;FT.                               ;AN000;
+;       XOR    AX,AX                         ;FT. make code page 0              ;AN000;
+;       LES    DI,DWORD PTR [SAVE_DI]        ;FT.                               ;AN000;
+;       ADD    DI,[SAVE_BX]                  ;FT. es:di -> beginning of entry   ;AN000;
+;       MOV    ES:[DI.EA_RC],EARCNOTFOUND    ;FT.                               ;AN000;
+;       POP    DI                            ;FT.                               ;AN000;
+;       JMP    SHORT okcdpg                  ;FT.                               ;AN000;
+;notdev:
+;       MOV    AX,[SI.sf_CodePage]           ;FT. get code page from  sft       ;AN000;
+;okcdpg:
+;       STOSW                                ;FT. put in buffer                 ;AN000;
+;       JMP    SHORT gotea                   ;FT.                               ;AN000;
+;eafiltyp:
+;       MOV    AL,[SI.sf_ATTR_HI]            ;FT. get high attribute            ;AN000;
+;       STOSB                                ;FT. put in buffer                 ;AN000;
+;
+;gotea:
+;       POP    SI                            ;FT. retore regs                   ;AN000;
+;       POP    DS                            ;FT.                               ;AN000;
+;       return                               ;FT.                               ;AN000;
+;EndProc GET_VALUE                                                               ;AN000;
+                                                                                ;AN000;
+                                                                                ;AN000;
+; Input:    [XA_handle] = device handle                                         ;AN000;
+;           [XA_type] = 4 , set                                                 ;AN000;
+;           AX= code page (set)
+;                       2,3 get                                                 ;AN000;
+; Function: get or set device code page                                         ;AN000;
+; Output:   carry clear, AX= device code page (get)                             ;AN000;
+;           carry set, error                                                    ;AN000;
+                                                                                ;AN000;
+;procedure   GSetDevCdPg,near                                                    ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       invoke SAVE_WORLD              ;FT. save all regs                       ;AN000;
+;       CMP    [XA_type],4             ;FT. set ?                               ;AN000;
+;       JZ     setpg                   ;FT. yes                                 ;AN000;
+;       MOV    CX,6AH                  ;FT. get selected code page              ;AN000;
+;       JMP    SHORT dogset            ;FT.                                     ;AN000;
+;setpg:                                                                          ;AN000;
+;       MOV    CX,4AH                  ;FT. set code page                       ;AN000;
+;IF  DBCS
+;
+;       invoke Save_World              ;FT. save all regs                       ;AN000;
+;       MOV    BX,AX                   ;FT. bx= code page id                    ;AN000;
+;       MOV    AL,7                    ;FT. get DBCS vectors                    ;AN000;
+;       MOV    DX,-1                   ;FT. get current country                 ;AN000;
+;       MOV    CX,5                    ;FT. minimum size                        ;AN000;
+;       MOV    DI,OFFSET DOSGROUP:DBCS_PACKET   ;FT.                            ;AN000;
+;       PUSH   CS                      ;FT.                                     ;AN000;
+;       POP    ES                      ;FT.                                     ;AN000;
+;       invoke $GetExtCntry            ;FT. get DBCS vectors                    ;AN000;
+;       JC     nlsfunc_err             ;FT. error                               ;AN000;
+;       LDS    SI,DWORD PTR DBCS_PACKET+1     ;FT.                              ;AN000;
+;       LODSW                                 ;FT. get vector length            ;AN000;
+;       MOV    CX,AX                          ;FT. cx=length                    ;AN000;
+;
+;       MOV    DI,OFFSET DOSGROUP:XA_PACKET+4   ;FT.                            ;AN000;
+;       PUSH   CS                      ;FT.                                     ;AN000;
+;       POP    ES                      ;FT.                                     ;AN000;
+;       REP    MOVSB                          ;FT.                              ;AN000;
+;       CLC                                   ;FT.                              ;AN000;
+;nlsfunc_err:
+;       invoke RESTORE_WORLD           ;FT. restore all regs                    ;AN000;
+;       JC     deverr                  ;FT.                                     ;AN000;
+;
+;ENDIF
+;       MOV    WORD PTR [XA_PACKET+2],AX  ;FT.                                  ;AN000;
+;dogset:                                                                         ;AN000;
+;       MOV    BX,[XA_handle]          ;FT. set up handle                       ;AN000;
+;       PUSH   CS                      ;FT. ds:dx -> packet                     ;AN000;
+;       POP    DS                      ;FT.                                     ;AN000;
+;       MOV    DX,OFFSET DOSGROUP:XA_PACKET  ;FT.                               ;AN000;
+;       MOV    AX,440CH                ;FT. IOCTL to char device by handle      ;AN000;
+;       invoke $IOCTL                        ;FT. issue get code page           ;AN000;
+;       JC     deverr                        ;FT. error                         ;AN000;
+;       invoke RESTORE_WORLD                 ;FT. restore all regs              ;AN000;
+;       MOV    AX,WORD PTR [XA_PACKET+2]     ;FT. get code page                 ;AN000;
+;       return                               ;FT.                               ;AN000;
+;deverr:                                                                         ;AN000;
+;       invoke RESTORE_WORLD                 ;FT. restore all regs              ;AN000;
+;       return                               ;FT. exit                          ;AN000;
+;                                                                               ;AN000;
+;EndProc GSetDevCdPg                                                             ;AN000;
+                                                                                ;AN000;
+
+; Input:    DS:SI -> query list
+;
+; Function: get max size                                                        ;AN000;
+; Output:   CX= size
+;           carry set error
+                                                                                ;AN000;
+;procedure   Get_max_EA_size,NEAR                                                ;AN000;
+;       ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP                   ;AN000;
+;                                                                               ;AN000;
+;       CMP    [SAVE_SI],0FFFFH              ;FT. get all ?                     ;AN000;
+;       JNZ    scan_query                    ;FT. no                            ;AN000;
+;       MOV    CX,[MAX_EA_SIZE]              ;FT. get max EA size                     ;AN000;
+;       JMP    SHORT gotit                   ;FT.
+;scan_query:
+;       LDS    SI,DWORD PTR [SAVE_SI]        ;FT. ds:si -> query list           ;AN000;
+;       LODSW                                ;FT. ax= number of entries         ;AN000;
+;       MOV    [SAVE_CX],AX                  ;FT.                               ;AN000;
+;       XOR    CX,CX                         ;FT. set initial size to 0         ;AN000;
+;       OR     AX,AX                         ;FT. if no entris                  ;AN000;
+;       JZ     gotit                         ;FT.    then return                ;AN000;
+;       MOV    CX,2                          ;FT. at lesat 2                    ;AN000;
+;NEXT_QEA:
+;       CALL   Search_EA                     ;FT. search EA                     ;AN000;
+;       JC     serror                        ;FT. wrong EA                      ;AN000;
+;       ADD    CX,size EA                    ;FT. get EA size                   ;AN000;
+;       ADD    CL,ES:[DI.EA_NAMELEN]         ;FT.                               ;AN000;
+;       ADC    CH,0                          ;FT.                               ;AN000;
+;       ADD    CX,ES:[DI.EA_VALLEN]          ;FT.                               ;AN000;
+;       DEC    CX                            ;FT.                               ;AN000;
+;       DEC    [SAVE_CX]                     ;FT. end of entris                 ;AN000;
+;       JZ     gotit                         ;FT. no                            ;AN000;
+;       MOV    AL,[SI.QEA_NAMELEN]           ;FT. update to next QEA            ;AN000;
+;       XOR    AH,AH                         ;FT. update to next QEA            ;AN000;
+;       ADD    SI,AX                         ;FT. update to next QEA            ;AN000;
+;       ADD    SI,size QEA                   ;FT.                               ;AN000;
+;       DEC    SI                            ;FT.                               ;AN000;
+;       JMP    next_QEA                      ;FT. do next                       ;AN000;
+;serror:
+;       MOV    AX,error_invalid_data         ;FT. set initial size to 0         ;AN000;
+;gotit:                                       ;FT.                               ;AN000;
+;       return                               ;FT. exit                          ;AN000;;FT. exit                          ;AN000;
+;
+;EndProc Get_max_EA_size                      ;FT. exit                          ;AN000;                                   ;AN000;
+                                                                                ;AN000;
+CODE    ENDS                                                                    ;AN000;
+END                                                                             ;AN000;
diff --git a/v4.0/src/DOS/FAT.ASM b/v4.0/src/DOS/FAT.ASM
new file mode 100644
index 0000000..971c427
--- /dev/null
+++ b/v4.0/src/DOS/FAT.ASM
@@ -0,0 +1,695 @@
+;       SCCSID = @(#)fat.asm    1.3 85/08/15
+;       SCCSID = @(#)fat.asm    1.3 85/08/15
+TITLE   FAT - FAT maintenance routines
+NAME    FAT
+; Low level local device routines for performing disk change sequence,
+;   setting cluster validity, and manipulating the FAT
+;
+;   IsEof
+;   UNPACK
+;   PACK
+;   MAPCLUSTER
+;   FATREAD_SFT
+;   FATREAD_CDS
+;   FAT_operation
+;
+;   Revision history:
+;
+;   AN000  version Jan. 1988
+;    A001  PTM        -- disk changed for look ahead buffers
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+FastDiv = TRUE
+
+        i_need  CURBUF,DWORD
+        i_need  CLUSSPLIT,BYTE
+        i_need  CLUSSAVE,WORD
+        i_need  CLUSSEC,DWORD           ;F.C. >32mb  ;AN000;
+        i_need  THISDRV,BYTE
+        i_need  THISDPB,DWORD
+        i_need  DEVCALL,BYTE
+        i_need  CALLMED,BYTE
+        i_need  CALLRBYT,BYTE
+        i_need  BUFFHEAD,DWORD
+        i_need  CALLXAD,DWORD
+        i_need  CALLBPB,DWORD
+        i_need  CDSADDR,DWORD
+        i_need  CDSCOUNT,BYTE
+        i_need  EXTERR,WORD
+        i_need  EXTERRPT,DWORD
+        i_need  CALLVIDM,DWORD
+        i_need  ReadOp,BYTE
+        i_need  FAILERR,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  VOLCHNG_FLAG,BYTE
+        i_need  HIGH_SECTOR,WORD
+        i_need  BUF_HASH_COUNT,WORD
+        i_need  BUF_HASH_PTR,DWORD
+        i_need  FIRST_BUFF_ADDR,WORD
+        i_need  SC_CACHE_COUNT,WORD            ;AN001;
+        i_need  CURSC_DRIVE,BYTE               ;AN001;
+
+
+Break <IsEOF - check the quantity in BX for EOF>
+
+;
+; IsEOF - check the fat value in BX for eof.
+;
+;   Inputs:     ES:BP point to DPB
+;               BX has fat value
+;   Outputs:    JAE eof
+;   Registers modified: none
+Procedure IsEof,NEAR
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP,DS:NOTHING,ES:NOTHING
+        Assert      ISDPB,<ES,BP>,"IsEOF"
+        CMP     ES:[BP.dpb_max_cluster],4096-10 ; is this 16 bit fat?
+        JAE     EOF16                   ; yes, check for eof there
+;J.K. 8/27/86
+;Modified to accept 0FF0h as an eof. This is to handle the diskfull case
+;of any media that has "F0"(Other) as a MediaByte.
+;Hopely, this does not create any side effect for those who may use any value
+;other than "FF8-FFF" as an Eof for their own file.
+        cmp     bx,0FF0h
+        je      IsEOF_other
+        CMP     BX,0FF8h                ; do the 12 bit compare
+IsEOF_other:
+        return
+EOF16:
+        CMP     BX,0FFF8h               ; 16 bit compare
+        return
+EndProc IsEof
+
+Break   <UNPACK -- UNPACK FAT ENTRIES>
+
+; Inputs:
+;       BX = Cluster number (may be full 16-bit quantity)
+;       ES:BP = Base of drive parameters
+; Outputs:
+;       DI = Contents of FAT for given cluster (may be full 16-bit quantity)
+;       Zero set means DI=0 (free cluster)
+;       Carry set means error (currently user FAILed to I 24)
+; SI Destroyed, No other registers affected. Fatal error if cluster too big.
+
+        procedure   UNPACK,NEAR
+        DOSAssume   CS,<DS>,"UnPack"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"Unpack"
+        CMP     BX,ES:[BP.dpb_max_cluster]
+        JA      HURTFAT
+        CALL    MAPCLUSTER
+ASSUME  DS:NOTHING
+        jc      DoContext
+        MOV     DI,[DI]
+        JNZ     High12                  ; MZ if high 12 bits, go get 'em
+        MOV     SI,ES:[BP.dpb_max_cluster]  ; MZ is this 16-bit fat?
+        CMP     SI,4096-10
+        JB      Unpack12                ; MZ No, go 'AND' off bits
+        OR      DI,DI                   ; MZ set zero condition code, clears carry
+        JMP     SHORT DoContext         ; MZ go do context
+
+High12:
+        SHR     DI,1
+        SHR     DI,1
+        SHR     DI,1
+        SHR     DI,1
+Unpack12:
+        AND     DI,0FFFH                ; Clears carry
+DoContext:
+        PUSH    SS
+        POP     DS
+        return
+
+HURTFAT:
+        MOV     ES:[BP.dpb_free_cnt],-1 ; Err in FAT must force recomp of freespace
+        PUSH    AX
+        MOV     AH,allowed_fail + 80h
+        MOV     Allowed,allowed_fail
+;
+; Signal Bad FAT to INT int_fatal_abort handler.  We have an invalid cluster.
+;
+        MOV     DI,0FFFH                ; In case INT int_fatal_abort returns (it shouldn't)
+        invoke  FATAL
+        CMP     AL,3
+        CLC
+        JNZ     OKU_RET                 ; Try to ignore bad FAT
+        STC                             ; User said FAIL
+OKU_RET:
+        POP     AX
+        return
+EndProc UNPACK
+
+Break   <PACK -- PACK FAT ENTRIES>
+
+; Inputs:
+;       BX = Cluster number
+;       DX = Data
+;       ES:BP = Pointer to drive DPB
+; Outputs:
+;       The data is stored in the FAT at the given cluster.
+;       SI,DX,DI all destroyed
+;       Carry set means error (currently user FAILed to I 24)
+;       No other registers affected
+
+        procedure   PACK,NEAR
+        DOSAssume   CS,<DS>,"Pack"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"Pack"
+        CALL    MAPCLUSTER
+ASSUME  DS:NOTHING
+        JC      DoContext
+        MOV     SI,[DI]
+        JZ      Aligned                 ; byte (not nibble) aligned
+        PUSH    CX                      ; move data to upper 12 bits
+        MOV     CL,4
+        SHL     DX,CL
+        POP     CX
+        AND     SI,0FH                  ; leave in original low 4 bits
+        JMP     SHORT PACKIN
+ALIGNED:
+        CMP     ES:[BP.dpb_max_cluster],4096-10 ; MZ 16 bit fats?
+        JAE     Pack16                  ; MZ yes, go clobber original data
+        AND     SI,0F000H               ; MZ leave in upper 4 bits of original
+        AND     DX,0FFFh                ; MZ store only 12 bits
+        JMP     SHORT PackIn            ; MZ go store
+Pack16:
+        XOR     SI,SI                   ; MZ no original data
+PACKIN:
+        OR      SI,DX
+        MOV     [DI],SI
+        LDS     SI,[CURBUF]
+        TEST    [SI.buf_flags],buf_dirty  ;LB. if already dirty                 ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      [SI.buf_flags],buf_dirty  ;LB.                                  ;AN000;
+yesdirty:                                 ;LB.                                  ;AN000;
+        CMP     BYTE PTR [CLUSSPLIT],0
+        Context DS
+        retz                            ; Carry clear
+        PUSH    AX
+        PUSH    BX
+        PUSH    CX
+        MOV     AX,[CLUSSAVE]
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+        ADD     SI,BUFINSIZ
+        MOV     [SI],AH
+        Context DS
+        PUSH    AX
+        MOV     DX,WORD PTR [CLUSSEC+2]            ;F.C. >32mb                 ;AN000;
+        MOV     WORD PTR [HIGH_SECTOR],DX          ;F.C. >32mb                 ;AN000;
+
+        MOV     DX,WORD PTR [CLUSSEC]
+        MOV     SI,1
+        XOR     AL,AL
+        invoke  GETBUFFRB
+        POP     AX
+        JC      POPP_RET
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        TEST    [DI.buf_flags],buf_dirty  ;LB. if already dirty                 ;AN000;
+        JNZ     yesdirty2                 ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      [DI.buf_flags],buf_dirty
+yesdirty2:
+        ADD     DI,BUFINSIZ
+        DEC     DI
+        ADD     DI,ES:[BP.dpb_sector_size]
+        MOV     [DI],AL
+        CLC
+POPP_RET:
+        PUSH    SS
+        POP     DS
+        POP     CX
+        POP     BX
+        POP     AX
+        return
+
+EndProc PACK
+
+Break   <MAPCLUSTER - BUFFER A FAT SECTOR>
+
+; Inputs:
+;       ES:BP Points to DPB
+;       BX Is cluster number
+; Function:
+;       Get a pointer to the cluster
+; Outputs:
+;       DS:DI Points to contents of FAT for given cluster
+;       DS:SI Points to start of buffer
+;       Zero Not set if cluster data is in high 12 bits of word
+;       Zero set if cluster data is in low 12 or 16 bits
+;       Carry set if failed.
+; SI is destroyed.
+
+        procedure   MAPCLUSTER,NEAR
+        DOSAssume   CS,<DS>,"MapCluster"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"MapCluster"
+        MOV     BYTE PTR [CLUSSPLIT],0
+        SaveReg <AX,BX,CX,DX>
+        MOV     AX,BX                   ; AX = BX
+        MOV     CX,4096-10
+        CMP     ES:[BP.dpb_max_cluster],CX  ; MZ 16 bit fat?
+        JAE     Map16                   ; MZ yes, do 16 bit algorithm
+        SHR     AX,1                    ; AX = BX/2
+Map16:                                  ; MZ skip prev => AX=2*BX
+        XOR     DI,DI                   ; >32mb     fat                         ;AN000;
+        ADD     AX,BX                   ; AX = 1.5*fat = byte offset in fat
+        ADC     DI,0                    ; >32mb     fat                         ;AN000;
+DoConvert:
+        MOV     CX,ES:[BP.dpb_sector_size]
+IF FastDiv
+;
+; Gross hack:  99% of all disks have 512 bytes per sector.  We test for this
+; case and apply a really fast algorithm to get the desired results
+;
+; Divide method takes 158 (XOR and DIV)
+; Fast method takes 20
+;
+; This saves a bunch.
+;
+        CMP     CX,512                  ; 4     Is this 512 byte sector?
+        JZ      Nodiv                   ;F.C. >32mb                             ;AN000;
+        JMP     DoDiv                   ; 4/16  No, go do divide
+Nodiv:                                  ;F.C. >32mb                             ;AN000;
+        MOV     DX,AX                   ; 2     get set for remainder
+        AND     DX,512-1                ; 4     Form remainder
+        MOV     AL,AH                   ; 2
+        SHR     AL,1                    ; 2
+        CBW                             ; 2     Fast divide by 512
+        OR      DI,DI                   ;>32mb  >64k ?                          ;AN000;
+        JZ      g64k                    ;>32mb  no                              ;AN000;
+        OR      AX,80H                  ;>32mb                                  ;AN000;
+g64k:
+ELSE
+        XOR     DX,DX                   ; 3
+        DIV     CX                      ; 155 AX is FAT sector # DX is sector index
+ENDIF
+DivDone:
+        ADD     AX,ES:[BP.dpb_first_FAT]
+        DEC     CX                      ; CX is sector size - 1
+        SaveReg <AX,DX,CX>
+        MOV     DX,AX
+        MOV     [HIGH_SECTOR],0         ;F.C. >32mb  low sector #
+        XOR     AL,AL
+        MOV     SI,1
+        invoke  GETBUFFRB
+        RestoreReg  <CX,AX,DX>          ; CX is sec siz-1, AX is offset in sec
+        JC      MAP_POP
+        LDS     SI,[CURBUF]
+ASSUME  DS:NOTHING
+        LEA     DI,[SI.BufInSiz]
+        ADD     DI,AX
+        CMP     AX,CX
+        JNZ     MAPRET
+        MOV     AL,[DI]
+        Context DS
+        INC     BYTE PTR [CLUSSPLIT]
+        MOV     BYTE PTR [CLUSSAVE],AL
+        MOV     WORD PTR [CLUSSEC],DX
+        MOV     WORD PTR [CLUSSEC+2],0        ;F.C. >32mb                       ;AN000;
+        INC     DX
+        MOV     [HIGH_SECTOR],0               ;F.C. >32mb  FAT sector <32mb     ;AN000;
+        XOR     AL,AL
+        MOV     SI,1
+        invoke  GETBUFFRB
+        JC      MAP_POP
+        LDS     SI,[CURBUF]
+ASSUME  DS:NOTHING
+        LEA     DI,[SI.BufInSiz]
+        MOV     AL,[DI]
+        Context DS
+        MOV     BYTE PTR [CLUSSAVE+1],AL
+        MOV     DI,OFFSET DOSGROUP:CLUSSAVE
+MAPRET:
+        RestoreReg  <DX,CX,BX>
+        XOR     AX,AX                   ; MZ allow shift to clear carry
+        CMP     ES:[BP.dpb_max_cluster],4096-10 ; MZ is this 16-bit fat?
+        JAE     MapSet                  ; MZ no, set flags
+        MOV     AX,BX
+MapSet:
+        TEST    AL,1                    ; set zero flag if not on boundary
+        RestoreReg  <AX>
+        return
+
+MAP_POP:
+        RestoreReg  <DX,CX,BX,AX>
+        return
+IF FastDiv
+DoDiv:
+        XOR     DX,DX                   ; 3
+        DIV     CX                      ; 155 AX is FAT sector # DX is sector index
+        JMP     DivDone                 ;15 total=35
+ENDIF
+
+EndProc MAPCLUSTER
+
+Break   <FATREAD_SFT/FATREAD_CDS -- CHECK DRIVE GET FAT>
+
+; Inputs:
+;       ES:DI points to an SFT for the drive of intrest (local only,
+;               giving a NET SFT will produce system crashing results).
+;       DS DOSGROUP
+; Function:
+;       Can be used by an SFT routine (like CLOSE) to invalidate buffers
+;       if disk changed.
+;       In other respects, same as FATREAD_CDS.
+;       (note ES:DI destroyed!)
+; Outputs:
+;       Carry set if error (currently user FAILed to I 24)
+; NOTE: This routine may cause FATREAD_CDS to "miss" a disk change
+;       as far as invalidating curdir_ID is concerned.
+;       Since getting a true disk changed on this call is a screw up
+;       anyway, that's the way it goes.
+
+        procedure  FATREAD_SFT,NEAR
+        DOSAssume   CS,<DS>,"FATRead_SFT"
+        ASSUME  ES:NOTHING
+
+        LES     BP,ES:[DI.sf_devptr]
+        Assert      ISDPB,<ES,BP>,"FatReadSFT"
+        MOV     AL,ES:[BP.dpb_drive]
+        MOV     [THISDRV],AL
+        invoke  GOTDPB                  ;Set THISDPB
+        CALL    FAT_GOT_DPB
+        return
+EndProc FATREAD_SFT
+
+; Inputs:
+;       DS:DOSGROUP
+;       ES:DI points to an CDS for the drive of intrest (local only,
+;               giving a NET or NUL CDS will produce system crashing results).
+; Function:
+;       If disk may have been changed, media is determined and buffers are
+;       flagged invalid. If not, no action is taken.
+; Outputs:
+;       ES:BP = Drive parameter block
+;       [THISDPB] = ES:BP
+;       [THISDRV] set
+;       Carry set if error (currently user FAILed to I 24)
+; DS preserved , all other registers destroyed
+
+        procedure   FATREAD_CDS,NEAR
+        DOSAssume   CS,<DS>,"FATRead_CDS"
+        ASSUME  ES:NOTHING
+
+        PUSH    ES
+        PUSH    DI
+        LES     BP,ES:[DI.curdir_devptr]
+        Assert  ISDPB,<ES,BP>,"FatReadCDS"
+        MOV     AL,ES:[BP.dpb_drive]
+        MOV     [THISDRV],AL
+        invoke  GOTDPB                  ;Set THISDPB
+        CALL    FAT_GOT_DPB
+        POP     DI                      ;Get back CDS pointer
+        POP     ES
+        retc
+        JNZ     NO_CHANGE               ;Media NOT changed
+; Media changed. We now need to find all CDS structures which use this
+; DPB and invalidate their ID pointers.
+MED_CHANGE:
+        XOR     AX,AX
+        DEC     AX                      ;AX = -1
+        PUSH    DS
+        MOV     CL,[CDSCOUNT]
+        XOR     CH,CH                   ; CX is number of structures
+        LDS     SI,ES:[DI.curdir_devptr] ; Find all CDS with this devptr
+ASSUME  DS:NOTHING
+        LES     DI,[CDSADDR]            ; Start here
+CHECK_CDS:
+        TEST    ES:[DI.curdir_flags],curdir_isnet
+        JNZ     NEXTCDS                 ; Leave NET guys alone!!
+        PUSH    ES
+        PUSH    DI
+        LES     DI,ES:[DI.curdir_devptr]
+        invoke  POINTCOMP
+        POP     DI
+        POP     ES
+        JNZ     NEXTCDS                 ; CDS not for this drive
+        TEST    ES:[DI.curdir_ID],AX
+        JZ      NEXTCDS                 ; If root, leave root
+        MOV     ES:[DI.curdir_ID],AX    ; else invalid
+NEXTCDS:
+        ADD     DI,SIZE curdir_list     ; Point to next CDS
+        LOOP    CHECK_CDS
+        POP     DS
+        DOSAssume   CS,<DS>,"FAT/NextCDS"
+NO_CHANGE:
+        LES     BP,[THISDPB]
+        CLC
+        return
+EndProc FATREAD_CDS
+
+Break   <Fat_Operation - miscellaneous fat stuff>
+
+        procedure   FAT_operation,NEAR
+FATERR:
+        DOSAssume   CS,<DS>,"FATERR"
+        MOV     ES:[BP.dpb_free_cnt],-1 ; Err in FAT must force recomp of freespace
+        AND     DI,STECODE              ; Put error code in DI
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        MOV     AH,2 + allowed_FAIL + allowed_RETRY ; While trying to read FAT
+        MOV     AL,BYTE PTR [THISDRV]    ; Tell which drive
+        invoke  FATAL1
+        LES     BP,[THISDPB]
+        CMP     AL,3
+        JNZ     FAT_GOT_DPB             ; User said retry
+        STC                             ; User said FAIL
+        return
+
+FAT_GOT_DPB:
+        Context DS
+        MOV     AL,DMEDHL
+        MOV     AH,ES:[BP.dpb_UNIT]
+        MOV     WORD PTR [DEVCALL],AX
+        MOV     BYTE PTR [DEVCALL.REQFUNC],DEVMDCH
+        MOV     [DEVCALL.REQSTAT],0
+        MOV     AL,ES:[BP.dpb_media]
+        MOV     BYTE PTR [CALLMED],AL
+        PUSH    ES
+        PUSH    DS
+        MOV     BX,OFFSET DOSGROUP:DEVCALL
+        LDS     SI,ES:[BP.dpb_driver_addr]  ; DS:SI Points to device header
+ASSUME  DS:NOTHING
+        POP     ES                      ; ES:BX Points to call header
+        invoke  DEVIOCALL2
+        Context DS
+        POP     ES                      ; Restore ES:BP
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JNZ     FATERR
+        XOR     AH,AH
+        XCHG    AH,ES:[BP.dpb_first_access] ; Reset dpb_first_access
+        MOV     AL,BYTE PTR [THISDRV]   ; Use physical unit number
+; See if we had changed volume id by creating one on the diskette
+        cmp     [VOLCHNG_FLAG],AL
+        jnz     CHECK_BYT
+        mov     [VOLCHNG_FLAG],-1
+        jmp     GOGETBPB                ; Need to get device driver to read in
+                                        ; new volume label.
+CHECK_BYT:
+        OR      AH,BYTE PTR [CALLRBYT]
+        JNS     CHECK_ZR                ; ns = 0 or 1
+        JMP     NEWDSK
+
+CHECK_ZR:
+        JZ      CHKBUFFDIRT             ; jump if I don't know
+        CLC
+        return                          ; If Media not changed (NZ)
+
+DISK_CHNG_ERR:
+ASSUME  DS:NOTHING
+        PUSH    ES
+        PUSH    BP
+        LES     BP,ES:[BP.dpb_driver_addr]  ; Get device pointer
+        TEST    ES:[BP.SDEVATT],DEVOPCL ; Did it set vol id?
+        POP     BP
+        POP     ES
+        JZ      FAIL_OPJ2               ; Nope, FAIL
+        PUSH    DS                      ; Save buffer pointer for ignore
+        PUSH    DI
+        Context DS
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        PUSH    ES
+        LES     DI,[CALLVIDM]           ; Get volume ID pointer
+        MOV     WORD PTR [EXTERRPT+2],ES
+        POP     ES
+        MOV     WORD PTR [EXTERRPT],DI
+        MOV     AX,error_I24_wrong_disk
+        MOV     [READOP],1              ; Write
+        invoke  HARDERR
+        POP     DI                      ; Get back buffer for ignore
+        POP     DS
+ASSUME  DS:NOTHING
+        CMP     AL,3
+FAIL_OPJ2:
+        JZ      FAIL_OP
+        JMP     FAT_GOT_DPB             ; Retry
+
+CHKBUFFDIRT:
+        DOSAssume   CS,<DS>,"FAT/ChkBuffDirt"
+;       LDS     DI,[BUFFHEAD]
+ASSUME  DS:NOTHING
+        XOR     DX,DX                            ;LB.                           ;AN000;
+        LDS     DI,[BUF_HASH_PTR]                ;LB. scan from 1st entry       ;AN000;
+        MOV     CX,[BUF_HASH_COUNT]              ;LB. get Hash entry count      ;AN000;
+
+scan_dirty:
+        CMP     [DI.Dirty_Count],0               ;LB. if not dirty              ;AN000;
+        JZ      GETNEXT                          ;LB.    get next hash entry    ;AN000;
+        PUSH    DS                               ;LB. save hash entry addr      ;AN000;
+        PUSH    DI                               ;LB.                           ;AN000;
+        invoke  Map_Entry                        ;LB.                           ;AN000;
+NBUFFER:                                ; Look for dirty buffers
+        CMP     AL,[DI.buf_ID]
+        JNZ     LFNXT                   ; Not for this unit
+        TEST    [DI.buf_flags],buf_dirty
+        JZ      LFNXT
+        POP     DI                                ;LB. restore regs              ;AN000;
+        POP     DS                                ;LB.                           ;AN000;
+        Context DS
+        CLC
+        return                          ; There is a dirty buffer, assume Media OK (NZ)
+
+FAIL_OP:
+        Context DS
+        STC
+        return
+
+ASSUME  DS:NOTHING
+LFNXT:
+        mov     DI,[DI.buf_next]            ;; 1/19/88
+        CMP     DI,[FIRST_BUFF_ADDR]        ;; 1/19/88
+        JNZ     NBUFFER
+        POP     DI                                ;LB. restore regs              ;AN000;
+        POP     DS                                ;LB.                           ;AN000;
+GETNEXT:
+        ADD     DI,size BUFFER_HASH_ENTRY         ;LB. next entry                ;AN000;
+        LOOP    scan_dirty                        ;LB. scan next entry           ;AN000;
+; If no dirty buffers, assume Media changed
+NEWDSK:
+        MOV     ES:[BP.dpb_free_cnt],-1 ; Media changed, must re-compute
+                                        ; NOTE: It is TECHNICALLY more correct
+ASSUME DS:NOTHING
+        XOR     DX,DX                   ;LB.                                      ;AN000;
+        MOV     [HIGH_SECTOR],DX        ;LB. scan from 1st entry                  ;AN000;
+        MOV     CX,[BUF_HASH_COUNT]     ;LB. get Hash entry count                 ;AN000;
+
+NxtHash:
+        invoke  GETCURHEAD              ;LB. get Hash entry buffer header         ;AN000;
+                                        ;  to do this AFTER the check for
+ASSUME  DS:NOTHING
+NXBUFFER:
+        CMP     AL,[DI.buf_ID]          ; For this drive?
+        JZ      OLDDRV2                 ;LB.  yes                                 ;AN000;
+        mov     DI,[DI.buf_next]        ;LB.  get next buffer  1/19/88            ;AN000;
+        JMP     SHORT SKPBUFF           ;LB.                                      ;AN000;
+OLDDRV2:
+        TEST    [DI.buf_flags],buf_dirty
+        JZ      OldDrv
+        JMP     Disk_Chng_Err           ; Disk changed but dirty buffers
+OLDDRV:
+        MOV     WORD PTR [DI.buf_ID],(buf_visit SHL 8) OR 0FFH  ; Free up buffer
+        invoke  SCANPLACE
+SKPBUFF:
+        CMP     DI,[FIRST_BUFF_ADDR]    ;LB.  end of chain  1/19/88               ;AN000;
+        JNZ     NXBUFFER                ;LB.  no                                  ;AN000;
+        INC     DX                      ;LB.                                      ;AN000;
+        LOOP    NxtHash                 ;LB.                                      ;AN000;
+        CMP     [SC_CACHE_COUNT],0      ;LB.  look ahead buffers ?                ;AN001;
+        JZ      GOGETBPB                ;LB.  no                                  ;AN001;
+        CMP     AL,[CURSC_DRIVE]        ;LB.  same as changed drive               ;AN001;
+        JNZ     GOGETBPB                ;LB.  no                                  ;AN001;
+        MOV     [CURSC_DRIVE],-1        ;LB.  invalidate look ahead buffers       ;AN000;
+GOGETBPB:
+        LDS     DI,ES:[BP.dpb_driver_addr]
+        TEST    [DI.SDEVATT],ISFATBYDEV
+        JNZ     GETFREEBUF
+        context DS
+        MOV     BX,2
+        CALL    UNPACK                  ; Read the first FAT sector into CURBUF
+FAIL_OPJ:
+        JC      FAIL_OP
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        JMP     SHORT GOTGETBUF
+
+GETFREEBUF:
+ASSUME  DS:NOTHING
+        PUSH    ES                      ; Get a free buffer for BIOS to use
+        PUSH    BP
+;       LDS     DI,[BUFFHEAD]
+        XOR     DX,DX                        ;LB.  fake to get 1st                ;AN000;
+        MOV     [HIGH_SECTOR],DX             ;LB.  buffer addr                    ;AN000;
+        invoke  GETCURHEAD                   ;LB.                                 ;AN000;
+
+        invoke  BUFWRITE
+        POP     BP
+        POP     ES
+        JC      FAIL_OPJ
+GOTGETBUF:
+        ADD     DI,BUFINSIZ
+        MOV     WORD PTR [CALLXAD+2],DS
+        Context DS
+        MOV     WORD PTR [CALLXAD],DI
+        MOV     AL,DBPBHL
+        MOV     AH,BYTE PTR ES:[BP.dpb_UNIT]
+        MOV     WORD PTR [DEVCALL],AX
+        MOV     BYTE PTR [DEVCALL.REQFUNC],DEVBPB
+        MOV     [DEVCALL.REQSTAT],0
+        MOV     AL,BYTE PTR ES:[BP.dpb_media]
+        MOV     [CALLMED],AL
+        PUSH    ES
+        PUSH    DS
+        PUSH    WORD PTR ES:[BP.dpb_driver_addr+2]
+        PUSH    WORD PTR ES:[BP.dpb_driver_addr]
+        MOV     BX,OFFSET DOSGROUP:DEVCALL
+        POP     SI
+        POP     DS                      ; DS:SI Points to device header
+ASSUME  DS:NOTHING
+        POP     ES                      ; ES:BX Points to call header
+        invoke  DEVIOCALL2
+        POP     ES                      ; Restore ES:BP
+        Context DS
+        MOV     DI,[DEVCALL.REQSTAT]
+        TEST    DI,STERR
+        JNZ     FATERRJ
+        MOV     AL,BYTE PTR ES:[BP.dpb_media]
+        LDS     SI,[CALLBPB]
+ASSUME  DS:NOTHING
+        MOV     ES:[BP].DPB_next_free,0 ; recycle scanning pointer
+        invoke  $SETDPB
+        LDS     DI,[CALLXAD]            ; Get back buffer pointer
+        MOV     AL,BYTE PTR ES:[BP.dpb_FAT_count]
+        MOV     [DI.buf_wrtcnt-BUFINSIZ],AL   ;>32mb                            ;AN000;
+        MOV     AX,ES:[BP.dpb_FAT_size]       ;>32mb                            ;AC000;
+        MOV     [DI.buf_wrtcntinc-BUFINSIZ],AX   ;>32mb Correct buffer info     ;AC000;
+
+        Context DS
+        XOR     AL,AL                   ;Media changed (Z), Carry clear
+        return
+
+FATERRJ: JMP    FATERR
+
+EndProc FAT_operation
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/FCB.ASM b/v4.0/src/DOS/FCB.ASM
new file mode 100644
index 0000000..2b51da6
--- /dev/null
+++ b/v4.0/src/DOS/FCB.ASM
@@ -0,0 +1,504 @@
+;       SCCSID = @(#)fcb.asm    1.2 85/07/23
+;       SCCSID = @(#)fcb.asm    1.2 85/07/23
+TITLE   FCB - FCB parse calls for MSDOS
+NAME    FCB
+; Low level routines for parsing names into FCBs and analyzing
+;    filename characters
+;
+;   MakeFcb
+;   NameTrans
+;   PATHCHRCMP
+;   GetLet
+;   TESTKANJ
+;   NORMSCAN
+;   DELIM
+;
+;   Revision history:
+;
+;       A000  version 4.00  Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+
+TableLook   equ -1
+
+Table   Segment
+Zero    label byte
+Table   ENDS
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include devsym.inc
+include doscntry.inc                    ;AN000;         2/12/KK
+.cref
+.list
+
+        i_need  Name1,BYTE
+        i_need  Creating,BYTE
+        i_need  Attrib,BYTE
+        i_need  SpaceFlag,BYTE
+        i_need  FILE_UCASE_TAB,byte        ;DOS 3.3
+        i_need  COUNTRY_CDPG,byte       ;AN000;         2/12/KK
+        i_need  DrvErr,BYTE             ;AN000;         2/12/KK
+        i_need  DOS34_FLAG,WORD         ;AN000;         2/12/KK
+
+        procedure   MakeFcb,NEAR
+ScanSeparator   =   1
+DRVBIT  EQU     2
+NAMBIT  EQU     4
+EXTBIT  EQU     8
+        MOV     BYTE PTR [SpaceFlag],0
+        XOR     DL,DL           ; Flag--not ambiguous file name
+        TEST    AL,DRVBIT       ; Use current drive field if default?
+        JNZ     DEFDRV
+        MOV     BYTE PTR ES:[DI],0      ; No - use default drive
+DEFDRV:
+        INC     DI
+        MOV     CX,8
+        TEST    AL,NAMBIT       ; Use current name fields as defualt?
+        XCHG    AX,BX           ; Save bits in BX
+        MOV     AL," "
+        JZ      FILLB           ; If not, go fill with blanks
+        ADD     DI,CX
+        XOR     CX,CX           ; Don't fill any
+FILLB:
+        REP     STOSB
+        MOV     CL,3
+        TEST    BL,EXTBIT       ; Use current extension as default
+        JZ      FILLB2
+        ADD     DI,CX
+        XOR     CX,CX
+FILLB2:
+        REP     STOSB
+        XCHG    AX,CX           ; Put zero in AX
+        STOSW
+        STOSW                   ; Initialize two words after to zero
+        SUB     DI,16           ; Point back at start
+        TEST    BL,ScanSeparator; Scan off separators if not zero
+        JZ      SKPSPC
+        CALL    SCANB           ; Peel off blanks and tabs
+        CALL    DELIM           ; Is it a one-time-only delimiter?
+        JNZ     NOSCAN
+        INC     SI              ; Skip over the delimiter
+SKPSPC:
+        CALL    SCANB           ; Always kill preceding blanks and tabs
+NOSCAN:
+        CALL    GETLET
+        JBE     NODRV           ; Quit if termination character
+ IF  DBCS                       ;AN000;
+        CALL    TESTKANJ        ;AN000;; 2/18/KK
+        JNE     NODRV           ;AN000;; 2/18/KK
+ ENDIF                          ;AN000;
+        CMP     BYTE PTR[SI],":"        ; Check for potential drive specifier
+        JNZ     NODRV
+        INC     SI              ; Skip over colon
+        SUB     AL,"@"          ; Convert drive letter to drive number (A=1)
+        JBE     BADDRV          ; Drive letter out of range
+
+        PUSH    AX
+        Invoke  GetVisDrv
+        POP     AX
+        JNC     HavDrv
+        CMP     [DrvErr],error_not_DOS_disk  ; if not FAt drive                 ;AN000;
+        JZ      HavDrv                       ; assume ok                        ;AN000;
+BADDRV:
+        MOV     DL,-1
+HAVDRV:
+        STOSB                   ; Put drive specifier in first byte
+        INC     SI
+        DEC     DI              ; Counteract next two instructions
+NODRV:
+        DEC     SI              ; Back up
+        INC     DI              ; Skip drive byte
+
+        entry   NORMSCAN
+
+        MOV     CX,8
+        CALL    GETWORD         ; Get 8-letter file name
+        CMP     BYTE PTR [SI],"."
+        JNZ     NODOT
+        INC     SI              ; Skip over dot if present
+        TEST    [DOS34_FLAG],DBCS_VOLID2                                        ;AN000;
+        JZ      VOLOK                                                           ;AN000;
+        MOVSB                   ; 2nd byte of DBCS                              ;AN000;
+        MOV     CX,2                                                            ;AN000;
+        JMP     SHORT contvol                                                   ;AN000;
+VOLOK:
+        MOV     CX,3            ; Get 3-letter extension
+contvol:
+        CALL    MUSTGETWORD
+NODOT:
+        MOV     AL,DL
+        return
+
+NONAM:
+        ADD     DI,CX
+        DEC     SI
+        return
+
+GETWORD:
+        CALL    GETLET
+        JBE     NONAM           ; Exit if invalid character
+        DEC     SI
+;
+; UGH!!! Horrible bug here that should be fixed at some point:
+; If the name we are scanning is longer than CX, we keep on reading!
+;
+MUSTGETWORD:
+        CALL    GETLET
+;
+; If spaceFlag is set then we allow spaces in a pathname
+;
+        JB      FILLNAM
+        JNZ     MustCheckCX
+        TEST    BYTE PTR [SpaceFlag],0FFh
+        JZ      FILLNAM
+        CMP     AL," "
+        JNZ     FILLNAM
+
+MustCheckCX:
+        JCXZ    MUSTGETWORD
+        DEC     CX
+        CMP     AL,"*"          ; Check for ambiguous file specifier
+        JNZ     NOSTAR
+        MOV     AL,"?"
+        REP     STOSB
+NOSTAR:
+        STOSB
+
+ IF   DBCS                                                        ;AN000;
+        CALL    TESTKANJ                                          ;AN000;
+        JZ      NOTDUAL3                                          ;AN000;
+        JCXZ    BNDERR          ; Attempt to straddle boundry     ;AN000;
+        MOVSB                   ; Transfer second byte            ;AN000;
+        DEC     CX                                                ;AN000;
+        JMP     MUSTGETWORD                                       ;AN000;
+BNDERR:                                                           ;AN000;
+        TEST    [DOS34_FLAG],DBCS_VOLID                           ;AN000;
+        JZ      notvolumeid                                       ;AN000;
+        TEST    [DOS34_FLAG],DBCS_VOLID2                          ;AN000;
+        JNZ     notvolumeid                                       ;AN000;
+        OR      [DOS34_FLAG],DBCS_VOLID2                          ;AN000;
+        JMP     MUSTGETWORD                                       ;AN000;
+
+notvolumeid:
+;;      INC     CX              ; Undo the store of the first byte
+        DEC     DI
+        MOV     AL," "          ;PTM.                              ;AN000;
+        STOSB                   ;PTM.                              ;AN000;
+        INC     SI              ;PTM.                              ;AN000;
+        JMP     MUSTGETWORD     ;PTM.                              ;AN000;
+
+NOTDUAL3:                                                          ;AN000;
+  ENDIF                                                            ;AN000;
+
+        CMP     AL,"?"
+        JNZ     MUSTGETWORD
+        OR      DL,1            ; Flag ambiguous file name
+        JMP     MUSTGETWORD
+FILLNAM:
+        MOV     AL," "
+        REP     STOSB
+        DEC     SI
+        return
+
+SCANB:
+        LODSB
+        CALL    SPCHK
+        JZ      SCANB
+ IF  DBCS                       ;AN000;                                                 ;AN000;
+        CMP     AL,81H          ;AN000;; 1ST BYTE OF DBCS BLANK 2/18/KK                 ;AN000;
+        JNE     SCANB_EXIT      ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+        CALL    TESTKANJ        ;AN000;; 2/23/KK  3/31/KK revoved                       ;AN000;
+        JE      SCANB_EXIT      ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+        CMP     BYTE PTR [SI],40H;AN000;H ; 2ND BYTE OF DBCS BLANK 2/18/KK 3/31/KK revove;AN000;
+        JNE     SCANB_EXIT      ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+        INC     SI              ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+        JMP     SCANB           ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+    SCANB_EXIT:                 ;AN000;; 2/18/KK  3/31/KK revoved                       ;AN000;
+ ENDIF                          ;AN000;
+        DEC     SI
+        return
+EndProc MakeFCB
+
+;
+; NameTrans is used by FindPath to scan off an element of a path.  We must
+; allow spaces in pathnames
+;
+;   Inputs:     DS:SI points to start of path element
+;   Outputs:    Name1 has unpacked name, uppercased
+;               ES = DOSGroup
+;               DS:SI advanced after name
+;   Registers modified: DI,AX,DX,CX
+procedure   NameTrans,near
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     BYTE PTR [SpaceFlag],1
+        context ES
+        MOV     DI,OFFSET DOSGROUP:NAME1
+        PUSH    DI
+        MOV     AX,'  '
+        MOV     CX,5
+        STOSB
+        REP     STOSW           ; Fill "FCB" at NAME1 with spaces
+        XOR     AL,AL           ; Set stuff for NORMSCAN
+        MOV     DL,AL
+        STOSB
+        POP     DI
+
+        CALL    NORMSCAN
+IF DBCS                         ;AN000;;KK.
+        MOV     AL,[NAME1]      ;AN000;;KK. check 1st char
+        invoke  testkanj        ;AN000;;KK. dbcs ?
+        JZ      notdbcs         ;AN000;;KK. no
+        return                  ;AN000;;KK. yes
+notdbcs:                        ;AN000;
+ENDIF                           ;AN000;
+        CMP     [NAME1],0E5H
+        retnz
+        MOV     [NAME1],5       ; Magic name translation
+        return
+
+EndProc nametrans
+
+Break   <GETLET, DELIM -- CHECK CHARACTERS AND CONVERT>
+
+If TableLook
+ChType  Macro   ch,bits
+        ORG     CharType-Zero+ch
+        db      bits
+        ENDM
+
+Table   SEGMENT
+        PUBLIC  CharType
+Public FCB001S,FCB001E
+FCB001S  label byte
+CharType    DB  256 dup (-1)
+        ChType  ".", <LOW (NOT (     fChk))>
+        ChType  '"', <LOW (NOT (fFCB+fChk))>
+        ChType  "/", <LOW (NOT (fFCB+fChk))>
+        ChType  "\", <LOW (NOT (fFCB+fChk))>
+        ChType  "[", <LOW (NOT (fFCB+fChk))>
+        ChType  "]", <LOW (NOT (fFCB+fChk))>
+        ChType  ":", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  "<", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  "|", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  ">", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  "+", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  "=", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  ";", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  ",", <LOW (NOT (fFCB+fChk+fDelim))>
+        ChType  0,   <LOW (NOT (fFCB+fChk))>           ; NUL
+        ChType  1,   <LOW (NOT (fFCB+fChk))>           ; ^A
+        ChType  2,   <LOW (NOT (fFCB+fChk))>           ; ^b
+        ChType  3,   <LOW (NOT (fFCB+fChk))>           ; ^c
+        ChType  4,   <LOW (NOT (fFCB+fChk))>           ; ^d
+        ChType  5,   <LOW (NOT (fFCB+fChk))>           ; ^e
+        ChType  6,   <LOW (NOT (fFCB+fChk))>           ; ^f
+        ChType  7,   <LOW (NOT (fFCB+fChk))>           ; ^g
+        ChType  8,   <LOW (NOT (fFCB+fChk))>           ; ^h
+        ChType  9,   <LOW (NOT (fFCB+fChk+fDelim+fSpChk))> ; Tab
+        ChType  10,  <LOW (NOT (fFCB+fChk))>           ; ^j
+        ChType  11,  <LOW (NOT (fFCB+fChk))>           ; ^k
+        ChType  12,  <LOW (NOT (fFCB+fChk))>           ; ^l
+        ChType  13,  <LOW (NOT (fFCB+fChk))>           ; ^m
+        ChType  14,  <LOW (NOT (fFCB+fChk))>           ; ^n
+        ChType  15,  <LOW (NOT (fFCB+fChk))>           ; ^o
+        ChType  16,  <LOW (NOT (fFCB+fChk))>           ; ^p
+        ChType  17,  <LOW (NOT (fFCB+fChk))>           ; ^q
+        ChType  18,  <LOW (NOT (fFCB+fChk))>           ; ^r
+        ChType  19,  <LOW (NOT (fFCB+fChk))>           ; ^s
+        ChType  20,  <LOW (NOT (fFCB+fChk))>           ; ^t
+        ChType  21,  <LOW (NOT (fFCB+fChk))>           ; ^u
+        ChType  22,  <LOW (NOT (fFCB+fChk))>           ; ^v
+        ChType  23,  <LOW (NOT (fFCB+fChk))>           ; ^w
+        ChType  24,  <LOW (NOT (fFCB+fChk))>           ; ^x
+        ChType  25,  <LOW (NOT (fFCB+fChk))>           ; ^y
+        ChType  26,  <LOW (NOT (fFCB+fChk))>           ; ^z
+        ChType  27,  <LOW (NOT (fFCB+fChk))>           ; ^[
+        ChType  28,  <LOW (NOT (fFCB+fChk))>           ; ^\
+        ChType  29,  <LOW (NOT (fFCB+fChk))>           ; ^]
+        ChType  30,  <LOW (NOT (fFCB+fChk))>           ; ^^
+        ChType  31,  <LOW (NOT (fFCB+fChk))>           ; ^_
+        ChType  " ", <LOW (NOT (     fChk+fDelim+fSpChk))>
+        ChType  255, -1
+FCB001E label byte
+Table   ENDS
+ENDIF
+;
+; Get a byte from [SI], convert it to upper case, and compare for delimiter.
+; ZF set if a delimiter, CY set if a control character (other than TAB).
+;
+; DOS 3.3 modification for file char upper case.    F.C. 5/29/86
+        procedure   GetLet,NEAR
+        LODSB
+  entry GetLet2                             ;AN000;; called by uCase
+        PUSH    BX
+        MOV     BX,OFFSET DOSGROUP:FILE_UCASE_TAB+2
+  getget:
+        CMP     AL,"a"
+        JB      CHK1
+        CMP     AL,"z"
+        JA      CHK1
+        SUB     AL,20H          ; Convert to upper case
+CHK1:
+        CMP     AL,80H          ; DOS 3.3
+        JB      GOTIT           ; DOS 3.3
+        SUB     AL,80H          ;translate to upper case with this index
+;
+        XLAT    BYTE PTR CS:[BX]
+If TableLook
+GOTIT:
+        PUSH    AX
+        MOV     BX,OFFSET DOSGROUP:CharType
+        XLAT    BYTE PTR CS:[BX]
+
+        TEST    AL,fChk
+        POP     AX
+        POP     BX
+        RET
+  entry GetLet3                              ;AN000; called by uCase
+        PUSH    BX                           ;AN000;
+        JMP     getget                       ;AN000;
+
+ELSE
+GOTIT:
+        POP     BX
+        CMP     AL,"."
+        retz
+        CMP     AL,'"'
+        retz
+        CALL    PATHCHRCMP
+        retz
+        CMP     AL,"["
+        retz
+        CMP     AL,"]"
+        retz
+ENDIF
+
+entry   DELIM
+
+IF TableLook
+        PUSH    AX
+        PUSH    BX
+        MOV     BX,OFFSET DOSGroup:CharType
+        XLAT    BYTE PTR CS:[BX]
+        TEST    AL,fDelim
+        POP     BX
+        POP     AX
+        RET
+ELSE
+        CMP     AL,":"
+        retz
+
+        CMP     AL,"<"
+        retz
+        CMP     AL,"|"
+        retz
+        CMP     AL,">"
+        retz
+
+        CMP     AL,"+"
+        retz
+        CMP     AL,"="
+        retz
+        CMP     AL,";"
+        retz
+        CMP     AL,","
+        retz
+ENDIF
+entry SPCHK
+IF  TableLook
+        PUSH    AX
+        PUSH    BX
+        MOV     BX,OFFSET DOSGroup:CharType
+        XLAT    BYTE PTR CS:[BX]
+        TEST    AL,fSpChk
+        POP     BX
+        POP     AX
+        RET
+ELSE
+        CMP     AL,9            ; Filter out tabs too
+        retz
+; WARNING! " " MUST be the last compare
+        CMP     AL," "
+        return
+ENDIF
+EndProc GetLet
+
+Procedure   PATHCHRCMP,NEAR
+        CMP     AL,'/'
+        JBE     PathRet
+        CMP     AL,'\'
+        return
+GotFor:
+        MOV     AL,'\'
+        return
+PathRet:
+        JZ      GotFor
+        return
+EndProc PathChrCMP
+
+
+ IF  DBCS
+;---------------------  2/12/KK
+; Function: Check if an input byte is in the ranges of DBCS vectors.
+;
+;   Input:   AL ; Code to be examined
+;
+;  Output:   ZF = 1 :  AL is SBCS      ZF = 0 : AL is a DBCS leading byte
+;
+;  Register:  All registers are unchanged except FL
+;
+procedure   TESTKANJ,NEAR                                                       ;AN000;
+        call    Chk_DBCS                                                        ;AN000;
+        jc      TK_DBCS                                                         ;AN000;
+        cmp     AL,AL           ; set ZF                                        ;AN000;
+        return                                                                  ;AN000;
+TK_DBCS:
+        PUSH    AX                                                              ;AN000;
+        XOR     AX,AX           ;Set ZF                                         ;AN000;
+        INC     AX              ;Reset ZF                                       ;AN000;
+        POP     AX                                                              ;AN000;
+        return                                                                  ;AN000;
+EndProc TESTKANJ                                                                ;AN000;
+;
+Chk_DBCS        PROC                                                            ;AN000;
+        PUSH    DS                                                              ;AN000;
+        PUSH    SI                                                              ;AN000;
+        PUSH    BX                                                              ;AN000;
+        Context DS                                                              ;AN000;
+        MOV     BX,offset DOSGROUP:COUNTRY_CDPG.ccSetDBCS                       ;AN000;
+        LDS     SI,[BX+1]               ; set EV address to DS:SI               ;AN000;
+        ADD     SI,2                    ; Skip length                           ;AN000;
+DBCS_LOOP:
+        CMP     WORD PTR [SI],0         ; terminator ?                          ;AN000;
+        JE      NON_DBCS                ; if yes, no DBCS                       ;AN000;
+        CMP     AL,[SI]                 ; else                                  ;AN000;
+        JB      DBCS01                  ; check if AL is                        ;AN000;
+        CMP     AL,[SI+1]               ; in a range of Ev                      ;AN000;
+        JA      DBCS01                  ; if yes, DBCS                          ;AN000;
+        STC                             ; else                                  ;AN000;
+        JMP     DBCS_EXIT               ; try next DBCS Ev                      ;AN000;
+DBCS01:
+        ADD     SI,2                                                            ;AN000;
+        JMP     DBCS_LOOP                                                       ;AN000;
+NON_DBCS:
+        CLC                                                                     ;AN000;
+DBCS_EXIT:
+        POP     BX                                                              ;AN000;
+        POP     SI                                                              ;AN000;
+        POP     DS                                                              ;AN000;
+        RET                                                                     ;AN000;
+Chk_DBCS        ENDP                                                            ;AN000;
+ ENDIF                                                                          ;AN000;
+CODE    ENDS
+    END
+                                                                                ;AN000;
diff --git a/v4.0/src/DOS/FCBIO.ASM b/v4.0/src/DOS/FCBIO.ASM
new file mode 100644
index 0000000..8b27d72
--- /dev/null
+++ b/v4.0/src/DOS/FCBIO.ASM
@@ -0,0 +1,1185 @@
+;       SCCSID = @(#)fcbio.asm  1.5 85/07/30
+;       SCCSID = @(#)fcbio.asm  1.5 85/07/30
+TITLE   FCBIO - FCB system calls
+NAME    FCBIO
+
+;
+; Ancient 1.0 1.1 FCB system calls
+;                                   regen   save
+;   $GET_FCB_POSITION       written none    none
+;   $FCB_DELETE             written none    none
+;   $GET_FCB_FILE_LENGTH    written none    none
+;   $FCB_CLOSE              written close   none
+;   $FCB_RENAME             written none    none
+;   SaveFCBInfo
+;   ResetLRU
+;   SetOpenAge
+;   LRUFCB
+;   FCBRegen
+;   BlastSFT
+;   CheckFCB
+;   SFTFromFCB
+;   FCBHardErr
+;
+;   Revision history:
+;
+;       Created: ARR 4 April 1983
+;                MZ  6 June  1983 completion of functions
+;                MZ 15 Dec   1983 Brain damaged programs close FCBs multiple
+;                                 times.  Change so successive closes work by
+;                                 always returning OK.  Also, detect I/O to
+;                                 already closed FCB and return EOF.
+;                MZ 16 Jan   1984 More braindamage.  Need to separate info
+;                                 out of sft into FCB for reconnection
+;
+;       A000     version 4.00  Jan. 1988
+;
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+INCLUDE FASTOPEN.INC
+.cref
+.list
+
+ AsmVars <Kanji>
+
+        I_need  OpenBuf,128             ; buffer for translating paths
+        I_need  RenBuf,128              ; buffer for rename paths
+        i_need  THISDPB,DWORD
+        i_need  EXTERR,WORD
+        i_need  ALLOWED,BYTE
+        I_need  ThisSFT,DWORD           ; SFT in use
+        I_need  WFP_start,WORD          ; pointer to canonical name
+        I_need  Ren_WFP,WORD            ; pointer to canonical name
+        I_need  Attrib,BYTE             ; Attribute for match attributes
+        I_need  sftFCB,DWORD            ; pointer to SFTs for FCB cache
+        I_need  FCBLRU,WORD             ; least recently used count
+        I_need  Proc_ID,WORD            ; current process ID
+        I_Need  Name1,14                ; place for device names
+        I_need  DEVPT,DWORD             ; device pointer
+        I_need  OpenLRU,WORD            ; open age
+        I_need  KeepCount,WORD          ; number of fcbs to keep
+        I_need  User_In_AX,WORD         ; user input system call.
+        I_need  JShare,DWORD            ; share jump table
+        I_need  FastOpenTable,BYTE      ; DOS 3.3 fastopen
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+        include bugtyp.asm
+endif
+
+
+Break <$Get_FCB_Position - set random record fields to current pos>
+
+;
+;   $Get_FCB_Position - look at an FCB, retrieve the current position from the
+;       extent and next record field and set the random record field to point
+;       to that record
+;
+;   Inputs:     DS:DX point to a possible extended FCB
+;   Outputs:    The random record field of the FCB is set to the current record
+;   Registers modified: all
+
+Procedure $Get_FCB_Position,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        invoke  GetExtended             ; point to FCB
+        invoke  GetExtent               ; DX:AX is current record
+        MOV     WORD PTR [SI.fcb_RR],AX ; drop in low order piece
+        MOV     [SI+fcb_RR+2],DL        ; drop in high order piece
+        CMP     [SI.fcb_RECSIZ],64
+        JAE     GetFCBBye
+        MOV     [SI+fcb_RR+2+1],DH      ; Set 4th byte only if record size < 64
+GetFCBBye:
+        transfer    FCB_Ret_OK
+EndProc $GET_FCB_POSITION
+
+Break <$FCB_Delete - remove several files that match the input FCB>
+
+;
+;   $FCB_delete - given an FCB, remove all directory entries in the current
+;       directory that have names that match the FCB's ?  marks.
+;
+;   Inputs:     DS:DX - point to an FCB
+;   Outputs:    directory entries matching the FCB are deleted
+;               AL = FF if no entries were deleted.
+;   Registers modified: all
+
+Procedure $FCB_Delete,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate place
+        invoke  TransFCB                ; convert FCB to path
+        JC      BadPath                 ; signal no deletions
+        Context DS
+        invoke  DOS_Delete              ; wham
+        JC      BadPath
+GoodPath:
+        transfer    FCB_Ret_OK          ; do a good return
+BadPath:
+;
+
+; Error code is in AX
+;
+        transfer    FCB_Ret_Err         ; let someone else signal the error
+EndProc $FCB_DELETE
+
+Break <$Get_FCB_File_Length - return the length of a file>
+
+;
+;   $Get_FCB_File_Length - set the random record field to the length of the
+;       file in records (rounded up if partial).
+;
+;   Inputs:     DS:DX - point to a possible extended FCB
+;   Outputs:    Random record field updated to reflect the number of records
+;   Registers modified: all
+
+Procedure   $Get_FCB_File_Length,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        invoke  GetExtended             ; get real FCB pointer
+                                        ; DX points to Input FCB
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        SaveReg <DS,SI>                 ; save pointer to true FCB
+        Invoke  TransFCB                ; Trans name DS:DX, sets SATTRIB
+        RestoreReg  <SI,DS>
+        JC      BadPath
+        SaveReg <DS,SI>                 ; save pointer
+        Context DS
+        invoke  Get_File_Info           ; grab the info
+        RestoreReg  <SI,DS>             ; get pointer back
+        JC      BadPath                 ; invalid something
+        MOV     DX,BX                   ; get high order size
+        MOV     AX,DI                   ; get low order size
+        MOV     BX,[SI.fcb_RECSIZ]      ; get his record size
+        OR      BX,BX                   ; empty record => 0 size for file
+        JNZ     GetSize                 ; not empty
+        MOV     BX,128
+GetSize:
+        MOV     DI,AX                   ; save low order word
+        MOV     AX,DX                   ; move high order for divide
+        XOR     DX,DX                   ; clear out high
+        DIV     BX                      ; wham
+        PUSH    AX                      ; save dividend
+        MOV     AX,DI                   ; get low order piece
+        DIV     BX                      ; wham
+        MOV     CX,DX                   ; save remainder
+        POP     DX                      ; get high order dividend
+        JCXZ    LengthStore             ; no roundup
+        ADD     AX,1
+        ADC     DX,0                    ; 32-bit increment
+LengthStore:
+        MOV     WORD PTR [SI.FCB_RR],AX ; store low order
+        MOV     [SI.FCB_RR+2],DL        ; store high order
+        OR      DH,DH
+        JZ      GoodPath                ; not storing insignificant zero
+        MOV     [SI.FCB_RR+3],DH        ; save that high piece
+GoodRet:
+        transfer    FCB_Ret_OK
+EndProc $GET_FCB_FILE_LENGTH
+
+Break <$FCB_Close - close a file>
+
+;
+;   $FCB_Close - given an FCB, look up the SFN and close it.  Do not free it
+;       as the FCB may be used for further I/O
+;
+;   Inputs:     DS:DX point to FCB
+;   Outputs:    AL = FF if file was not found on disk
+;   Registers modified: all
+
+Procedure $FCB_Close,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        XOR     AL,AL                   ; default search attributes
+        invoke  GetExtended             ; DS:SI point to real FCB
+        JZ      NoAttr                  ; not extended
+        MOV     AL,[SI-1]               ; get attributes
+NoAttr:
+        MOV     [Attrib],AL             ; stash away found attributes
+        invoke  SFTFromFCB
+        JC      GoodRet                 ; MZ 16 Jan Assume death
+;
+; If the sharer is present, then the SFT is not regenable.  Thus, there is
+; no need to set the SFT's attribute.
+;
+;;; 9/8/86 F.C. save SFT attribute and restore it back when close is done
+        MOV     AL,ES:[DI].sf_attr
+        XOR     AH,AH
+        PUSH    AX
+;;; 9/8/86 F.C. save SFT attribute and restore it back when close is done
+        invoke  CheckShare
+        JNZ     NoStash
+        MOV     AL,Attrib
+        MOV     ES:[DI].sf_attr,AL      ; attempted attribute for close
+NoStash:
+        MOV     AX,[SI].FCB_FDATE       ; move in the time and date
+        MOV     ES:[DI].sf_date,AX
+        MOV     AX,[SI].FCB_FTIME
+        MOV     ES:[DI].sf_time,AX
+        MOV     AX,[SI].FCB_FilSiz
+        MOV     WORD PTR ES:[DI].sf_size,AX
+        MOV     AX,[SI].FCB_FilSiz+2
+        MOV     WORD PTR ES:[DI].sf_size+2,AX
+        OR      ES:[DI].sf_Flags,sf_close_nodate
+        Context DS                      ; let Close see variables
+        invoke  DOS_Close               ; wham
+        LES     DI,ThisSFT
+;;; 9/8/86 F.C. restore SFT attribute
+        POP     CX
+        MOV     ES:[DI].sf_attr,CL
+;;; 9/8/86 F.C. restore SFT attribute
+        PUSHF
+        TEST    ES:[DI.sf_ref_count],-1 ; zero ref count gets blasted
+        JNZ     CloseOK
+        PUSH    AX
+        MOV     AL,'M'
+        invoke  BlastSFT
+        POP     AX
+CloseOK:
+        POPF
+        JNC     GoodRet
+        CMP     AL,error_invalid_handle
+        JZ      GoodRet
+        MOV     AL,error_file_not_found
+        transfer    FCB_Ret_Err
+EndProc $FCB_CLOSE
+
+Break   <$FCB_Rename - change names in place>
+
+;
+;   $FCB_Rename - rename a file in place within a directory.  Renames multiple
+;       files copying from the meta characters.
+;
+;   Inputs:     DS:DX point to an FCB.  The normal name field is the source
+;                   name of the files to be renamed.  Starting at offset 11h
+;                   in the FCB is the destination name.
+;   Outputs:    AL = 0 -> no error occurred and all files were renamed
+;               AL = FF -> some files may have been renamed but:
+;                   rename to existing file or source file not found
+;   Registers modified: all
+
+Procedure $FCB_Rename,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        invoke  GetExtended             ; get pointer to real FCB
+        SaveReg <DX>
+        MOV     AL,[SI]                 ; get drive byte
+        ADD     SI,10h                  ; point to destination
+        MOV     DI,OFFSET DOSGroup:RenBuf   ; point to destination buffer
+        SaveReg <<WORD PTR DS:[SI]>,DS,SI>  ; save source pointer for TransFCB
+        MOV     DS:[SI],AL              ; drop in real drive
+        MOV     DX,SI                   ; let TransFCB know where the FCB is
+        invoke  TransFCB                ; munch this pathname
+        RestoreReg  <SI,DS,<WORD PTR DS:[SI]>>  ; get path back
+        RestoreReg  <DX>                ; Original FCB pointer
+        JC      BadRen                  ; bad path -> error
+        MOV     SI,WFP_Start            ; get pointer
+        MOV     Ren_WFP,SI              ; stash it
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate spot
+        invoke  TransFCB                ; wham
+                                        ; NOTE that this call is pointing
+                                        ;  back to the ORIGINAL FCB so
+                                        ;  SATTRIB gets set correctly
+        JC      BadRen                  ; error
+        invoke  DOS_Rename
+        JC      BadRen
+        transfer    FCB_Ret_OK
+BadRen:
+;
+; AL has error code
+;
+        transfer    FCB_Ret_Err
+
+EndProc $FCB_RENAME
+
+Break <Misbehavior fixers>
+
+;
+;   FCBs suffer from several problems.  First, they are maintained in the
+;   user's space so he may move them at will.  Second, they have a small
+;   reserved area that may be used for system information.  Third, there was
+;   never any "rules for behavior" for FCBs; there was no protocol for their
+;   usage.
+;
+;   This results in the following misbehavior:
+;
+;       infinite opens of the same file:
+;
+;       While (TRUE) {                  While (TRUE) {
+;           FCBOpen (FCB);                  FCBOpen (FCB);
+;           Read (FCB);                     Write (FCB);
+;           }                               }
+;
+;       infinite opens of different files:
+;
+;       While (TRUE) {                  While (TRUE) {
+;           FCBOpen (FCB[i++]);             FCBOpen (FCB[i++]);
+;           Read (FCB);                     Write (FCB);
+;           }                               }
+;
+;       multiple closes of the same file:
+;
+;       FCBOpen (FCB);
+;       while (TRUE)
+;           FCBClose (FCB);
+;
+;       I/O after closing file:
+;
+;       FCBOpen (FCB);
+;       while (TRUE) {
+;           FCBWrite (FCB);
+;           FCBClose (FCB);
+;           }
+;
+;   The following is am implementation of a methodology for emulating the
+;   above with the exception of I/O after close.  We are NOT attempting to
+;   resolve that particular misbehavior.  We will enforce correct behaviour in
+;   FCBs when they refer to a network file or when there is file sharing on
+;   the local machine.
+;
+;   The reserved fields of the FCB (10 bytes worth) is divided up into various
+;   structures depending on the file itself and the state of operations of the
+;   OS.  The information contained in this reserved field is enough to
+;   regenerate the SFT for the local non-shared file.  It is assumed that this
+;   regeneration procedure may be expensive.  The SFT for the FCB is
+;   maintained in a LRU cache as the ONLY performance inprovement.
+;
+;   No regeneration of SFTs is attempted for network FCBs.
+;
+;   To regenerate the SFT for a local FCB, it is necessary to determine if the
+;   file sharer is working.  If the file sharer is present then the SFT is not
+;   regenerated.
+;
+;   Finally, if there is no local sharing, the full name of the file is no
+;   longer available.  We can make up for this by using the following
+;   information:
+;
+;       The Drive number (from the DPB).
+;       The physical sector of the directory that contains the entry.
+;       The relative position of the entry in the sector.
+;       The first cluster field.
+;       The last used SFT.
+;      OR In the case of a device FCB
+;       The low 6 bits of sf_flags (indicating device type)
+;       The pointer to the device header
+;
+;
+;   We read in the particular directory sector and examine the indicated
+;   directory entry.  If it matches, then we are kosher; otherwise, we fail.
+;
+;   Some key items need to be remembered:
+;
+;       Even though we are caching SFTs, they may contain useful sharing
+;       information.  We enforce good behavior on the FCBs.
+;
+;       Network support must not treat FCBs as impacting the ref counts on
+;       open VCs.  The VCs may be closed only at process termination.
+;
+;       If this is not an installed version of the DOS, file sharing will
+;       always be present.
+;
+;       We MUST always initialize lstclus to = firclus when regenerating a
+;       file. Otherwise we start allocating clusters up the wazoo.
+;
+;       Always initialize, during regeneration, the mode field to both isFCB
+;       and open_for_both.  This is so the FCB code in the sharer can find the
+;       proper OI record.
+;
+;   The test bits are:
+;
+;       00 -> local file
+;       40 -> sharing local
+;       80 -> network
+;       C0 -> local device
+
+Break   <SaveFCBInfo - store pertinent information from an SFT into the FCB>
+
+;
+;   SaveFCBInfo - given an FCB and its associated SFT, copy the relevant
+;       pieces of information into the FCB to allow for subsequent
+;       regeneration. Poke LRU also.
+;
+;   Inputs:     ThisSFT points to a complete SFT.
+;               DS:SI point to the FCB (not an extended one)
+;   Outputs:    The relevant reserved fields in the FCB are filled in.
+;               DS:SI preserved
+;               ES:DI point to sft
+;   Registers modified: All
+;
+
+Procedure   SaveFCBInfo,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        LES     DI,ThisSFT
+        Assert  ISSFT,<ES,DI>,"SaveFCBInfo"
+        invoke  IsSFTNet
+        JZ      SaveLocal               ; if not network then save local info
+;
+;----- In net support -----
+;
+        MOV     AX,WORD PTR ES:[DI].sf_serial_ID        ;AN000;;IFS.  save IFS ID
+        MOV     WORD PTR [SI].FCB_netID,ax              ;AN000;;IFS.
+;       SaveReg <ES,DI>
+;       LES     DI,DWORD PTR ES:[DI].sf_netid
+;       MOV     WORD PTR [SI].FCB_netID,DI  ; save net ID
+;       MOV     WORD PTR [SI].FCB_netID+2,ES
+;       RestoreReg  <DI,ES>
+        MOV     BL,FCBNETWORK
+;
+;----- END In net support -----
+;
+IF debug
+        JMP     SaveSFN
+ELSE
+        JMP     SHORT SaveSFN
+ENDIF
+SaveLocal:
+        IF      Installed
+        Invoke  CheckShare
+        JZ      SaveNoShare             ; no sharer
+        JMP     SaveShare               ; sharer present
+
+SaveNoShare:
+        TEST    ES:[DI].sf_flags,devid_device
+        JNZ     SaveNoShareDev          ; Device
+;
+; Save no sharing local file information
+;
+        MOV     AX,WORD PTR ES:[DI].sf_dirsec ; get directory sector F.C.
+        MOV     [SI].fcb_nsl_dirsec,AX
+        MOV     AL,ES:[DI].sf_dirpos    ; location in sector
+        MOV     [SI].fcb_nsl_dirpos,AL
+        MOV     AX,ES:[DI].sf_firclus   ; first cluster
+        MOV     [SI].fcb_nsl_firclus,AX
+        MOV     BL,00
+;
+; Create the bits field from the dirty/device bits of the flags word and the
+; mode byte
+;
+SetFCBBits:
+        MOV     AX,ES:[DI].sf_flags
+        AND     AL,0C0h                 ; mask off drive bits
+        OR      AL,BYTE PTR ES:[DI].sf_mode ; stick in open mode
+        MOV     [SI].fcb_nsl_bits,AL    ; save dirty info
+        JMP     SaveSFN                 ; go and save SFN
+
+;
+; Save no sharing local device information
+;
+SaveNoShareDev:
+        MOV     AX,WORD PTR ES:[DI].sf_devptr
+        MOV     WORD PTR [SI].FCB_nsld_drvptr,AX
+        MOV     AX,WORD PTR ES:[DI].sf_devptr + 2
+        MOV     WORD PTR [SI].FCB_nsld_drvptr + 2,AX
+        MOV     BL,FCBDEVICE
+        JMP     SetFCBBits              ; go and save SFN
+
+SaveShare:
+        ENDIF
+;
+;----- In share support -----
+;
+if installed
+        Call    JShare + 10 * 4
+else
+        Call    ShSave
+endif
+;
+;----- end in share support -----
+;
+SaveSFN:
+        MOV     AX,ES:[DI].sf_flags
+        AND     AL,3Fh                  ; get real drive
+        OR      AL,BL
+        MOV     [SI].fcb_l_drive,AL
+        LEA     AX,[DI-SFTable]
+;
+; Adjust for offset to table.
+;
+        SUB     AX,WORD PTR SftFCB
+        MOV     BL,SIZE sf_entry
+        DIV     BL
+        MOV     [SI].FCB_sfn,AL         ; last used SFN
+        MOV     AX,FCBLRU               ; get lru count
+        INC     AX
+        MOV     WORD PTR ES:[DI].sf_LRU,AX
+        JNZ     SimpleStuff
+;
+; lru flag overflowed.  Run through all FCB sfts and adjust:  LRU < 8000h
+; get set to 0.  Others -= 8000h.  This LRU = 8000h
+;
+        MOV     BX,sf_position
+        invoke  ResetLRU
+;
+; Set new LRU to AX
+;
+SimpleStuff:
+        MOV     FCBLRU,AX
+        return
+EndProc SaveFCBInfo
+
+Break   <ResetLRU - reset overflowed lru counts>
+
+;
+;   ResetLRU - during lru updates, we may wrap at 64K.  We must walk the
+;   entire set of SFTs and subtract 8000h from their lru counts and truncate
+;   at 0.
+;
+;   Inputs:     BX is offset into SFT field where lru firld is kept
+;               ES:DI point to SFT currently being updated
+;   Outputs:    All FCB SFTs have their lru fields truncated
+;               AX has 8000h
+;   Registers modified: none
+
+Procedure   ResetLRU,NEAR
+        ASSUME CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        Assert  ISSFT,<ES,DI>,"ResetLRU"
+        MOV     AX,8000h
+        SaveReg <ES,DI>
+        LES     DI,sftFCB               ; get pointer to head
+        MOV     CX,ES:[DI].sfCount
+        LEA     DI,[DI].sfTable         ; point at table
+ovScan:
+        SUB     WORD PTR ES:[DI+BX],AX  ; decrement lru count
+        JA      ovLoop
+        MOV     WORD PTR ES:[DI.BX],AX  ; truncate at 0
+ovLoop:
+        ADD     DI,SIZE SF_Entry        ; advance to next
+        LOOP    ovScan
+        RestoreReg  <DI,ES>
+        MOV     ES:[DI+BX],AX
+        return
+EndProc ResetLRU
+
+Break   <SetOpenAge - update the open age of a SFT>
+
+;
+;   SetOpenAge - In order to maintain the first N open files in the FCB cache,
+;   we keep the 'open age' or an LRU count based on opens.  We update the
+;   count here and fill in the appropriate field.
+;
+;   Inputs:     ES:DI point to SFT
+;   Outputs:    ES:DI has the open age field filled in.
+;               If open age has wraparound, we will have subtracted 8000h
+;                   from all open ages.
+;   Registers modified: AX
+;
+
+Procedure   SetOpenAge,NEAR
+        ASSUME CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        Assert  ISSFT,<ES,DI>,"SetOpenAge"
+        MOV     AX,OpenLRU
+        INC     AX
+        MOV     ES:[DI].sf_OpenAge,AX
+        JNZ     SetDone
+        MOV     BX,sf_Position+2
+        invoke  ResetLRU
+SetDone:
+        MOV     OpenLRU,AX
+        return
+EndProc SetOpenAge
+
+Break   <LRUFCB - perform LRU on FCB sfts>
+
+;
+;   LRUFCB - find LRU fcb in cache.  Set ThisSFT and return it.  We preserve
+;       the first keepcount sfts if they are network sfts or if sharing is
+;       loaded.  If carry is set then NO BLASTING is NECESSARY.
+;
+;   Inputs:     none
+;   Outputs:    ES:DI point to SFT
+;               ThisSFT points to SFT
+;               SFT is zeroed
+;               Carry set of closes failed
+;   Registers modified: none
+;
+
+Procedure   LRUFCB,NEAR
+        ASSUME CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        Invoke  Save_World
+;
+; Find nth oldest NET/SHARE FCB.  We want to find its age for the second scan
+; to find the lease recently used one that is younger than the open age.  We
+; operate be scanning the list n times finding the least age that is greater
+; or equal to the previous minimum age.
+;
+;   BP is the count of times we need to go through this loop.
+;   AX is the current acceptable minimum age to consider
+;
+        mov     bp,KeepCount            ; k = keepcount;
+        XOR     AX,AX                   ; low = 0;
+;
+; If we've scanned the table n times, then we are done.
+;
+lru1:
+        CMP     bp,0                    ; while (k--) {
+        JZ      lru75
+        DEC     bp
+;
+; Set up for scan.
+;
+;   AX is the minimum age for consideration
+;   BX is the minimum age found during the scan
+;   SI is the position of the entry that corresponds to BX
+;
+        MOV     BX,-1                   ;     min = 0xffff;
+        MOV     si,BX                   ;     pos = 0xffff;
+        LES     DI,SFTFCB               ;     for (CX=FCBCount; CX>0; CX--)
+        MOV     CX,ES:[DI].sfCount
+        LEA     DI,[DI].sfTable
+;
+; Innermost loop.  If the current entry is free, then we are done.  Or, if the
+; current entry is busy (indicating a previous aborted allocation), then we
+; are done.  In both cases, we use the found entry.
+;
+lru2:
+        cmp     es:[di].sf_ref_count,0
+        jz      lru25
+        cmp     es:[di].sf_ref_count,sf_busy
+        jnz     lru3
+;
+; The entry is usable without further scan.  Go and use it.
+;
+lru25:
+        MOV     si,DI                   ;             pos = i;
+        JMP     lru11                   ;             goto got;
+;
+; See if the entry is for the network or for the sharer.
+;
+;  If for the sharer or network then
+;       if the age < current minimum AND >= allowed minimum then
+;           this entry becomes current minimum
+;
+lru3:
+        TEST    ES:[DI].sf_flags,sf_isnet   ;     if (!net[i]
+        JNZ     lru35
+if installed
+        Invoke  CheckShare              ;               && !sharing)
+        JZ      lru5                    ;         else
+ENDIF
+;
+; This SFT is for the net or is for the sharer.  See if it less than the
+; current minimum.
+;
+lru35:
+        MOV     DX,ES:[DI].sf_OpenAge
+        CMP     DX,AX                   ;         if (age[i] >= low &&
+        JB      lru5
+        CMP     DX,BX
+        JAE     lru5                    ;             age[i] < min) {
+;
+; entry is new minimum.  Remember his age.
+;
+        mov     bx,DX                   ;             min = age[i];
+        mov     si,di                   ;             pos = i;
+;
+; End of loop.  gp back for more
+;
+lru5:
+add     di,size sf_entry
+        loop    lru2                    ;             }
+;
+; The scan is complete.  If we have successfully found a new minimum (pos != -1)
+; set then threshold value to this new minimum + 1.  Otherwise, the scan is
+; complete.  Go find LRU.
+;
+lru6:   cmp     si,-1                   ; position not -1?
+        jz      lru75                   ; no, done with everything
+        lea     ax,[bx+1]               ; set new threshold age
+        jmp     lru1                    ; go and loop for more
+lru65:  stc
+        jmp     short   lruDead         ;         return -1;
+;
+; Main loop is done.  We have AX being the age+1 of the nth oldest sharer or
+; network entry.  We now make a second pass through to find the LRU entry
+; that is local-no-share or has age >= AX
+;
+lru75:
+        mov     bx,-1                   ; min = 0xffff;
+        mov     si,bx                   ; pos = 0xffff;
+        LES     DI,SFTFCB               ; for (CX=FCBCount; CX>0; CX--)
+        MOV     CX,ES:[DI].sfCount
+        LEA     DI,[DI].sfTable
+;
+; If this is is local-no-share then go check for LRU else if age >= threshold
+; then check for lru.
+;
+lru8:
+        TEST    ES:[DI].sf_flags,sf_isnet
+        jnz     lru85                   ; is for network, go check age
+        invoke  CheckShare              ; sharer here?
+        jz      lru86                   ; no, go check lru
+;
+; Network or sharer.  Check age
+;
+lru85:
+        cmp     es:[di].sf_OpenAge,ax
+        jb      lru9                    ; age is before threshold, skip it
+;
+; Check LRU
+;
+lru86:
+        cmp     es:[di].sf_LRU,bx       ; is LRU less than current LRU?
+        jae     lru9                    ; no, skip this
+        mov     si,di                   ; remember position
+        mov     bx,es:[di].sf_LRU       ; remember new minimum LRU
+;
+; Done with this entry, go back for more.
+;
+lru9:
+        add     di,size sf_entry
+        loop    lru8
+;
+; Scan is complete.  If we found NOTHING that satisfied us then we bomb
+; out.  The conditions here are:
+;
+;   No local-no-shares AND all net/share entries are older than threshold
+;
+lru10:
+        cmp     si,-1                   ; if no one f
+        jz      lru65                   ;     return -1;
+lru11:
+        mov     di,si
+        MOV     WORD PTR ThisSFT,DI     ; set thissft
+        MOV     WORD PTR ThisSFT+2,ES
+;
+; If we have sharing or thisSFT is a net sft, then close it until ref count
+; is 0.
+;
+        TEST    ES:[DI].sf_flags,sf_isNet
+        JNZ     LRUClose
+IF INSTALLED
+        Invoke  CheckShare
+        JZ      LRUDone
+ENDIF
+;
+; Repeat close until ref count is 0
+;
+LRUClose:
+        Context DS
+        LES     DI,ThisSFT
+        CMP     ES:[DI].sf_ref_count,0  ; is ref count still <> 0?
+        JZ      LRUDone                 ; nope, all done
+
+;       Message     1,"LRUFCB: closing "
+;       MessageNum  <WORD PTR THISSFT+2>
+;       Message     1,":"
+;       MessageNum  <WORD PTR THISSFT>
+
+        Invoke  DOS_Close
+        jnc     LRUClose                ; no error => clean up
+        cmp     al,error_invalid_handle
+        jz      LRUClose
+        stc
+        JMP     short LRUDead
+LRUDone:
+        XOR     AL,AL
+        invoke  BlastSFT                ; fill SFT with 0 (AL)
+LRUDead:
+        Invoke  Restore_World
+        ASSUME  DS:NOTHING
+        LES     DI,ThisSFT
+        Assert  ISSFT,<ES,DI>,"LRUFCB return"
+        retnc
+        MOV     AL,error_FCB_unavailable
+        return
+EndProc LRUFCB
+
+Break   <FCBRegen - regenerate a sft from the info in the FCB>
+
+;
+;   FCBRegen - examine reserved field of FCB and attempt to generate the SFT
+;       from it.
+;
+;   Inputs:     DS:SI point to FCB
+;   Outputs:    carry clear Filled in SFT
+;               Carry set unrecoverable error
+;   Registers modified: all
+
+Procedure   FCBRegen,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+;
+; General data filling.  Mode is sf_isFCB + open_for_both, date/time we do
+; not fill, size we do no fill, position we do not fill,
+; bit 14 of flags = TRUE, other bits = FALSE
+;
+        MOV     AL,[SI].fcb_l_drive
+;
+; We discriminate based on the first two bits in the reserved field.
+;
+        TEST    AL,FCBSPECIAL           ; check for no sharing test
+        JZ      RegenNoSharing          ; yes, go regen from no sharing
+;
+; The FCB is for a network or a sharing based system.  At this point we have
+; already closed the SFT for this guy and reconnection is impossible.
+;
+; Remember that he may have given us a FCB with bogus information in it.
+; Check to see if sharing is present or if the redir is present.  If either is
+; around, presume that we have cycled out the FCB and give the hard error.
+; Otherwise, just return with carry set.
+;
+        invoke  CheckShare              ; test for sharer
+        JNZ     RegenFail               ; yep, fail this.
+        MOV     AX,multNet SHL 8        ; install check on multnet
+        INT     2FH
+        OR      AL,AL                   ; is it there?
+        JZ      RegenDead               ; no, just fail the operation
+RegenFail:
+        MOV     AX,User_In_AX
+        cmp     AH,fcb_close
+        jz      RegenDead
+        invoke  FCBHardErr              ; massive hard error.
+RegenDead:
+        STC
+        return                          ; carry set
+;
+; Local FCB without sharing.  Check to see if sharing is loaded.  If so
+; fail the operation.
+;
+RegenNoSharing:
+        invoke  CheckShare              ; Sharing around?
+        JNZ     RegenFail
+;
+; Find an SFT for this guy.
+;
+        invoke  LRUFcb
+        retc
+        MOV     ES:[DI].sf_mode,SF_IsFCB + open_for_both + sharing_compat
+        AND     AL,3Fh                  ; get drive number for flags
+        CBW
+        OR      AX,sf_close_noDate      ; normal FCB operation
+;
+; The bits field consists of the upper two bits (dirty and device) from the
+; SFT and the low 4 bits from the open mode.
+;
+        MOV     CL,[SI].FCB_nsl_bits    ; stick in dirty bits.
+        MOV     CH,CL
+        AND     CH,0C0h                 ; mask off the dirty/device bits
+        OR      AL,CH
+        AND     CL,access_mask          ; get the mode bits
+        MOV     BYTE PTR ES:[DI].sf_mode,CL
+        MOV     ES:[DI].sf_flags,AX     ; initial flags
+        MOV     AX,Proc_ID
+        MOV     ES:[DI].sf_PID,AX
+        SaveReg <DS,SI,ES,DI>
+        Context ES
+        MOV     DI,OFFSET DOSGroup:Name1
+        MOV     CX,8
+        INC     SI                      ; Skip past drive byte to name in FCB
+RegenCopyName2:
+        LODSB
+
+ IF  DBCS                               ;AN000;
+        invoke  testkanj                ;AN000;
+        jz      notkanj9                ;AN000;
+        STOSB                           ;AN000;
+        DEC     CX                      ;AN000;
+        JCXZ    DoneNam2                ;AN000; ; Ignore split kanji char error
+        LODSB                           ;AN000;
+        jmp     short StuffChar2        ;AN000;
+                                        ;AN000;
+notkanj9:                               ;AN000;
+ ENDIF                                  ;AN000;
+
+        Invoke  UCase
+StuffChar2:
+        STOSB
+        LOOP    RegenCopyName2
+DoneNam2:
+        Context DS
+        MOV     [ATTRIB],attr_hidden + attr_system + attr_directory
+                                        ; Must set this to something interesting
+                                        ; to call DEVNAME.
+        Invoke  DevName                 ; check for device
+        ASSUME  DS:NOTHING,ES:NOTHING
+        RestoreReg  <DI,ES,SI,DS>
+        JC      RegenFileNoSharing      ; not found on device list => file
+;
+; Device found.  We can ignore disk-specific info
+;
+        MOV     BYTE PTR ES:[DI].sf_flags,BH   ; device parms
+        MOV     ES:[DI].sf_attr,0       ; attribute
+        LDS     SI,DEVPT                ; get device driver
+        MOV     WORD PTR ES:[DI].sf_devptr,SI
+        MOV     WORD PTR ES:[DI].sf_devptr+2,DS
+        return                          ; carry is clear
+
+RegenDeadJ:
+        JMP     RegenDead
+;
+; File found.  Just copy in the remaining pieces.
+;
+RegenFileNoSharing:
+        MOV     AX,ES:[DI].sf_flags
+        AND     AX,03Fh
+        SaveReg <DS,SI>
+        Invoke  Find_DPB
+        MOV     WORD PTR ES:[DI].sf_devptr,SI
+        MOV     WORD PTR ES:[DI].sf_devptr+2,DS
+        RestoreReg  <SI,DS>
+        jc      RegenDeadJ              ; if find DPB fails, then drive
+                                        ; indicator was bogus
+        MOV     AX,[SI].FCB_nsl_dirsec
+        MOV     WORD PTR ES:[DI].sf_dirsec,AX
+        MOV     WORD PTR ES:[DI].sf_dirsec+2,0  ;AN000;>32mb
+        MOV     AX,[SI].FCB_nsl_firclus
+        MOV     ES:[DI].sf_firclus,AX
+        MOV     ES:[DI].sf_lstclus,AX
+        MOV     AL,[SI].FCB_nsl_dirpos
+        MOV     ES:[DI].sf_dirpos,AL
+        INC     ES:[DI].sf_ref_count    ; Increment reference count.
+                                        ; Existing FCB entries would be
+                                        ; flushed unnecessarily because of
+                                        ; check in CheckFCB of the ref_count.
+                                        ; July 22/85 - BAS
+        LEA     SI,[SI].FCB_name
+        LEA     DI,[DI].sf_name
+        MOV     CX,fcb_extent-fcb_name
+RegenCopyName:
+        LODSB
+
+        IF      DBCS                    ;AN000;
+        invoke  testkanj
+        jz      notkanj1
+        STOSB
+        DEC     CX
+        JCXZ    DoneNam                 ; Ignore split kanji char error
+        LODSB
+        jmp     short StuffChar
+
+notkanj1:
+        ENDIF                           ;AN000;
+
+        Invoke  UCase
+StuffChar:
+        STOSB
+        LOOP    RegenCopyName
+DoneNam:
+        clc
+        return
+EndProc FCBRegen
+
+;
+;   BlastSFT - fill SFT with garbage
+;
+;   Inputs: ES:DI point to SFT
+;           AL has fill
+;   Outputs: SFT is filled with nonsense
+;           *FLAGS PRESERVED*
+;   Registers modified: CX
+
+Procedure   BlastSFT,NEAR
+        SaveReg <DI>
+        MOV     CX,SIZE sf_entry
+        REP     STOSB
+        RestoreReg  <DI>
+        MOV     ES:[DI].sf_ref_count,0  ; set ref count
+        MOV     ES:[DI].sf_LRU,0        ; set lru
+        MOV     ES:[DI].sf_OpenAge,-1   ; Set open age
+        return
+EndProc BlastSFT
+
+Break   <CheckFCB - see if the SFT pointed to by the FCB is still OK>
+
+;   CheckFCB - examine an FCB and its contents to see if it needs to be
+;   regenerated.
+;
+;   Inputs:     DS:SI point to FCB (not extended)
+;               AL is SFT index
+;   Outputs:    Carry Set - FCB needs to be regened
+;               Carry clear - FCB is OK. ES:DI point to SFT
+;   Registers modified: AX and BX
+
+Procedure   CheckFCB,NEAR
+        ASSUME DS:NOTHING,ES:NOTHING
+        LES     DI,sftFCB
+        CMP     BYTE PTR ES:[DI].SFCount,AL
+        JC      BadSFT
+        MOV     BL,SIZE sf_entry
+        MUL     BL
+        LEA     DI,[DI].sftable
+        ADD     DI,AX
+        MOV     AX,Proc_ID
+        CMP     ES:[DI].sf_PID,AX
+        JNZ     BadSFT                  ; must match process
+        CMP     ES:[DI].sf_ref_count,0
+        JZ      BadSFT                  ; must also be in use
+        MOV     AL,[SI].FCB_l_Drive
+        TEST    AL,FCBSPECIAL           ; a special FCB?
+        JZ      CheckNoShare            ; No. try local or device
+;
+; Since we are a special FCB, try NOT to use a bogus test instruction.
+; FCBSHARE is a superset of FCBNETWORK.
+;
+        PUSH    AX
+        AND     AL,FCBMASK
+        CMP     AL,FCBSHARE             ; net FCB?
+        POP     AX
+        JNZ     CheckNet                ; yes
+;
+;----- In share support -----
+;
+if installed
+        Call    JShare + 11 * 4
+else
+        Call    ShChk
+endif
+        JC      BadSFT
+        JMP     SHORT CheckD
+;
+;----- End in share support -----
+;
+CheckFirClus:
+        CMP     BX,ES:[DI].sf_firclus
+        JNZ     BadSFT
+CheckD: AND     AL,3Fh
+        MOV     AH,BYTE PTR ES:[DI].sf_flags
+        AND     AH,3Fh
+        CMP     AH,AL
+        retz                            ; carry is clear
+BadSFT: STC
+        return                          ; carry is clear
+CheckNet:
+;
+;----- In net support -----
+;
+;       MOV     AX,[SI].FCB_net_handle
+;       CMP     AX,WORD PTR ES:[DI].sf_NETID+4
+;       JNZ     BadSFT
+;       MOV     AX,WORD PTR [SI].FCB_netID
+;       CMP     AX,WORD PTR ES:[DI].sf_netid
+;       JNZ     BadSFT
+        MOV     AX,WORD PTR [SI].FCB_netID        ;AN000;IFS.DOS 4.00
+        CMP     AX,WORD PTR ES:[DI].sf_serial_ID  ;AN000;IFS.DOS 4.00
+        JNZ     BadSFT
+;
+;----- END In net support -----
+;
+        return
+
+CheckNoShare:
+        TEST    AL,FCBDEVICE            ; Device?
+        JNZ     CheckNoShareDev         ; Yes
+;
+; Check no sharing local file
+;
+        MOV     BX,[SI].FCB_nsl_Dirsec
+        CMP     WORD PTR ES:[DI].sf_dirsec+2,0  ;AN000;F.C. >32mb
+        JNZ     BadSFt                          ;AN000;F.C. >32mb
+
+        CMP     BX,WORD PTR ES:[DI].sf_dirsec   ;AN000;F.C. >32mb
+        JNZ     BadSFT
+        MOV     BL,[SI].FCB_nsl_Dirpos
+        CMP     BL,ES:[DI].sf_dirpos
+        JNZ     BadSFt
+;
+; Since the bits field comes from two different spots, compare them separately.
+;
+        MOV     BL,[SI].FCB_nsl_bits
+        MOV     BH,BYTE PTR ES:[DI].sf_flags
+        XOR     BH,BL
+        AND     BH,0C0h
+        JNZ     BadSFT                  ; dirty/device bits are different
+        XOR     BL,BYTE PTR ES:[DI].sf_mode
+        AND     BL,access_mask
+        JNZ     BadSFT                  ; access modes are different
+; Make sure that the names are the same in the FCB and the SFT
+; This case can appear under the following scenario:
+;               Create  FOO
+;               Rename  FOO -> BAR
+;               Open    BAR
+; The SFT will still contain the name for the old file name.
+; July 30/85 - BAS
+        PUSH    DI
+        PUSH    SI
+        LEA     DI,[DI].sf_name
+        LEA     SI,[SI].fcb_name
+        MOV     CX,11
+        REPE    CMPSB
+        POP     SI
+        POP     DI
+        JNZ     BadSFT
+        MOV     BX,[SI].FCB_nsl_firclus
+        JMP     CheckFirClus
+
+CheckNoShareDev:
+        MOV     BX,WORD PTR [SI].FCB_nsld_drvptr
+        CMP     BX,WORD PTR ES:[DI].sf_devptr
+        JNZ     BadSFT
+        MOV     BX,WORD PTR [SI].FCB_nsld_drvptr + 2
+        CMP     BX,WORD PTR ES:[DI].sf_devptr + 2
+        JNZ     BadSFT
+        JMP     CheckD
+
+EndProc CheckFCB
+
+Break   <SFTFromFCB - take a FCB and obtain a SFT from it>
+
+;
+;   SFTFromFCB - the workhorse of this compatability crap.  Check to see if
+;       the SFT for the FCB is Good.  If so, make ThisSFT point to it.  If not
+;       good, get one from the cache and regenerate it.  Overlay the LRU field
+;       with PID
+;
+;   Inputs:     DS:SI point to FCB
+;   Outputs:    ThisSFT point to appropriate SFT
+;               Carry clear -> OK ES:DI -> SFT
+;               Carry set -> error in ax
+;   Registers modified: ES,DI, AX
+
+Procedure   SFTFromFCB,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        SaveReg <AX,BX>
+        MOV     AL,[SI].fcb_sfn         ; set SFN for check
+        invoke  CheckFCB
+        RestoreReg  <BX,AX>
+        MOV     WORD PTR ThisSFT,DI     ; set thissft
+        MOV     WORD PTR ThisSFT+2,ES
+        JNC     SetSFT                  ; no problems, just set thissft
+
+        fmt     typFCB,LevCheck,<"FCB $x:$x does not match SFT $x:$x\n">,<DS,SI,ES,DI>
+
+        Invoke  Save_World
+        invoke  FCBRegen
+        Invoke  Restore_World           ; restore world
+        MOV     AX,EXTERR
+        retc
+
+;       Message 1,<"FCBRegen Succeeded",13,10>
+
+SetSFT: LES     DI,ThisSFT
+        PUSH    Proc_ID                 ; set process id
+        POP     ES:[DI].sf_PID
+        return                          ; carry is clear
+EndProc SFTFromFCB
+
+Break   <FCBHardErr - generate INT 24 for hard errors on FCBS>
+
+;
+;   FCBHardErr - signal to a user app that he is trying to use an
+;       unavailable FCB.
+;
+;   Inputs:     none.
+;   Outputs:    none.
+;   Registers modified: all
+;
+
+Procedure   FCBHardErr,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     AX,error_FCB_Unavailable
+        MOV     [ALLOWED],allowed_FAIL
+        LES     BP,[THISDPB]
+        MOV     DI,1                            ; Fake some registers
+        MOV     CX,DI
+        MOV     DX,ES:[BP.dpb_first_sector]
+        invoke  HARDERR
+        STC
+        return
+EndProc FCBHardErr
+
+CODE ENDS
+END
diff --git a/v4.0/src/DOS/FCBIO2.ASM b/v4.0/src/DOS/FCBIO2.ASM
new file mode 100644
index 0000000..ec0ee3e
--- /dev/null
+++ b/v4.0/src/DOS/FCBIO2.ASM
@@ -0,0 +1,722 @@
+;       SCCSID = @(#)fcbio2.asm 1.2 85/07/23
+;       SCCSID = @(#)fcbio2.asm 1.2 85/07/23
+TITLE   FCBIO2 - FCB system calls
+NAME    FCBIO2
+
+;
+; Ancient 1.0 1.1 FCB system calls
+;                                   regen   save
+;   GetRR
+;   GetExtent
+;   SetExtent
+;   GetExtended
+;   GetRecSize
+;   FCBIO
+;   $FCB_OPEN               written ACC     ACC
+;   $FCB_CREATE             written ACC     ACC
+;   $FCB_RANDOM_WRITE_BLOCK written fcbio   fcbio
+;   $FCB_RANDOM_READ_BLOCK  written fcbio   fcbio
+;   $FCB_SEQ_READ           written fcbio   fcbio
+;   $FCB_SEQ_WRITE          written fcbio   fcbio
+;   $FCB_RANDOM_READ        written fcbio   fcbio
+;   $FCB_RANDOM_WRITE       written fcbio   fcbio
+;
+;   Revision history:
+;
+;       Created: ARR 4 April 1983
+;                MZ  6 June  1983 completion of functions
+;                MZ 15 Dec   1983 Brain damaged programs close FCBs multiple
+;                                 times.  Change so successive closes work by
+;                                 always returning OK.  Also, detect I/O to
+;                                 already closed FCB and return EOF.
+;                MZ 16 Jan   1984 More braindamage.  Need to separate info
+;                                 out of sft into FCB for reconnection
+;
+;       A000    version 4.00  Jan. 1988
+;
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include version.inc
+.cref
+.list
+
+        EXTRN   DOS_Read:NEAR, DOS_Write:NEAR
+        EXTRN   DOS_Open:NEAR, DOS_Create:NEAR
+
+        I_need  DMAAdd,DWORD            ; current user's DMA address
+        I_need  OpenBuf,128             ; buffer for translating paths
+        I_need  ThisSFT,DWORD           ; SFT in use
+        I_need  sftFCB,DWORD            ; pointer to SFTs for FCB cache
+        I_need  FCBLRU,WORD             ; least recently used count
+        I_need  DISK_FULL,BYTE          ; flag for disk full
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+        include bugtyp.asm
+endif
+
+IF      BUFFERFLAG
+
+        I_need  BUF_EMS_MODE,BYTE
+        I_need  BUF_EMS_LAST_PAGE,DWORD
+        I_need  BUF_EMS_FIRST_PAGE,DWORD
+        I_need  BUF_EMS_SAFE_FLAG,BYTE
+        I_need  BUF_EMS_NPA640,WORD
+        I_need  BUF_EMS_PAGE_FRAME,WORD
+        I_need  BUF_EMS_PFRAME,WORD
+        I_need  LASTBUFFER,DWORD
+
+        extrn   restore_user_map:near
+        extrn   Setup_EMS_Buffers:near
+
+ENDIF
+
+
+; Defintions for FCBOp flags
+
+Random  =   2                           ; random operation
+FCBRead =   4                           ; doing a read
+Block   =   8                           ; doing a block I/O
+
+Break <GetRR - return the random record field in DX:AX>
+
+;
+;   GetRR - correctly load DX:AX with the random record field (3 or 4 bytes)
+;       from the FCB pointed to by DS:SI
+;
+;   Inputs:     DS:SI point to an FCB
+;               BX has record size
+;   Outputs:    DX:AX contain the contents of the random record field
+;   Registers modified: none
+
+Procedure   GetRR,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        MOV     AX,WORD PTR [SI.FCB_RR] ; get low order part
+        MOV     DX,WORD PTR [SI.FCB_RR+2]   ; get high order part
+        CMP     BX,64                   ; ignore MSB of RR if recsiz > 64
+        JB      GetRRBye
+        XOR     DH,DH
+GetRRBye:
+        return
+EndProc GetRR
+
+Break <GetExtent - retrieve next location for sequential IO>
+
+;
+;   GetExtent - Construct the next record to perform I/O from the EXTENT and
+;       NR fields in the FCB.
+;
+;   Inputs:     DS:SI - point to FCB
+;   Outputs:    DX:AX contain the contents of the random record field
+;   Registers modified: none
+
+Procedure   GetExtent,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        MOV     AL,[SI.fcb_NR]          ; get low order piece
+        MOV     DX,[SI.fcb_EXTENT]      ; get high order piece
+        SHL     AL,1
+        SHR     DX,1
+        RCR     AL,1                    ; move low order bit of DL to high order of AH
+        MOV     AH,DL
+        MOV     DL,DH
+        XOR     DH,DH
+        return
+EndProc GetExtent
+
+Break <SetExtent - update the extent/NR field>
+
+;
+;   SetExtent - change the position of an FCB by filling in the extent/NR
+;       fields
+;
+;   Inputs:     DS:SI point to FCB
+;               DX:AX is a record location in file
+;   Outputs:    Extent/NR fields are filled in
+;   Registers modified: CX
+
+Procedure SetExtent,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        SaveReg <AX,DX>
+        MOV     CX,AX
+        AND     AL,7FH                  ; next rec field
+        MOV     [SI.fcb_NR],AL
+        AND     CL,80H                  ; save upper bit
+        SHL     CX,1
+        RCL     DX,1                    ; move high bit of CX to low bit of DX
+        MOV     AL,CH
+        MOV     AH,DL
+        MOV     [SI.fcb_EXTENT],AX      ; all done
+        RestoreReg  <DX,AX>
+        return
+EndProc SetExtent
+
+Break <GetExtended - find FCB in potential extended fcb>
+
+;
+;   GetExtended - Make DS:SI point to FCB from DS:DX
+;
+;   Inputs:     DS:DX point to a possible extended FCB
+;   Outputs:    DS:SI point to the FCB part
+;               zeroflag set if not extended fcb
+;   Registers modified: SI
+
+Procedure   GetExtended,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        MOV     SI,DX                   ; point to Something
+        CMP     BYTE PTR DS:[SI],-1     ; look for extention
+        JNZ     GetBye                  ; not there
+        ADD     SI,7                    ; point to FCB
+GetBye:
+        CMP     SI,DX                   ; set condition codes
+        return
+EndProc GetExtended
+
+Break <GetRecSize - return in BX the FCB record size>
+
+;
+;   GetRecSize - return in BX the record size from the FCB at DS:SI
+;
+;   Inputs:     DS:SI point to a non-extended FCB
+;   Outputs:    BX contains the record size
+;   Registers modified: None
+
+Procedure   GetRecSize,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     BX,[SI.fcb_RECSIZ]      ; get his record size
+        OR      BX,BX                   ; is it nul?
+        retnz
+        MOV     BX,128                  ; use default size
+        MOV     [SI.fcb_RECSIZ],BX      ; stuff it back
+        return
+EndProc GetRecSize
+
+BREAK <FCBIO - do internal FCB I/O>
+
+;
+;   FCBIO - look at FCBOP and merge all FCB operations into a single routine.
+;
+;   Inputs:     FCBOP flags which operations need to be performed
+;               DS:DX point to FCB
+;               CX may have count of number of records to xfer
+;   Outputs:    AL has error code
+;   Registers modified: all
+
+Procedure   FCBIO,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+PUBLIC FCBIO001S,FCBIO001E
+FCBIO001S:
+        LocalVar    FCBErr,BYTE
+        LocalVar    cRec,WORD
+        LocalVar    RecPos,DWORD
+        LocalVar    RecSize,WORD
+        LocalVar    bPos,DWORD
+        LocalVar    cByte,WORD
+        LocalVar    cResult,WORD
+        LocalVar    cRecRes,WORD
+        LocalVar    FCBOp,BYTE
+FCBIO001E:
+        Enter
+
+FEOF    EQU     1
+FTRIM   EQU     2
+        MOV     FCBOp,AL
+        MOV     FCBErr,0                ;   FCBErr = 0;
+        invoke  GetExtended             ;   FCB = GetExtended ();
+        TEST    FCBOp,BLOCK             ;   if ((OP&BLOCK) == 0)
+        JNZ     GetPos
+        MOV     CX,1                    ;       cRec = 1;
+GetPos:
+        MOV     cRec,CX                 ;*Tail coalesce
+        invoke  GetExtent               ;   RecPos = GetExtent ();
+        invoke  GetRecSize              ;   RecSize = GetRecSize ();
+        MOV     RecSize,BX
+        TEST    FCBOp,RANDOM            ;   if ((OP&RANDOM) <> 0)
+        JZ      GetRec
+        invoke  GetRR                   ;       RecPos = GetRR ();
+GetRec:
+        MOV     RecPosL,AX              ;*Tail coalesce
+        MOV     RecPosH,DX
+        invoke  SetExtent               ;   SetExtent (RecPos);
+        MOV     AX,RecPosH              ;   bPos = RecPos * RecSize;
+        MUL     BX
+        MOV     DI,AX
+        MOV     AX,RecPosL
+        MUL     BX
+        ADD     DX,DI
+        MOV     bPosL,AX
+        MOV     bPosH,DX
+        MOV     AX,cRec                 ;   cByte = cRec * RecSize;
+        MUL     BX
+        MOV     cByte,AX
+        ADD     AX,WORD PTR DMAAdd      ;   if (cByte+DMA > 64K) {
+        ADC     DX,0
+        JZ      DoOper
+        MOV     FCBErr,FTRIM            ;       FCBErr = FTRIM;
+        MOV     AX,WORD PTR DMAAdd      ;       cRec = (64K-DMA)/RecSize;
+        NEG     AX
+        JNZ     DoDiv
+        DEC     AX
+DoDiv:
+        XOR     DX,DX
+        DIV     BX
+        MOV     cRec,AX
+        MUL     BX                      ;       cByte = cRec * RecSize;
+        MOV     cByte,AX                ;       }
+DoOper:
+        XOR     BX,BX
+        MOV     cResult,BX              ;   cResult = 0;
+        CMP     cByte,BX                ;   if (cByte <> 0 ||
+        JNZ     DoGetExt
+        TEST    FCBErr,FTRIM            ;       (FCBErr&FTRIM) == 0) {
+IF debug
+        JZ      DoGetExt
+        JMP     SkipOp
+ELSE
+        JZ      SKP_SkipOp
+        JMP     SkipOp
+SKP_SkipOp:
+ENDIF
+DoGetExt:
+        invoke  SFTFromFCB              ;       if (!SFTFromFCB (SFT,FCB))
+        JNC     ContinueOp
+FCBDeath:
+        invoke  FCB_Ret_Err             ; signal error, map for extended
+        MOV     cRecRes,0               ; no bytes transferred
+        MOV     FCBErr,FEOF             ;           return FTRIM;
+        JMP     FCBSave                 ; bam!
+ContinueOp:
+        Assert  ISSFT,<ES,DI>,"ContinueOP"
+        MOV     AX,WORD PTR [SI].fcb_filsiz
+        MOV     WORD PTR ES:[DI].sf_size,AX
+        MOV     AX,WORD PTR [SI].fcb_filsiz+2
+        MOV     WORD PTR ES:[DI].sf_size+2,AX
+        MOV     AX,bPosL
+        MOV     DX,bPosH
+        MOV     WORD PTR ES:[DI.sf_position],AX
+        XCHG    WORD PTR ES:[DI.sf_position+2],DX
+        PUSH    DX                      ; save away Open age.
+        MOV     CX,cByte                ;       cResult =
+
+;       int     3
+
+        MOV     DI,OFFSET DOSGroup:DOS_Read ;       *(OP&FCBRead ? DOS_Read
+        TEST    FCBOp,FCBRead           ;                        : DOS_Write)(cRec);
+        JNZ     DoContext
+        MOV     DI,OFFSET DOSGroup:DOS_Write
+DoContext:
+        SaveReg <BP,DS,SI>
+        Context DS
+;; Fix for disk full
+        CALL    DI
+        RestoreReg  <SI,DS,BP>
+        ASSUME  DS:NOTHING
+
+IF      BUFFERFLAG
+        pushf
+        push    ax
+        push    bx
+
+        cmp     cs:[BUF_EMS_MODE], -1
+        jz      dos_fcb_call_done
+        call    restore_user_map
+        mov     ax, word ptr cs:[BUF_EMS_LAST_PAGE]
+        cmp     cs:[BUF_EMS_PFRAME], ax
+        je      dos_fcb_call_done
+        mov     word ptr cs:[LASTBUFFER], -1
+        mov     cs:[BUF_EMS_PFRAME], ax
+        mov     ax, word ptr cs:[BUF_EMS_LAST_PAGE+2]
+        mov     cs:[BUF_EMS_PAGE_FRAME], ax
+        mov     cs:[BUF_EMS_SAFE_FLAG], 1
+        call    Setup_EMS_Buffers
+
+dos_fcb_call_done:
+        pop     bx
+        pop     ax
+        popf
+ENDIF
+
+        JC      FCBDeath
+
+        CMP     BYTE PTR [DISK_FULL],0  ; treat disk full as error
+        JZ      NODSKFULL
+        MOV     BYTE PTR [DISK_FULL],0  ; clear the flag
+        MOV     FCBerr,FEOF             ; set disk full flag
+NODSKFULL:
+;; Fix for disk full
+        MOV     cResult,CX
+        invoke  SaveFCBInfo             ;       SaveFCBInfo (FCB);
+        Assert  ISSFT,<ES,DI>,"FCBIO/SaveFCBInfo"
+%out WARNING!!! Make sure sf_position+2 is OpenAGE
+        POP     WORD PTR ES:[DI].sf_Position+2  ; restore open age
+        MOV     AX,WORD PTR ES:[DI].sf_size
+        MOV     WORD PTR [SI].fcb_filsiz,AX
+        MOV     AX,WORD PTR ES:[DI].sf_size+2
+        MOV     WORD PTR [SI].fcb_filsiz+2,AX
+                                        ;       }
+SkipOp:
+        MOV     AX,cResult              ;   cRecRes = cResult / RecSize;
+        XOR     DX,DX
+        DIV     RecSize
+        MOV     cRecRes,AX
+        ADD     RecPosL,AX              ;   RecPos += cRecResult;
+        ADC     RecPosH,0
+;
+; If we have not gotten the expected number of records, we signal an EOF
+; condition.  On input, this is EOF.  On output this is usually disk full.
+; BUT...  Under 2.0 and before, all device output IGNORED this condition.  So
+; do we.
+;
+        CMP     AX,cRec                 ;   if (cRecRes <> cRec)
+        JZ      TryBlank
+        TEST    FCBOp,FCBRead           ;       if (OP&FCBRead || !DEVICE)
+        JNZ     SetEOF
+        TEST    ES:[DI].sf_flags,devid_device
+        JNZ     TryBlank
+SetEOF:
+        MOV     FCBErr,FEOF             ;       FCBErr = FEOF;
+TryBlank:                               ;
+        OR      DX,DX                   ;   if (cResult%RecSize <> 0) {
+        JZ      SetExt
+        ADD     RecPosL,1               ;       RecPos++;
+        ADC     RecPosH,0
+        TEST    FCBOp,FCBRead           ;       if(OP&FCBRead) <> 0) {
+        JZ      SetExt
+        INC     cRecRes                 ;       cRecRes++;
+        MOV     FCBErr,FTRIM + FEOF     ;       FCBErr = FTRIM | FEOF;
+        MOV     CX,RecSize              ;       Blank (RecSize-cResult%RecSize,
+        SUB     CX,DX                   ;              DMA+cResult);
+        XOR     AL,AL
+        LES     DI,DMAAdd
+        ADD     DI,cResult
+        REP     STOSB                   ;   }   }
+SetExt:
+        MOV     DX,RecPosH
+        MOV     AX,RecPosL
+        TEST    FCBOp,RANDOM            ;   if ((OP&Random) == 0 ||
+        JZ      DoSetExt
+        TEST    FCBOp,BLOCK             ;       (OP&BLOCK) <> 0)
+        JZ      TrySetRR
+DoSetExt:
+        invoke  SetExtent               ;       SetExtent (RecPos, FCB);
+TrySetRR:
+        TEST    FCBOp,BLOCK             ;   if ((op&BLOCK) <> 0)
+        JZ      TryReturn
+        MOV     WORD PTR [SI.FCB_RR],AX ;       FCB->RR = RecPos;
+        MOV     BYTE PTR [SI.FCB_RR+2],DL
+        CMP     [SI.fcb_RECSIZ],64
+        JAE     TryReturn
+        MOV     [SI+fcb_RR+2+1],DH      ; Set 4th byte only if record size < 64
+TryReturn:
+        TEST    FCBOP,FCBRead           ;   if (!(FCBOP & FCBREAD)) {
+        JNZ     FCBSave
+        SaveReg <DS>                    ;       FCB->FDate = date;
+        Invoke  Date16                  ;       FCB->FTime = time;
+        RestoreReg  <DS>
+        MOV     [SI].FCB_FDate,AX
+        MOV     [SI].FCB_FTime,DX       ;       }
+FCBSave:
+        TEST    FCBOp,BLOCK             ;   if ((op&BLOCK) <> 0)
+        JZ      DoReturn
+        MOV     CX,cRecRes              ;       user_CX = cRecRes;
+        invoke  Get_User_Stack
+        MOV     [SI.User_CX],CX
+DoReturn:
+        MOV     AL,FCBErr               ;   return (FCBERR);
+        Leave
+        return
+EndProc FCBIO
+
+Break <$FCB_Open - open an old-style FCB>
+
+;
+;   $FCB_Open - CPM compatability file open.  The user has formatted an FCB
+;       for us and asked to have the rest filled in.
+;
+;   Inputs:     DS:DX point to an unopenned FCB
+;   Outputs:    AL indicates status 0 is ok FF is error
+;               FCB has the following fields filled in:
+;                   Time/Date Extent/NR Size
+
+Procedure $FCB_Open,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        MOV     AX,sharing_Compat+Open_For_Both
+        MOV     CX,OFFSET DOSGroup:DOS_Open
+;
+; The following is common code for Creation and openning of FCBs.  AX is
+; either attributes (for create) or open mode (for open)...  DS:DX points to
+; the FCB
+;
+DoAccess:
+        SaveReg <DS,DX,CX,AX>           ; save FCB pointer away
+        MOV     DI,OFFSET DOSGroup:OpenBuf
+        invoke  TransFCB                ; crunch the fcb
+        RestoreReg  <AX,CX,DX,DS>       ; get fcb
+        JNC     FindFCB                 ; everything seems ok
+FCBOpenErr:
+;
+; AL has error code
+;
+        transfer    FCB_Ret_Err
+FindFCB:
+        invoke  GetExtended             ; DS:SI will point to FCB
+        invoke  LRUFCB                  ; get a sft entry (no error)
+        JC      HardMessage
+        ASSUME  ES:NOTHING
+
+;       Message 1,"Entering "
+;       MessageNum  ES
+;       Message 1,":"
+;       MessageNum  DI
+;       Message 1,<13,10>
+
+        MOV     ES:[DI].sf_mode,sf_ISFCB
+        SaveReg <DS,SI,BX>              ; save fcb pointer
+        MOV     SI,CX
+        Context DS                      ; let DOS_Open see variables
+        CALL    SI                      ; go open the file
+        RestoreReg  <BX,SI,DS>          ; get fcb
+        ASSUME  DS:NOTHING
+        LES     DI,ThisSFT              ; get sf pointer
+        JNC     FCBOK                   ; operation succeeded
+        Assert  ISSFT,<ES,DI>,"DeadFCB"
+failopen:
+        PUSH    AX
+        MOV     AL,"R"                  ; clear out field (free sft)
+        invoke  BlastSFT
+        POP     AX
+        CMP     AX,error_too_many_open_files
+        JZ      HardMessage
+        CMP     AX,error_sharing_buffer_exceeded
+        jnz     DeadFCB
+HardMessage:
+        PUSH    AX
+        invoke  FCBHardErr
+        POP     AX
+DeadFCB:
+        transfer    FCB_Ret_Err
+FCBOK:
+        invoke  IsSFTNet                       ;AN007;F.C. >32mb  Non Fat file?
+        JNZ     FCBOK2                         ;AN007;F.C. >32mb  yes
+        invoke  CheckShare                     ;AN000;F.C. >32mb  share around?
+        JNZ     FCBOK2                         ;AN000;F.C. >32mb  yes
+        CMP     WORD PTR ES:[DI].sf_dirsec+2,0 ;AN000;F.C. >32mb  if dirsec >32mb
+        JZ      FCBOK2                         ;AN000;F.C. >32mb    then error
+        MOV     AX,error_sys_comp_not_loaded   ;AN000;F.C. >32mb
+        JMP     failopen                       ;AN000;F.C. >32mb
+FCBOK2:
+
+        INC     ES:[DI].sf_ref_count    ; increment reference count
+        invoke  SaveFCBInfo
+        Assert  ISSFT,<ES,DI>,"FCBOK"
+        invoke  SetOpenAge
+        Assert  ISSFT,<ES,DI>,"FCBOK/SetOpenAge"
+        TEST    ES:[DI].sf_flags,devid_device
+        JNZ     FCBNoDrive              ; do not munge drive on devices
+        MOV     AL,DS:[SI]              ; get drive byte
+        invoke  GetThisDrv              ; convert
+        INC     AL
+        MOV     DS:[SI],AL              ; stash in good drive letter
+FCBNoDrive:
+        MOV     [SI].FCB_RecSiz,80h     ; stuff in default record size
+        MOV     AX,ES:[DI].SF_Time      ; set time
+        MOV     [SI].FCB_FTime,AX
+        MOV     AX,ES:[DI].SF_Date      ; set date
+        MOV     [SI].FCB_FDate,AX
+        MOV     AX,WORD PTR ES:[DI].SF_Size ; set sizes
+        MOV     [SI].FCB_FILSIZ,AX
+        MOV     AX,WORD PTR ES:[DI].SF_Size+2
+        MOV     [SI].FCB_FILSIZ+2,AX
+        XOR     AX,AX                   ; convenient zero
+        MOV     [SI].FCB_Extent,AX      ; point to beginning of file
+;
+; We must scan the set of FCB SFTs for one that appears to match the current
+; one.  We cheat and use CheckFCB to match the FCBs.
+;
+        LES     DI,SFTFCB               ; get the pointer to head of the list
+        MOV     AH,BYTE PTR ES:[DI].sfCount ; get number of SFTs to scan
+OpenScan:
+        CMP     AL,[SI].fcb_sfn         ; don't compare ourselves
+        JZ      SkipCheck
+        SaveReg <AX>                    ; preserve count
+        invoke  CheckFCB                ; do they match
+        RestoreReg  <AX>                ; get count back
+        JNC     OpenFound               ; found a match!
+SkipCheck:
+        INC     AL                      ; advance to next FCB
+        CMP     AL,AH                   ; table full?
+        JNZ     OpenScan                ; no, go for more
+OpenDone:
+        xor     al,al                   ; return success
+        return
+;
+; The SFT at ES:DI is the one that is already in use for this FCB.  We set the
+; FCB to use this one.  We increment its ref count.  We do NOT close it at all.
+; Consider:
+;
+;   open (foo)  delete (foo) open (bar)
+;
+; This causes us to recycle (potentially) bar through the same local SFT as
+; foo even though foo is no longer needed; this is due to the server closing
+; foo for us when we delete it.  Unfortunately, we cannot see this closure.
+; If we were to CLOSE bar, the server would then close the only reference to
+; bar and subsequent I/O would be lost to the redirector.
+;
+; This gets solved by NOT closing the sft, but zeroing the ref count
+; (effectively freeing the SFT) and informing the sharer (if relevant) that
+; the SFT is no longer in use.  Note that the SHARER MUST keep its ref counts
+; around.  This will allow us to access the same file through multiple network
+; connections and NOT prematurely terminate when the ref count on one
+; connection goes to zero.
+;
+OpenFound:
+        MOV     [SI].fcb_SFN,AL         ; assign with this
+        INC     ES:[DI].sf_ref_count    ; remember this new invocation
+        MOV     AX,FCBLRU               ; update LRU counts
+        MOV     ES:[DI].sf_LRU,AX
+;
+; We have an FCB sft that is now of no use.  We release sharing info and then
+; blast it to prevent other reuse.
+;
+        context DS
+        LES     DI,ThisSFT
+        DEC     ES:[DI].sf_ref_count    ; free the newly allocated SFT
+        invoke  ShareEnd
+        Assert  ISSFT,<ES,DI>,"Open blasting"
+        MOV     AL,'C'
+        invoke  BlastSFT
+        JMP     OpenDone
+EndProc $FCB_Open
+
+BREAK   <$FCB_Create - create a new directory entry>
+
+;
+;   $FCB_Create - CPM compatability file create.  The user has formatted an
+;       FCB for us and asked to have the rest filled in.
+;
+;   Inputs:     DS:DX point to an unopenned FCB
+;   Outputs:    AL indicates status 0 is ok FF is error
+;               FCB has the following fields filled in:
+;                   Time/Date Extent/NR Size
+
+Procedure $FCB_Create,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     CX,OFFSET DOSGroup:DOS_Create   ; routine to call
+        XOR     AX,AX                   ; attributes to create
+        invoke  GetExtended             ; get extended FCB
+        JZ      DoAccessJ               ; not an extended FCB
+        MOV     AL,[SI-1]               ; get attributes
+DoAccessJ:
+        JMP     DoAccess                ; do dirty work
+EndProc $FCB_Create
+
+BREAK <$FCB_Random_write_Block - write a block of records to a file >
+
+;
+;   $FCB_Random_Write_Block - retrieve a location from the FCB, seek to it
+;       and write a number of blocks from it.
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = 0 write was successful and the FCB position is updated
+;               AL <> 0 Not enough room on disk for the output
+;
+
+Procedure $FCB_Random_Write_Block,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,Random+Block
+        JMP     FCBIO
+EndProc $FCB_Random_Write_Block
+
+BREAK <$FCB_Random_Read_Block - read a block of records to a file >
+
+;
+;   $FCB_Random_Read_Block - retrieve a location from the FCB, seek to it
+;       and read a number of blocks from it.
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = error codes defined above
+;
+
+Procedure $FCB_Random_Read_Block,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,Random+FCBRead+Block
+        JMP     FCBIO
+EndProc $FCB_Random_Read_Block
+
+BREAK <$FCB_Seq_Read - read the next record from a file >
+
+;
+;   $FCB_Seq_Read - retrieve the next record from an FCB and read it into
+;       memory
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = error codes defined above
+;
+
+Procedure $FCB_Seq_Read,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,FCBRead
+        JMP     FCBIO
+EndProc $FCB_Seq_Read
+
+BREAK <$FCB_Seq_Write - write the next record to a file >
+
+;
+;   $FCB_Seq_Write - retrieve the next record from an FCB and write it to the
+;       file
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = error codes defined above
+;
+
+Procedure $FCB_Seq_Write,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,0
+        jmp     FCBIO
+EndProc $FCB_SEQ_WRITE
+
+BREAK <$FCB_Random_Read - Read a single record from a file >
+
+;
+;   $FCB_Random_Read - retrieve a location from the FCB, seek to it and read a
+;       record from it.
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = error codes defined above
+;
+
+Procedure $FCB_Random_Read,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,Random+FCBRead
+        jmp     FCBIO                   ; single block
+EndProc $FCB_RANDOM_READ
+
+BREAK <$FCB_Random_Write - write a single record to a file >
+
+;
+;   $FCB_Random_Write - retrieve a location from the FCB, seek to it and write
+;       a record to it.
+;
+;   Inputs:     DS:DX point to an FCB
+;   Outputs:    AL = error codes defined above
+;
+
+Procedure $FCB_Random_Write,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,Random
+        jmp     FCBIO
+EndProc $FCB_RANDOM_WRITE
+
+CODE ENDS
+END
+
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/FILE.ASM b/v4.0/src/DOS/FILE.ASM
new file mode 100644
index 0000000..9fca034
--- /dev/null
+++ b/v4.0/src/DOS/FILE.ASM
@@ -0,0 +1,909 @@
+;       SCCSID = @(#)file.asm   1.2 85/07/23
+;       SCCSID = @(#)file.asm   1.2 85/07/23
+TITLE   FILE - Pathname related system calls
+NAME    FILE
+
+;
+; Pathname related system calls.  These will be passed direct text of the
+; pathname from the user.  They will need to be passed through the macro
+; expander prior to being sent through the low-level stuff.  I/O specs are
+; defined in DISPATCH.  The system calls are:
+;
+;   $Open             written
+;   $Creat            written
+;   $ChMod            written
+;   $Unlink           written
+;   $Rename           written
+;   $CreateTempFile   written
+;   $CreateNewFile    written
+;   $Extended_Open    written  DOS 4.00
+;   GetIOParms        written  DOS 4.00
+;
+;   Revision history:
+;
+;       Created: MZ 4 April 1983
+;       A000   version 4.00  Jan. 1988
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+include dossym.inc
+include devsym.inc
+include fastopen.inc
+include EA.inc                       ;AN000;
+include version.inc
+.cref
+.list
+.sall
+
+        EXTRN   DOS_OPEN:NEAR,DOS_CREATE:NEAR,DOS_Create_New:NEAR
+
+IF      NOT IBMCOPYRIGHT
+        extrn   Set_EXT_mode:near
+ENDIF
+
+        I_need  WFP_Start,WORD          ; pointer to beginning of expansion
+        I_Need  ThisCDS,DWORD           ; pointer to curdir in use
+        I_need  ThisSft,DWORD           ; SFT pointer for DOS_Open
+        I_need  pJFN,DWORD              ; temporary spot for pointer to JFN
+        I_need  JFN,WORD                ; word JFN for process
+        I_need  SFN,WORD                ; word SFN for process
+        I_Need  OpenBuf,128             ; buffer for filename
+        I_Need  RenBuf,128              ; buffer for filename in rename
+        I_need  Sattrib,BYTE            ; byte attribute to search for
+        I_need  Ren_WFP,WORD            ; pointer to real path
+        I_need  cMeta,BYTE
+        I_need  EXTERR,WORD             ; extended error code
+        I_need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
+        i_need  JShare,DWORD            ; share jump table
+        I_need  fSharing,BYTE           ; TRUE => via ServerDOSCall
+        I_need  FastOpenTable,BYTE
+        I_need  CPSWFLAG,BYTE           ;AN000;FT. cpsw falg
+        I_need  EXTOPEN_FLAG,WORD       ;AN000;FT. extended file open flag
+        I_need  EXTOPEN_ON,BYTE         ;AN000;FT. extended open flag
+        I_need  EXTOPEN_IO_MODE,WORD    ;AN000;FT. IO mode
+        I_need  XA_from,BYTE            ;AN000;;FT. for get/set XA
+        I_need  SAVE_ES,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_DI,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_DS,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_SI,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_DX,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_BX,WORD            ;AN000;;FT. for get/set XA
+        I_need  SAVE_CX,WORD            ;AN000;;FT. for get/set XA
+        I_need  NO_FILTER_DPATH,DWORD   ;AN000;; pointer to original path of dest
+        I_need  Temp_Var,WORD           ;AN000;;
+        I_need  DOS34_FLAG,WORD         ;AN000;;
+        I_need  Temp_Var2,WORD          ;AN000;;
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+BREAK <$Open - open a file from a path string>
+
+;
+;   $Open - given a path name in DS:DX and an open mode in AL, access the file
+;       and return a handle
+;   Inputs:     DS:DX - pointer to asciz name
+;               AL - open mode
+;   Outputs:    Carry Set - AX has error code for invalid open
+;               Carry Clear - AX has per process handle number
+;   Registers modified: most
+
+Procedure   $Open,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        fmt TypSysCall,LevLog,<"Open\n">
+        fmt TypSysCall,LevArgs,<" Mode = $x file = '$S'\n">,<AX,DS,DX>
+        XOR     AH,AH
+Entry $Open2                            ;AN000;
+        mov     ch,attr_hidden+attr_system+attr_directory
+        call    SetAttrib
+        MOV     CX,OFFSET DOSGroup:DOS_Open ; address of routine to call
+        SaveReg <AX>                    ; Save mode on stack
+IF DBCS                                 ;AN000;
+        MOV     [Temp_Var],0            ;AN000;KK. set variable with 0
+ENDIF                                   ;AN000;
+
+AccessFile:
+;
+; Grab a free SFT.
+;
+IF  DBCS                                ;AN000;
+        TEST    [Temp_Var],8            ;AN000;;KK. volume id bit set                  ;AN000;
+        JZ      novol                   ;AN000;;KK. no                                 ;AN000;
+        OR      [DOS34_FLAG],DBCS_VOLID ;AN000;;KK. set bit for transpath              ;AN000;
+novol:                                  ;AN000;
+ENDIF                                   ;AN000;
+        EnterCrit   critSFT
+        invoke  SFNFree                 ; get a free sfn
+        LeaveCrit   critSFT
+        JC      OpenFailJ               ; oops, no free sft's
+        MOV     SFN,BX                  ; save the SFN for later
+        fmt     TypAccess,LevSFN,<"AccessFile setting SFN to $x\n">,<BX>
+        MOV     WORD PTR [ThisSFT],DI   ; save the SF offset
+        MOV     WORD PTR [ThisSFT+2],ES ; save the SF segment
+;
+; Find a free area in the user's JFN table.
+;
+        invoke  JFNFree                 ; get a free jfn
+        JNC     SaveJFN
+OpenFailJ:
+        JMP     OpenFail                ; there were free JFNs... try SFN
+SaveJFN:
+        MOV     WORD PTR [pJFN],DI      ; save the jfn offset
+        MOV     WORD PTR [pJFN+2],ES    ; save the jfn segment
+        MOV     [JFN],BX                ; save the jfn itself
+;
+; We have been given an JFN.  We lock it down to prevent other tasks from
+; reusing the same JFN.
+;
+        MOV     BX,SFN
+        MOV     ES:[DI],BL              ; assign the JFN
+        MOV     SI,DX                   ; get name in appropriate place
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        SaveReg <CX>                    ; save routine to call
+        invoke  TransPath               ; convert the path
+        RestoreReg  <BX>                ; restore routine to call
+        LDS     SI,ThisSFT
+        ASSUME  DS:NOTHING
+        JC      OpenCleanJ              ; no error, go and open file
+        CMP     cMeta,-1
+        JZ      SetSearch
+        MOV     AL,error_file_not_found ; no meta chars allowed
+OpenCleanJ:
+        JMP     OpenClean
+SetSearch:
+        RestoreReg  <AX>                ; Mode (Open), Attributes (Create)
+;
+; We need to get the new inheritance bits.
+;
+        xor     cx,cx
+        CMP     BX,OFFSET DOSGroup:DOS_OPEN
+        JNZ     DoOper
+        TEST    AL,sharing_no_inherit   ; look for no inher
+        JZ      DoOper
+        AND     AL,07Fh                 ; mask off inherit bit
+        MOV     CX,sf_no_inherit
+DoOper:
+        MOV     [SI].sf_mode,0          ; initialize mode field to 0
+        MOV     [SI.SF_mft],0           ; clean out sharing info
+;
+;------------------------------------------------------------HKN 8/7/88
+;       Check if this is an extended open. If so you must set the 
+;       modes in sf_mode. Call Set_EXT_mode to do all this. See
+;       Set_EXT_mode in creat.asm
+;
+IF      NOT IBMCOPYRIGHT
+
+        push    es      ; set up es:di to point to SFT
+        push    di
+        push    ds
+        pop     es
+        push    si
+        pop     di
+        call    Set_EXT_mode
+        pop     di
+        pop     es
+
+ENDIF
+
+;-----------------------------------------------------------------------
+
+        Context DS
+        SaveReg <CX>
+        CALL    BX                      ; blam!
+        RestoreReg  <CX>
+        LDS     SI,ThisSFT
+        ASSUME  DS:NOTHING
+        JC      OpenE2                  ;AN000;FT. chek extended open hooks first
+;
+; The SFT was successfully opened.  Remove busy mark.
+;
+OpenOK:
+        ASSUME  DS:NOTHING
+;       MOV     AL,[SI].sf_attr_hi      ;AN000;FT. save file type for EXEC
+;       MOV     BYTE PTR [Temp_Var2],AL ;AN000;FT.
+        MOV     [SI].sf_ref_count,1
+        OR      [SI].sf_flags,CX        ; set no inherit bit if necessary
+;
+; If the open mode is 70, we scan the system for other SFT's with the same
+; contents.  If we find one, then we can 'collapse' thissft onto the already
+; opened one.  Otherwise we use this new one.  We compare uid/pid/mode/mft
+;
+; Since this is only relevant on sharer systems, we stick this code into the
+; sharer.
+;
+        MOV     AX,JFN
+if installed
+        Call    JShare + 12 * 4
+else
+        Call    ShCol
+endif
+        fmt     TypAccess,LevSFN,<"AccessFile setting SFN to -1\n">
+        MOV     SFN,-1                  ; clear out sfn pointer
+        fmt     TypSysCall,LevLog,<"Open/CreateXX: return $x\n">,<AX>
+        transfer    Sys_Ret_OK          ; bye with no errors
+;Extended Open hooks check
+OpenE2:                                    ;AN000;;EO.
+        CMP     AX,error_invalid_parameter ;AN000;;EO. IFS extended open ?
+        JNZ     OpenE                      ;AN000;;EO. no.
+        JMP     OpenCritLeave              ;AN000;;EO. keep handle
+
+;Extended Open hooks check
+;
+; AL has error code.  Stack has argument to dos_open/dos_create.
+;
+OpenClean:
+        fmt TypSysCall,LevLog,<"Return value from transpath $x\n">,<AX>
+        RestoreReg  <bx>                ; clean off stack
+OpenE:
+        MOV     [SI.SF_Ref_Count],0     ; release SFT
+        LDS     SI,pJFN
+        MOV     BYTE PTR [SI],0FFh      ; free the SFN...
+        JMP     SHORT OpenCritLeave
+
+OpenFail:
+        STI
+        RestoreReg  <CX>                ; Clean stack
+OpenCritLeave:
+        MOV     SFN,-1                  ; remove mark.
+        fmt TypSysCall,LevLog,<"Open/CreateXX: error $x\n">,<AX>
+;; File Tagging DOS 4.00
+        CMP     CS:[EXTERR],error_Code_Page_Mismatched  ;AN000;;FT. code page mismatch
+        JNZ     NORERR                                  ;AN000;;FT. no
+        transfer From_GetSet                            ;AN000;;FT. yes
+NORERR:                                                 ;AN000;
+
+;; File Tagging DOS 4.00
+        transfer    Sys_Ret_Err         ; no free, return error
+
+EndProc $Open
+
+BREAK <$Creat - create a brand-new file>
+
+;
+;   $Creat - create the directory entry specified in DS:DX and give it the
+;       initial attributes contained in CX
+;   Inputs:     DS:DX - ASCIZ path name
+;               CX - initial attributes
+;   Outputs:    Carry set - AX has error code
+;               Carry reset - AX has handle
+;   Registers modified: all
+
+Procedure   $Creat,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        fmt TypSysCall,LevLog,<"Create\n">
+        fmt TypSysCall,LevArgs,<" Att = $x file = '$S'\n">,<CX,DS,DX>
+IF DBCS                                 ;AN000;
+        MOV     [Temp_Var],CX           ;AN000;KK. set variable with attribute        ;AN000;
+ENDIF                                   ;AN000;
+        SaveReg <CX>                    ; Save attributes on stack
+        MOV     CX,OFFSET DOSGroup:DOS_Create; routine to call
+AccessSet:
+        mov     SAttrib,attr_hidden+attr_system
+        JMP     AccessFile              ; use good ol' open
+EndProc $Creat
+
+BREAK <$CHMOD - change file attributes>
+;
+;   Assembler usage:
+;           LDS     DX, name
+;           MOV     CX, attributes
+;           MOV     AL,func (0=get, 1=set)
+;           INT     21h
+;   Error returns:
+;           AX = error_path_not_found
+;           AX = error_access_denied
+;
+
+        procedure $CHMOD,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        SaveReg <AX,CX>                 ; save function and attributes
+        MOV     SI,DX                   ; get things in appropriate places
+        invoke  TransPathSet            ; get correct path
+        RestoreReg  <CX,AX>             ; and get function and attrs back
+        JC      ChModErr                ; errors get mapped to path not found
+        Context DS                      ; set up for later possible calls
+        CMP     cMeta,-1
+        JNZ     ChModErr
+        MOV     [SAttrib],attr_hidden+attr_system+attr_directory
+        SUB     AL,1                    ; fast way to discriminate
+        JB      ChModGet                ; 0 -> go get value
+        JZ      ChModSet                ; 1 -> go set value
+        MOV     EXTERR_LOCUS,errLoc_Unk ; Extended Error Locus
+        error   error_invalid_function  ; bad value
+ChModGet:
+        invoke  Get_File_Info           ; suck out the ol' info
+        JC      ChModE                  ; error codes are already set for ret
+        invoke  Get_User_stack          ; point to user saved vaiables
+        MOV     [SI.User_CX],AX         ; return the attributes
+        transfer    Sys_Ret_OK          ; say sayonara
+ChModSet:
+        MOV     AX,CX                   ; get attrs in position
+        invoke  Set_File_Attribute      ; go set
+        JC      ChModE                  ; errors are set
+        transfer    Sys_Ret_OK
+ChModErr:
+        mov     al,error_path_not_found
+ChmodE:
+        Transfer    SYS_RET_ERR
+EndProc $ChMod
+
+BREAK <$UNLINK - delete a file entry>
+;
+;   Assembler usage:
+;           LDS     DX, name
+;           IF VIA SERVER DOS CALL
+;            MOV     CX,SEARCH_ATTRIB
+;           MOV     AH, Unlink
+;           INT     21h
+;
+;   Error returns:
+;           AX = error_file_not_found
+;              = error_access_denied
+;
+
+        procedure $UNLINK,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        SaveReg <CX>                    ; Save possible CX input parm
+        MOV     SI,DX                   ; Point at input string
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; temp spot for path
+        invoke  TransPathSet            ; go get normalized path
+        RestoreReg <CX>
+        JC      ChModErr                ; badly formed path
+        CMP     cMeta,-1                ; meta chars?
+        JNZ     NotFound
+        Context DS
+        mov     ch,attr_hidden+attr_system   ; unlink appropriate files
+        call    SetAttrib
+        invoke  DOS_Delete              ; remove that file
+        JC      UnlinkE                 ; error is there
+
+
+        transfer    Sys_Ret_OK          ; okey doksy
+NotFound:
+        MOV     AL,error_path_not_found
+UnlinkE:
+        transfer    Sys_Ret_Err         ; bye
+EndProc $UnLink
+
+BREAK <$RENAME - move directory entries around>
+;
+;   Assembler usage:
+;           LDS     DX, source
+;           LES     DI, dest
+;           IF VIA SERVER DOS CALL
+;            MOV     CX,SEARCH_ATTRIB
+;           MOV     AH, Rename
+;           INT     21h
+;
+;   Error returns:
+;           AX = error_file_not_found
+;              = error_not_same_device
+;              = error_access_denied
+
+        procedure $RENAME,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        SaveReg <CX,DS,DX>              ; save source and possible CX arg
+        PUSH    ES
+        POP     DS                      ; move dest to source
+        MOV     SI,DI                   ; save for offsets
+        MOV     DI,OFFSET DOSGroup:RenBuf
+
+        MOV     WORD PTR [NO_FILTER_DPATH],SI   ;AN000;;IFS. save them for IFS
+        MOV     WORD PTR [NO_FILTER_DPATH+2],DS ;AN000;;IFS.
+
+        invoke  TransPathSet            ; munge the paths
+        PUSH    WFP_Start               ; get pointer
+        POP     Ren_WFP                 ; stash it
+        RestoreReg <SI,DS,CX>           ; get back source and possible CX arg
+epjc2:  JC      ChModErr                ; get old error
+        CMP     cMeta,-1
+        JNZ     NotFound
+        SaveReg <CX>                    ; Save possible CX arg
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        invoke  TransPathSet            ; wham
+        RestoreReg <CX>
+        JC      EPJC2
+        Context DS
+        CMP     cMeta,-1
+        JB      NotFound
+
+        PUSH    WORD PTR [THISCDS]         ;AN000;;MS.save thiscds
+        PUSH    WORD PTR [THISCDS+2]       ;AN000;;MS.
+        MOV     DI,OFFSET DOSGROUP:OpenBuf ;AN000;;MS.
+        PUSH    SS                         ;AN000;;MS.
+        POP     ES                         ;AN000;;MS.es:di-> source
+        XOR     AL,AL                      ;AN000;;MS.scan all CDS
+rnloop:                                    ;AN000;
+        invoke  GetCDSFromDrv              ;AN000;;MS.
+        JC      dorn                       ;AN000;;MS.  end of CDS
+        invoke  StrCmp                     ;AN000;;MS.  current dir ?
+        JZ      rnerr                      ;AN000;;MS.  yes
+        INC     AL                         ;AN000;;MS.  next
+        JMP     rnloop                     ;AN000;;MS.
+rnerr:                                     ;AN000;
+        ADD     SP,4                       ;AN000;;MS. pop thiscds
+        error   error_current_directory    ;AN000;;MS.
+dorn:                                      ;AN000;
+        POP     WORD PTR SS:[THISCDS+2]    ;AN000;;MS.
+        POP     WORD PTR SS:[THISCDS]      ;AN000;;MS.
+        Context DS
+        mov     ch,attr_directory+attr_hidden+attr_system; rename appropriate files
+        call    SetAttrib
+        invoke  DOS_Rename              ; do the deed
+        JC      UnlinkE                 ; errors
+
+
+        transfer    Sys_Ret_OK
+EndProc $Rename
+
+Break <$CreateNewFile - Create a new directory entry>
+
+;
+;   CreateNew - Create a new directory entry.  Return a file handle if there
+;       was no previous directory entry, and fail if a directory entry with
+;       the same name existed previously.
+;
+;   Inputs:     DS:DX point to an ASCIZ file name
+;               CX contains default file attributes
+;   Outputs:    Carry Clear:
+;                   AX has file handle opened for read/write
+;               Carry Set:
+;                   AX has error code
+;   Registers modified: All
+
+        Procedure $CreateNewFile,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        fmt TypSysCall,LevLog,<"CreateNew\n">
+        fmt TypSysCall,LevArgs,<" Att = $x file = '$S'\n">,<CX,DS,DX>
+IF DBCS                                 ;AN000;
+        MOV     [Temp_Var],CX           ;AN000;KK. set variable with attribute
+ENDIF                                   ;AN000;
+        SaveReg <CX>                    ; Save attributes on stack
+        MOV     CX,OFFSET DOSGroup:DOS_Create_New   ; routine to call
+        JMP     AccessSet               ; use good ol' open
+EndProc $CreateNewFile
+
+Break   <HexToAsciz - convert a number to hex and store it in memory>
+
+;
+;   HexToAsciz - used to convert register into a hex number.
+;
+;   Inputs:     AX contains the number
+;               ES:DI point to destination
+;   Outputs:    ES:DI updated
+;   Registers modified: DI,CX
+
+Procedure   HexToAsciz,NEAR
+        mov     cx,4                    ; 4 digits in AX
+GetDigit:
+        SaveReg <CX>                    ; preserve count
+        mov     cl,4
+        ROL     AX,CL                   ; move leftmost nibble into rightmost
+        SaveReg <AX>                    ; preserve remainder of digits
+        AND     AL,0Fh                  ; grab low nibble
+        ADD     AL,'0'                  ; turn into digit
+        CMP     AL,'9'                  ; bigger than 9
+        JBE     DoStore                 ; no, stash it
+        ADD     AL,'A'-'0'-10           ; convert into uppercase letter
+DoStore:
+        STOSB                           ; drop in the character
+        RestoreReg <AX,CX>              ; regain the number and count
+        loop    GetDigit                ; while there's more digits, go do 'em
+        return
+EndProc HexToAsciz
+
+Break   <$CreateTempFile - create a unique name>
+
+;
+;   $CreateTemp - given a directory, create a unique name in that directory.
+;       Method used is to get the current time, convert to a name and attempt
+;       a create new.  Repeat until create new succeeds.
+;
+;   Inputs:     DS:DX point to a null terminated directory name.
+;               CX  contains default attributes
+;   Outputs:    Unique name is appended to DS:DX directory.
+;               AX has handle
+;   Registers modified: all
+
+        Procedure $CreateTempFile,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        fmt TypSysCall,LevLog,<"CreateTmp\n">
+        fmt TypSysCall,LevArgs,<" Att = $x dir = '$S'\n">,<CX,DS,DX>
+PUBLIC FILE001S,FILE001E
+FILE001S:
+        LocalVar    EndPtr,DWORD
+        LocalVar    FilPtr,DWORD
+        LocalVar    Attr,WORD
+FILE001E:
+        Enter
+        TEST    CX,NOT attr_changeable
+        JZ      OKatts                  ; Ok if no non-changeable bits set
+;
+; We need this "hook" here to detect these cases (like user sets one both of
+; vol_id and dir bits) because of the structure of the or $CreateNewFile loop
+; below.  The code loops on error_access_denied, but if one of the non
+; changeable attributes is specified, the loop COULD be infinite or WILL be
+; infinite because CreateNewFile will fail with access_denied always.  Thus we
+; need to detect these cases before getting to the loop.
+;
+        MOV     AX,error_access_denied
+        JMP     SHORT SETTMPERR
+
+OKatts:
+        MOV     attr,CX                 ; save attribute
+        MOV     FilPtrL,DX              ; pointer to file
+        MOV     FilPtrH,DS
+        MOV     EndPtrH,DS              ; seg pointer to end of dir
+        PUSH    DS
+        POP     ES                      ; destination for nul search
+        MOV     DI,DX
+        MOV     CX,DI
+        NEG     CX                      ; number of bytes remaining in segment
+ IF  DBCS                               ;AN000;
+Kloop:                                  ;AN000;; 2/13/KK
+        MOV     AL, BYTE PTR ES:[DI]    ;AN000;; 2/13/KK
+        INC     DI                      ;AN000;; 2/13/KK
+        OR      AL,AL                   ;AN000;; 2/13/KK
+        JZ      GOTEND                  ;AN000;; 2/13/KK
+        invoke  testkanj                ;AN000;; 2/13/KK
+        jz      Kloop                   ;AN000;; 2/13/KK
+        inc     di                      ;AN000;; Skip over second kanji byte 2/13/KK
+        CMP     BYTE PTR ES:[DI],0      ;AN000;; 2/13/KK
+        JZ      STOREPTH                ;AN000; When char before NUL is sec Kanji byte
+                                        ;AN000; do not look for path char. 2/13/KK
+        jmp     Kloop                   ;AN000; 2/13/KK
+GOTEND:                                 ;AN000; 2/13/KK
+ ELSE                                   ;AN000;
+        OR      CX,CX                   ;AN000;MS.  cx=0 ? ds:dx on segment boundary
+        JNZ     okok                    ;AN000;MS.  no
+        MOV     CX,-1                   ;AN000;MS.
+okok:                                   ;AN000;
+        XOR     AX,AX                   ;AN000;
+        REPNZ   SCASB                   ;AN000;
+ ENDIF                                  ;AN000;
+        DEC     DI                      ; point back to the null
+        MOV     AL,ES:[DI-1]            ; Get char before the NUL
+        invoke  PathChrCmp              ; Is it a path separator?
+        JZ      SETENDPTR               ; Yes
+STOREPTH:
+        MOV     AL,'\'
+        STOSB                           ; Add a path separator (and INC DI)
+SETENDPTR:
+        MOV     EndPtrL,DI              ; pointer to the tail
+CreateLoop:
+        Context DS                      ; let ReadTime see variables
+        SaveReg <BP>
+        invoke  ReadTime                ; go get time
+        RestoreReg  <BP>
+;
+; Time is in CX:DX.  Go drop it into the string.
+;
+        les     di,EndPtr               ; point to the string
+        mov     ax,cx
+        call    HexToAsciz              ; store upper word
+        mov     ax,dx
+        call    HexToAsciz              ; store lower word
+        xor     al,al
+        STOSB                           ; nul terminate
+        LDS     DX,FilPtr               ; get name
+ASSUME  DS:NOTHING
+        MOV     CX,Attr                 ; get attr
+        SaveReg <BP>
+        CALL    $CreateNewFile          ; try to create a new file
+        RestoreReg  <BP>
+        JNC     CreateDone              ; failed, go try again
+;
+; The operation failed and the error has been mapped in AX.  Grab the extended
+; error and figure out what to do.
+;
+        mov     ax,ExtErr
+        cmp     al,error_file_exists
+        jz      CreateLoop              ; file existed => try with new name
+        cmp     al,error_access_denied
+        jz      CreateLoop              ; access denied (attr mismatch)
+
+;       CMP     AL,error_file_exists    ; certain errors cause failure
+;       JZ      CreateLoop
+;       CMP     AL,error_access_denied
+;       JNZ     SETTMPERR               ; Error out
+;       CMP     [EXTERR],error_cannot_make  ; See if it's REALLY an att mismatch
+;       JNZ     CreateLoop              ; It was, try again
+;       MOV     AL,error_cannot_make    ; Return this "extended" error
+
+SETTMPERR:
+        STC
+CreateDone:
+        Leave
+        JC      CreateFail
+        transfer    Sys_Ret_OK          ; success!
+CreateFail:
+        transfer    Sys_Ret_Err
+EndProc $CreateTempFile
+
+Break   <SetAttrib - set the search attrib>
+
+;
+;   SetAttrib will set the search attribute (SAttrib) either to the normal
+;   (CH) or to the value in CL if the current system call is through
+;   serverdoscall.
+;
+;   Inputs:     fSharing == FALSE => set sattrib to CH
+;               fSharing == TRUE => set sattrib to CL
+;   Outputs:    none
+;   Registers changed:  CX
+
+procedure   SetAttrib,NEAR
+        assume  ds:nothing,es:nothing
+        test    fSharing,-1
+        jnz     Set
+        mov     cl,ch
+Set:
+        mov     SAttrib,cl
+        return
+EndProc SetAttrib
+
+
+Break   <Extended_Open- Extended open the file>
+
+; Input: AL= 0 reserved  AH=6CH
+;        BX= mode
+;        CL= create attribute  CH=search attribute (from server)
+;        DX= flag
+;        DS:SI = file name
+;        ES:DI = parm list
+;                          DD  SET EA list (-1) null
+;                          DW  n  parameters
+;                          DB  type (TTTTTTLL)
+;                          DW  IOMODE
+; Function: Extended Open
+; Output: carry clear
+;                    AX= handle
+;                    CX=1 file opened
+;                       2 file created/opened
+;                       3 file replaced/opened
+;         carry set: AX has error code
+;
+
+
+procedure   $Extended_Open,NEAR                                ;AN000;
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP  ;AN000;
+
+        MOV     [XA_from],0               ;AN000;EO. init for set XA
+        MOV     [EXTOPEN_FLAG],DX         ;AN000;EO. save ext. open flag
+        MOV     [EXTOPEN_IO_MODE],0       ;AN000;EO. initialize IO mode
+        TEST    DX,reserved_bits_mask     ;AN000;EO. reserved bits 0  ?
+        JNZ     ext_inval2                ;AN000;EO. no
+        MOV     AH,DL                     ;AN000;EO. make sure flag is right
+        CMP     DL,0                      ;AN000;EO. all fail ?
+        JZ      ext_inval2                ;AN000;EO. yes, error
+        AND     DL,exists_mask            ;AN000;EO. get exists action byte
+        CMP     DL,2                      ;AN000;EO, > 02
+        JA      ext_inval2                ;AN000;EO. yes ,error
+        AND     AH,not_exists_mask        ;AN000;EO. get no exists action byte
+        CMP     AH,10H                    ;AN000;EO. > 10
+        JA      ext_inval2                ;AN000;EO. yes error
+
+;       CMP     DI,-1                     ;AN000;EO. null parm list
+;       JZ      no_parm                   ;AN000;EO. yes
+;                                         ;AN000;EO
+;       PUSH    CX                        ;AN000;EO.
+;                                         ;AN000;EO.
+;       MOV     CX,ES:[DI.EXT_NUM_OF_PARM];AN000;EO. get number of parms
+;       OR      CX,CX                     ;AN000;EO. 0 pamrs ?
+;       JZ      parmend                   ;AN000;EO. yes
+;       PUSH    SI                        ;AN000;EO.
+;       PUSH    DS                        ;AN000;EO.
+;       MOV     SI,DI                     ;AN000;EO.
+;       ADD     SI,size EXT_OPEN_PARM     ;AN000;EO. position to 1st parm
+;       PUSH    ES                        ;AN000;EO.
+;       POP     DS                        ;AN000;EO. ds:si -> parm list
+;       CALL    GetIOParms                ;AN000;EO.
+;       POP     DS                        ;AN000;EO.
+;       POP     SI                        ;AN000;EO.
+;parmend:                                 ;AN000;EO
+;       POP     CX                        ;AN000;EO. restore CX
+;no_parm:                                 ;AN000;EO.
+        MOV     [SAVE_ES],ES              ;AN000;EO. save API parms
+        MOV     [SAVE_DI],DI              ;AN000;EO.
+        PUSH    [EXTOPEN_FLAG]            ;AN000;EO.
+        POP     [SAVE_DX]                 ;AN000;EO.
+        MOV     [SAVE_CX],CX              ;AN000;EO.
+        MOV     [SAVE_BX],BX              ;AN000;EO.
+        MOV     [SAVE_DS],DS              ;AN000;EO.
+        MOV     [SAVE_SI],SI              ;AN000;EO.
+        MOV     DX,SI                     ;AN000;EO. ds:dx points to file name
+        MOV     AX,BX                     ;AN000;EO. ax= mode
+
+;       TEST    [EXTOPEN_FLAG],no_code_page_check    ;AN000;EO. check no  code page
+;       JNZ     no_cdpg_chk                      ;AN000;;EO.  no
+        JMP     SHORT goopen2                    ;AN000;;EO.  do nromal
+ext_inval2:                                      ;AN000;;EO.
+        error   error_Invalid_Function           ;AN000;EO..  invalid function
+ext_inval_parm:                                  ;AN000;EO..
+        POP     CX                               ;AN000;EO..  pop up satck
+        POP     SI                               ;AN000;EO..
+        error   error_Invalid_data               ;AN000;EO..  invalid parms
+error_return:                                    ;AN000;EO.
+        ret                                      ;AN000;EO..  return with error
+;no_cdpg_chk:                                           EO.
+;       MOV     [CPSWFLAG],0                     ;AN000;EO..  set CPSW flag off
+goopen2:                                         ;AN000;
+        TEST    BX,int_24_error                  ;AN000;EO..  disable INT 24 error ?
+        JZ      goopen                           ;AN000;EO..  no
+        OR      [EXTOPEN_ON],EXT_OPEN_I24_OFF    ;AN000;EO..  set bit to disable
+
+goopen:                                          ;AN000;
+        OR      [EXTOPEN_ON],EXT_OPEN_ON         ;AN000;EO..  set Extended Open active
+        AND     [EXTOPEN_FLAG],0FFH              ;AN000;EO.create new ?
+        CMP     [EXTOPEN_FLAG],ext_exists_fail + ext_nexists_create ;AN000;FT.
+        JNZ     chknext                          ;AN000;;EO.  no
+        invoke  $CreateNewFile                   ;AN000;;EO.  yes
+        JC      error_return                     ;AN000;;EO.  error
+        CMP     [EXTOPEN_ON],0                   ;AN000;;EO.  IFS does it
+        JZ      ok_return2                       ;AN000;;EO.  yes
+        MOV     [EXTOPEN_FLAG],action_created_opened ;AN000;EO. creted/opened
+        MOV     [XA_from],By_Create              ;AN000;;EO.  for set xa
+        JMP     setXAttr                         ;AN000;;EO.  set XAs
+ok_return2:
+        transfer SYS_RET_OK                      ;AN000;;EO.
+chknext:
+        TEST    [EXTOPEN_FLAG],ext_exists_open   ;AN000;;EO.  exists open
+        JNZ     exist_open                       ;AN000;;EO.  yes
+        invoke  $Creat                           ;AN000;;EO.  must be replace open
+        JC      error_return                     ;AN000;;EO.  return with error
+        CMP     [EXTOPEN_ON],0                   ;AN000;;EO.  IFS does it
+        JZ      ok_return2                       ;AN000;;EO.  yes
+        MOV     [EXTOPEN_FLAG],action_created_opened  ;AN000;EO. prsume create/open
+        MOV     [XA_from],By_Create              ;AN000;EO.  for set xa
+        TEST    [EXTOPEN_ON],ext_file_not_exists      ;AN000;;EO. file not exists ?
+        JNZ     setXAttr                              ;AN000;;EO. no
+        MOV     [EXTOPEN_FLAG],action_replaced_opened ;AN000;;EO. replaced/opened
+        MOV     [XA_from],0                           ;AN000;EO. for set xa
+        JMP     SHORT setXAttr                        ;AN000;;EO. set XAs
+error_return2:
+        ret                                      ;AN000;;EO.  return with error
+                                                 ;AN000;
+exist_open:                                      ;AN000;
+        test    fSharing,-1                      ;AN000;;EO. server doscall?
+        jz      noserver                         ;AN000;;EO. no
+        MOV     CL,CH                            ;AN000;;EO. cl=search attribute
+
+noserver:
+        invoke  $Open2                           ;AN000;;EO.  do open
+        JNC     ext_ok                           ;AN000;;EO.
+        CMP     [EXTOPEN_ON],0                   ;AN000;;EO.  error and IFS call
+        JZ      error_return2                    ;AN000;;EO.  return with error
+local_extopen:
+
+        CMP     AX,error_file_not_found          ;AN000;;EO.  file not found error
+        JNZ     error_return2                    ;AN000;;EO.  no,
+        TEST    [EXTOPEN_FLAG],ext_nexists_create;AN000;;EO.  want to fail
+        JNZ     do_creat                         ;AN000;;EO.  yes
+        JMP     extexit                          ;AN000;;EO.  yes
+do_creat:
+        MOV     [XA_from],By_Create              ;AN000;;EO.  for set xa
+        MOV     CX,[SAVE_CX]                     ;AN000;;EO.  get ds:dx for file name
+        LDS     SI,DWORD PTR [SAVE_SI]           ;AN000;;EO.  cx = attribute
+        MOV     DX,SI                            ;AN000;;EO.
+        invoke  $Creat                           ;AN000;;EO.  do create
+        JC      extexit                          ;AN000;;EO.  error
+        MOV     [EXTOPEN_FLAG],action_created_opened  ;AN000;;EO. is created/opened
+        JMP     SHORT setXAttr                        ;AN000;;EO.   set XAs
+
+ext_ok:
+        CMP     [EXTOPEN_ON],0                   ;AN000;;EO.  IFS call ?
+        JZ      ok_return                        ;AN000;;EO.  yes
+        MOV     [EXTOPEN_FLAG],action_opened     ;AN000;;EO.  opened
+setXAttr:
+;       LES     DI,DWORD PTR [SAVE_DI]  ;AN000;EO.
+        PUSH    AX                      ;AN000;;EO. save handle for final
+;       MOV     BX,AX                   ;AN000;;EO. bx= handle
+;       MOV     AX,04H                  ;AN000;;EO. set extended attr by handle
+;       PUSH    DS                      ;AN000;;EO. save file name addr
+;       PUSH    DX                      ;AN000;;EO.
+;       CMP     DI,-1                   ;AN000;;EO. null parm list
+;       JZ      nosetea                 ;AN000;;EO. yes
+;       CMP     WORD PTR ES:[DI],-1     ;AN000;;EO. null set list
+;       JZ      nosetea                 ;AN000;;EO. yes
+;       LES     DI,DWORD PTR ES:[DI]    ;AN000;;EO. es:di -> set list
+;       invoke  $File_times             ;AN000;;EO.
+;nosetea:                               ;AN000; EO
+;       POP     DX                      ;AN000;;EO. restore file name addr
+;       POP     DS                      ;AN000;;EO.
+;       JC      extexit2                ;AN000;;EO.
+        invoke  get_user_stack          ;AN000;;EO.
+        MOV     AX,[EXTOPEN_FLAG]       ;AN000;;EO.
+        MOV     [SI.USER_CX],AX         ;AN000;;EO. set action code for cx
+        POP     AX                      ;AN000;;EO.
+        MOV     [SI.USER_AX],AX         ;AN000;;EO. set handle for ax
+
+ok_return:                              ;AN000;
+        transfer SYS_RET_OK             ;AN000;;EO.
+
+extexit2:                               ;AN000; ERROR RECOVERY
+
+        POP     BX                      ;AN000;EO. close the handle
+        PUSH    AX                      ;AN000;EO. save error code from set XA
+        CMP     [EXTOPEN_FLAG],action_created_opened    ;AN000;EO. from create
+        JNZ     justopen                ;AN000;EO.
+        LDS     SI,DWORD PTR [SAVE_SI]           ;AN000;EO.  cx = attribute
+        LDS     DX,DWORD PTR [SI]                ;AN000;EO.
+        invoke  $UNLINK                 ;AN000;EO. delete the file
+        JMP     SHORT reserror          ;AN000;EO.
+
+justopen:                               ;AN000;
+        invoke  $close                  ;AN000;EO. pretend never happend
+reserror:                               ;AN000;
+        POP     AX                      ;AN000;EO. retore error code from set XA
+        JMP     SHORT extexit           ;AN000;EO.
+
+
+ext_file_unfound:                       ;AN000;
+        MOV     AX,error_file_not_found ;AN000;EO.
+        JMP     SHORT extexit           ;AN000;EO.
+ext_inval:                               ;AN000;
+        MOV     AX,error_invalid_function;AN000;EO.
+extexit:
+        transfer SYS_RET_ERR            ;AN000;EO.
+
+EndProc $Extended_Open                  ;AN000;
+
+
+Break   <GetIOParms - get IO parms form extended open parm list>
+
+;
+;
+;   Inputs: DS:SI -> IO parm list
+;           CX= number of parms
+;   Function: get IO parms from parm list
+;   Outputs:  [EXT_IOMODE]= IO mode parm
+
+;procedure   GetIOParms,NEAR
+;       assume  ds:nothing,es:nothing
+;
+;       LODSB                                   ; get parm type                 ;AN000;
+;       CMP     AL,0*100B+10B                   ; have IOMODE                   ;AN000;
+;       JE      SET_IOMODE                                                      ;AN000;
+;       AND     AL,00000011B                    ; decode it                     ;AN000;
+;       JZ      SKIP_ASCIIZ                                                     ;AN000;
+;       DEC     AL                                                              ;AN000;
+;       JZ      SKIP_LEN                                                        ;AN000;
+;;      DEC     AL                                                              ;AN000;
+;       JZ      SKIP_WORD                                                       ;AN000;
+;SKIP_DWORD:                                     ; copy DWORD parm               ;AN000;
+;       LODSW                                                                   ;AN000;
+;SKIP_WORD:                                      ; copy WORD parm                ;AN000;
+;       LODSW                                                                   ;AN000;
+;       JMP     SHORT NEXT_PARM                                                 ;AN000;
+;SET_IOMODE:                                     ; copy IOMODE                   ;AN000;
+;       LODSW                                                                   ;AN000;
+;       MOV     [EXTOPEN_IO_MODE],AX                                            ;AN000;
+;       JMP     SHORT NEXT_PARM                                                 ;AN000;
+;SKIP_LEN:                                       ; copy LENGTH parm              ;AN000;
+;       LODSW                                                                   ;AN000;
+;       ADD     SI,AX                                                           ;AN000;
+;       JMP     SHORT NEXT_PARM                                                 ;AN000;
+;SKIP_ASCIIZ:                                    ; copy ASCIIZ parm              ;AN000;
+;       LODSB                                                                   ;AN000;
+;       OR      AL,AL                                                           ;AN000;
+;       JNE     SKIP_ASCIIZ                                                     ;AN000;
+;NEXT_PARM:                                                                      ;AN000;
+;       LOOP    GetIOParms                                                      ;AN000;
+;       return                                                                  ;AN000;
+;EndProc GetIOParms                                                              ;AN000;
+
+
+CODE ENDS
+END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/FINFO.ASM b/v4.0/src/DOS/FINFO.ASM
new file mode 100644
index 0000000..0df2bc1
--- /dev/null
+++ b/v4.0/src/DOS/FINFO.ASM
@@ -0,0 +1,286 @@
+;       SCCSID = @(#)finfo.asm  1.1 85/04/11
+TITLE   FILE_INFO - Internal Get/Set File Info routines
+NAME    FILE_INFO
+; Low level routines for returning file information and setting file
+;   attributes
+;
+;   GET_FILE_INFO
+;   SET_FILE_ATTRIBUTE
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include fastxxxx.inc
+include fastopen.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  THISCDS,DWORD
+        i_need  CURBUF,DWORD
+        i_need  NoSetDir,BYTE
+        i_need  THISDRV,BYTE
+        I_need  EXTERR_CLASS,BYTE
+        I_need  EXTERR_ACTION set
+        I_need  EXTERR_LOCUS,BYTE
+        i_need  DMAADD,DWORD
+        i_need  FastOpenFlg,BYTE
+
+SUBTTL GET_FILE_INFO -- Get File Information
+PAGE
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [SATTRIB] Is attribute of search, determines what files can be found
+; Function:
+;       Get Information about a file
+; Returns:
+;       CARRY CLEAR
+;           AX = Attribute of file
+;           CX = Time stamp of file
+;           DX = Date stamp of file
+;           BX:DI = Size of file (32 bit)
+;       CARRY SET
+;           AX is error code
+;               error_file_not_found
+;                       Last element of path not found
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+; DS preserved, others destroyed
+
+        procedure   GET_FILE_INFO,NEAR
+        DOSAssume   CS,<DS>,"Get_File_Info"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     Local_Info
+;       invoke  OWN_SHARE2                     ;IFS. IFS owns share ?           ;AN000;
+;       JZ      ifsshare                       ;IFS. yes                        ;AN000;
+;       PUSH    WORD PTR [DMAADD+2]            ;IFS. save DMAADD                ;AN000;
+;       PUSH    WORD PTR [DMAADD]              ;IFS.                            ;AN000;
+;       invoke  IFS_SEARCH_FIRST               ;IFS. do search first            ;AN000;
+;       JC      nofiles                        ;IFS. file not existing          ;AN000;
+delete_next_file:                              ;IFS.                            ;AN000;
+;       invoke  IFS_REN_DEL_CHECK              ;IFS. do REN_DEL_CHECK           ;AN000;
+;       JNC     share_okok                     ;IFS. share ok                   ;AN000;
+;       MOV     AX,error_sharing_violation     ;IFS. share violation            ;AN000;
+;       JMP     SHORT nofiles                  ;IFS.                            ;AN000;
+share_okok:
+;       POP     WORD PTR [DMAADD]              ;IFS. retor DMAADD               ;AN000;
+;       POP     WORD PTR [DMAADD+2]            ;IFS.                            ;AN000;
+ifsshare:
+IF NOT Installed
+        transfer NET_GET_FILE_INFO
+ELSE
+        MOV     AX,(multNET SHL 8) OR 15
+        INT     2FH
+        return
+ENDIF
+nofiles:
+;       POP     WORD PTR [DMAADD]              ;IFS. retor DMAADD               ;AN000;
+;       POP     WORD PTR [DMAADD+2]            ;IFS.                            ;AN000;
+;       ret                                    ;IFS. return
+
+LOCAL_INFO:
+        EnterCrit   critDisk
+        MOV     [NoSetDir],1            ; if we find a dir, don't change to it
+        invoke  Get_FAST_PATH
+info_check:
+        JNC     info_check_dev
+
+NO_PATH:
+        DOSAssume   CS,<DS>,"FINFO/No_Path"
+        ASSUME  ES:NOTHING
+
+        JNZ     bad_path
+        OR      CL,CL
+        JZ      bad_path
+info_no_file:
+        MOV     AX,error_file_not_found
+BadRet:
+        STC
+justRet:
+        LeaveCrit   critDisk
+        return
+
+bad_path:
+        MOV     AX,error_path_not_found
+        jmp     BadRet
+
+info_check_dev:
+        OR      AH,AH
+        JS      info_no_file            ; device
+        PUSH    DS
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+        MOV     SI,BX
+        XOR     BX,BX                   ; Assume size=0 (dir)
+        MOV     DI,BX
+        MOV     CX,[SI.dir_time]
+        MOV     DX,[SI.dir_date]
+        XOR     AH,AH
+        MOV     AL,[SI.dir_attr]
+        TEST    AL,attr_directory
+        JNZ     NO_SIZE
+        MOV     DI,[SI.dir_size_l]
+        MOV     BX,[SI.dir_size_h]
+NO_SIZE:
+        POP     DS
+        CLC
+        jmp     JustRet
+EndProc GET_FILE_INFO
+
+Break   <SET_FILE_ATTRIBUTE -- Set File Attribute>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [SATTRIB] is attribute of search (determines what files may be found)
+;       AX is new attributes to give to file
+; Function:
+;       Set File Attributes
+; Returns:
+;       CARRY CLEAR
+;           No error
+;       CARRY SET
+;           AX is error code
+;               error_file_not_found
+;                       Last element of path not found
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_access_denied
+;                       Attempt to set an attribute which cannot be set
+;                       (attr_directory, attr_volume_ID)
+;               error_sharing_violation
+;                       Sharing mode of file did not allow the change
+;                       (this request requires exclusive write/read access)
+;                       (INT 24H generated)
+; DS preserved, others destroyed
+
+        procedure   SET_FILE_ATTRIBUTE,NEAR
+        DOSAssume   CS,<DS>,"Set_File_Attribute"
+        ASSUME  ES:NOTHING
+
+        TEST    AX,NOT attr_changeable
+        JZ      set_look
+BAD_ACC:
+        MOV     ExtErr_Locus,errLoc_UNK
+        MOV     ExtErr_Class,errClass_Apperr
+        MOV     ExtErr_Action,errAct_Abort
+        MOV     AX,error_access_denied
+        STC
+        return
+
+set_look:
+        Invoke  TestNet
+        JNC     Local_Set
+
+IF NOT Installed
+        transfer NET_SEQ_SET_FILE_ATTRIBUTE
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 14
+        INT     2FH
+        POP     BX                      ; clean stack
+        return
+ENDIF
+
+LOCAL_SET:
+        EnterCrit   critDisk
+        PUSH    AX                      ; Save new attributes
+        MOV     [NoSetDir],1            ; if we find a dir, don't change to it
+        invoke  GetPath                 ; get path through fastopen if there     ;AC000;
+        JNC     set_check_device
+        POP     BX                      ; Clean stack (don't zap AX)
+        JMP     NO_PATH
+
+set_check_device:
+        OR      AH,AH
+        JNS     set_check_share
+        POP     AX
+        LeaveCrit   critDisk
+        JMP     BAD_ACC                 ; device
+
+set_check_share:
+        POP     AX                      ; Get new attributes
+        invoke  REN_DEL_Check
+        JNC     set_do
+        MOV     AX,error_sharing_violation
+        jmp     short   ok_bye
+
+set_do:
+        LES     DI,[CURBUF]
+        AND     BYTE PTR ES:[BX].dir_attr,NOT attr_changeable
+        OR      BYTE PTR ES:[BX].dir_attr,AL
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI.buf_flags],buf_dirty
+yesdirty:
+        MOV     AL,[THISDRV]
+;;;; 10/1/86 F.C update fastopen cache
+        PUSH    DX
+        PUSH    DI
+        MOV     AH,0              ; dir entry update
+        MOV     DL,AL             ; drive number A=0,B=1,,
+        MOV     DI,BX             ; ES:DI -> dir entry
+        invoke  FastOpen_Update
+        POP     DI
+        POP     DX
+;;;; 9/11/86 F.C update fastopen cache
+        invoke  FlushBuf
+        JNC     OK_BYE
+        MOV     AX,error_file_not_found
+OK_BYE:
+        LeaveCrit   critDisk
+        return
+
+EndProc SET_FILE_ATTRIBUTE
+
+
+
+        procedure   GET_FAST_PATH,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        OR      [FastOpenFlg],FastOpen_Set ;FO. trigger fastopen                ;AN000;
+        invoke  GetPath
+        PUSHF                          ;FO.                                     ;AN000;
+        AND    [FastOpenFlg],Fast_yes  ;FO. clear all fastopen flags            ;AN000;
+        POPF                           ;FO.                                     ;AN000;
+        return
+
+EndProc GET_FAST_PATH
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/GETSET.ASM b/v4.0/src/DOS/GETSET.ASM
new file mode 100644
index 0000000..70c8cd3
--- /dev/null
+++ b/v4.0/src/DOS/GETSET.ASM
@@ -0,0 +1,912 @@
+;       SCCSID = @(#)getset.asm 1.2 85/07/23
+TITLE  GETSET - GETting and SETting MS-DOS system calls
+NAME   GETSET
+;
+; System Calls which get and set various things
+;
+;   $GET_VERSION
+;   $GET_VERIFY_ON_WRITE
+;   $SET_VERIFY_ON_WRITE
+;   $INTERNATIONAL
+;   $GET_DRIVE_FREESPACE
+;   $GET_DMA
+;   $SET_DMA
+;   $GET_DEFAULT_DRIVE
+;   $SET_DEFAULT_DRIVE
+;   $GET_INTERRUPT_VECTOR
+;   $SET_INTERRUPT_VECTOR
+;   RECSET
+;   $CHAR_OPER
+;   $GetExtendedError                  DOS 3.3
+;   Get_Global_CdPg                    DOS 4.0
+;   $ECS_CALL                          DOS 4.0
+;
+;   Revision history:
+;
+;       Created: ARR 30 March 1983
+;
+;       A000   version 4.0   Jan. 1988
+;       A006   D503-- fake version for IBMCACHE
+;       A008   P4070- faske version for MS WINDOWS
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+IFNDEF  ALTVECT
+ALTVECT EQU     0                       ; FALSE
+ENDIF
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include devsym.inc
+include doscntry.inc
+.cref
+.list
+
+        i_need  USERNUM,WORD
+        i_need  MSVERS,WORD
+        i_need  VERFLG,BYTE
+        i_need  CNTCFLAG,BYTE
+        i_need  DMAADD,DWORD
+        i_need  CURDRV,BYTE
+        i_need  chSwitch,BYTE
+        i_need  COUNTRY_CDPG,byte             ;DOS 3.3
+        I_need  CDSCount,BYTE
+        I_need  ThisCDS,DWORD
+        i_need  EXTERR,WORD
+        i_need  EXTERR_ACTION,BYTE
+        i_need  EXTERR_CLASS,BYTE
+        i_need  EXTERR_LOCUS,BYTE
+        i_need  EXTERRPT,DWORD
+        i_need  UCASE_TAB,BYTE
+        i_need  FILE_UCASE_TAB,BYTE
+        i_need  InterCon,BYTE
+        i_need  CURRENTPDB,WORD
+        i_need  DBCS_TAB,BYTE                      ;AN000;
+        i_need  Special_version,WORD               ;AN006;
+        i_need  Fake_Count,BYTE                    ;AN008;
+        i_need  NLS_YES,BYTE                       ;AN000;
+        i_need  NLS_yes2,BYTE                      ;AN000;
+        i_need  NLS_NO,BYTE                        ;AN000;
+        i_need  NLS_no2,BYTE                       ;AN000;
+
+
+BREAK <$Get_Version -- Return DOS version number>
+        procedure   $GET_VERSION,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Return DOS version number
+; Outputs:
+;       OEM number in BH
+;       User number in BL:CX (24 bits)
+;       Version number as AL.AH in binary
+;       NOTE: On pre 1.28 DOSs AL will be zero
+
+        context DS
+        MOV     BX,[USERNUM + 2]
+        MOV     CX,[USERNUM]
+        MOV     AX,[MSVERS]
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_CX],CX
+        CMP     CS:[Fake_Count],0FFH               ;AN008;
+        JZ      reg                                ;AN008;
+        CMP     CS:[Fake_Count],0                  ;AN008;
+        JZ      usual                              ;AN008;
+        DEC     CS:[Fake_Count]                    ;AN008;
+reg:                                               ;AN008;
+        CMP     CS:[Special_version],0             ;AN006;
+        JZ      usual                              ;AN006;
+        MOV     AX,CS:[Special_version]            ;AN006;
+usual:                                             ;AN006;
+        MOV     [SI.user_AX],AX         ; Really only sets AH
+        return
+EndProc $GET_VERSION
+
+BREAK <$Get_Verify_on_Write - return verify-after-write flag>
+        procedure   $GET_VERIFY_ON_WRITE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       none.
+; Function:
+;       returns flag
+; Returns:
+;       AL = value of VERIFY flag
+
+        MOV     AL,[VERFLG]
+        return
+EndProc $GET_VERIFY_ON_WRITE
+
+BREAK <$Set_Verify_on_Write - Toggle verify-after-write flag>
+        procedure   $SET_VERIFY_ON_WRITE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       AL = desired value of VERIFY flag
+; Function:
+;       Sets flag
+; Returns:
+;       None
+
+        AND     AL,1
+        MOV     [VERFLG],AL
+        return
+EndProc $SET_VERIFY_ON_WRITE
+
+BREAK <$International - return country-dependent information>
+;
+; Inputs:
+;       MOV     AH,International
+;       MOV     AL,country      (al = 0 => current country)
+;      [MOV     BX,country]
+;       LDS     DX,block
+;       INT     21
+; Function:
+;       give users an idea of what country the application is running
+; Outputs:
+;       IF DX != -1 on input (get country)
+;         AL = 0 means return current country table.
+;         0<AL<0FFH means return country table for country AL
+;         AL = 0FF means return country table for country BX
+;         No Carry:
+;            Register BX will contain the 16-bit country code.
+;            Register AL will contain the low 8 bits of the country code.
+;            The block pointed to by DS:DX is filled in with the information
+;            for the particular country.
+;               BYTE  Size of this table excluding this byte and the next
+;               BYTE  Country code represented by this table
+;                       A sequence of n bytes, where n is the number specified
+;                       by the first byte above and is not > internat_block_max,
+;                       in the correct order for being returned by the
+;                       INTERNATIONAL call as follows:
+;               WORD    Date format 0=mdy, 1=dmy, 2=ymd
+;               5 BYTE  Currency symbol null terminated
+;               2 BYTE  thousands separator null terminated
+;               2 BYTE  Decimal point null terminated
+;               2 BYTE  Date separator null terminated
+;               2 BYTE  Time separator null terminated
+;               1 BYTE  Bit field.  Currency format.
+;                       Bit 0.  =0 $ before #  =1 $ after #
+;                       Bit 1.  no. of spaces between # and $ (0 or 1)
+;               1 BYTE  No. of significant decimal digits in currency
+;               1 BYTE  Bit field.  Time format.
+;                       Bit 0.  =0 12 hour clock  =1 24 hour
+;               DWORD   Call address of case conversion routine
+;               2 BYTE  Data list separator null terminated.
+;         Carry:
+;            Register AX has the error code.
+;       IF DX = -1 on input (set current country)
+;         AL = 0 is an error
+;         0<AL<0FFH means set current country to country AL
+;         AL = 0FF means set current country to country BX
+;         No Carry:
+;           Current country SET
+;           Register AL will contain the low 8 bits of the country code.
+;         Carry:
+;            Register AX has the error code.
+
+
+        procedure   $INTERNATIONAL,NEAR   ; DOS 3.3
+ASSUME  DS:NOTHING,ES:NOTHING
+        CMP     AL,0FFH
+        JZ      BX_HAS_CODE             ; -1 means country code is in BX
+        MOV     BL,AL                   ; Put AL country code in BX
+        XOR     BH,BH
+BX_HAS_CODE:
+        PUSH    DS
+        POP     ES
+        PUSH    DX
+        POP     DI                      ; User buffer to ES:DI
+        context DS
+        CMP     DI,-1
+        JZ      international_set
+        OR      BX,BX
+        JNZ     international_find
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG
+        JMP     SHORT international_copy
+
+international_find:
+        MOV     BP,0                     ; flag it for GetCntry only
+        CALL    international_get
+        JC      errtn
+        CMP     BX,0                     ; nlsfunc finished it ?
+        JNZ     SHORT international_copy ; no, copy by myself
+        MOV     BX,DX                    ; put country back
+        JMP     SHORT international_ok3
+
+international_get:
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG
+        CMP     BX,[SI.ccDosCountry]     ; = current country id
+        retz                             ; return if equal
+        MOV     DX,BX
+        XOR     BX,BX                    ; bx = 0, default code page
+        CallInstall NLSInstall,NLSFUNC,0 ; check if NLSFUNC in memory
+        CMP     AL,0FFH
+        JNZ     interr                     ; not in memory
+        CMP     BP,0                     ; GetCntry ?
+        JNZ     stcdpg
+        CallInstall GetCntry,NLSFUNC,4   ; get country info
+        JMP     chkok
+stcdpg:
+        CallInstall SetCodePage,NLSFUNC,3  ; set country info
+chkok:
+        CMP     AL,0                       ; success ?
+        retz                               ; yes
+setcarry:
+        STC                              ; set carry
+        ret
+interr:
+        MOV     AL,0FFH                    ; flag nlsfunc error
+        JMP     setcarry
+
+international_copy:
+        MOV     BX,[SI.ccDosCountry]     ; = current country id
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG.ccDFormat
+        MOV     CX,OLD_COUNTRY_SIZE
+        REP     MOVSB                    ;copy country info
+international_ok3:
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_BX],BX
+international_ok:
+        MOV     AX,BX                ; Return country code in AX too.
+        transfer SYS_RET_OK
+
+international_set:
+ASSUME  DS:DOSGROUP
+        MOV     BP,1                 ; flag it for SetCodePage only
+        CALL    international_get
+        JNC     international_ok
+errtn:
+        CMP     AL,0FFH
+        JZ      errtn2
+        transfer SYS_RET_ERR         ; return what we got from NLSFUNC
+errtn2:
+        error   error_Invalid_Function  ; NLSFUNC not existent
+
+
+EndProc $INTERNATIONAL
+
+
+
+BREAK <$GetExtCntry - return extended country-dependent information>
+;
+; Inputs:
+;       if AL >= 20H
+;         AL= 20H    capitalize single char, DL= char
+;             21H    capitalize string ,CX= string length
+;             22H    capitalize ASCIIZ string
+;             23H    YES/NO check, DL=1st char DH= 2nd char (DBCS)
+;             80H bit 0 = use normal upper case table
+;                     1 = use file upper case table
+;          DS:DX points to string
+;
+;       else
+;
+;       MOV     AH,GetExtCntry   ; DOS 3.3
+;       MOV     AL,INFO_ID      ( info type,-1  selects all)
+;       MOV     BX,CODE_PAGE    ( -1 = active code page )
+;       MOV     DX,COUNTRY_ID   ( -1 = active country )
+;       MOV     CX,SIZE         ( amount of data to return)
+;       LES     DI,COUNTRY_INFO ( buffer for returned data )
+;       INT     21
+; Function:
+;       give users extended country dependent information
+;       or capitalize chars
+; Outputs:
+;         No Carry:
+;            extended country info is succesfully returned
+;         Carry:
+;            Register AX has the error code.
+;            AX=0, NO    for YES/NO CHECK
+;               1, YES
+
+
+        procedure   $GetExtCntry,NEAR   ; DOS 3.3
+ASSUME  DS:NOTHING,ES:NOTHING
+        CMP     AL,CAP_ONE_CHAR         ;AN000;MS. < 20H ?
+        JAE     capcap                  ;AN000;MS.
+        JMP     notcap                  ;AN000;MS. yes
+capcap:                                 ;AN000;
+        TEST    AL,UPPER_TABLE          ;AN000;MS. which upper case table
+        JNZ     fileupper               ;AN000;MS. file upper case
+        MOV     BX,OFFSET DOSGROUP:UCASE_TAB+2 ;AN000;MS. get normal upper case
+        JMP     SHORT capit                        ;AN000;MS.
+fileupper:                                         ;AN000;
+        MOV     BX,OFFSET DOSGROUP:FILE_UCASE_TAB+2;AN000;MS. get file upper case
+capit:                                  ;AN000;
+        CMP     AL,CAP_ONE_CHAR         ;AN000;;MS.cap one char ?
+        JNZ     chkyes                  ;AN000;;MS. no
+        MOV     AL,DL                   ;AN000;;MS. set up AL
+        invoke  GETLET3                 ;AN000;;MS. upper case it
+        invoke  get_user_stack          ;AN000;;MS. get user stack
+        MOV     byte ptr [SI.user_DX],AL;AN000;;MS. user's DL=AL
+        JMP     SHORT nono              ;AN000;;MS. done
+chkyes:                                 ;AN000;
+        CMP     AL,CHECK_YES_NO         ;AN000;;MS. check YES or NO ?
+        JNZ     capstring               ;AN000;;MS. no
+        XOR     AX,AX                   ;AN000;;MS. presume NO
+IF  DBCS                                ;AN000;
+        PUSH    AX                      ;AN000;;MS.
+        MOV     AL,DL                   ;AN000;;MS.
+        invoke  TESTKANJ                ;AN000;;MS. DBCS ?
+        POP     AX                      ;AN000;;MS.
+        JNZ     dbcs_char               ;AN000;;MS. yes, return error
+ENDIF                                   ;AN000;
+                                        ;AN000;
+        CMP     DL,NLS_YES              ;AN000;;MS. is 'Y' ?
+        JZ      yesyes                  ;AN000;;MS. yes
+        CMP     DL,NLS_yes2             ;AN000;;MS. is 'y' ?
+        JZ      yesyes                  ;AN000;;MS. yes
+        CMP     DL,NLS_NO               ;AN000;;MS. is  'N'?
+        JZ      nono                    ;AN000;;MS. no
+        CMP     DL,NLS_no2              ;AN000;;MS. is 'n' ?
+        JZ      nono                    ;AN000;;MS. no
+dbcs_char:                              ;AN000;
+        INC     AX                      ;AN000;;MS. not YES or NO
+yesyes:                                 ;AN000'
+        INC     AX                      ;AN000;;MS. return 1
+nono:                                   ;AN000;
+        transfer SYS_RET_OK             ;AN000;;MS. done
+capstring:                              ;AN000;
+        MOV     SI,DX                   ;AN000;;MS. si=dx
+        CMP     AL,CAP_STRING           ;AN000;;MS. cap string ?
+        JNZ     capascii                ;AN000;;MS. no
+        CMP     CX,0                    ;AN000;;MS. check count 0
+        JZ      nono                    ;AN000;;MS. yes finished
+concap:                                 ;AN000;
+        LODSB                           ;AN000;;MS. get char
+ IF  DBCS                               ;AN000;;MS.
+        invoke  TESTKANJ                ;AN000;;MS. DBCS ?
+        JZ      notdbcs                 ;AN000;;MS. no
+        INC     SI                      ;AN000;;MS. skip 2 chars
+        DEC     CX                      ;AN000;;MS. bad input, one DBCS char at end
+        JZ      nono                    ;AN000;;MS. yes
+        JMP     SHORT next99            ;AN000;;MS.
+notdbcs:                                ;AN000;
+ ENDIF                                  ;AN000;
+
+        invoke  GETLET3                 ;AN000;;MS. upper case it
+        MOV     byte ptr [SI-1],AL      ;AN000;;MS. store back
+next99:                                 ;AN000;
+        LOOP    concap                  ;AN000;;MS. continue
+        JMP     nono                    ;AN000;;MS. done
+capascii:                               ;AN000;
+        CMP     AL,CAP_ASCIIZ           ;AN000;;MS. cap ASCIIZ string ?
+        JNZ     capinval                ;AN000;;MS. no
+concap2:                                ;AN000;
+        LODSB                           ;AN000;;MS. get char
+        CMP     AL,0                    ;AN000;;MS. end of string ?
+        JZ      nono                    ;AN000;;MS. yes
+ IF  DBCS                               ;AN000;;MS.
+        invoke  TESTKANJ                ;AN000;;MS. DBCS ?
+        JZ      notdbcs2                ;AN000;;MS. no
+        CMP     BYTE PTR [SI],0         ;AN000;;MS. bad input, one DBCS char at end
+        JZ      nono                    ;AN000;;MS. yes
+        INC     SI                      ;AN000;;MS. skip 2 chars
+        JMP     concap2                 ;AN000;;MS.
+notdbcs2:                               ;AN000;
+ ENDIF                                  ;AN000;
+        invoke  GETLET3                 ;AN000;;MS. upper case it
+        MOV     byte ptr [SI-1],AL      ;AN000;;MS. store back
+        JMP     concap2                 ;AN000;;MS. continue
+
+
+notcap:
+        CMP     CX,5                    ; minimum size is 5
+        JB      sizeerror
+        context DS
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG
+        CMP     DX,-1                   ; active country ?
+        JNZ     GETCDPG                 ; no
+        MOV     DX,[SI.ccDosCountry]    ; get active country id
+GETCDPG:
+        CMP     BX,-1                   ; active code page?
+        JNZ     CHKAGAIN                ; no, check again
+        MOV     BX,[SI.ccDosCodePage]   ; get active code page id
+CHKAGAIN:
+        CMP     DX,[SI.ccDosCountry]    ; same as active country id?
+        JNZ     CHKNLS                  ; no
+        CMP     BX,[SI.ccDosCodePage]   ; same as active code page id?
+        JNZ     CHKNLS                  ; no
+CHKTYPE:
+        MOV     BX,[SI.ccSysCodePage]   ; bx = sys code page id
+;       CMP     AL,SetALL               ; select all?
+;       JNZ     SELONE
+;       MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG.ccNumber_of_entries
+SELONE:
+        PUSH    CX                      ; save cx
+        MOV     CX,[SI.ccNumber_of_entries]
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG.ccSetUcase
+NXTENTRY:
+        CMP     AL,[SI]                 ; compare info type
+        JZ      FOUNDIT
+        ADD     SI,5                    ; next entry
+        LOOP    NXTENTRY
+        POP     CX
+capinval:
+        error   error_Invalid_Function  ; info type not found
+FOUNDIT:
+        MOVSB                           ; move info id byte
+        POP     CX                      ; retsore char count
+        CMP     AL,SetCountryInfo       ; select country info type ?
+        JZ      setsize
+        MOV     CX,4                    ; 4 bytes will be moved
+        MOV     AX,5                    ; 5 bytes will be returned in CX
+OK_RETN:
+        REP     MOVSB                   ; copy info
+        MOV     CX,AX                   ; CX = actual length returned
+        MOV     AX,BX                   ; return sys code page in ax
+GETDONE:
+        invoke  get_user_stack          ; return actual length to user's CX
+        MOV     [SI.user_CX],CX
+        transfer SYS_RET_OK
+setsize:
+        SUB     CX,3                    ; size after length field
+        CMP     WORD PTR [SI],CX        ; less than table size
+        JAE     setsize2                ; no
+        MOV     CX,WORD PTR [SI]        ; truncate to table size
+setsize2:
+        MOV     ES:[DI],CX              ; copy actual length to user's
+        ADD     DI,2                    ; update index
+        ADD     SI,2
+        MOV     AX,CX
+        ADD     AX,3                    ; AX has the actual length
+        JMP     OK_RETN                 ; go move it
+CHKNLS:
+        XOR     AH,AH
+        PUSH    AX                         ; save info type
+        POP     BP                         ; bp = info type
+        CallInstall NLSInstall,NLSFUNC,0 ; check if NLSFUNC in memory
+        CMP     AL,0FFH
+        JZ      NLSNXT                     ;     in memory
+sizeerror:
+        error   error_Invalid_Function
+NLSNXT: CallInstall GetExtInfo,NLSFUNC,2  ;get extended info
+        CMP     AL,0                       ; success ?
+        JNZ     NLSERROR
+        MOV     AX,[SI.ccSysCodePage]   ; ax = sys code page id
+        JMP     GETDONE
+NLSERROR:
+        transfer SYS_RET_ERR            ; return what is got from NLSFUNC
+
+EndProc $GetExtCntry
+
+BREAK <$GetSetCdPg - get or set global code page>
+;
+; Inputs:
+;       MOV     AH,GetSetCdPg   ; DOS 3.3
+;       MOV     AL,n            ; n = 1 : get code page, n = 2 : set code page
+;       MOV     BX,CODE_PAGE    ( set code page only)
+;       INT     21
+; Function:
+;       get or set the global code page
+; Outputs:
+;         No Carry:
+;            global code page is set    (set global code page)
+;            BX = active code page id   (get global code page)
+;            DX = system code page id   (get global code page)
+;         Carry:
+;            Register AX has the error code.
+
+
+        procedure   $GetSetCdPg,NEAR   ; DOS 3.3
+ASSUME  DS:NOTHING,ES:NOTHING
+        context DS
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG
+        CMP     AL,1                   ; get global code page
+        JNZ     setglpg                ; set global cod epage
+        MOV     BX,[SI.ccDosCodePage]  ; get active code page id
+        MOV     DX,[SI.ccSysCodePage]  ; get sys code page id
+        invoke  get_user_stack
+ASSUME DS:NOTHING
+        MOV     [SI.user_BX],BX        ; update returned bx
+        MOV     [SI.user_DX],DX        ; update returned dx
+OK_RETURN:
+        transfer SYS_RET_OK
+ASSUME DS:DOSGROUP
+setglpg:
+        CMP     AL,2
+        JNZ     nomem
+;;;;;;; CMP     BX,[SI.ccDosCodePage]  ; same as active code page
+;;;;;;; JZ      OK_RETURN              ; yes
+        MOV     DX,[SI.ccDosCountry]
+        CallInstall NLSInstall,NLSFUNC,0 ; check if NLSFUNC in memory
+        CMP     AL,0FFH
+        JNZ     nomem                      ; not in memory
+        CallInstall SetCodePage,NLSFUNC,1  ;set the code page
+        CMP     AL,0                       ; success ?
+        JZ      OK_RETURN                  ; yes
+        CMP     AL,65                      ; set device code page failed
+        JNZ     seterr
+        MOV     AX,65
+        MOV     [EXTERR],AX
+        MOV     [EXTERR_ACTION],errACT_Ignore
+        MOV     [EXTERR_CLASS],errCLASS_HrdFail
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        transfer   From_GetSet
+
+seterr:
+        transfer  SYS_RET_ERR
+nomem:
+        error   error_Invalid_Function ; function not defined
+;
+EndProc $GetSetCdPg
+
+
+
+
+BREAK <$Get_Drive_Freespace -- Return bytes of free disk space on a drive>
+        procedure   $GET_DRIVE_FREESPACE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       DL = Drive number
+; Function:
+;       Return number of free allocation units on drive
+; Outputs:
+;       BX = Number of free allocation units
+;       DX = Total Number of allocation units on disk
+;       CX = Sector size
+;       AX = Sectors per allocation unit
+;          = -1 if bad drive specified
+; This call returns the same info in the same registers (except for FAT pointer)
+;      as the old FAT pointer calls
+
+        context DS
+        MOV     AL,DL
+        invoke  GetThisDrv              ; Get drive
+SET_AX_RET:
+        JC      BADFDRV
+        invoke  DISK_INFO
+        XCHG    DX,BX
+        JC      SET_AX_RET              ; User FAILed to I 24
+        XOR     AH,AH                   ; Chuck Fat ID byte
+DoSt:
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_DX],DX
+        MOV     [SI.user_CX],CX
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_AX],AX
+        return
+BADFDRV:
+;       MOV     AL,error_invalid_drive  ; Assume error
+        invoke  FCB_RET_ERR
+        MOV     AX,-1
+        JMP     DoSt
+EndProc $GET_DRIVE_FREESPACE
+
+BREAK <$Get_DMA, $Set_DMA -- Get/Set current DMA address>
+        procedure   $GET_DMA,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Get DISK TRANSFER ADDRESS
+; Returns:
+;       ES:BX is current transfer address
+
+        MOV     BX,WORD PTR [DMAADD]
+        MOV     CX,WORD PTR [DMAADD+2]
+        invoke  get_user_stack
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_ES],CX
+        return
+EndProc $GET_DMA
+
+        procedure   $SET_DMA,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       DS:DX is desired new disk transfer address
+; Function:
+;       Set DISK TRANSFER ADDRESS
+; Returns:
+;       None
+
+        MOV     WORD PTR [DMAADD],DX
+        MOV     WORD PTR [DMAADD+2],DS
+        return
+EndProc $SET_DMA
+
+BREAK <$Get_Default_Drive, $Set_Default_Drive -- Set/Get default drive>
+        procedure   $GET_DEFAULT_DRIVE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Return current drive number
+; Returns:
+;       AL = drive number
+
+        MOV     AL,[CURDRV]
+        return
+EndProc $GET_DEFAULT_DRIVE
+
+        procedure   $SET_DEFAULT_DRIVE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       DL = Drive number for new default drive
+; Function:
+;       Set the default drive
+; Returns:
+;       AL = Number of drives, NO ERROR RETURN IF DRIVE NUMBER BAD
+
+        MOV     AL,DL
+        INC     AL                      ; A=1, b=2...
+        invoke  GetVisDrv               ; see if visible drive
+        JC      SETRET                  ; errors do not set
+;       LDS     SI,ThisCDS              ; get CDS
+;       TEST    [SI].curdir_flags,curdir_splice ; was it spliced?
+;       JNZ     SetRet                  ; yes, do not set
+        MOV     [CURDRV],AL             ; no, set
+SETRET:
+        MOV     AL,[CDSCOUNT]           ; let user see what the count really is
+RET17:  return
+EndProc $SET_DEFAULT_DRIVE
+
+BREAK <$Get_Interrupt_Vector - Get/Set interrupt vectors>
+        procedure   $GET_INTERRUPT_VECTOR,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       AL = interrupt number
+; Function:
+;       Get the interrupt vector
+; Returns:
+;       ES:BX is current interrupt vector
+
+        CALL    RECSET
+        LES     BX,DWORD PTR ES:[BX]
+        invoke  get_user_stack
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_ES],ES
+        return
+EndProc $GET_INTERRUPT_VECTOR
+
+        procedure   $SET_INTERRUPT_VECTOR,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       AL = interrupt number
+;       DS:DX is desired new interrupt vector
+; Function:
+;       Set the interrupt vector
+; Returns:
+;       None
+
+        CALL    RECSET
+        CLI                             ; Watch out!!!!! Folks sometimes use
+        MOV     ES:[BX],DX              ;   this for hardware ints (like timer).
+        MOV     ES:[BX+2],DS
+        STI
+        return
+EndProc $SET_INTERRUPT_VECTOR
+
+        IF      ALTVECT
+TABLE   SEGMENT
+VECIN:
+; INPUT VECTORS
+Public GSET001S,GSET001E
+GSET001S  label byte
+        DB      22H                     ; Terminate
+        DB      23H                     ; ^C
+        DB      24H                     ; Hard error
+        DB      28H                     ; Spooler
+LSTVEC  DB      ?                       ; ALL OTHER
+
+VECOUT:
+; GET MAPPED VECTOR
+        DB      int_terminate
+        DB      int_ctrl_c
+        DB      int_fatal_abort
+        DB      int_spooler
+LSTVEC2 DB      ?                       ; Map to itself
+
+NUMVEC  =       VECOUT-VECIN
+GSET001E label byte
+TABLE   ENDS
+        ENDIF
+
+procedure   RECSET,NEAR
+
+        IF      ALTVECT
+        context ES
+        MOV     [LSTVEC],AL             ; Terminate list with real vector
+        MOV     [LSTVEC2],AL            ; Terminate list with real vector
+        MOV     CX,NUMVEC               ; Number of possible translations
+        MOV     DI,OFFSET DOSGROUP:VECIN    ; Point to vectors
+        REPNE   SCASB
+        MOV     AL,ES:[DI+NUMVEC-1]     ; Get translation
+        ENDIF
+
+        XOR     BX,BX
+        MOV     ES,BX
+        MOV     BL,AL
+        SHL     BX,1
+        SHL     BX,1
+        return
+EndProc recset
+
+BREAK <$Char_Oper - hack on paths, switches so that xenix can look like PCDOS>
+;
+; input:    AL = function:
+;                   0 - read switch char
+;                   1 - set switch char (char in DL)
+;                   2 - read device availability
+;                       Always returns available
+;                   3 - set device availability
+;                       No longer supported (NOP)
+; output:   (get) DL - character/flag
+;
+        procedure   $CHAR_OPER,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        context DS
+        CMP     AL,1
+        JB      CharGetSw
+        JZ      CharSetSw
+        CMP     AL,3
+        JB      CharGetDev
+        JZ      CharSetDev
+        MOV     AL,-1
+        return
+CharGetSw:
+        MOV     DL,chSwitch
+        JMP     SHORT CharSet
+CharSetSw:
+        MOV     chSwitch,DL
+        return
+CharGetDev:
+        MOV     DL,-1
+CharSet:
+        Invoke  Get_User_Stack
+        ASSUME  DS:NOTHING
+        MOV     [SI.User_DX],DX
+CharSetDev:
+        return
+EndProc $CHAR_OPER
+
+BREAK <$GetExtendedError - Return Extended DOS error code>
+;
+; input:    None
+; output:   AX = Extended error code (0 means no extended error)
+;           BL = recommended action
+;           BH = class of error
+;           CH = locus of error
+;           ES:DI = may be pointer
+;
+        procedure   $GetExtendedError,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        Context DS
+        MOV     AX,[EXTERR]
+        LES     DI,[EXTERRPT]
+        MOV     BX,WORD PTR [EXTERR_ACTION]     ; BL = Action, BH = Class
+        MOV     CH,[EXTERR_LOCUS]
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_DI],DI
+        MOV     [SI.user_ES],ES
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_CX],CX
+        transfer SYS_RET_OK
+EndProc $GetExtendedError
+
+BREAK <$Get_Global_CdPg  - Return Global Code Page>
+;
+; input:    None
+; output:   AX = Global Code Page
+;
+        procedure   Get_Global_CdPg,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        PUSH    SI
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG
+        MOV     AX,CS:[SI.ccDosCodePage]
+        POP     SI
+        return
+EndProc Get_Global_CdPg
+
+;-------------------------------Start of DBCS 2/13/KK
+BREAK   <ECS_call - Extended Code System support function>
+
+ASSUME  DS:NOTHING, ES:NOTHING
+
+        procedure   $ECS_call,NEAR
+
+; Inputs:
+;       AL = 0  get lead byte table
+;               on return DS:SI has the table location
+;
+;       AL = 1  set / reset interim console flag
+;               DL = flag (00H or 01H)
+;               no return
+;
+;       AL = 2  get interim console flag
+;               on return DL = current flag value
+;
+;       AL = OTHER then error, and returns with:
+;               AX = error_invalid_function
+;
+;  NOTE: THIS CALL DOES GUARANTEE THAT REGISTER OTHER THAN
+;        SS:SP WILL BE PRESERVED!
+
+ IF  DBCS                                                                       ;AN000;
+                                                                                ;AN000;
+        or      al, al                  ; AL = 0 (get table)?                   ;AN000;
+        je      get_lbt                                                         ;AN000;
+        cmp     al, SetInterimMode      ; AL = 1 (set / reset interim flag)?    ;AN000;
+        je      set_interim                                                     ;AN000;
+        cmp     al, GetInterimMode      ; AL = 2 (get interim flag)?            ;AN000;
+        je      get_interim                                                     ;AN000;
+        error   error_invalid_function                                          ;AN000;
+                                                                                ;AN000;
+get_lbt:                                ; get lead byte table                   ;AN000;
+        push    ax                                                              ;AN000;
+        push    bx                                                              ;AN000;
+        push    ds                                                              ;AN000;
+        context DS                                                              ;AN000;
+        MOV     BX,offset DOSGROUP:COUNTRY_CDPG.ccSetDBCS                       ;AN000;
+        MOV     AX,[BX+1]               ; set EV address to DS:SI               ;AN000;
+        MOV     BX,[BX+3]                                                       ;AN000;
+        ADD     AX,2                    ; Skip Lemgth                           ;AN000;
+        invoke  get_user_stack                                                  ;AN000;
+ assume ds:nothing                                                              ;AN000;
+        MOV     [SI.user_SI], AX                                                ;AN000;
+        MOV     [SI.user_DS], BX                                                ;AN000;
+        pop     ds                                                              ;AN000;
+        pop     bx                                                              ;AN000;
+        pop     ax                                                              ;AN000;
+        transfer SYS_RET_OK                                                     ;AN000;
+
+set_interim:                            ; Set interim console flag              ;AN000;
+        push    dx                                                              ;AN000;
+        and     dl,01                   ; isolate bit 1                         ;AN000;
+        mov     [InterCon], dl                                                  ;AN000;
+        push    ds                                                              ;AN000;
+        mov     ds, [CurrentPDB]                                                ;AN000;
+        mov     byte ptr ds:[PDB_InterCon], dl  ; update value in pdb           ;AN000;
+        pop     ds                                                              ;AN000;
+        pop     dx                                                              ;AN000;
+        transfer SYS_RET_OK                                                     ;AN000;
+
+get_interim:                                                                    ;AN000;
+        push    dx                                                              ;AN000;
+        push    ds                                                              ;AN000;
+        mov     dl,[InterCon]                                                   ;AN000;
+        invoke  get_user_stack          ; get interim console flag              ;AN000;
+ assume ds:nothing                                                              ;AN000;
+        mov     [SI.user_DX],DX                                                 ;AN000;
+        pop     ds                                                              ;AN000;
+        pop     dx                                                              ;AN000;
+        transfer SYS_RET_OK                                                     ;AN000;
+ ELSE                                                                           ;AN000;
+        or      al, al                  ; AL = 0 (get table)?  ;AN000;
+        jnz     okok                                           ;AN000;
+get_lbt:                                                       ;AN000;
+        invoke  get_user_stack                                 ;AN000;
+ assume ds:nothing                                             ;AN000;
+        MOV     [SI.user_SI], Offset Dosgroup:DBCS_TAB+2       ;AN000;
+        MOV     [SI.user_DS], CS                               ;AN000;
+okok:                                                          ;AN000;
+        transfer SYS_RET_OK             ;                      ;AN000;
+
+ ENDIF                                                         ;AN000;
+
+$ECS_call endp                                                 ;AN000;
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/HANDLE.ASM b/v4.0/src/DOS/HANDLE.ASM
new file mode 100644
index 0000000..e67c2ae
--- /dev/null
+++ b/v4.0/src/DOS/HANDLE.ASM
@@ -0,0 +1,893 @@
+;       SCCSID = @(#)handle.asm 1.1 85/04/10
+TITLE   HANDLE - Handle-related system calls
+NAME    HANDLE
+;
+; Handle related system calls for MSDOS 2.X.  Only top-level system calls
+; are present.  I/O specs are defined in DISPATCH.  The system calls are:
+;
+;   $Close     written
+;   $Commit    written            DOS 3.3  F.C. 6/4/86
+;   $ExtHandle written            DOS 3.3  F.C. 6/4/86
+;   $Read      written
+;   Align_Buffer                  DOS 4.00
+;   $Write     written
+;   $LSeek     written
+;   $FileTimes written
+;   $Dup       written
+;   $Dup2      written
+;
+;   Revision history:
+;
+;       Created: MZ 28 March 1983
+;                MZ 15 Dec   1982 Jeff Harbers and Multiplan hard disk copy
+;                                 rely on certain values in AX when $CLOSE
+;                                 succeeds even though we document it as
+;                                 always trashing AX.
+;
+;       A000  version 4.00  Jan. 1988
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include EA.inc
+include version.inc
+.cref
+.list
+.sall
+
+        EXTRN   DOS_Read:NEAR, DOS_Write:NEAR
+
+IF      BUFFERFLAG
+        extrn   save_user_map:near
+        extrn   restore_user_map:near
+        extrn   Setup_EMS_Buffers:near
+ENDIF
+
+        I_need  ThisSFT,DWORD           ; pointer to SFT entry
+        I_need  DMAAdd,DWORD            ; old-style DMA address
+        I_Need  EXTERR_LOCUS,byte       ; Extended Error Locus
+        I_need  FailErr,BYTE            ; failed error flag
+        I_need  User_ID,WORD            ; current effective user_id
+        i_need  JShare,DWORD            ; jump table
+        I_need  CurrentPDB,WORD         ; current process data block
+        I_need  EXTOPEN_ON,BYTE         ;AN000;FT. flag for extended open
+;       I_need  XA_device,BYTE          ;AN000; XA device
+        I_need  XA_type,BYTE            ;AN000; extended open subfunction
+;       I_need  XA_handle,WORD          ;AN000; handle
+        I_need  THISCDS,DWORD           ;AN000;
+        I_need  DUMMYCDS,128            ;AN000;
+        I_need  SAVE_ES,WORD            ;AN000; saved ES
+        I_need  SAVE_DI,WORD            ;AN000; saved DI
+        I_need  SAVE_DS,WORD            ;AN000; saved DS
+        I_need  SAVE_SI,WORD            ;AN000; saved SI
+        I_need  SAVE_CX,WORD            ;AN000; saved CX
+
+IF      BUFFERFLAG
+
+        I_need  BUF_EMS_MODE,BYTE
+        I_need  BUF_EMS_LAST_PAGE,DWORD
+        I_need  BUF_EMS_FIRST_PAGE,DWORD
+        I_need  BUF_EMS_SAFE_FLAG,BYTE
+        I_need  BUF_EMS_NPA640,WORD
+        I_need  BUF_EMS_PAGE_FRAME,WORD
+        I_need  BUF_EMS_PFRAME,WORD
+        I_need  LASTBUFFER,DWORD
+
+ENDIF
+
+;       I_need  XA_ES,WORD              ;AN000; extended find
+;       I_need  XA_BP,WORD              ;AN000; extended find
+;       I_need  XA_from,BYTE            ;AN000; for filetimes
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+BREAK <$Close - return a handle to the system>
+
+;
+;   Assembler usage:
+;           MOV     BX, handle
+;           MOV     AH, Close
+;           INT     int_command
+;
+;   Error return:
+;           AX = error_invalid_handle
+;
+;   No registers returned
+
+Procedure   $Close,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        fmt TypSysCall,LevLog,<"$p Close\n">
+        fmt TypSysCall,LevArgs,<"$p  Handle = $x\n">,<BX>
+;
+; Grab the SFT pointer from the JFN.
+;
+        call    CheckOwner              ; get system file entry
+        JC      CloseError              ; error return
+        fmt TypAccess,LevSFN,<"$p  Close SFT $x:$x\n">,<es,di>
+        context DS                      ; For DOS_CLOSE
+        MOV     WORD PTR [ThisSFT],DI   ; save offset of pointer
+        MOV     WORD PTR [ThisSFT+2],ES ; save segment value
+;
+; DS:SI point to JFN table entry.
+; ES:DI point to SFT
+;
+; We now examine the user's JFN entry; If the file was a 70-mode file (network
+; FCB, we examine the ref count on the SFT;  if it was 1, we free the JFN.
+; If the file was not a net FCB, we free the JFN too.
+;
+        CMP     ES:[DI].sf_ref_count,1  ; will the SFT become free?
+        JZ      FreeJFN                 ; yes, free JFN anyway.
+        MOV     AL,BYTE PTR ES:[DI].sf_mode
+        AND     AL,sharing_mask
+        CMP     AL,sharing_net_fcb
+        JZ      PostFree                ; 70-mode and big ref count => free it
+;
+; The JFN must be freed.  Get the pointer to it and replace the contents with
+; -1.
+;
+FreeJFN:
+        Invoke  pJFNFromHandle          ;   d = pJFN (handle);
+        fmt TypAccess,LevSFN,<"$p  Close jfn pointer $x:$x\n">,<es,di>
+        MOV     BYTE PTR ES:[DI],0FFh   ; release the JFN
+PostFree:
+;
+; ThisSFT is correctly set, we have DS = DOSGROUP.  Looks OK for a DOS_CLOSE!
+;
+        invoke  DOS_Close
+;
+; DOS_Close may return an error.  If we see such an error, we report it but
+; the JFN stays closed because DOS_Close always frees the SFT!
+;
+        JC      CloseError
+        fmt TypSysCall,LevLog,<"$p: Close ok\n">
+        MOV     AH,close                ; MZ Bogus multiplan fix
+        transfer    Sys_Ret_OK
+CloseError:
+        ASSUME  DS:NOTHING
+        fmt TypSysCall,LevLog,<"$p: Close error $x\n">,<AX>
+        transfer    Sys_Ret_Err
+EndProc $Close
+
+BREAK <$Commit - commit the file>
+
+;
+;   Assembler usage:
+;           MOV     BX, handle
+;           MOV     AH, Commit
+;           INT     int_command
+;
+;   Error return:
+;           AX = error_invalid_handle
+;
+;   No registers returned
+
+Procedure   $Commit,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+;
+; Grab the SFT pointer from the JFN.
+;
+        call    CheckOwner              ; get system file entry
+        JC      Commiterror             ; error return
+        context DS                      ; For DOS_COMMIT
+        MOV     WORD PTR [ThisSFT],DI   ; save offset of pointer
+        MOV     WORD PTR [ThisSFT+2],ES ; save segment value
+;
+; ES:DI point to SFT
+;
+;
+; ThisSFT is correctly set, we have DS = DOSGROUP.  Looks OK for a DOS_COMMIT
+;
+        invoke  DOS_COMMIT
+;
+;
+        JC      Commiterror
+        MOV     AH,Commit               ;
+        transfer    Sys_Ret_OK
+Commiterror:
+        ASSUME  DS:NOTHING
+        transfer    Sys_Ret_Err
+EndProc $Commit
+
+
+BREAK <$ExtHandle - extend handle count>
+
+;
+;   Assembler usage:
+;           MOV     BX, Number of Opens Allowed (MAX=65534;66535 is
+;           MOV     AX, 6700H                    reserved to mark SFT
+;           INT     int_command                  busy )
+;
+;   Error return:
+;           AX = error_not_enough_memory
+;                or error_too_many_open_files
+;   No registers returned
+
+Procedure   $ExtHandle,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+;
+;
+;
+        XOR     BP,BP                   ; 0: enlarge   1: shrink  2:psp
+        CMP     BX,FilPerProc           ;  < 20
+        JAE     getpdb                  ;  no
+        MOV     BX,FilPerProc           ;  bx = 20
+
+getpdb:
+        MOV     ES,[CurrentPDB]         ; get user process data block
+        MOV     CX,ES:[PDB_JFN_Length]  ; get number of handle allowed
+        CMP     BX,CX                   ; the requested == current
+        JE      ok_done                 ; yes and exit
+        JA      larger                  ; go allocate new table
+
+        MOV     BP,1                    ; shrink
+        MOV     DS,WORD PTR ES:[PDB_JFN_Pointer+2] ;
+        MOV     SI,BX                   ;
+        SUB     CX,BX                   ; get difference
+chck_handles:
+        CMP     BYTE PTR DS:[SI],-1     ; scan through handles to ensure close
+        JNZ     too_many_files          ; status
+        INC     SI
+        LOOP    chck_handles
+        CMP     BX,FilPerProc           ; = 20
+        JA      larger                  ; no
+
+        MOV     BP,2                    ; psp
+        MOV     DI,PDB_JFN_Table        ; es:di -> jfn table in psp
+        PUSH    BX
+        JMP     movhandl
+
+larger:
+        CMP     BX,-1                   ; 65535 is not allowed
+        JZ      invalid_func
+        CLC
+        PUSH    BX                      ; save requested number
+        ADD     BX,0FH                  ; adjust to paragraph boundary
+        MOV     CL,4
+        RCR     BX,CL                   ; DOS 4.00 fix                          ;AC000;
+        AND     BX,1FFFH                ; clear most 3 bits
+
+        PUSH    BP
+        invoke  $ALLOC                  ; allocate memory
+        POP     BP
+        JC      no_memory               ; not enough meory
+
+        MOV     ES,AX                   ; es:di points to new table memory
+        XOR     DI,DI
+movhandl:
+        MOV     DS,[CurrentPDB]         ; get user PDB address
+
+        TEST    BP,3                    ; enlarge ?
+        JZ      enlarge                 ; yes
+        POP     CX                      ; cx = the amount you shrink
+        PUSH    CX
+        JMP     copy_hand
+ok_done:
+        transfer    Sys_Ret_OK
+too_many_files:
+        MOV     AL,error_too_many_open_files
+        transfer    Sys_Ret_Err
+enlarge:
+        MOV     CX,DS:[PDB_JFN_Length]    ; get number of old handles
+copy_hand:
+        MOV     DX,CX
+        LDS     SI,DS:[PDB_JFN_Pointer]   ; get old table pointer
+ASSUME DS:NOTHING
+        REP     MOVSB                   ; copy infomation to new table
+
+        POP     CX                      ; get new number of handles
+        PUSH    CX                      ; save it again
+        SUB     CX,DX                   ; get the difference
+        MOV     AL,-1                   ; set availability to handles
+        REP     STOSB
+
+        MOV     DS,[CurrentPDB]         ; get user process data block
+        CMP     WORD PTR DS:[PDB_JFN_Pointer],0  ; check if original table pointer
+        JNZ     update_info             ; yes, go update PDB entries
+        PUSH    BP
+        PUSH    DS                      ; save old table segment
+        PUSH    ES                      ; save new table segment
+        MOV     ES,WORD PTR DS:[PDB_JFN_Pointer+2] ; get old table segment
+        invoke  $DEALLOC                ; deallocate old table meomory
+        POP     ES                      ; restore new table segment
+        POP     DS                      ; restore old table segment
+        POP     BP
+
+update_info:
+        TEST    BP,2                    ; psp?
+        JZ      non_psp                 ; no
+        MOV     WORD PTR DS:[PDB_JFN_Pointer],PDB_JFN_Table   ; restore
+        JMP     final
+non_psp:
+        MOV     WORD PTR DS:[PDB_JFN_Pointer],0  ; new table pointer offset always 0
+final:
+        MOV     WORD PTR DS:[PDB_JFN_Pointer+2],ES  ; update table pointer segment
+        POP     DS:[PDB_JFN_Length]      ; restore new number of handles
+        transfer   Sys_Ret_Ok
+no_memory:
+        POP     BX                      ; clean stack
+        MOV     AL,error_not_enough_memory
+        transfer    Sys_Ret_Err
+invalid_func:
+        MOV     AL,error_invalid_function
+        transfer    Sys_Ret_Err
+EndProc $ExtHandle
+
+BREAK <$READ - Read from a file handle>
+;
+;   Assembler usage:
+;           LDS     DX, buf
+;           MOV     CX, count
+;           MOV     BX, handle
+;           MOV     AH, Read
+;           INT     int_command
+;         AX has number of bytes read
+;   Errors:
+;           AX = read_invalid_handle
+;              = read_access_denied
+;
+;   Returns in register AX
+
+procedure   $READ,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        fmt TypSysCall,LevLog,<"Read\n">
+        fmt TypSysCall,LevArgs,<" Handle $x Cnt $x Buf $x:$x\n">,<BX,CX,DS,DX>
+        MOV     SI,OFFSET DOSGROUP:DOS_Read
+ReadDo:
+        invoke  pJFNFromHandle
+        JC      ReadError
+        MOV     AL,ES:[DI]
+        call    CheckOwner              ; get the handle
+        JNC     ReadSetup               ; no errors do the operation
+ReadError:
+        fmt TypSysCall,LevLog,<"Read/Write error $x\n">,<AX>
+        transfer    SYS_RET_ERR         ; go to error traps
+ReadSetup:
+        MOV     WORD PTR [ThisSFT],DI   ; save offset of pointer
+        MOV     WORD PTR [ThisSFT+2],ES ; save segment value
+;; Extended Open
+        TEST    ES:[DI.sf_mode],INT_24_ERROR  ;AN000;;EO. need i24
+        JZ      needi24                       ;AN000;;EO. yes
+        OR      [EXTOPEN_ON],EXT_OPEN_I24_OFF ;AN000;;EO. set it off
+needi24:                                      ;AN000;
+
+;; Extended Open
+        SaveReg <<WORD PTR [DMAAdd]>, <WORD PTR [DMAAdd+2]>>
+;;;;;   BAD SPOT FOR 286!!! SEGMENT ARITHMETIC!!!
+        CALL    Align_Buffer            ;AN000;MS. align user's buffer
+;;;;;   END BAD SPOT FOR 286!!! SEGMENT ARITHMETIC!!!
+
+IF      BUFFERFLAG
+
+;       int     3
+;       cmp     [BUF_EMS_MODE], -1
+;       jz      dos_call
+;       call    choose_buf_page
+;       jc      ReadError
+;       call    save_user_map
+
+;dos_call:
+ENDIF
+        context DS                      ; go for DOS addressability
+        CALL    SI                      ; indirect call to operation
+        RestoreReg <<WORD PTR [DMAAdd+2]>, <WORD PTR [DMAAdd]>>
+
+IF      BUFFERFLAG
+        pushf
+        push    ax
+        push    bx
+
+        cmp     cs:[BUF_EMS_MODE], -1
+        jz      dos_call_done
+        call    restore_user_map
+        mov     ax, word ptr cs:[BUF_EMS_LAST_PAGE]
+        cmp     cs:[BUF_EMS_PFRAME], ax
+        je      dos_call_done
+        mov     word ptr cs:[LASTBUFFER], -1
+        mov     cs:[BUF_EMS_PFRAME], ax
+        mov     ax, word ptr cs:[BUF_EMS_LAST_PAGE+2]
+        mov     cs:[BUF_EMS_PAGE_FRAME], ax
+        mov     cs:[BUF_EMS_SAFE_FLAG], 1
+        call    Setup_EMS_Buffers
+
+dos_call_done:
+        pop     bx
+        pop     ax
+        popf
+ENDIF
+
+IF      NOT     BUFFERFLAG
+        JC      ReadError               ; if error, say bye bye
+ELSE
+        jmp     tmp_rerr
+tmp_rerr:
+        jc      ReadError
+ENDIF
+
+        MOV     AX,CX                   ; get correct return in correct reg
+        fmt TypSysCall,LevLog,<"Read/Write cnt done $x\n">,<AX>
+        transfer    sys_ret_ok          ; successful return
+EndProc $READ
+
+;
+;   Input: DS:DX points to user's buffer addr
+;   Function: rearrange segment and offset for READ/WRITE buffer
+;   Output: [DMAADD] set
+;
+;
+
+procedure   Align_Buffer,NEAR           ;AN000;
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP  ;AN000;
+        MOV     BX,DX                   ; copy offset
+        SaveReg <CX>                    ; don't stomp on count
+        MOV     CL,4                    ; bits to shift bytes->para
+        SHR     BX,CL                   ; get number of paragraphs
+        RestoreReg  <CX>                ; get count back
+        MOV     AX,DS                   ; get original segment
+        ADD     AX,BX                   ; get new segment
+        MOV     DS,AX                   ; in seg register
+        AND     DX,0Fh                  ; normalize offset
+        MOV     WORD PTR [DMAAdd],DX    ; use user DX as offset
+        MOV     WORD PTR [DMAAdd+2],DS  ; use user DS as segment for DMA
+        return                          ;AN000;
+EndProc Align_Buffer                    ;AN000;
+
+BREAK <$WRITE - write to a file handle>
+
+;
+;   Assembler usage:
+;           LDS     DX, buf
+;           MOV     CX, count
+;           MOV     BX, handle
+;           MOV     AH, Write
+;           INT     int_command
+;         AX has number of bytes written
+;   Errors:
+;           AX = write_invalid_handle
+;              = write_access_denied
+;
+;   Returns in register AX
+
+procedure   $WRITE,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        fmt TypSysCall,LevLog,<"Write\n">
+        fmt TypSysCall,LevArgs,<" Handle $x Cnt $x Buf $x:$x\n">,<BX,CX,DS,DX>
+        MOV     SI,OFFSET DOSGROUP:DOS_Write
+        JMP     ReadDo
+EndProc $Write
+
+BREAK <$LSEEK - move r/w pointer>
+
+;
+;   Assembler usage:
+;           MOV     DX, offsetlow
+;           MOV     CX, offsethigh
+;           MOV     BX, handle
+;           MOV     AL, method
+;           MOV     AH, LSeek
+;           INT     int_command
+;         DX:AX has the new location of the pointer
+;   Error returns:
+;           AX = error_invalid_handle
+;              = error_invalid_function
+;   Returns in registers DX:AX
+
+procedure   $LSEEK,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        call    CheckOwner              ; get system file entry
+LSeekError:
+
+IF      BUFFERFLAG
+        JC      TMP_RERR
+ELSE
+        JC      ReadError               ; error return
+ENDIF
+        CMP     AL,2                    ; is the seek value correct?
+        JBE     LSeekDisp               ; yes, go dispatch
+        MOV     EXTERR_LOCUS,errLoc_Unk ; Extended Error Locus
+        error   error_invalid_function  ; invalid method
+LSeekDisp:
+        CMP     AL,1                    ; best way to dispatch; check middle
+        JB      LSeekStore              ; just store CX:DX
+        JA      LSeekEOF                ; seek from end of file
+        ADD     DX,WORD PTR ES:[DI.SF_Position]
+        ADC     CX,WORD PTR ES:[DI.SF_Position+2]
+LSeekStore:
+        MOV     AX,CX                   ; AX:DX
+        XCHG    AX,DX                   ; DX:AX is the correct value
+LSeekSetpos:
+        MOV     WORD PTR ES:[DI.SF_Position],AX
+        MOV     WORD PTR ES:[DI.SF_Position+2],DX
+        invoke  Get_user_stack
+        MOV     DS:[SI.User_DX],DX      ; return DX:AX
+        transfer    SYS_RET_OK          ; successful return
+
+LSeekEOF:
+        TEST    ES:[DI.sf_flags],sf_isnet
+        JNZ     Check_LSeek_Mode        ; Is Net
+LOCAL_LSeek:
+        ADD     DX,WORD PTR ES:[DI.SF_Size]
+        ADC     CX,WORD PTR ES:[DI.SF_Size+2]
+        JMP     LSeekStore              ; go and set the position
+
+Check_LSeek_Mode:
+        TEST    ES:[DI.sf_mode],sf_isfcb
+        JNZ     LOCAL_LSeek             ; FCB treated like local file
+        MOV     AX,ES:[DI.sf_mode]
+        AND     AX,sharing_mask
+        CMP     AX,sharing_deny_none
+        JZ      NET_LSEEK               ; LSEEK exported in this mode
+        CMP     AX,sharing_deny_read
+        JNZ     LOCAL_LSeek             ; Treated like local Lseek
+NET_LSEEK:
+;        JMP     LOCAL_LSeek
+; REMOVE ABOVE INSTRUCTION TO ENABLE DCR 142
+        CallInstall Net_Lseek,multNet,33
+        JNC     LSeekSetPos
+        transfer    SYS_RET_ERR
+
+EndProc $LSeek
+
+BREAK <FileTimes - modify write times on a handle>
+
+;
+;   Assembler usage:
+;           MOV AH, FileTimes (57H)
+;           MOV AL, func
+;           MOV BX, handle
+;       ; if AL = 1 then then next two are mandatory
+;           MOV CX, time
+;           MOV DX, date
+;           INT 21h
+;       ; if AL = 0 then CX/DX has the last write time/date
+;       ; for the handle.
+;
+;       AL=02            get extended attributes
+;          BX=handle
+;          CX=size of buffer (0, return max size )
+;          DS:SI query list (si=-1, selects all EA)
+;          ES:DI buffer to hold EA list
+;
+;       AL=03            get EA name list
+;          BX=handle
+;          CX=size of buffer (0, return max size )
+;          ES:DI buffer to hold name list
+;
+;       AL=04            set extended attributes
+;          BX=handle
+;          ES:DI buffer of EA list
+;
+;
+;
+;
+;   Error returns:
+;           AX = error_invalid_function
+;              = error_invalid_handle
+;
+
+procedure   $File_Times,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        CMP     AL,2                    ; correct subfunction?
+        JAE     gsetxa
+        JMP     filetimes_ok            ; Yes, continue
+;;;; DOS 4.00                           ;AN000;
+gsetxa:                                 ;AN000;
+        EnterCrit   critSFT             ;AN000;;FT. enter critical section
+        CMP     AL,4                    ;AN000;;FT. =4
+        JBE     gshandle                ;AN000;;FT. 2,3,4   do get/set by handle
+funcerr:                                ;AN000;
+        JMP     inval_func              ;AN000;;FT. invalid function
+                                        ;AN000;
+gshandle:                               ;AN000;
+        MOV     [SAVE_ES],ES            ;AN000;;FT. save regs
+        MOV     [SAVE_DI],DI            ;AN000;;FT.
+        MOV     [SAVE_DS],DS            ;AN000;;FT. save regs
+        MOV     [SAVE_SI],SI            ;AN000;;FT.
+        MOV     [SAVE_CX],CX            ;AN000;;FT.
+        MOV     [XA_TYPE],AL            ;AN000;;FT.
+                                        ;AN000;
+;       MOV     [XA_handle],BX          ;AN000;    ;FT. save handle
+        CALL    CheckOwner              ;AN000;    ;FT. get sf pointer
+        JNC     getsetit                ;AN000;    ;FT. good handle
+        LeaveCrit   critSFT             ;AN000;    ;FT. leave critical section
+        JMP     LSeekError              ;AN000;    ;FT. turkey handle
+                                        ;AN000;
+getsetit:                               ;AN000;
+        MOV     WORD PTR [ThisSFT],DI   ;AN000;       ;FT. set ThisSFT
+        MOV     WORD PTR [ThisSFT+2],ES ;AN000;       ;FT. set ThisSFT
+;       TEST    ES:[DI.sf_mode],INT_24_ERROR   ;AN000;;FT. mask INT 24
+;       JZ      nomask                         ;AN000;;FT. no
+;       OR      [EXTOPEN_ON],EXT_OPEN_I24_OFF  ;AN000;;FT. set bit for I24 handler
+nomask:                                        ;AN000;
+        TEST    ES:[DI.sf_flags],sf_isnet      ;AN000;;FT. remote handle
+        JZ      localhandle                    ;AN000;;FT. no
+        LeaveCrit   critSFT                    ;AN000;;FT. doesn't support Network
+
+        MOV     BL,[XA_TYPE]                   ;AN000;;FT.
+IFSsearch:                                     ;AN000;
+        MOV     AX,(multNET SHL 8) or 45       ;AN000;;FT. Get/Set XA support
+        INT     2FH                            ;AN000;
+        JC      getseterror                    ;AN000;;FT. error
+        transfer    SYS_RET_OK                 ;AN000;;FT.
+localhandle:                                   ;AN000;
+;       TEST    ES:[DI.sf_flags],devid_device  ;AN000;;FT. device
+;       JZ      getsetfile8                    ;AN000;;FT. no
+;       MOV     [XA_device],1                  ;AN000;;FT. indicating device
+;       JMP     SHORT doXA                     ;AN000;;FT. do XA
+getsetfile8:                                   ;AN000;
+;       MOV     [XA_device],0                  ;AN000;;FT. indicating File
+;       LES     BP,ES:[DI.sf_devptr]           ;AN000;;FT. ES:BP -> DPB
+
+doXA:                                          ;AN000;
+;       MOV     [XA_from],By_XA                ;AN000;;FT. from get/set XA
+;       PUSH    [SAVE_ES]                      ;AN000;;FT. save XA list
+;       PUSH    [SAVE_DI]                      ;AN000;;FT. save XA list
+
+        invoke  GetSet_XA                      ;AN000;;FT. issue Get/Set XA
+;       POP     SI                             ;AN000;;FT. DS:SI -> XA list
+;       POP     DS                             ;AN000;
+        JC      getexit                        ;AN000;;FT. error
+;       CMP     [XA_device],0                  ;AN000;;FT. device ?
+;       JNZ     ftok                           ;AN000;;FT. yes, exit
+;       MOV     AX,4                           ;AN000;;FT. function 4 for ShSU
+;       CMP     [XA_type],4                    ;AN000;;FT. set XA
+;       JNZ     ftok                           ;AN000;;FT. no
+;
+;
+;       LES     DI,[ThisSFT]                   ;AN000;;FT. es:di -> sft
+;       CMP     WORD PTR [SI],0                ;AN000;;FT. null list ?
+;       JNZ     do_share                       ;AN000;;FT. no
+        JMP     SHORT ftok                     ;AN000;;FT. return
+getexit:                                       ;AN000;;FT.
+        LeaveCrit   critSFT                    ;AN000;;FT. leave critical section
+
+
+getseterror:                                   ;AN000;
+        transfer    SYS_RET_ERR                ;AN000;;FT. mark file as dirty
+inval_func:
+
+;;;;; DOS 4.00
+        MOV     EXTERR_LOCUS,errLoc_Unk ; Extended Error Locus
+        error   error_invalid_function  ; give bad return
+filetimes_ok:
+        call    CheckOwner              ; get sf pointer
+        JNC     gsdt
+        JMP     LSeekError              ; turkey handle
+gsdt:
+        OR      AL,AL                   ; is it Get?
+        JNZ     filetimes_set           ; no, go set the time
+        CLI
+        MOV     CX,ES:[DI.sf_Time]      ; suck out time
+        MOV     DX,ES:[DI.sf_Date]      ; and date
+        STI
+        invoke  Get_user_stack          ; obtain place to return it
+        MOV     [SI.user_CX],CX         ; and stash in time
+        MOV     [SI.user_DX],DX         ; and stask in date
+ext_done:
+        transfer    SYS_RET_OK          ; and say goodnight
+filetimes_set:
+        EnterCrit   critSFT
+        MOV     ES:[DI.sf_Time],CX      ; drop in new time
+        MOV     ES:[DI.sf_Date],DX      ; and date
+        XOR     AX,AX
+do_share:
+if installed
+        Call    JShare + 14 * 4
+else
+        Call    ShSU
+endif
+datetimeflg:
+        AND     ES:[DI.sf_Flags],NOT devid_file_clean
+        OR      ES:[DI.sf_Flags],sf_close_nodate
+ftok:
+        LeaveCrit   critSFT
+        transfer    SYS_RET_OK          ; mark file as dirty and return
+EndProc $File_Times
+
+BREAK <$DUP - duplicate a jfn>
+;
+;   Assembler usage:
+;           MOV     BX, fh
+;           MOV     AH, Dup
+;           INT     int_command
+;         AX has the returned handle
+;   Errors:
+;           AX = dup_invalid_handle
+;              = dup_too_many_open_files
+Procedure   $DUP,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        MOV     AX,BX                   ; save away old handle in AX
+        invoke  JFNFree                 ; free handle? into ES:DI, new in BX
+DupErrorCheck:
+        JC      DupErr                  ; nope, bye
+        SaveReg <ES,DI>                 ; save away SFT
+        RestoreReg  <SI,DS>             ; into convenient place DS:SI
+        XCHG    AX,BX                   ; get back old handle
+        call    CheckOwner              ; get sft in ES:DI
+        JC      DupErr                  ; errors go home
+        invoke  DOS_Dup_Direct
+        invoke  pJFNFromHandle          ; get pointer
+        MOV     BL,ES:[DI]              ; get SFT number
+        MOV     DS:[SI],BL              ; stuff in new SFT
+        transfer    SYS_RET_OK          ; and go home
+DupErr: transfer    SYS_RET_ERR
+
+EndProc $Dup
+
+BREAK <$DUP2 - force a dup on a particular jfn>
+;
+;   Assembler usage:
+;           MOV     BX, fh
+;           MOV     CX, newfh
+;           MOV     AH, Dup2
+;           INT     int_command
+;   Error returns:
+;           AX = error_invalid_handle
+;
+Procedure   $Dup2,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        SaveReg <BX,CX>                 ; save source
+        MOV     BX,CX                   ; get one to close
+        invoke  $Close                  ; close destination handle
+        RestoreReg  <BX,AX>             ; old in AX, new in BX
+        invoke  pJFNFromHandle          ; get pointer
+        JMP     DupErrorCheck           ; check error and do dup
+EndProc $Dup2
+
+Break   <CheckOwner - verify ownership of handles from server>
+
+;
+;   CheckOwner - Due to the ability of the server to close file handles for a
+;   process without the process knowing it (delete/rename of open files, for
+;   example), it is possible for the redirector to issue a call to a handle
+;   that it soes not rightfully own.  We check here to make sure that the
+;   issuing process is the owner of the SFT.  At the same time, we do a
+;   SFFromHandle to really make sure that the SFT is good.
+;
+;   Inputs:     BX has the handle
+;               User_ID is the current user
+;   Output:     Carry Clear => ES:DI points to SFT
+;               Carry Set => AX has error code
+;   Registers modified: none
+;
+
+Procedure   CheckOwner,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        invoke  SFFromHandle
+        retc
+        push    ax
+        mov     ax,user_id
+        cmp     ax,es:[di].sf_UID
+        pop     ax
+        retz
+        mov     al,error_invalid_handle
+        stc
+        return
+EndProc CheckOwner
+
+;-------------------------------------------------------------------------
+;       Function name   :       choose_buf_page
+;       Inputs          :       DMAADD = Xaddr
+;                               cx = # of bytes to transfer
+;       Outputs         :       if NC
+;
+;                               SAFE_FLAG - 0 ==> page is safe. no need to
+;                                                 detect collision between
+;                                                 user & system buffer.
+;                               SAFE_FLAG - 1 ==> page is unsafe. Must check
+;                                                 for collision
+;
+;                               CY - error
+;
+;
+;       High Level Alogrithm:
+;
+;       1. If Xaddr. is above the first physical page above 640K
+;          2. choose that page
+;          3. set safe flag
+;       4. else
+;          5. choose highest page above 640K
+;          6. If 6 or more pages above 640k
+;             7. Set safe flag                          
+;          8. else
+;             9. if Xaddr. + # of bytes to transfer does not spill into the
+;                chosen page
+;                10. set safe flag
+;             11.else
+;                12. clear safe flag
+;             13.endif
+;          14.endif
+;       15.endif
+;
+;----------------------------------------------------------------------------
+;Procedure      choose_buf_page,near
+;
+;       assume cs:dosgroup, ds:nothing, es:nothing, ss:dosgroup
+;
+;       push    cx
+;       push    bx
+;       push    dx
+;       push    si
+;       push    ds
+;       push    ax
+;
+;       mov     ax, word ptr [DMAADD+2]
+;       and     ax, 0fc00h      ; page segment of transfer segment
+;
+;       cmp     ax, word ptr [BUF_EMS_FIRST_PAGE]
+;       ja      pick_first
+;       
+;       cmp     [BUF_EMS_NPA640], 6
+;       jae     safe_pick_last
+;
+;       add     cx, word ptr [DMAADD]   ; get final offset 
+;       mov     bx, cx
+;
+;       mov     cl, 4
+;       shr     bx, cl          ; get # of paragraphs
+;       mov     ax, word ptr [DMAADD+2] ; get initial segment
+;       add     ax, bx          ; get final segment
+;
+;       and     ax, 0fc00h
+;       cmp     ax, word ptr [BUF_EMS_LAST_PAGE]
+;       jne     safe_pick_last
+;
+;       mov     [BUF_EMS_SAFE_FLAG], 0
+;       jmp     fin_choose_page
+;
+;safe_pick_last:
+;       mov     [BUF_EMS_SAFE_FLAG], 1
+;       jmp     fin_choose_page
+;
+;;pick_last:
+;;      mov     ax, word ptr [BUF_EMS_LAST_PAGE]
+;;      mov     [BUF_EMS_PFRAME], ax
+;;      mov     ax, word ptr [BUF_EMS_LAST_PAGE+2]
+;;      mov     [BUF_EMS_PAGE_FRAME], ax
+;;      xor     ax, ax
+;;      jmp     fin_choose_page
+;
+;pick_first:
+;       mov     ax, word ptr [BUF_EMS_FIRST_PAGE]
+;       cmp     [BUF_EMS_PFRAME], ax
+;       je      fin_choose_page
+;       mov     word ptr [LASTBUFFER], -1
+;       mov     [BUF_EMS_PFRAME], ax
+;       mov     ax, word ptr [BUF_EMS_FIRST_PAGE+2]
+;       mov     [BUF_EMS_PAGE_FRAME], ax
+;       mov     [BUF_EMS_SAFE_FLAG], 1
+;       call    Setup_EMS_Buffers
+;       jmp     fin_choose_page
+;
+;err_choose_page:
+;       stc
+;
+;fin_choose_page:
+;       clc
+;
+;       pop     ax
+;       pop     ds
+;       pop     si
+;       pop     dx
+;       pop     bx
+;       pop     cx
+;       return
+;
+;EndProc        choose_buf_page 
+;
+
+CODE    ENDS
+END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/HIGHSW.ASM b/v4.0/src/DOS/HIGHSW.ASM
new file mode 100644
index 0000000..9bd758f
--- /dev/null
+++ b/v4.0/src/DOS/HIGHSW.ASM
@@ -0,0 +1,29 @@
+;       SCCSID = @(#)highsw.asm 1.1 85/04/10
+TRUE    EQU     0FFFFH
+FALSE   EQU     NOT TRUE
+
+; Use the switches below to produce the standard Microsoft version or the IBM
+; version of the operating system
+MSVER   EQU     TRUE
+IBM     EQU     FALSE
+WANG    EQU     FALSE
+ALTVECT EQU     FALSE
+
+; Set this switch to cause DOS to move itself to the end of memory
+HIGHMEM EQU     TRUE
+
+        IF      IBM
+ESCCH   EQU     0                       ; character to begin escape seq.
+TOGLPRN EQU     TRUE                    ;One key toggles printer echo
+ZEROEXT EQU     TRUE
+        ELSE
+        IF      WANG                    ;Are we assembling for WANG?
+ESCCH   EQU     1FH                     ;Yes. Use 1FH for escape character
+        ELSE
+ESCCH   EQU     1BH
+        ENDIF
+CANCEL  EQU     "X"-"@"                 ;Cancel with Ctrl-X
+TOGLPRN EQU     FALSE                   ;Separate keys for printer echo on
+                                        ;and off
+ZEROEXT EQU     TRUE
+        ENDIF
diff --git a/v4.0/src/DOS/IFS.ASM b/v4.0/src/DOS/IFS.ASM
new file mode 100644
index 0000000..2893f28
--- /dev/null
+++ b/v4.0/src/DOS/IFS.ASM
@@ -0,0 +1,523 @@
+
+
+
+.xlist                                                                    ;AN000;
+include    dosseg.asm                                                     ;AN000;
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'                                       ;AN000;
+        ASSUME  CS:DOSGROUP,  SS:DOSGROUP                                 ;AN000;
+.xcref                                                                    ;AN000;
+include    dossym.inc                                                     ;AN000;
+include    devsym.inc                                                     ;AN000;
+include    doscntry.inc                                                   ;AN000;
+.cref                                                                     ;AN000;
+.list
+StackSize   =   180h                    ; gross but effective
+
+        i_need  VERFLG                 ; verify status flag               ;AN000;
+        i_need  CNTCFLAG               ; break status flag                ;AN000;
+        i_need  CPSWFLAG               ; CP switch logic ON/OFF           ;AN000;
+        I_need  CURRENTPDB,WORD        ; Current process identifier       ;AN000;
+        I_need  HIGH_SECTOR,WORD                                          ;AN000;
+        I_need  BUF_HASH_COUNT,WORD                                       ;AN000;
+        I_need  FAILERR,WORD                                              ;AN000;
+        I_need  USER_ID,WORD                                              ;AN000;
+        I_need  CALLDEVAD,DWORD       ;                                   ;AN000;
+        I_need  SYSINITVAR,WORD                                           ;AN000;
+        I_need  MYNAME,16             ; NetBIOS name                      ;AN000;
+        I_need  RETRYCOUNT,WORD       ; retry count                       ;AN000;
+        I_need  COUNTRY_CDPG,BYTE                                         ;AN000;
+        i_need  DAY,BYTE              ; date                              ;AN000;
+        i_need  MONTH,BYTE                                                ;AN000;
+        i_need  YEAR,WORD                                                 ;AN000;
+        i_need  CURBUF,DWORD                                              ;AN000;
+        i_need  IFS_DRIVER_ERR,WORD                                       ;AN000;
+        i_need  DOS34_FLAG,WORD       ; IFS function Read/Write flag      ;AN000;
+        i_need  Callback_SS,WORD      ;                                   ;AN000;
+        i_need  Callback_SP,WORD                                          ;AN000;
+        i_need  SaveBX,WORD                                               ;AN000;
+        i_need  Temp_Var,WORD                                             ;AN000;
+        i_need  INDOS,BYTE                                                ;AN000;
+        i_need  DskStack,BYTE                                             ;AN000;
+        i_need  IOStack,BYTE                                              ;AN000;
+        i_need  Callback_flag,BYTE                                        ;AN000;
+
+DOSINFO     STRUC                                                         ;AN000;
+bsize     dw    0                                                         ;AN000;
+files     dw    0                                                         ;AN000;
+fcbs1     dw    0                                                         ;AN000;
+fcbs2     dw    0                                                         ;AN000;
+buffers   dw    0                                                         ;AN000;
+          dw    0                                                         ;AN000;
+lastdrv   dw    0                                                         ;AN000;
+secsize   dw    0                                                         ;AN000;
+DosInfo       ENDS                                                        ;AN000;
+
+
+
+        extrn   ABSDRD:NEAR              ;AN000;
+        extrn   ABSDWRT:NEAR             ;AN000;
+        extrn   READTIME:NEAR            ;AN000;
+        extrn   CHECKFLUSH:NEAR          ;AN000;
+        extrn   GETCURHEAD:NEAR          ;AN000;
+
+
+;******************************************************************************
+; *
+; *      MODULE: IFS_DOSCALL
+; *
+; *      FUNCTION: IFS to DOS function request dispatcher
+; *
+; *      FUNCTION: This procedure dispatches the IFS DOS service requests
+; *                by calling various DOS service routines
+; *
+; *      CALLING SEQUENCE:
+; *
+; *                CALL  DWORD PTR IFS_DOSCALL@
+; *
+; *
+; *      RETURN SEQUENCE:
+; *
+; *                If AX = 0    No error
+; *
+; *                If AX <> 0   Error
+; *                   AX = Error Code:
+; *
+; *
+; *      INTERNAL REFERENCES:   None
+; *
+; *
+; *      EXTERNAL REFERENCES:   STRATEGY, INTERRUPT, ABSDRD, ABSDWRT,
+; *                             FIND_SECTOR, MARK_SECTOR, WRITE_BUFFR,
+; *                             READ_BUFFR, WRITE_BUFFR, FREE_BUFFR,
+; *                             GET_DOS_INFO, FLUSH_BUFF
+; *
+; *      NOTES:  None
+; *
+; *      REVISION HISTORY:  New
+; *
+; *      COPYRIGHT:  "MS DOS IFS Function"
+; *                  "Version 1.00 (C) Copyright 1988 Microsoft Corporation"
+; *                  "Licensed Material - Program Property of Microsoft"
+; *
+; *************************************************************************
+
+
+
+
+
+PROCEDURE   IFS_DOSCALL,FAR                                               ;AN000;
+ assume DS:NOTHING,ES:NOTHING                                             ;AN000;
+
+         CLI                    ;                                         ;AN000;
+         CMP     AH,39          ;                                         ;AN000;
+         JNZ     others         ;                                         ;AN000;
+         INC     CS:[INDOS]     ; in DOS                                  ;AN000;
+         JMP     Dosend         ;                                         ;AN000;
+others:
+         CMP     AH,40          ;                                         ;AN000;
+         JNZ     others2        ;                                         ;AN000;
+         DEC     CS:[INDOS]     ; out DOS                                 ;AN000;
+         JMP     Dosend         ;                                         ;AN000;
+others2:
+         CMP     AH,38          ;                                         ;AN000;
+         JNZ     not_stack      ;                                         ;AN000;
+         PUSH    CS             ;                                         ;AN000;
+         POP     DS             ;                                         ;AN000;
+         MOV     SI,OFFSET DOSGROUP:IOSTACK                               ;AN000;
+         MOV     CX,stacksize                                             ;AN000;
+         JMP     Dosend         ;                                         ;AN000;
+                                ;                                         ;AN000;
+not_stack:                      ;                                         ;AN000;
+         MOV     CS:[Temp_Var],DS; save ds for strcmp strcpy              ;AN000;
+         PUSH    CS             ;                                         ;AN000;
+         POP     DS             ;                                         ;AN000;
+ assume DS:DOSGROUP                                                       ;AN000;
+         INC     [INDOS]        ; in DOS                                  ;AN000;
+         PUSH    CX             ; save cx                                 ;AN000;
+         PUSH    DX             ; save cx                                 ;AN000;
+         MOV     CX,SS          ; cx=stack                                ;AN000;
+         MOV     DX,CS          ; cx=stack                                ;AN000;
+         CMP     CX,DX          ; dosgroup stack ?                        ;AN000;
+         POP     DX             ; save cx                                 ;AN000;
+         POP     CX             ; restore cx                              ;AN000;
+         JZ      withSS_SP      ; yes                                     ;AN000;
+         MOV     [Callback_SS],SS ;save SS:SP                             ;AN000;
+         MOV     [Callback_SP],SP                                         ;AN000;
+         MOV     [SaveBX],BX    ;                                         ;AN000;
+         MOV     BX,CS          ; prepare system stack                    ;AN000;
+         MOV     SS,BX          ;                                         ;AN000;
+         MOV     SP,OFFSET DOSGROUP:DSKSTACK                              ;AN000;
+         MOV     BX,[SaveBX]    ;                                         ;AN000;
+         MOV     [Callback_flag],1  ;set flag                             ;AN000;
+withSS_SP:                      ;                                         ;AN000;
+         STI                                                              ;AN000;
+ ASSUME DS:NOTHING                                                        ;AN000;
+;        OR      [DOS34_FLAG],Force_I24_Fail                              ;AN000;
+;                                                                         ;AN000;
+;        cmp     ah,0            ; call Strategy routine ??               ;AN000;
+;        jne     dos_chk_ah1     ; jump if not                            ;AN000;
+;        CALL    STRATEGY        ; else call strategy routine             ;AN000;
+;        jmp     dos_exit        ; then exit                              ;AN000;
+                                                                          ;AN000;
+;Dos_Chk_Ah1:                                                              ;AN000;
+;        cmp     ah,1            ; call interrupt routine                 ;AN000;
+;        jne     dos_chk_ah2     ; jump if not                            ;AN000;
+;        CALL    INTERRUPT       ; else call interrupt routine            ;AN000;
+;        jmp     dos_exit        ; then exit                              ;AN000;
+                                                                          ;AN000;
+;Dos_Chk_Ah2:                                                              ;AN000;
+;        cmp     ah,4                                     ;AN000;
+;        jae     Dos_Chk_Ah8                              ;AN000;
+;        mov     High_Sector,si  ; save HI sector word    ;AN000;
+;        mov     dx,di           ; save low sector        ;AN000;
+;        push    es                                       ;AN000;
+;        invoke  FIND_DPB        ; ds:si -> DPB           ;AN000;
+;        mov     bp,si                                    ;AN000;
+;        push    ds                                       ;AN000;
+;        pop     es              ; es:bp -> DPB           ;AN000;
+;        pop     ds              ; DS:BX-->Input buffer   ;AN000;
+;
+;        cmp     ah,2            ; absolute read ??                       ;AN000;
+;        jne     dos_chk_ah3     ; jump if not                            ;AN000;
+;
+;        invoke  DSKREAD         ; else do absolute read                  ;AN000;
+;        jmp     dos_exit        ; then return                            ;AN000;
+
+;Dos_Chk_Ah3:                                                              ;AN000;
+;        invoke  DSKWRITE        ; do absolute write                      ;AN000;
+;        jmp     dos_exit        ; then exit                              ;AN000;
+
+
+
+Dos_chk_ah32:                                                             ;AN000;
+         cmp     ah,32
+         jne     str_cmp                                    ;AN000;
+         CALL    GET_DOS_INFO    ; else get DOS information ;AN000;
+         jmp     SHORT dos_exit                             ;AN000;              ;AN000;
+str_cmp:                                                                  ;AN000;
+         mov     DS,[Temp_Var]    ; restore DS                            ;AN000;
+         cmp     ah,36                                      ;AN000;
+         jne     str_cpy                                    ;AN000;
+         invoke  strcmp          ; string compare           ;AN000;
+         jmp     SHORT dos_exit                                           ;AN000;
+str_cpy:                                                                  ;AN000;
+         cmp     ah,37                                      ;AN000;
+         jne     dos_error                                  ;AN000;
+         invoke  strcpy          ; string copy              ;AN000;
+         jmp     SHORT dos_exit                                           ;AN000;
+
+Dos_Error:                                                                ;AN000;
+         stc
+                                                            ;AN000;
+Dos_Exit:                                                                 ;AN000;
+         CLI                                                              ;AN000;
+         PUSHF                                                            ;AN000;
+         AND     [DOS34_FLAG],No_Force_I24_Fail                           ;AN000;
+         DEC     [INDOS]         ; exit DOS                               ;AN000;
+         CMP     [Callback_flag],0  ;from dosgroup
+         JZ      noSS_SP            ;yes                                  ;AN000;
+         MOV     [Callback_flag],0  ;                                     ;AN000;
+         POPF                                               ;AN000;
+         MOV     SP,CS:[Callback_SP];                                        ;AN000;
+         MOV     SS,CS:[Callback_SS]; restore user's SS:SP                   ;AN000;
+         JMP     SHORT DOSend                               ;AN000;
+noSS_SP:                                                    ;AN000;
+         POPF
+Dosend:
+         STI                     ;                                        ;AN000;
+
+         ret                     ;return                                  ;AN000;
+
+
+ENDPROC   IFS_DOSCALL                                       ;AN000;
+
+
+
+
+
+; ****************************************************************************
+; *
+; *      MODULE: STRATEGY
+; *
+; *      FUNCTION: Call Strategy Routine
+; *
+; *      FUNCTION: This procedure dispatches the IFS DOS service requests
+; *                by calling various DOS service functions
+; *
+; *      INPUT:    ES:BX ---> Device Request Header
+; *                AL  = Drive #
+; *
+; *                CALL STRATEGY
+; *
+; *      OUTPUT:   output of driver
+; *
+; *      INTERNAL REFERENCES:   None
+; *
+; *
+; *      EXTERNAL REFERENCES:   GETTHISDRV
+; *
+; *      NOTES:  None
+; *
+; *      REVISION HISTORY:  New
+; *
+; *************************************************************************
+
+;PROCEDURE   STRATEGY,NEAR                                                 ;AN000;
+
+;        INVOKE  FIND_DPB                ; get DPB from drive number       ;AN000;
+;                                        ; DS:SI-->DPB for drive           ;AN000;
+;        LDS     DI,DS:[SI.DPB_Driver_Addr]   ; get driver addres from DPB ;AN000;
+;        MOV     DX,WORD PTR [DI.SDEVSTRAT]    ;get strategy routine address;AN000;
+;Driver_Call:                                                              ;AN000;
+;        MOV     WORD PTR [CALLDEVAD],DX        ; save it                  ;AN000;
+;        MOV     WORD PTR [CALLDEVAD+2],DS      ;                          ;AN000;
+;        CALL    DWORD  PTR  [CALLDEVAD]        ; call strategy routine    ;AN000;
+;STRAT_Exit:                                                               ;AN000;
+;        RET                                    ; return                   ;AN000;
+
+;ENDPROC   STRATEGY                                                        ;AN000;
+
+
+
+
+
+
+
+
+; ****************************************************************************
+; *
+; *      MODULE: INTERRUPT
+; *
+; *      FUNCTION: This procedure calls the interrupt routine of the drive
+; *                specified in the drive#.
+; *
+; *      INPUT:    AL = Drive #
+; *
+; *
+; *      OUTPUT:   output of driver
+; *
+; *
+; *      INTERNAL REFERENCES:   None
+; *
+; *
+; *      EXTERNAL REFERENCES:   FIND_DPB
+; *
+; *      NOTES:  None
+; *
+; *      REVISION HISTORY:  New
+; *
+; *************************************************************************
+
+;PROCEDURE    INTERRUPT,NEAR                                               ;AN000;
+
+;        INVOKE  FIND_DPB                ; get DPB from drive number       ;AN000;
+;        LDS     DI,DS:[SI.DPB_Driver_Addr]   ; get driver addres from DPB ;AN000;
+;        MOV     DX,WORD PTR [DI.SDEVINT]     ; get interrupt routine addrs;AN000;
+;        JMP     Driver_Call                                               ;AN000;
+
+;ENDPROC  INTERRUPT                                                        ;AN000;
+
+
+
+
+
+
+
+
+; ************************************************************************* *
+; *
+; *      MODULE: Get_Dos_Info
+; *
+; *      FUNCTION: Get DOS information
+; *
+; *      INPUT:    AL = Dos info code
+; *
+; *      OUTPUT:   Dos Information  in registers
+; *
+; *      INTERNAL REFERENCES:   None
+; *
+; *
+; *      EXTERNAL REFERENCES:   READTIME, $GETEXTCNTRY
+; *
+; *      NOTES:  None
+; *
+; *      REVISION HISTORY:  New
+; *
+; *************************************************************************
+
+PROCEDURE  GET_DOS_INFO,NEAR                                               ;AN000;
+
+        cmp    al,0                     ; TIME and DATE ??                 ;AN000;
+        jne    chk_al1                                                     ;AN000;
+
+        Invoke  ReadTime                ; get time in CX:DX                ;AN000;
+
+        push    cx                      ; save time                        ;AN000;
+        push    dx                                                         ;AN000;
+
+        MOV     CX,[YEAR]                                                  ;AN000;
+        ADD     CX,1980                                                    ;AN000;
+        MOV     DX,WORD PTR [DAY]       ; fetch both day and month         ;AN000;
+
+        pop     bx                      ; bh = seconds  bl = hundredths    ;AN000;
+        pop     ax                      ; ah = hour  al = minutes          ;AN000;
+                                        ; cx = year  dh = month            ;AN000;
+        jmp     get_info_exit                                              ;AN000;
+
+
+chk_al1:                                ; Active process info ??           ;AN000;
+        cmp    al,1                                                        ;AN000;
+        jne    chk_al2                  ; no, try next                     ;AN000;
+        MOV     BX,[CurrentPDB]        ; BX = active process ID            ;AN000;
+        mov     DX,[User_ID]           ; User ID                           ;AN000;
+        jmp     get_info_exit          ; exit                              ;AN000;
+
+
+chk_al2:                                                                   ;AN000;
+;       cmp    al,2                    ; get CPSW info ??                  ;AN000;
+;       jne    chk_al3                 ; jump if not                       ;AN000;
+;       MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG                            ;AN000;
+;       MOV     BX,[SI.ccDosCodePage]  ; get dos code page id in BX        ;AN000;
+;       MOV     DL,CPSWFLAG            ; get CP Switch status              ;AN000;
+;       jmp     get_info_exit          ; exit                              ;AN000;
+
+
+chk_al3:
+;       cmp    al,3                    ; get CTRL BRK status ??            ;AN000;
+;       jne    chk_al4                                                     ;AN000;
+;       mov    dl,CNTCFLAG             ; DL = break status flag            ;AN000;
+;       jmp    get_info_exit           ; exit                              ;AN000;
+
+
+chk_al4:
+;       cmp    al,4                    ; get Verify status ??              ;AN000;
+;       jne    chk_al5
+;       mov    dl,VERFLG               ; DL = verify status flag           ;AN000;
+;       jmp    get_info_exit           ; exit                              ;AN000;
+
+
+chk_al5:
+        cmp    al,5                   ; Config.sys info ??                 ;AN000;
+        jne    chk_al6                                                     ;AN000;
+
+        mov     si,OFFSET DOSGROUP:SYSINITVAR    ; DS:SI-->SysInitVar      ;AN000;
+        push    ds                                                         ;AN000;
+        push    si                                                         ;AN000;
+        lds     si,[si].Sysi_SFT      ; get SFT address                    ;AN000;
+        mov     ax,[si].SFCount       ; get number of files                ;AN000;
+        lds     si,[si].SFlink        ; get next SFT table                 ;AN000;
+        cmp     si,-1                 ; end of table                       ;AN000;
+        jz      nomore                ;                                    ;AN000;
+        add     ax,[si].SFCount       ;                                    ;AN000;
+nomore:                               ;                                    ;AN000;
+        mov     es:[di].files,ax         ; save files= value               ;AN000;
+        pop     si                                                         ;AN000;
+        pop     ds                                                         ;AN000;
+        mov     ax,[si].Sysi_MaxSec      ; get maximum sector size         ;AN000;
+        mov     es:[di].secsize,ax       ; save files= value               ;AN000;
+        mov     ax,[si].Sysi_Keep        ;                                 ;AN000;
+        mov     es:[di].fcbs2,ax         ;                                 ;AN000;
+        lds     si,[si].Sysi_FCB      ; get FCB address                    ;AN000;
+        mov     ax,[si].SFCount       ; get number of fcbs                 ;AN000;
+        mov     es:[di].fcbs1,ax         ; save fcbs=  value               ;AN000;
+        jmp     get_info_exit                                              ;AN000;
+
+
+
+chk_al6:                                                                  ;AN000;
+        cmp    al,6                     ; get machine name ??             ;AN000;
+        jne    chk_al7                  ; no, check next function         ;AN000;
+        context  DS                                                       ;AN000;
+        mov     si,offset DOSGroup:MyName   ; DS:SI-->name string         ;AN000;
+                                        ; ES:DI-->return buffer           ;AN000;
+        add     di,2                    ; skip max return size            ;AN000;
+        mov     cx,15                   ; name size                       ;AN000;
+Chk6_Loop:                                                                ;AN000;
+        rep     movsb                   ; copy machine name to return buffer;AN000;
+        xor     al,al                   ; set 16th byte is 0               ;AN000;
+        stosb                                                              ;AN000;
+        jmp     get_info_exit           ; return                           ;AN000;
+                                                                           ;AN000;
+                                                                           ;AN000;
+Chk_Al7:                                                                   ;AN000;
+;       cmp     al,7                    ; get country information ??       ;AN000;
+;       jne     chk_al8                 ; no, try next function            ;AN000;
+;       mov     al,dl                   ; AL = info ID                     ;AN000;
+;       mov     bx,-1                   ; select active code page          ;AN000;
+;       mov     dx,-1                   ; select active country            ;AN000;
+;       mov     cx,-1                   ; get all                          ;AN000;
+;       INVOKE  $getExtCntry            ; get country info                 ;AN000;
+;       jmp     SHORT Get_Info_Exit     ; exit                             ;AN000;
+
+
+Chk_Al8:                                                                   ;AN000;
+        cmp     al,8                    ; get share retry count ??         ;AN000;
+        jne     bad_param               ; no, Bad parameter                ;AN000;
+        mov     bx,RetryCount           ; BX = Share retry count           ;AN000;
+        jmp     SHORT Get_Info_Exit           ; exit                       ;AN000;
+
+Bad_Param:                              ; Bad parameter                    ;AN000;
+        stc                             ;                                  ;AN000;
+
+Get_Info_Exit:                          ; exit                             ;AN000;
+
+        ret                                                                ;AN000;
+
+
+ENDPROC   GET_DOS_INFO                                                     ;AN000;
+
+
+
+
+
+
+
+
+; ************************************************************************* *
+; *
+; *      MODULE: $IFS_IOCTL
+; *
+; *      FUNCTION: Handle IFS Driver IOCTL calls
+; *
+; *      INPUT:    AH = 6B  function code
+; *                AL = XX  00 = Drive IOCTL, 01 = Psudo device IOCTL
+; *                CX = 00  Reserved
+; *                BL = XX  Device Number
+; *                DS:DX    Pointer to Buffer
+; *
+; *      OUTPUT:
+; *                IF CARRY = 0  No Error
+; *                IF CARRY = 1  Error
+; *                      AX = ERROR CODE
+; *
+; *      INTERNAL REFERENCES:   None
+; *
+; *
+; *      EXTERNAL REFERENCES:   INT 2F
+; *
+; *      NOTES:  None
+; *
+; *      REVISION HISTORY:  New
+; *************************************************************************
+
+PROCEDURE  $IFS_IOCTL,NEAR                                                 ;AN000;
+
+        PUSH    AX                                                         ;AN000;
+        MOV     AX,(multnet SHL 8) OR 47    ; pass control to IFS Func     ;AN000;
+        INT     2FH                                                        ;AN000;
+        POP     BX                                                         ;AN000;
+        JC      ABB_ERR                                                    ;AN000;
+        TRANSFER   SYS_RET_OK                 ; return                     ;AN000;
+
+ABB_ERR:                                                                   ;AN000;
+        transfer SYS_RET_ERR                ; error return                 ;AN000;
+
+ENDPROC  $IFS_IOCTL                                                        ;AN000;
+
+
+
+CODE    ENDS                                                               ;AN000;
+    END                                                                    ;AN000;
+
+
diff --git a/v4.0/src/DOS/IOCTL.ASM b/v4.0/src/DOS/IOCTL.ASM
new file mode 100644
index 0000000..8007244
--- /dev/null
+++ b/v4.0/src/DOS/IOCTL.ASM
@@ -0,0 +1,745 @@
+;       SCCSID = @(#)IOCTL.INC  1.15 85/09/05
+TITLE   IOCTL - IOCTL system call
+NAME    IOCTL
+
+;
+;
+; IOCTL system call.
+;
+;
+; $IOCTL
+;
+;   Revision history:
+;
+;       Created: ARR 4 April 1983
+;
+;       GenericIOCTL added:             KGS     22 April 1985
+;
+;       A000    version 4.00    Jan. 1988
+
+
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include ioctl.inc
+include ifssym.inc                       ;AN000;
+.cref
+.list
+
+        i_need  THISCDS,DWORD
+        i_need  IOCALL,BYTE
+        i_need  IOMED,BYTE
+        i_need  IOSCNT,WORD
+        i_need  IOXAD,DWORD
+        I_need  RetryCount,WORD
+        I_need  RetryLoop,WORD
+        I_need  EXTERR_LOCUS,BYTE
+        I_need  OPENBUF,BYTE
+        I_need  ExtErr,WORD
+        I_need  DrvErr,BYTE
+        I_need  USER_IN_AX,WORD                 ;AN000;
+        I_need  Temp_Var2,WORD                  ;AN000;
+
+BREAK <IOCTL - munge on a handle to do device specific stuff>
+
+;
+;   Assembler usage:
+;           MOV     BX, Handle
+;           MOV     DX, Data
+;
+;       (or LDS     DX,BUF
+;           MOV     CX,COUNT)
+;
+;           MOV     AH, Ioctl
+;           MOV     AL, Request
+;           INT     21h
+;
+;   AH = 0  Return a combination of low byte of sf_flags and device driver
+;           attribute word in DX, handle in BX:
+;           DH = high word of device driver attributes
+;           DL = low byte of sf_flags
+;        1  Set the bits contained in DX to sf_flags.  DH MUST be 0.  Handle
+;           in BX.
+;        2  Read CX bytes from the device control channel for handle in BX
+;           into DS:DX.  Return number read in AX.
+;        3  Write CX bytes to the device control channel for handle in BX from
+;           DS:DX.  Return bytes written in AX.
+;        4  Read CX bytes from the device control channel for drive in BX
+;           into DS:DX.  Return number read in AX.
+;        5  Write CX bytes to the device control channel for drive in BX from
+;           DS:DX.  Return bytes written in AX.
+;        6  Return input status of handle in BX. If a read will go to the
+;           device, AL = 0FFh, otherwise 0.
+;        7  Return output status of handle in BX. If a write will go to the
+;           device, AL = 0FFh, otherwise 0.
+;        8  Given a drive in BX, return 1 if the device contains non-
+;           removable media, 0 otherwise.
+;        9  Return the contents of the device attribute word in DX for the
+;           drive in BX.  0200h is the bit for shared.  1000h is the bit for
+;           network. 8000h is the bit for local use.
+;        A  Return 8000h if the handle in BX is for the network or not.
+;        B  Change the retry delay and the retry count for the system. BX is
+;           the count and CX is the delay.
+;
+;   Error returns:
+;           AX = error_invalid_handle
+;              = error_invalid_function
+;              = error_invalid_data
+;
+;-------------------------------------------------------------------------------
+;
+;   This is the documentation copied from DOS 4.0 it is much better
+;   than the above
+;
+;       There are several basic forms of IOCTL calls:
+;
+;
+;       ** Get/Set device information:  **
+;
+;       ENTRY   (AL) = function code
+;                 0 - Get device information
+;                 1 - Set device information
+;               (BX) = file handle
+;               (DX) = info for "Set Device Information"
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (DX) = info for "Get Device Information"
+;       USES    ALL
+;
+;
+;       **  Read/Write Control Data From/To Handle  **
+;
+;       ENTRY   (AL) = function code
+;                 2 - Read device control info
+;                 3 - Write device control info
+;               (BX) = file handle
+;               (CX) = transfer count
+;               (DS:DX) = address for data
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (AX) = count of bytes transfered
+;       USES    ALL
+;
+;
+;       **  Read/Write Control Data From/To Block Device  **
+;
+;       ENTRY   (AL) = function code
+;                 4 - Read device control info
+;                 5 - Write device control info
+;               (BL) = Drive number (0=default, 1='A', 2='B', etc)
+;               (CX) = transfer count
+;               (DS:DX) = address for data
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (AX) = count of bytes transfered
+;       USES    ALL
+;
+;
+;       **  Get Input/Output Status  **
+;
+;       ENTRY   (AL) = function code
+;                 6 - Get Input status
+;                 7 - Get Output Status
+;               (BX) = file handle
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (AL) = 00 if not ready
+;                 (AL) = FF if ready
+;       USES    ALL
+;
+;
+;       **  Get Drive Information  **
+;
+;       ENTRY   (AL) = function code
+;                 8 - Check for removable media
+;                 9 - Get device attributes
+;               (BL) = Drive number (0=default, 1='A', 2='B', etc)
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (AX) = 0/1 media is removable/fixed (func. 8)
+;                 (DX) = device attribute word (func. 9)
+;       USES    ALL
+;
+;
+;       **  Get Redirected bit  **
+;
+;       ENTRY   (AL) = function code
+;                 0Ah - Network stuff
+;               (BX) = file handle
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (DX) = SFT flags word, 8000h set if network file
+;       USES    ALL
+;
+;
+;       **  Change sharer retry parameters  **
+;
+;       ENTRY   (AL) = function code
+;                 0Bh - Set retry parameters
+;               (CX) = retry loop count
+;               (DX) = number of retries
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;       USES    ALL
+;
+;
+;   =================================================================
+;
+;       **  New Standard Control  **
+;
+;       ALL NEW IOCTL FACILITIES SHOULD USE THIS FORM.  THE OTHER
+;       FORMS ARE OBSOLETE.
+;
+;   =================================================================
+;
+;       ENTRY   (AL) = function code
+;                 0Ch - Control Function subcode
+;               (BX) = File Handle
+;               (CH) = Category Indicator
+;               (CL) = Function within category
+;               (DS:DX) = address for data, if any
+;               (SI) = Passed to device as argument, use depends upon function
+;               (DI) = Passed to device as argument, use depends upon function
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (SI) = Return value, meaning is function dependent
+;                 (DI) = Return value, meaning is function dependent
+;                 (DS:DX) = Return address, use is function dependent
+;       USES    ALL
+;
+;    ============== Generic IOCTL Definitions for DOS 3.2 ============
+;     (See dos/ioctl.mac for more info)
+;
+;       ENTRY   (AL) = function code
+;                 0Dh - Control Function subcode
+;               (BL) = Drive Number (0 = Default, 1= 'A')
+;               (CH) = Category Indicator
+;               (CL) = Function within category
+;               (DS:DX) = address for data, if any
+;               (SI) = Passed to device as argument, use depends upon function
+;               (DI) = Passed to device as argument, use depends upon function
+;
+;       EXIT    'C' set if error
+;                 (AX) = error code
+;               'C' clear if OK
+;                 (DS:DX) = Return address, use is function dependent
+;       USES    ALL
+;
+
+        procedure   $IOCTL,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     SI,DS                   ; Stash DS for calls 2,3,4 and 5
+        context DS
+        CMP     AL,3
+        JBE     ioctl_check_char        ; char  device
+        JMP     ioctl_check_block       ; Block device
+ioctl_check_char:
+        invoke  SFFromHandle            ; ES:DI -> SFT
+        JNC     ioctl_check_permissions ; have valid handle
+ioctl_bad_handle:
+        error   error_invalid_handle
+
+ioctl_check_permissions:
+        CMP     AL,2
+        JAE     ioctl_control_string
+        CMP     AL,0
+        MOV     AL,BYTE PTR ES:[DI.sf_flags]; Get low byte of flags
+        JZ      ioctl_read              ; read the byte
+        PUSH    DX                      ;AN000;MS.
+        AND     DH,0FEH                 ;AN000;MS.allow DH=01H
+        POP     DX                      ;AN000;MS.
+        JZ      ioctl_check_device      ; can I set with this data?
+        error   error_invalid_data      ; no DH <> 0
+
+ioctl_bad_funj2:
+        JMP     ioctl_bad_fun
+
+ioctl_check_device:
+        TEST    AL,devid_device         ; can I set this handle?
+        JZ      do_exception            ; no, it is a file.
+        OR      DL,devid_device         ; Make sure user doesn't turn off the
+                                        ;   device bit!! He can muck with the
+                                        ;   others at will.
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        MOV     BYTE PTR ES:[DI.sf_flags],DL  ;AC000;MS.; Set flags
+do_exception:
+        OR      BYTE PTR ES:[DI.sf_flags+1],DH;AN000;MS.;set 100H bit for disk full
+
+        transfer    SYS_RET_OK
+
+
+
+
+
+ioctl_read:
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        XOR     AH,AH
+        TEST    AL,devid_device         ; Should I set high byte
+        JZ      ioctl_no_high           ; no
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        LES     DI,ES:[DI.sf_devptr]    ; Get device pointer
+        MOV     AH,BYTE PTR ES:[DI.SDEVATT+1]   ; Get high byte
+ioctl_no_high:
+        MOV     DX,AX
+        invoke  get_user_stack
+        MOV     [SI.user_DX],DX
+        transfer    SYS_RET_OK
+
+ioctl_control_string:
+        TEST    ES:[DI.sf_flags],devid_device   ; can I?
+        JNZ     ioctl_ctl_str_1
+        JMP     ioctl_bad_fun                   ; No it is a file
+ioctl_ctl_str_1:
+        TEST    ES:[DI.sf_flags],sf_isnet       ;AN000;IFS.; IFS ?
+        JZ      localrw                         ;AN000;IFS.; no
+        JMP     callifs                         ;AN000;IFS.; call IFS
+localrw:
+        MOV     [EXTERR_LOCUS],errLOC_SerDev
+        LES     DI,ES:[DI.sf_devptr]    ; Get device pointer
+        XOR     BL,BL                   ; Unit number of char dev = 0
+        JMP     ioctl_do_string
+
+ioctl_get_devj:
+        JMP     ioctl_get_dev
+
+ioctl_check_block:
+        DEC     AL
+        DEC     AL                      ; 4=2,5=3,6=4,7=5,8=6,9=7,10=8,11=9
+        CMP     AL,3
+        JBE     ioctl_get_devj
+        CMP     AL,6
+        JAE     ioctl_rem_media_check
+
+        MOV     AH,1
+        SUB     AL,4                    ; 6=0,7=1
+        JZ      ioctl_get_status
+        MOV     AH,3
+ioctl_get_status:
+        PUSH    AX
+        invoke  GET_IO_SFT
+        POP     AX
+        JNC     DO_IOFUNC
+        JMP     ioctl_bad_handle        ; invalid SFT
+
+DO_IOFUNC:
+        invoke  IOFUNC
+        MOV     AH,AL
+        MOV     AL,0FFH
+        JNZ     ioctl_status_ret
+        INC     AL
+ioctl_status_ret:
+        transfer SYS_RET_OK
+
+ioctl_rem_media_check:                  ; 4=2,5=3,6=4,7=5,8=6,9=7,10=8,11=9
+        JE      ioctl_rem_mediaj
+
+        SUB     AL,7                    ; 9=0,10=1,11=2,12=3,13=4,14=5,15=6
+        JNZ     Rem_med_chk_1
+        JMP     Ioctl_Drive_attr
+
+ioctl_rem_mediaj:
+        jmp     ioctl_rem_media
+
+ioctl_bad_funj4:
+        jmp     ioctl_bad_fun
+
+Rem_med_chk_1:
+
+        DEC     AL                      ; 10=0,11=1,12=2,13=3,14=4,15=5
+        jnz     Set_Retry_chk
+        Jmp     Ioctl_Handle_redirj
+
+Set_Retry_chk:
+        DEC     AL                      ; 11=0,12=1,13=2,14=3,15=4
+        JZ      Set_Retry_Parameters
+
+        DEC     AL                      ; 12=0,13=1,14=2,15=3
+        JZ      GENERICIOCTLHANDLE
+
+        DEC     AL                      ; 13=0,14=1,15=2
+        JZ      GENERICIOCTL
+
+        CMP     AL,2
+        JA      ioctl_bad_funj4
+        JMP     ioctl_drive_owner
+Set_Retry_Parameters:
+        MOV     RetryLoop,CX            ; 0 retry loop count allowed
+        OR      DX,DX                   ; zero retries not allowed
+        JNZ     goodtr
+        JMP     IoCtl_Bad_Fun
+goodtr:
+        MOV     RetryCount,DX           ; Set new retry count
+doneok:
+        transfer        Sys_Ret_Ok      ; Done
+
+; Generic IOCTL entry point.
+;       here we invoke the Generic IOCTL using the IOCTL_Req structure.
+;       SI:DX -> Users Device Parameter Table
+;       IOCALL -> IOCTL_Req structure
+GENERICIOCTLHANDLE:
+        invoke  SFFromHandle            ; Get SFT for device.
+        jnc     goodh
+        JMP     ioctl_bad_handlej
+goodh:
+;       test    word ptr [DI.sf_flags],sf_isnet
+        CALL    TEST_IFS_REMOTE         ;AN000;;IFS. test if remote
+        JZ      okokok                  ;AN000;;IFS.
+        jmp     ioctl_bad_fun           ; Cannot do this over net.
+okokok:
+        TEST    [DI.sf_flags],sf_isnet  ;AN000;IFS.; local IFS
+        JNZ     callifs                 ;AN000;IFS.; yes
+
+
+        mov     [EXTERR_LOCUS],ErrLOC_Serdev
+        les     di,es:[di.sf_devptr]    ; Get pointer to device.
+        jmp     short Do_GenIOCTL
+
+GENERICIOCTL:
+        mov     [EXTERR_LOCUS],ErrLOC_Disk
+        cmp     ch,IOC_DC               ; Only disk devices are allowed to use
+        jne     ioctl_bad_fun           ; no handles with Generic IOCTL.
+        CALL    Check_If_Net            ; ES:DI := Get_hdr_block of device in BL
+        JNZ     ioctl_bad_fun           ; There are no "net devices", and they
+        PUSH    ES                      ;   certainly don't know how to do this ;AN000;
+        PUSH    DI                               ;AN000;IFS.
+        LES     DI,[THISCDS]                     ;AN000;IFS.     ;
+        TEST    ES:[DI.curdir_flags],curdir_isnet;AN000;IFS.     ; local IFS ?
+        POP     DI                               ;AN000;IFS.
+        POP     ES                               ;AN000;IFS.
+        JZ      Do_GenIOCTL                      ;AN000;IFS.     ; no
+callifs:
+        CMP     byte ptr [User_In_AX+1],69H  ;AN000;         ;IFS.
+        JNZ     is44xx                       ;AN000;         ;IFS.
+        MOV     AX,440DH                     ;AN000;         ;IFS.
+        PUSH    AX                           ;AN000;         ;IFS.
+        JMP     SHORT callrose               ;AN000;         ;IFS.
+is44xx:
+        PUSH    [User_In_AX]                 ;AN000;         ;IFS. call IFSFUNC
+callrose:
+        MOV     DS,SI                        ;AN000;         ;IFS.
+        MOV     AX,(multNET SHL 8) or  43    ;AN000;         ;IFS.
+        INT     2FH                          ;AN000;         ;IFS.
+        POP     BX                           ;AN000;         ;IFS.
+        JNC     doneok                       ;AN000;         ;IFS.
+        MOV     DI,AX                        ;AN000;         ;IFS.
+        JMP     device_err                   ;AN000;         ;IFS.
+Do_GenIOCTL:
+        test    ES:[DI.SDEVATT],DEV320  ; Can device handle Generic IOCTL funcs
+        jz      ioctl_bad_fun
+        PUSH    ES                      ; DEVIOCALL2 expects Device header block
+        PUSH    DI                      ; in DS:SI
+        ;set up Generic IOCTL Request Block
+        MOV     byte ptr IOCALL.ReqLen,(size IOCTL_Req)
+        MOV     byte ptr IOCALL.ReqFunc,GENIOCTL
+        MOV     byte ptr IOCALL.ReqUnit,BL
+        MOV     byte ptr IOCALL.MajorFunction,CH
+        MOV     byte ptr IOCALL.MinorFunction,CL
+        MOV     word ptr IOCALL.Reg_SI,SI
+        MOV     word ptr IOCALL.Reg_DI,DI
+        MOV     word ptr IOCALL.GenericIOCTL_Packet,DX
+        MOV     word ptr IOCALL.GenericIOCTL_Packet + 2,SI
+
+        MOV     BX,offset DOSGROUP:IOCALL
+
+        PUSH    SS
+        POP     ES
+
+ASSUME DS:NOTHING                       ; DS:SI -> Device header.
+        POP     SI
+        POP     DS
+        jmp     ioctl_do_IO             ; Perform Call to device driver
+
+IOCtl_Handle_RedirJ:
+        JMP     IOCTL_Handle_Redir
+ioctl_bad_fun:
+        error   error_invalid_function
+
+ioctl_bad_handlej:
+        jmp     ioctl_bad_handle
+
+; Function 8
+ioctl_rem_media:
+        CALL    Check_If_Net
+        JNZ     ioctl_bad_fun           ; There are no "net devices", and they
+                                        ;   certainly don't know how to do this
+                                        ;   call.
+        TEST    ES:[DI.SDEVATT],DEVOPCL ; See if device can
+        JZ      ioctl_bad_fun           ; NO
+        MOV     [IOCALL.REQFUNC],DEVRMD
+        MOV     AL,REMHL
+        MOV     AH,BL                   ; Unit number
+        MOV     WORD PTR [IOCALL.REQLEN],AX
+        XOR     AX,AX
+        MOV     [IOCALL.REQSTAT],AX
+        PUSH    ES
+        POP     DS
+ASSUME  DS:NOTHING
+        MOV     SI,DI                   ; DS:SI -> driver
+        PUSH    SS
+        POP     ES
+        MOV     BX,OFFSET DOSGROUP:IOCALL   ; ES:BX -> Call header
+        SaveReg <DS,SI>
+        invoke  DEVIOCALL2
+        RestoreReg <SI,DS>
+        MOV     AX,[IOCALL.REQSTAT]     ; Get Status word
+        AND     AX,STBUI                ; Mask to busy bit
+        MOV     CL,9
+        SHR     AX,CL                   ; Busy bit to bit 0
+        transfer    SYS_RET_OK
+
+; Function 9
+Ioctl_Drive_attr:
+
+;;;;;   MOV     AL,BL                   ;AC000;; Drive
+;;;;;   invoke  GETTHISDRV              ;AC000;
+;;;;;                                   ;AC000;
+;;;;;   JC      ioctl_drv_err           ; drive not valid
+        call    Get_Driver_BL
+        JC      ioctl_drv_err           ; drive not valid
+        MOV     AX,[Temp_Var2]          ;AN000;IFS.
+        mov     dx,word ptr es:[di.SDEVATT]     ; get device attribute word
+        MOV     BL,AL                   ; Phys letter to BL (A=0)
+        LES     DI,[THISCDS]
+;;;;;   TEST    ES:[DI.curdir_flags],curdir_isnet
+        CALL    TEST_IFS_REMOTE2        ;AN000;IFS. test if remote
+        JZ      IOCTLShare
+        OR      DX,1000h
+IOCTLShare:
+        Context DS
+ASSUME  DS:NOTHING
+        MOV     SI,OFFSET DOSGROUP:OPENBUF
+        ADD     BL,"A"
+        MOV     [SI],BL
+        MOV     WORD PTR [SI+1],003AH   ; ":",0
+        MOV     AX,0300H
+        CLC
+        INT     int_IBM
+        JNC     ioctlLocal              ; Not shared
+        OR      DX,0200H                ; Shared, bit 9
+IOCTLLocal:
+        TEST    ES:[DI].curdir_flags,curdir_local
+        JZ      ioctl_set_dx
+        OR      DX,8000h
+
+ioctl_set_DX:
+        invoke  get_user_stack
+        MOV     [SI.user_DX],DX
+        transfer    SYS_RET_OK
+
+ioctl_drv_err:
+        MOV     AL,[DrvErr]             ;AN000;IFS. DrvErr is saved in GetThisDrv
+        transfer SYS_RET_ERR            ;AN000;IFS.
+
+; Function 10
+Ioctl_Handle_redir:
+        invoke  SFFromHandle            ; ES:DI -> SFT
+        JNC     ioctl_got_sft           ; have valid handle
+        error   error_invalid_handle
+
+ioctl_got_sft:
+        MOV     DX,ES:[DI.sf_flags]     ; Get flags
+        JMP     ioctl_set_DX
+
+ioctl_bad_funj:
+        JMP     ioctl_bad_fun
+
+ioctl_get_dev:
+        DOSAssume   CS,<DS>,"IOCTL/IOCtl_Get_Dev"
+        CALL    Check_If_Net
+        JNZ     ioctl_bad_funj          ; There are no "net devices", and they
+                                        ;   certainly don't know how to do this
+                                        ;   call.
+ioctl_do_string:
+        TEST    ES:[DI.SDEVATT],DEVIOCTL; See if device accepts control
+        JZ      ioctl_bad_funj          ; NO
+        DEC     AL
+        DEC     AL
+        JZ      ioctl_control_read
+        MOV     [IOCALL.REQFUNC],DEVWRIOCTL
+        JMP     SHORT ioctl_control_call
+ioctl_control_read:
+        MOV     [IOCALL.REQFUNC],DEVRDIOCTL
+ioctl_control_call:
+        MOV     AL,DRDWRHL
+ioctl_setup_pkt:
+        MOV     AH,BL                   ; Unit number
+        MOV     WORD PTR [IOCALL.REQLEN],AX
+        XOR     AX,AX
+        MOV     [IOCALL.REQSTAT],AX
+        MOV     [IOMED],AL
+        MOV     [IOSCNT],CX
+        MOV     WORD PTR [IOXAD],DX
+        MOV     WORD PTR [IOXAD+2],SI
+        PUSH    ES
+        POP     DS
+ASSUME  DS:NOTHING
+        MOV     SI,DI                   ; DS:SI -> driver
+        PUSH    SS
+        POP     ES
+        MOV     BX,OFFSET DOSGROUP:IOCALL   ; ES:BX -> Call header
+ioctl_do_IO:
+        invoke  DEVIOCALL2
+        TEST    [IOCALL.REQSTAT],STERR      ;Error?
+        JNZ     Ioctl_string_err
+        MOV     AX,[IOSCNT]             ; Get actual bytes transferred
+        transfer    SYS_RET_OK
+
+Ioctl_string_err:
+        MOV     DI,[IOCALL.REQSTAT]     ;Get Error
+device_err:
+        AND     DI,STECODE              ; mask out irrelevant bits
+        MOV     AX,DI
+        invoke  SET_I24_EXTENDED_ERROR
+        mov     ax, cs:extErr
+        transfer    SYS_RET_ERR
+
+Get_Driver_BL:
+        DOSAssume   CS,<DS>,"Get_Driver_BL"
+        ASSUME  ES:NOTHING
+; BL is drive number (0=default)
+; Returns pointer to device in ES:DI, unit number in BL if carry clear
+; No regs modified
+
+        PUSH    AX
+        MOV     AL,BL                   ; Drive
+        invoke  GETTHISDRV
+        JNC     ioctl_goodrv            ;AC000;IFS.
+        CMP     AL,error_not_dos_disk   ;AN000;IFS.   if unknow media then
+        JZ      ioctl_goodrv            ;AN000;IFS.      let it go
+        STC                             ;AN000;IFS.   else
+        JMP     SHORT ioctl_bad_drv     ;AN000;IFS.      error
+ioctl_goodrv:
+        XOR     BL,BL                   ; Unit zero on Net device
+        MOV     [EXTERR_LOCUS],errLOC_Net
+        LES     DI,[THISCDS]
+;       TEST    ES:[DI.curdir_flags],curdir_isnet
+        CALL    TEST_IFS_REMOTE2        ;AN000;;IFS. test if remote
+        LES     DI,ES:[DI.curdir_devptr]; ES:DI -> Dpb or net dev
+        JNZ     got_dev_ptr             ; Is net
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        MOV     BL,ES:[DI.dpb_UNIT]     ; Unit number
+        LES     DI,ES:[DI.dpb_driver_addr]  ; Driver addr
+got_dev_ptr:
+        CLC
+        MOV     [Temp_Var2],AX               ;AN000;IFS.
+ioctl_bad_drv:
+        POP     AX
+        return
+
+;
+; Checks if the device is over the net or not. Returns result in ZERO flag.
+; If no device is found, the return address is popped off the stack, and a
+; jump is made to ioctl_drv_err.
+;
+; On Entry:
+; Registers same as those for Get_Driver_BL
+;
+; On Exit:
+; ZERO flag     - set if not a net device
+;               - reset if net device
+; ES:DI -> the device
+;
+Check_If_Net:
+        CALL    Get_Driver_BL
+        JC      ioctl_drv_err_pop       ; invalid drive letter
+entry TEST_IFS_REMOTE2
+        PUSH    ES
+        PUSH    DI
+        LES     DI,[THISCDS]
+        TEST    ES:[DI.curdir_flags],curdir_isnet
+        JZ      belocal                        ;AN000;   ;IFS.
+        LES     DI,ES:[DI.curdir_ifs_hdr]      ;AN000;   ;IFS.  test if remote
+TEST_REMOTE:                                   ;AN000;
+        TEST    ES:[DI.ifs_attribute],IFSREMOTE;AN000;   ;IFS.
+belocal:
+        POP     DI
+        POP     ES
+        ret
+
+ioctl_drv_err_pop:
+        pop     ax                      ; pop off return address
+        jmp     ioctl_drv_err
+
+ioctl_bad_funj3:
+        jmp     ioctl_bad_fun
+
+ioctl_string_errj:
+        jmp     ioctl_string_err
+
+; Functions 14 and 15
+ioctl_drive_owner:
+        Call    Check_If_Net
+        JNZ     ioctl_bad_funj3         ; There are no "net devices", and they
+                                        ;   certainly don't know how to do this
+                                        ;   call.
+        TEST    ES:[DI.SDEVATT],DEV320  ; See if device can handle this
+        JZ      ioctl_bad_funj3         ; NO
+        dec     al
+        jz      GetOwner
+        MOV     [IOCALL.REQFUNC],DEVSETOWN
+        jmp     short ioctl_do_own
+GetOwner:
+        MOV     [IOCALL.REQFUNC],DEVGETOWN
+ioctl_do_own:
+        MOV     AL,OWNHL
+        MOV     AH,BL                   ; Unit number
+        MOV     WORD PTR [IOCALL.REQLEN],AX
+        XOR     AX,AX
+        MOV     [IOCALL.REQSTAT],AX
+        PUSH    ES
+        POP     DS
+ASSUME  DS:NOTHING
+        MOV     SI,DI                   ; DS:SI -> driver
+        PUSH    SS
+        POP     ES
+        MOV     BX,OFFSET DOSGROUP:IOCALL   ; ES:BX -> Call header
+        SaveReg <DS,SI>
+        invoke  DEVIOCALL2
+        RestoreReg <SI,DS>
+        test    [IOCALL.REQSTAT],STERR
+        jnz     ioctl_string_errj
+        MOV     AL,BYTE PTR [IOCALL.REQUNIT]    ; Get owner returned by device
+                                                ; owner returned is 1-based.
+        transfer    SYS_RET_OK
+
+EndProc $IOCTL
+
+
+;Input: ES:DI -> SFT
+;Functions: test if a remote file
+;Output: Z flag set, local file
+;
+
+        procedure   TEST_IFS_REMOTE,NEAR  ;AN000;
+        ASSUME  DS:NOTHING,ES:NOTHING     ;AN000;
+
+        TEST    ES:[DI.sf_flags],sf_isnet ;AN000;;IFS.  ifs ?
+        JZ      nonifs                    ;AN000;;IFS.  no
+        PUSH    ES                     ;AN000;;IFS. save regs
+        PUSH    DI                     ;AN000;;IFS.
+        LES     DI,ES:[DI.sf_IFS_hdr]  ;AN000;;IFS. get ifs header
+        JMP     TEST_REMOTE            ;AN000;;IFS.
+nonifs:                                ;AN000;
+        return                         ;AN000;;IFS.
+EndProc TEST_IFS_REMOTE                ;AN000;
+
+CODE ENDS
+END
diff --git a/v4.0/src/DOS/ISEARCH.ASM b/v4.0/src/DOS/ISEARCH.ASM
new file mode 100644
index 0000000..bfae821
--- /dev/null
+++ b/v4.0/src/DOS/ISEARCH.ASM
@@ -0,0 +1,364 @@
+;       SCCSID = @(#)isearch.asm        1.1 85/04/10
+TITLE   DOS_SEARCH - Internal SEARCH calls for MS-DOS
+NAME    DOS_SEARCH
+; Low level routines for doing local and NET directory searches
+;
+;   DOS_SEARCH_FIRST
+;   DOS_SEARCH_NEXT
+;   RENAME_NEXT
+;
+;   Revision history:
+;
+;       Created: ARR 30 March 1983
+;       A000    version 4.00  Jan. 1988
+;       A001    PTM 3564 -- serach for fastopen
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+INCLUDE fastopen.inc
+INCLUDE fastxxxx.inc
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  NoSetDir,BYTE
+        i_need  Creating,BYTE
+        i_need  THISCDS,DWORD
+        i_need  CURBUF,DWORD
+        i_need  DMAADD,DWORD
+        i_need  DummyCDS,128
+        i_need  THISDPB,DWORD
+        i_need  THISDRV,BYTE
+        i_need  NAME1,BYTE
+        i_need  ATTRIB,BYTE
+        i_need  DIRSTART,WORD
+        i_need  LASTENT,WORD
+        i_need  FOUND_DEV,BYTE
+        I_need  WFP_Start,WORD
+        i_need  EXTERR_LOCUS,BYTE
+        i_need  FastopenFlg,BYTE
+        I_need  DOS34_FLAG,WORD
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [SATTRIB] Is attribute of search, determines what files can be found
+;       [DMAADD] Points to 53 byte buffer
+; Function:
+;       Initiate a search for the given file spec
+; Outputs:
+;       CARRY CLEAR
+;           The 53 bytes ot DMAADD are filled in as follows:
+;
+;       LOCAL
+;           Drive Byte (A=1, B=2, ...) High bit clear
+;               NEVER STORE DRIVE BYTE AFTER  found_it
+;           11 byte search name with Meta chars in it
+;           Search Attribute Byte, attribute of search
+;           WORD LastEnt value
+;           WORD DirStart
+;           4 byte pad
+;           32 bytes of the directory entry found
+;       NET
+;           21 bytes First byte has high bit set
+;           32 bytes of the directory entry found
+;
+;       CARRY SET
+;           AX = error code
+;               error_no_more_files
+;                       No match for this file
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+; DS preserved, others destroyed
+
+        procedure   DOS_SEARCH_FIRST,NEAR
+        DOSAssume   CS,<DS>,"DOS_Search_First"
+        ASSUME  ES:NOTHING
+
+        LES     DI,[THISCDS]
+        CMP     DI,-1
+        JNZ     TEST_RE_NET
+IF NOT Installed
+        transfer NET_SEQ_SEARCH_FIRST
+ELSE
+        MOV     AX,(multNET SHL 8) OR 25
+        INT     2FH
+        return
+ENDIF
+
+TEST_RE_NET:
+        TEST    ES:[DI.curdir_flags],curdir_isnet
+        JZ      LOCAL_SEARCH_FIRST
+IF NOT Installed
+        transfer NET_SEARCH_FIRST
+ELSE
+        MOV     AX,(multNET SHL 8) OR 27
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_SEARCH_FIRST:
+        EnterCrit   critDisk
+        TEST    [DOS34_FLAG],SEARCH_FASTOPEN  ;AN000;
+        JZ      NOFN                          ;AN000;
+        OR      [FastOpenflg],Fastopen_Set    ;AN000;
+NOFN:                                         ;AN000;
+        MOV     [NoSetDir],1            ; if we find a dir, don't change to it
+        CALL    CHECK_QUESTION          ;AN000;;FO. is '?' in path
+        JNC     norm_getpath            ;AN000;;FO. no
+        AND     [FastOpenflg],Fast_yes  ;AN000;;FO. reset fastopen
+norm_getpath:
+        invoke  GetPath
+getdone:
+        JNC     find_check_dev
+        JNZ     bad_path
+        OR      CL,CL
+        JZ      bad_path
+find_no_more:
+        MOV     AX,error_no_more_files
+BadBye:
+        AND     CS:[FastOpenflg],Fast_yes  ;AN000;;FO. reset fastopen
+
+        STC
+        LeaveCrit   critDisk
+        return
+
+bad_path:
+        MOV     AX,error_path_not_found
+        JMP     BadBye
+
+find_check_dev:
+        OR      AH,AH
+        JNS     found_entry
+        MOV     [LastEnt],-1            ; Cause DOS_SEARCH_NEXT to fail
+        INC     [Found_Dev]             ; Tell DOS_RENAME we found a device
+found_entry:
+;
+; We set the physical drive byte here Instead of after found_it; Doing
+; a search-next may not have wfp_start set correctly
+;
+        LES     DI,[DMAADD]
+        MOV     SI,WFP_Start            ; get pointer to beginning
+        LODSB
+        SUB     AL,'A'-1                ; logical drive
+        STOSB                           ; High bit not set (local)
+found_it:
+        LES     DI,[DMAADD]
+        INC     DI
+        PUSH    DS                      ;FO.;AN001; save ds
+        TEST    [Fastopenflg],Set_For_Search      ;FO.;AN001; from fastopen
+        JZ      notfast                           ;FO.;AN001;
+        MOV     SI,BX                             ;FO.;AN001;
+        MOV     DS,WORD PTR [CURBUF+2]            ;FO.;AN001;
+        JMP     SHORT movmov                      ;FO.;AN001;
+
+
+notfast:
+        MOV     SI,OFFSET DOSGROUP:NAME1; find_buf 2 = formatted name
+movmov:
+; Special E5 code
+        MOVSB
+        CMP     BYTE PTR ES:[DI-1],5
+        JNZ     NOTKANJB
+        MOV     BYTE PTR ES:[DI-1],0E5H
+NOTKANJB:
+
+        MOV     CX,10
+        REP     MOVSB
+        POP     DS                      ;FO.;AN001; restore ds
+
+
+        MOV     AL,[Attrib]
+        STOSB
+        PUSH    AX                      ; Save AH device info
+        MOV     AX,[LastEnt]
+        STOSW
+        MOV     AX,[DirStart]
+        STOSW
+; 4 bytes of 21 byte cont structure left for NET stuff
+        ADD     DI,4
+        POP     AX                      ; Recover AH device info
+        OR      AH,AH
+        JS      DOSREL                  ; Device entry is DOSGROUP relative
+        CMP     WORD PTR [CURBUF],-1
+        JNZ     OKSTORE
+        TEST    [FastOPenFlg],Set_For_Search ;AN000;;FO. from fastopen and is good
+        JNZ     OKSTORE                      ;AN000;;FO.
+
+
+
+        ; The user has specified the root directory itself, rather than some
+        ; contents of it. We can't "find" that.
+        MOV     WORD PTR ES:[DI-8],-1   ; Cause DOS_SEARCH_NEXT to fail by
+                                        ;   stuffing a -1 at Lastent
+        JMP     find_no_more
+
+OKSTORE:
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+DOSREL:
+        MOV     SI,BX                   ; SI-> start of entry
+
+; NOTE: DOS_RENAME depends on BX not being altered after this point
+
+        MOV     CX,SIZE dir_entry
+;;;;; 7/29/86
+        MOV     AX,DI                   ; save the 1st byte addr
+        REP     MOVSB
+        MOV     DI,AX                   ; restore 1st byte addr
+        CMP     BYTE PTR ES:[DI],05H    ; special char check
+        JNZ     NO05
+        MOV     BYTE PTR ES:[DI],0E5H   ; convert it back to E5
+NO05:
+
+;;;;; 7/29/86
+        AND     CS:[FastOpenflg],Fast_yes  ;AN000;;FO. reset fastopen
+        context DS
+        CLC
+        LeaveCrit   critDisk
+        return
+
+EndProc DOS_SEARCH_FIRST
+
+BREAK <DOS_SEARCH_NEXT - scan for subsequent matches>
+
+; Inputs:
+;       [DMAADD] Points to 53 byte buffer returned by DOS_SEARCH_FIRST
+;           (only first 21 bytes must have valid information)
+; Function:
+;       Look for subsequent matches
+; Outputs:
+;       CARRY CLEAR
+;           The 53 bytes at DMAADD are updated for next call
+;               (see DOS_SEARCH_FIRST)
+;       CARRY SET
+;           AX = error code
+;               error_no_more_files
+;                       No more files to find
+; DS preserved, others destroyed
+
+        procedure   DOS_SEARCH_NEXT,NEAR
+        DOSAssume   CS,<DS>,"DOS_Search_Next"
+        ASSUME  ES:NOTHING
+
+        LES     DI,[DMAADD]
+        MOV     AL,ES:[DI]
+        TEST    AL,80H                  ; Test for NET
+        JZ      LOCAL_SEARCH_NEXT
+IF NOT Installed
+        transfer NET_SEARCH_NEXT
+ELSE
+        MOV     AX,(multNET SHL 8) OR 28
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_SEARCH_NEXT:
+;AL is drive A=1
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        EnterCrit   critDisk
+        MOV     WORD PTR ThisCDS,OFFSET DOSGROUP:DummyCDS
+        MOV     WORD PTR ThisCDS+2,CS
+        ADD     AL,'A'-1
+        invoke  InitCDS
+
+;       invoke  GetThisDrv              ; Set CDS pointer
+
+        JC      No_files                ; Bogus drive letter
+        LES     DI,[THISCDS]            ; Get CDS pointer
+        LES     BP,ES:[DI.curdir_devptr]; Get DPB pointer
+        invoke  GOTDPB                  ; [THISDPB] = ES:BP
+
+        mov     AL,ES:[BP.dpb_drive]
+        mov     ThisDrv,AL
+
+        MOV     WORD PTR [CREATING],0E500H
+        MOV     [NoSetDir],1            ; if we find a dir, don't change to it
+        LDS     SI,[DMAADD]
+ASSUME  DS:NOTHING
+        LODSB                           ; Drive Byte
+
+;       DEC     AL
+;       MOV     [THISDRV],AL
+
+        entry   RENAME_NEXT             ; Entry used by DOS_RENAME
+
+        context ES                      ; THIS BLOWS ES:BP POINTER TO DPB
+        MOV     DI,OFFSET DOSGROUP:NAME1
+        MOV     CX,11
+        REP     MOVSB                   ; Search name
+        LODSB                           ; Attribute
+        MOV     [ATTRIB],AL
+        LODSW                           ; LastEnt
+        OR      AX,AX
+        JNS     cont_load
+No_files:
+        JMP     find_no_more
+
+cont_load:
+        PUSH    AX                      ; Save LastEnt
+        LODSW                           ; DirStart
+        MOV     BX,AX
+        context DS
+        LES     BP,[THISDPB]            ; Recover ES:BP
+        invoke  SetDirSrch
+        JNC     SEARCH_GOON
+        POP     AX                      ; Clean stack
+        JMP     No_files
+
+SEARCH_GOON:
+        invoke  StartSrch
+        POP     AX
+        invoke  GetEnt
+        JC      No_files
+        invoke  NextEnt
+        JC      No_files
+        XOR     AH,AH                   ; If Search_Next, can't be a DEV
+        JMP     found_it
+
+EndProc DOS_SEARCH_NEXT
+
+
+;Input: [WFP_START]= pointer to final path
+;Function: check '?' char
+;Output: carry clear, if no '?'
+;        carry set, if '?' exists
+
+        procedure   CHECK_QUESTION,NEAR ;AN000;
+        ASSUME  ES:NOTHING,DS:NOTHING   ;AN000;
+
+        PUSH    CS                      ;AN000;;FO.
+        POP     DS                      ;AN000;;FO. ds:si -> final path
+        MOV     SI,[WFP_START]          ;AN000;;FO.
+getnext:                                ;AN000;
+        LODSB                           ;AN000;;FO. get char
+        OR      AL,AL                   ;AN000;;FO. is it null
+        JZ      NO_Question             ;AN000;;FO. yes
+        CMP     AL,'?'                  ;AN000;;FO. is '?'
+        JNZ     getnext                 ;AN000;;FO. no
+        STC                             ;AN000;;FO.
+NO_Question:                            ;AN000;
+        return                          ;AN000;;FO.
+
+EndProc CHECK_QUESTION                  ;AN000;
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/KSTRIN.ASM b/v4.0/src/DOS/KSTRIN.ASM
new file mode 100644
index 0000000..1eeee39
--- /dev/null
+++ b/v4.0/src/DOS/KSTRIN.ASM
@@ -0,0 +1,690 @@
+;       SCCSID = @(#)strin.asm  1.2 85/04/18
+;
+;       Revision history:
+;          A000  version 4.00   Jan. 1988
+;
+Break
+
+; Inputs:
+;       DS:DX Point to an input buffer
+; Function:
+;       Fill buffer from console input until CR
+; Returns:
+;       None
+
+        procedure   $STD_CON_STRING_INPUT,NEAR   ;System call 10
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     AX,SS
+        MOV     ES,AX
+        MOV     SI,DX
+        XOR     CH,CH
+        LODSW
+        mov     cs:Temp_Var,si   ;AN000;   ; 3/31/KK
+;
+; AL is the buffer length
+; AH is the template length
+;
+        OR      AL,AL
+        retz                    ;Buffer is 0 length!!?
+        MOV     BL,AH           ;Init template counter
+        MOV     BH,CH           ;Init template counter
+ ;
+ ; BL is the number of bytes in the template
+ ;
+        CMP     AL,BL
+        JBE     NOEDIT          ;If length of buffer inconsistent with contents
+        CMP     BYTE PTR [BX+SI],c_CR
+        JZ      EDITON          ;If CR correctly placed EDIT is OK
+;
+; The number of chars in the template is >= the number of chars in buffer or
+; there is no CR at the end of the template.  This is an inconsistant state
+; of affairs.  Pretend that the template was empty:
+;
+NOEDIT:
+        MOV     BL,CH           ;Reset buffer
+EDITON:
+        MOV     DL,AL
+        DEC     DX              ;DL is # of bytes we can put in the buffer
+;
+; Top level.  We begin to read a line in.
+;
+NEWLIN:
+        MOV     AL,[CARPOS]
+        MOV     [STARTPOS],AL   ;Remember position in raw buffer
+        PUSH    SI
+        MOV     DI,OFFSET DOSGROUP:INBUF        ;Build the new line here
+        MOV     [INSMODE],CH    ;Insert mode off
+        MOV     BH,CH           ;No chars from template yet
+        MOV     DH,CH           ;No chars to new line yet
+        call    IntCNE0         ;AN000; Get first char                   2/17/KK
+        jz      SavCh           ;AN000; if ZF set then interim character 2/17/KK
+        CMP     AL,c_LF         ;Linefeed
+        JNZ     GOTCH           ;Filter out LF so < works
+;
+; This is the main loop of reading in a character and processing it.
+;
+;   BH is the index of the next byte in the template
+;   BL is the length of the template
+;   DH is the number of bytes in the buffer
+;   DL is the length of the buffer
+;
+entry   GETCH
+        call    IntCNE0         ;AN000;; 2/17/KK
+        jz      SavCh           ;AN000;; if ZF set then interim character 2/17/KK
+GOTCH:
+;
+; ^F ignored in case BIOS did not flush the input queue.
+;
+        CMP     AL,"F"-"@"
+        JZ      GETCH
+;
+; If the leading char is the function-key lead byte
+;
+        CMP     AL,[ESCCHAR]
+        JNZ     ARM03           ;AN000;; 2/17/KK
+        Jmp     ESCC            ;AN000;; 2/17/KK
+ARM03:                          ;AN000;; 2/17/KK
+;
+; Rubout and ^H are both destructive backspaces.
+;
+        CMP     AL,c_DEL
+        JZ      BACKSPJ0        ;AN000; 2/17/KK
+        CMP     AL,c_BS
+        JNZ     ARM04           ;AN000;; 2/17/KK
+BACKSPJ0:                       ;AN000;; 2/17/KK
+        Jmp     BACKSPJ         ;AN000;; 2/17/KK
+ARM04:                          ;AN000;; 2/17/KK
+;
+; ^W deletes backward once and then backs up until a letter is before the
+; cursor
+;
+        CMP     AL,"W" - "@"
+; The removal of the comment characters before the jump statement will
+; cause ^W to backup a word.
+;***    JZ      WordDel
+        NOP
+        NOP
+        CMP     AL,"U" - "@"
+; The removal of the comment characters before the jump statement will
+; cause ^U to clear a line.
+;***    JZ      LineDel
+        NOP
+        NOP
+
+;
+; CR terminates the line.
+;
+        CMP     AL,c_CR
+        JNZ     ARM01           ;AN000;; 2/17/KK
+        Jmp     ENDLIN          ;AN000;; 2/17/KK
+ARM01:                          ;AN000;; 2/17/KK
+;
+; LF goes to a new line and keeps on reading.
+;
+        CMP     AL,c_LF
+        JNZ     ARM00           ;AN000;; 2/17/KK
+        Jmp     PHYCRLF         ;AN000;; 2/17/KK
+ARM00:                          ;AN000;; 2/17/KK
+;
+; ^X (or ESC) deletes the line and starts over
+;
+        CMP     AL,[CANCHAR]
+        JNZ     SAVCH           ;AN000;; 2/13/KK
+        JMP     KILNEW          ;AN000;; 2/13/KK
+InterLoop:                      ;AN000;; 2/17/KK
+        call    IntCNE0         ;AN000;; Get another interim character 2/17/KK
+;
+; Otherwise, we save the input character.
+;
+SAVCH:
+        pushf                   ;AN000; 2/17/KK
+        CMP     DH,DL
+        JAE     BUFFUL                  ; buffer is full.
+;----------------------------- Start of DBCS 2/13/KK
+
+        invoke  TESTKANJ                ;AN000;
+        JZ      ISNORM                  ;AN000;
+        INC     DH                      ;AN000;
+        CMP     DH,DL                   ;AN000;
+        JB      GOTROOM                 ;AN000;
+        DEC     DH                      ;AN000;; No room for second byte
+        call    IntCNE0                 ;AN000;; Get second byte
+        JMP     SHORT BUFFUL            ;AN000;
+                                        ;AN000;
+GOTROOM:                                ;AN000;
+        STOSB                           ;AN000;; Store first byte
+        popf                            ;AN000;
+        call    outchax                 ;AN000;
+        call    IntCNE0                 ;AN000;; Get second byte
+        pushf                           ;AN000;
+        STOSB                           ;AN000;; Store second byte
+        INC     DH                      ;AN000;
+        popf                            ;AN000;
+        call    outchax                 ;AN000;
+        jnz     ContIn1                 ;AN000;; interim character?
+        call    InterCheck              ;AN000;
+        call    InterCheck              ;AN000;
+        jmp     short InterLoop         ;AN000;; not interim skip another check
+
+ISNORM:
+;----------------------------- End of DBCS 2/13/KK
+        STOSB                           ;AN000;
+        INC     DH                      ;AN000;; increment count in buffer.
+        popf                            ;AN000;; 2/17/KK
+        invoke  BUFOUTx                 ;AN000;; Print control chars nicely 2/17/KK
+        jnz     ContIn1                 ;AN000;; 2/17/KK
+        call    InterCheck              ;AN000;; 2/17/KK
+        jmp     short InterLoop         ;AN000;; 2/17/KK
+CONTIN1:                                ;AN000;; 2/13/KK
+;;;CONTIN:                              ;AN000;; 2/13/KK
+        CMP     BYTE PTR [INSMODE],0
+        JNZ     GETCH0                  ; insertmode => don't advance template
+        CMP     BH,BL
+        JAE     GETCH0                  ; no more characters in template
+        INC     SI                      ; Skip to next char in template
+        INC     BH                      ; remember position in template
+
+        PUSH    AX                      ;
+        MOV     AL,BYTE PTR [SI-1]      ;AN000;;                    2/13/KK
+        invoke  TESTKANJ                ;AN000;;                    2/13/KK
+        POP     AX                      ;AN000;;                    2/13/KK
+        JZ      GETCH0                  ;AN000;; Wasn't a dual byte 2/13/KK
+        INC     SI                      ;AN000;; Was a dual byte,   2/13/KK
+        INC     BH                      ;AN000;;     skip one more  2/13/KK
+GETCH0:                                 ;AN000;; 2/17/KK
+        JMP     GETCH                   ;AN000;; 2/17/KK
+
+BACKSPJ: JMP    SHORT BACKSP
+
+BUFFUL:
+        popf                            ;AN000;; 2/17/KK
+        MOV     AL,7                    ;AN000;; Bell to signal full buffer
+        invoke  OUTT
+        JMP     GETCH
+;                                               2/17/KK
+;       Reduce character count, reduce pointer  2/17/KK
+;                                               2/17/KK
+InterCheck:                             ;AN000;;       2/17/KK
+        dec     dh                      ;AN000;; adjust count          2/17/KK
+        dec     di                      ;AN000;; adjust buffer pointer 2/17/KK
+        ret                             ;AN000;;                       2/17/KK
+
+ESCC:
+        transfer    OEMFunctionKey      ; let the OEM's handle the key dispatch
+
+ENDLIN:
+        STOSB                           ; Put the CR in the buffer
+        invoke  OUTT                    ; Echo it
+        POP     DI                      ; Get start of user buffer
+        MOV     [DI-1],DH               ; Tell user how many bytes
+        INC     DH                      ; DH is length including CR
+COPYNEW:
+        SaveReg <DS,ES>
+        RestoreReg <DS,ES>              ; XCHG ES,DS
+        MOV     SI,OFFSET DOSGROUP:INBUF
+        MOV     CL,DH                   ; set up count
+        REP     MOVSB                   ; Copy final line to user buffer
+        return
+;
+; Output a CRLF to the user screen and do NOT store it into the buffer
+;
+PHYCRLF:
+        invoke  CRLF
+        JMP     GETCH
+
+;
+; Delete the previous line
+;
+LineDel:
+        OR      DH,DH
+        JNZ     bridge00        ;AN000;; 2/13/KK
+        JMP     GetCh           ;AN000;; 2/13/KK
+bridge00:                       ;AN000;; 2/13/KK
+        Call    BackSpace
+        JMP     LineDel
+
+;
+; delete the previous word.
+;
+WordDel:
+WordLoop:
+        Call    BackSpace               ; backspace the one spot
+        OR      DH,DH
+        JZ      GetChJ
+        MOV     AL,ES:[DI-1]
+        cmp     al,'0'
+        jb      GetChj
+        cmp     al,'9'
+        jbe     WordLoop
+        OR      AL,20h
+        CMP     AL,'a'
+        JB      GetChJ
+        CMP     AL,'z'
+        JBE     WordLoop
+GetChJ:
+        JMP     GetCh
+;
+; The user wants to throw away what he's typed in and wants to start over.  We
+; print the backslash and then go to the next line and tab to the correct spot
+; to begin the buffered input.
+;
+        entry   KILNEW
+        MOV     AL,"\"
+        invoke  OUTT            ;Print the CANCEL indicator
+        POP     SI              ;Remember start of edit buffer
+PUTNEW:
+        invoke  CRLF            ;Go to next line on screen
+        MOV     AL,[STARTPOS]
+        invoke  TAB             ;Tab over
+        JMP     NEWLIN          ;Start over again
+
+
+;
+; Destructively back up one character position
+;
+entry   BackSp
+        Call    BackSpace
+        JMP     GetCh
+
+BackSpace:
+        OR      DH,DH
+        JZ      OLDBAK          ;No chars in line, do nothing to line
+        CALL    BACKUP          ;Do the backup
+        MOV     AL,ES:[DI]      ;Get the deleted char
+        invoke  TESTKANJ        ;AN000;2/13/KK
+        JNZ     OLDBAK          ;AN000; Was a dual byte, done  2/13/KK
+        CMP     AL," "
+        JAE     OLDBAK          ;Was a normal char
+        CMP     AL,c_HT
+        JZ      BAKTAB          ;Was a tab, fix up users display
+;; 9/27/86 fix for ctrl-U backspace
+        CMP     AL,"U"-"@"      ; ctrl-U is a section symbol not ^U
+        JZ      OLDBAK
+        CMP     AL,"T"-"@"      ; ctrl-T is a paragraphs symbol not ^T
+        JZ      OLDBAK
+;; 9/27/86 fix for ctrl-U backspace
+        CALL    BACKMES         ;Was a control char, zap the '^'
+OLDBAK:
+        CMP     BYTE PTR [INSMODE],0
+        retnz                   ;In insert mode, done
+        OR      BH,BH
+        retz                    ;Not advanced in template, stay where we are
+        DEC     BH              ;Go back in template
+        DEC     SI
+;-------------------------- Start of DBCS 2/13/KK
+        OR      BH,BH           ;AN000;
+        retz                    ;AN000;; If we deleted one char and it was the only
+                                ;AN000;;  one, could not have dual byte
+;;;;    POP     AX              ;AN000;; Get start of template
+;;;;    PUSH    AX              ;AN000;; Put it back on stack
+        mov     ax,cs:Temp_Var  ;AN000;; 3/31/KK
+        XCHG    AX,SI           ;AN000;
+LOOKDUAL:                       ;AN000;
+        CMP     SI,AX           ;AN000;
+        JAE     ATLOC           ;AN000;
+        PUSH    AX              ;AN000;
+        MOV     AL,BYTE PTR [SI];AN000;
+        invoke  TESTKANJ        ;AN000;
+        POP     AX              ;AN000;
+        JZ      ONEINC          ;AN000;
+        INC     SI              ;AN000;
+ONEINC:                         ;AN000;
+        INC     SI              ;AN000;
+        JMP     SHORT LOOKDUAL  ;AN000;
+                                ;AN000;
+ATLOC:                          ;AN000;
+        retz                    ;AN000;; Correctly pointing to start of single byte
+        DEC     AX              ;AN000;; Go back one more to correctly point at start
+        DEC     BH              ;AN000;        ; of dual byte
+        MOV     SI,AX           ;AN000;
+        return                  ;AN000;
+;-------------------------- End of DBCS 2/13/KK
+
+BAKTAB:
+        PUSH    DI
+        DEC     DI              ;Back up one char
+        STD                     ;Go backward
+        MOV     CL,DH           ;Number of chars currently in line
+        MOV     AL," "
+        PUSH    BX
+        MOV     BL,7            ;Max
+        JCXZ    FIGTAB          ;At start, do nothing
+FNDPOS:
+        SCASB                   ;Look back
+        JNA     CHKCNT
+        CMP     BYTE PTR ES:[DI+1],9
+        JZ      HAVTAB          ;Found a tab
+        DEC     BL              ;Back one char if non tab control char
+CHKCNT:
+        LOOP    FNDPOS
+FIGTAB:
+        SUB     BL,[STARTPOS]
+HAVTAB:
+        SUB     BL,DH
+        ADD     CL,BL
+        AND     CL,7            ;CX has correct number to erase
+        CLD                     ;Back to normal
+        POP     BX
+        POP     DI
+        JZ      OLDBAK          ;Nothing to erase
+TABBAK:
+        invoke  BACKMES
+        LOOP    TABBAK          ;Erase correct number of chars
+        JMP     SHORT OLDBAK
+
+BACKUP:
+        DEC     DH              ;Back up in line
+        DEC     DI
+;-------------------------Start of DBCS 2/13/KK
+        OR      DH,DH                   ;AN000;
+        JZ      BACKMES                 ;AN000;; If deleted one and got only, no dual
+        MOV     AX,DI                   ;AN000;
+        MOV     DI,OFFSET DOSGROUP:INBUF;AN000;
+LOOKDUAL2:                              ;AN000;
+        CMP     DI,AX                   ;AN000;
+        JAE     ATLOC2                  ;AN000;
+        PUSH    AX                      ;AN000;
+        MOV     AL,BYTE PTR ES:[DI]     ;AN000;
+        invoke  TESTKANJ                ;AN000;
+        POP     AX                      ;AN000;
+        JZ      ONEINC2                 ;AN000;
+        INC     DI                      ;AN000;
+ONEINC2:                                ;AN000;
+        INC     DI                      ;AN000;
+        JMP     SHORT LOOKDUAL2         ;AN000;
+                                        ;AN000;
+ATLOC2:                                 ;AN000;
+        JE      BACKMES                 ;AN000;; Correctly deleted single byte
+        DEC     AX                      ;AN000; Go back one more to correctly delete dual byte
+        DEC     DH                      ;AN000;
+        MOV     DI,AX                   ;AN000;
+        CALL    BACKMES                 ;AN000;
+;---------------------------End of DBCS 2/13/KK
+BACKMES:
+        MOV     AL,c_BS         ;Backspace
+        invoke  OUTT
+        MOV     AL," "          ;Erase
+        invoke  OUTT
+        MOV     AL,c_BS         ;Backspace
+        JMP     OUTT            ;Done
+
+;User really wants an ESC character in his line
+        entry   TwoEsc
+        MOV     AL,[ESCCHAR]
+        JMP     SAVCH
+
+;Copy the rest of the template
+        entry   COPYLIN
+        MOV     CL,BL           ;Total size of template
+        SUB     CL,BH           ;Minus position in template, is number to move
+        JMP     SHORT COPYEACH
+
+        entry   CopyStr
+        invoke  FINDOLD         ;Find the char
+        JMP     SHORT COPYEACH  ;Copy up to it
+
+;Copy one char from template to line
+        entry   COPYONE
+        MOV     CX,1                    ;AN000;;               2/13/KK
+        MOV     AL,[SI]                 ;AN000;; get char      2/13/KK
+        invoke  TestKanj                ;AN000;; is it kanji?  2/13/KK
+        JZ      CopyEach                ;AN000;; no, go do copy2/13/KK
+        INC     CX                      ;AN000;; do 2 byte copy2/13/KK
+
+;Copy CX chars from template to line
+COPYEACH:
+        MOV     BYTE PTR [INSMODE],0    ;All copies turn off insert mode
+        CMP     DH,DL
+        JZ      GETCH2                  ;At end of line, can't do anything
+        CMP     BH,BL
+        JZ      GETCH2                  ;At end of template, can't do anything
+        LODSB
+        STOSB
+;----------------------------- Start of DBCS 2/13/KK
+        INC     BH                      ;AN000;; Ahead in template
+        INC     DH                      ;AN000;; Ahead in line
+        CALL    TestKanj                ;AN000;; 2 byte character?
+        JZ      CopyLoop                ;AN000;; no, go copy next
+        CMP     DH,DL                   ;AN000;; over boundary?
+        JNZ     CopyBoth                ;AN000;; no, move both
+        DEC     BH                      ;AN000;; yes, backup template
+        DEC     DH                      ;AN000;; back up line
+        DEC     SI                      ;AN000;; patch (from Dohhaku)
+        DEC     DI                      ;AN000;; remember to backup after previous move
+        JMP     GetCh                   ;AN000;; go get next char
+                                        ;AN000;
+CopyBoth:                               ;AN000;
+        invoke  BUFOUT                  ;AN000;; output the first byte
+        LODSB                           ;AN000;; get the second
+        STOSB                           ;AN000;; move the second
+        INC     BH                      ;AN000;; bump template
+        INC     DH                      ;AN000;; bump line
+        DEC     CX                      ;AN000;; dump byte count
+CopyLoop:                               ;AN000;
+        invoke  BUFOUT                  ;AN000;
+        LOOP    COPYEACH                ;AN000;
+;;;;;   invoke  BUFOUT
+;;;;;   INC     BH                      ;Ahead in template
+;;;;;   INC     DH                      ;Ahead in line
+;;;;;   LOOP    COPYEACH
+;----------------------------- End of DBCS 2/13/KK
+GETCH2:
+        JMP     GETCH
+
+;Skip one char in template
+        entry   SKIPONE
+        CMP     BH,BL
+        JZ      GETCH2                  ;At end of template
+        INC     BH                      ;Ahead in template
+        INC     SI
+        PUSH    AX                      ;AN000;; 2/13/KK
+        MOV     AL,BYTE PTR [SI-1]      ;AN000;; 2/13/KK
+        invoke  TESTKANJ                ;AN000;; 2/13/KK
+        POP     AX                      ;AN000;; 2/13/KK
+        JZ      GETCH2                  ;AN000;; 2/13/KK
+        INC     BH                      ;AN000;; 2/13/KK
+        INC     SI                      ;AN000;; 2/13/KK
+        JMP     GETCH
+
+        entry   SKIPSTR
+        invoke  FINDOLD                 ;Find out how far to go
+        ADD     SI,CX                   ;Go there
+        ADD     BH,CL
+        JMP     GETCH
+
+;Get the next user char, and look ahead in template for a match
+;CX indicates how many chars to skip to get there on output
+;NOTE: WARNING: If the operation cannot be done, the return
+;       address is popped off and a jump to GETCH is taken.
+;       Make sure nothing extra on stack when this routine
+;       is called!!! (no PUSHes before calling it).
+
+TABLE   SEGMENT                         ;AN000;; 2/17/KK
+Public  KISTR001S,KISTR001E             ;AN000;; 2/17/KK
+KISTR001S       label   byte            ;AN000;; 2/17/KK
+LOOKSIZ DB      0                       ;AN000;; 0 if byte, NZ if word  2/17/KK
+KISTR001E       label   byte            ;AN000;; 2/17/KK
+TABLE   ENDS                            ;AN000;; 2/17/KK
+
+FINDOLD:
+        MOV     [LOOKSIZ],0             ;AN000;; Initialize to byte    2/13/KK
+        call    IntCNE1                 ;AN000;;                       2/17/KK
+        CMP     AL,[ESCCHAR]            ;AN000;; did he type a function key?
+;;;;;   JNZ     FindSetup               ;AN000;; no, set up for scan   2/13/KK
+        JNZ     TryKanj                 ;AN000;; no, continue testing  2/13/KK
+        call    IntCNE1                 ;AN000;;                       2/17/KK
+        JMP     NotFnd                         ; go try again
+;;;;;;;FindSetup:                       ;AN000;; 2/13/KK
+TryKanj:                                ;AN000;; 2/13/KK
+        invoke  TESTKANJ                ;AN000;; 2/13/KK
+        JZ      GOTLSIZ                 ;AN000;; 2/13/KK
+        INC     [LOOKSIZ]               ;AN000;; Gonna look for a word  2/13/KK
+        PUSH    AX                      ;AN000;; Save first byte        2/13/KK
+        call    IntCNE1                 ;AN000;;                       2/17/KK
+        POP     CX                      ;AN000;; 2/13/KK
+        MOV     AH,AL                   ;AN000;; 2/13/KK
+        MOV     AL,CL                   ;AN000;; AX is dual byte sequence to look for
+        XOR     CX,CX                   ;AN000;; Re-zero CH     2/13/KK
+GOTLSIZ:
+        MOV     CL,BL
+        SUB     CL,BH           ;CX is number of chars to end of template
+        JZ      NOTFND          ;At end of template
+        DEC     CX              ;Cannot point past end, limit search
+        JZ      NOTFND          ;If only one char in template, forget it
+        PUSH    AX                      ;AN000;; 2/13/KK
+        MOV     AL,BYTE PTR [SI]        ;AN000;; 2/13/KK
+        invoke  TESTKANJ                ;AN000;; 2/13/KK
+        POP     AX                      ;AN000;; 2/13/KK
+        JZ      NOTDUAL5                ;AN000;; 2/13/KK
+        DEC     CX                      ;AN000;; And one more besides   2/13/KK
+        JZ      NOTFND                  ;AN000;; If only one char in template, forget it
+NOTDUAL5:                               ;AN000;; 2/13/KK
+        PUSH    ES
+        PUSH    DS
+        POP     ES
+        PUSH    DI
+        MOV     DI,SI           ;Template to ES:DI
+;;;;    INC     DI                2/13/KK
+;;;;    REPNE   SCASB           ;Look  2/13/KK
+;--------------------- Start of DBCS 2/13/KK
+        PUSH    AX                      ;AN000;
+        MOV     AL,BYTE PTR ES:[DI]     ;AN000;
+        invoke  TESTKANJ                ;AN000;
+        POP     AX                      ;AN000;
+        JZ      ONEINC5                 ;AN000;
+        INC     DI                      ;AN000;; We will skip at least something
+ONEINC5:                                ;AN000;
+        INC     DI                      ;AN000;
+        CMP     [LOOKSIZ],0             ;AN000;
+        JNZ     LOOKWORD                ;AN000;
+LOOKBYTE:                               ;AN000;
+        PUSH    AX                      ;AN000;
+        MOV     AL,BYTE PTR ES:[DI]     ;AN000;
+        invoke  TESTKANJ                ;AN000;
+        POP     AX                      ;AN000;
+        JZ      TESTITB                 ;AN000;
+        INC     DI                      ;AN000;
+        INC     DI                      ;AN000;
+        DEC     CX                      ;AN000;
+        LOOP    LOOKBYTE                ;AN000;
+        JMP     SHORT ATNOTFND          ;AN000;
+                                        ;AN000;
+TESTITB:                                ;AN000;
+        DEC     CX                      ;AN000;
+        CMP     AL,ES:[DI]              ;AN000;
+        JZ      ATSPOT                  ;AN000;
+        INC     DI                      ;AN000;
+        INC     CX                      ;AN000;; Counter next instruction
+        LOOP    LOOKBYTE                ;AN000;
+ATNOTFND:                               ;AN000;
+        XOR     AL,AL                   ;AN000;
+        INC     AL                      ;AN000;; Set NZ
+ATSPOT:                         ; 2/13/K;AN000;K
+;--------------------- End of DBCS 2/13/KK
+        POP     DI
+        POP     ES
+        JNZ     NOTFND          ;Didn't find the char
+        NOT     CL              ;Turn how far to go into how far we went
+        ADD     CL,BL           ;Add size of template
+        SUB     CL,BH           ;Subtract current pos, result distance to skip
+        return
+
+NOTFND:
+        POP     BP              ;Chuck return address
+        JMP     GETCH
+;------------------------- Start of DBCS 2/13/KK
+LOOKWORD:                              ;AN000;
+        PUSH    AX                     ;AN000;
+        MOV     AL,BYTE PTR ES:[DI]    ;AN000;
+        invoke  TESTKANJ               ;AN000;
+        POP     AX                     ;AN000;
+        JNZ     TESTITW                ;AN000;
+        INC     DI                     ;AN000;
+        LOOP    LOOKWORD               ;AN000;
+        JMP     SHORT ATNOTFND         ;AN000;
+                                       ;AN000;
+TESTITW:                               ;AN000;
+        DEC     CX                     ;AN000;
+        CMP     AX,ES:[DI]             ;AN000;
+        JZ      ATSPOT                 ;AN000;
+        INC     DI                     ;AN000;
+        INC     DI                     ;AN000;
+        LOOP    LOOKWORD               ;AN000; ; Performs second DEC of CX
+        JMP     SHORT ATNOTFND         ;AN000;
+;------------------------- End of DBCS 2/13/KK
+
+entry   REEDIT
+        MOV     AL,"@"          ;Output re-edit character
+        invoke  OUTT
+        POP     DI
+        PUSH    DI
+        PUSH    ES
+        PUSH    DS
+        invoke  COPYNEW         ;Copy current line into template
+        POP     DS
+        POP     ES
+        POP     SI
+        MOV     BL,DH           ;Size of line is new size template
+        JMP     PUTNEW          ;Start over again
+
+        entry   EXITINS
+        entry   ENTERINS
+        NOT     BYTE PTR [INSMODE]
+        JMP     GETCH
+
+;Put a real live ^Z in the buffer (embedded)
+        entry   CTRLZ
+        MOV     AL,"Z"-"@"
+        JMP     SAVCH
+
+;Output a CRLF
+        entry   CRLF
+        MOV     AL,c_CR
+        invoke  OUTT
+        MOV     AL,c_LF
+        JMP     OUTT
+
+EndProc $STD_CON_STRING_INPUT
+
+;-------------- Start of DBCS 2/17/KK
+PUBLIC  IntCNE0                         ;AN000;
+procedure       IntCNE0,near            ;AN000;
+        push    word ptr [InterCon]     ;AN000;
+        mov     [InterCon],01           ;AN000;
+get_com:                                ;AN000;
+        invoke  INTER_CON_INPUT_NO_ECHO ;AN000;; get a byte character
+        pop     word ptr [InterCon]     ;AN000;
+        ret                             ;AN000;
+IntCNE0 endp                            ;AN000;
+                                        ;AN000;
+procedure       IntCNE1,near            ;AN000;
+        push    word ptr [InterCon]     ;AN000;
+        mov     [InterCon],00           ;AN000;
+        jmp     short get_com           ;AN000;
+IntCNE1 endp                            ;AN000;
+                                        ;AN000;
+        procedure       outchax,near    ;AN000;
+        pushf                           ;AN000;
+        mov     [SaveCurFlg],0          ;AN000;
+        jnz     sj1                     ;AN000;
+        mov     [SaveCurFlg],1          ;AN000;
+sj1:                                    ;AN000;
+        CALL    OUTCHA                  ;AN000;
+        mov     [SaveCurFlg],0          ;AN000;
+        popf                            ;AN000;
+        ret                             ;AN000;
+outchax endp                            ;AN000;
+                                        ;AN000;
+        procedure       bufoutx,near    ;AN000;
+        pushf                           ;AN000;
+        mov     [SaveCurFlg],0          ;AN000;
+        jnz     sj2                     ;AN000;
+        mov     [SaveCurFlg],1          ;AN000;
+sj2:                                    ;AN000;
+        invoke  BUFOUT                  ;AN000;
+        mov     [SaveCurFlg],0          ;AN000;
+        popf                            ;AN000;
+        ret                             ;AN000;
+bufoutx endp                            ;AN000;
+;-------------- End of DBCS 2/17/KK
diff --git a/v4.0/src/DOS/LOCK.ASM b/v4.0/src/DOS/LOCK.ASM
new file mode 100644
index 0000000..2089882
--- /dev/null
+++ b/v4.0/src/DOS/LOCK.ASM
@@ -0,0 +1,372 @@
+;       SCCSID = @(#)lock.asm   1.1 85/04/10
+TITLE   LOCK ROUTINES - Routines for file locking
+NAME    LOCK
+
+;
+;   LOCK_CHECK
+;   LOCK_VIOLATION
+;   $LockOper
+;
+;   Revision history:
+;     A000   version 4.00   Jan. 1988
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xlist
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include lock.inc                     ;AN000;
+.cref
+.list
+
+AsmVars <IBM, Installed>
+
+Installed = TRUE
+
+        i_need  THISSFT,DWORD
+        i_need  THISDPB,DWORD
+        i_need  EXTERR,WORD
+        i_need  ALLOWED,BYTE
+        i_need  RetryCount,WORD
+        I_need  fShare,BYTE
+        I_Need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
+        i_need  JShare,DWORD
+        i_need  Lock_Buffer,DWORD       ;AN000; DOS 4.00
+        i_need  Temp_Var,WORD           ;AN000; DOS 4.00
+
+BREAK <$LockOper - Lock Calls>
+
+;
+;   Assembler usage:
+;           MOV     BX, Handle         (DOS 3.3)
+;           MOV     CX, OffsetHigh
+;           MOV     DX, OffsetLow
+;           MOV     SI, LengthHigh
+;           MOV     DI, LengthLow
+;           MOV     AH, LockOper
+;           MOV     AL, Request
+;           INT     21h
+;
+;   Error returns:
+;           AX = error_invalid_handle
+;              = error_invalid_function
+;              = error_lock_violation
+;
+;   Assembler usage:
+;           MOV     AX, 5C??           (DOS 4.00)
+;
+;                                   0? lock all
+;                                   8? lock write
+;                                   ?2 lock multiple
+;                                   ?3 unlock multiple
+;                                   ?4 lock/read
+;                                   ?5 write/unlock
+;                                   ?6 add (lseek EOF/lock/write/unlock)
+;           MOV     BX, Handle
+;           MOV     CX, count or size
+;           LDS     DX, buffer
+;           INT     21h
+;
+;   Error returns:
+;           AX = error_invalid_handle
+;              = error_invalid_function
+;              = error_lock_violation
+
+        procedure   $LockOper,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+;       MOV     BP,AX                   ;MS. BP=AX                              ;AN000;
+;       AND     BP,7FH                  ;MS. clear bit 7                        ;AN000;
+;       CMP     BP,Lock_add             ;MS. supported function ?               ;AN000;
+;       JA      lock_bad_func           ;MS. no,                                ;AN000;
+
+        CMP     AL,1                    ;AN000;;MS. no,
+        JA      lock_bad_func           ;AN000;;MS. no,
+
+        PUSH    DI                             ; Save LengthLow
+        invoke  SFFromHandle                   ; ES:DI -> SFT
+        JNC     lock_do                        ; have valid handle
+        POP     DI                             ; Clean stack
+        error   error_invalid_handle
+lock_bad_func:
+        MOV     EXTERR_LOCUS,errLoc_Unk        ; Extended Error Locus
+        error   error_invalid_function
+
+; Align_buffer call has been deleted, since it corrupts the DTA  (6/5/88) P5013
+
+lock_do:
+;       PUSH    AX                      ;AN000;;MS. save ax
+;       PUSH    BX                      ;AN000;;MS. save handle
+;       MOV     [Temp_Var],DX           ;AN000;;MS. save DX
+;       invoke  Align_Buffer            ;AN000;;MS. align ds:dx and set DMAADD
+;       POP     BX                      ;AN000;;MS. restore handle
+;       POP     AX                      ;AN000;;MS. save ax
+                                        ;AN000;
+;       CMP     BP,Unlock_all           ;AN000;;MS. old function 0 or 1 ?
+;       JA      chk_lock_mul            ;AN000;;MS. no, new function
+;       TEST    AL,80H                  ;AN000;;MS. 80H bit on ?
+;       JZ      old_33                  ;AN000;;MS. no, old DOS 3.3 interface
+;       MOV     CX,1                    ;AN000;;MS. adjust for new interface
+;       ADD     BP,2                    ;AN000;;MS.
+;       JMP     SHORT chk_lock_mul      ;AN000;;MS.
+old_33:
+        MOV     BX,AX                   ;AN000;;MS. save AX
+                                        ;AN000;
+;;      MOV     DX,[Temp_Var]           ;AN000;;MS. retore DX  (P5013) 6/5/88
+
+        MOV     BP, OFFSET DOSGROUP:Lock_Buffer ;AN000;;MS. get DOS LOCK buffer
+        MOV     WORD PTR [BP.Lock_position],DX  ;AN000;;MS. set low offset
+        MOV     WORD PTR [BP.Lock_position+2],CX;AN000;;MS. set high offset
+        POP     CX                              ;AN000;;MS. get low length
+        MOV     WORD PTR [BP.Lock_length],CX    ;AN000;;MS. set low length
+        MOV     WORD PTR [BP.Lock_length+2],SI  ;AN000;;MS. set high length
+        MOV     CX,1                            ;AN000;;MS. one range
+        PUSH    CS                              ;AN000;;MS.
+        POP     DS                              ;AN000;;MS. DS:DX points to
+        MOV     DX,BP                           ;AN000;;MS.   Lock_Buffer
+        TEST    AL,Unlock_all                   ;AN000;;MS. function 1
+        JNZ     DOS_Unlock                      ;AN000;;MS. yes
+        JMP     DOS_Lock                        ;AN000;;MS. function 0
+;;chk_lock_mul:                                 ;AN000;
+;       POP     SI                              ;AN000;;MS. pop low length
+;       TEST    ES:[DI.sf_flags],sf_isnet       ;AN000;;MS. net handle?
+;       JZ      LOCAL_DOS_LOCK                  ;AN000;;MS. no
+;       invoke  OWN_SHARE                       ;AN000;;MS. IFS owns share ?
+;       JNZ     LOCAL_DOS_LOCK                  ;AN000;;MS. no
+;       MOV     BX,AX                           ;AN000;;MS. BX=AX
+;       CallInstall NET_XLock,multNet,10        ;AN000;;MS. issue Net Extended Lock
+;       MOV     [Temp_Var],CX                   ;AN000;;MS. cx= retuened from IFS
+;       JMP     ValChk                          ;AN000;;MS. check return
+;LOCAL_DOS_LOCK:                                ;AN000;
+;       CMP     BP,Lock_mul_range               ;AN000;;MS. lock mul range?
+;       JNZ     unmul                           ;AN000;;MS. lock mul range?
+;       JMP     LOCAL_LOCK                      ;AN000;;MS. yes
+;unmul:
+;       CMP     BP,Unlock_mul_range             ;AN000;;MS. unlock mul range?
+;       JZ      LOCAL_UNLOCK                    ;AN000;;MS. yes
+;       CMP     BP,Lock_read                    ;AN000;;MS. lock read?
+;       JNZ     chk_write_unlock                ;AN000;;MS. no
+;       CALL    Set_Lock_Buffer                 ;AN000;;MS. set DOS lock buffer
+;       CALL    Set_Lock                        ;AN000;;MS. set the lock
+;       JC      lockerror                       ;AN000;;MS. error
+;       invoke  $READ                           ;AN000;;MS. do read
+;       JC      lockerror                       ;AN000;;MS. error
+;lockend:                                       ;AN000;
+;       transfer SYS_RET_OK                     ;AN000;;MS. return
+;chk_write_unlock:                              ;AN000;
+;       CMP     BP,Write_unlock                 ;AN000;;MS. write unlock ?
+;       JNZ     Lock_addf                       ;AN000;;MS. no
+;       CALL    Set_Lock_Buffer                 ;AN000;;MS. set DOS lock buffer
+;WriteUnlock:                                   ;AN000;
+;       PUSH    AX                              ;AN000;;MS. save AX for unlock
+;       invoke  $WRITE                          ;AN000;;MS. do write
+;       MOV     [Temp_Var],AX                   ;AN000;;MS. save number of bytes writ
+;       POP     AX                              ;AN000;;MS. restore AX
+;       JC      lockerror                       ;AN000;;MS. error
+;       MOV     CX,1                            ;AN000;;MS. one range unlock
+;       PUSH    CS                              ;AN000;;MS.
+;       POP     DS                              ;AN000;;MS. DS:DX points to
+;       MOV     DX,OFFSET DOSGROUP:Lock_Buffer  ;AN000;;MS.  Lock_BUffer
+;       JMP     LOCAL_UNLOCK                    ;AN000;;MS. do unlock
+;Lock_addf:                                     ;AN000;
+;       MOV     SI,WORD PTR ES:[DI.SF_Size]      ;AN000;;MS. must be lock add
+;       MOV     WORD PTR ES:[DI.SF_Position],SI  ;AN000;;MS. set file position to
+;       MOV     SI,WORD PTR ES:[DI.SF_Size+2]    ;AN000;;MS. EOF
+;       MOV     WORD PTR ES:[DI.SF_Position+2],SI;AN000;;MS.
+;       CALL    Set_Lock_Buffer                  ;AN000;;MS. set DOS lock buffer
+;       CALL    Set_Lock                         ;AN000;;MS. set the lock
+;       JC      lockerror                        ;AN000;;MS. error
+;       JMP     WriteUnlock                      ;AN000;;MS. do write unlock
+                                                 ;AN000;;MS.
+DOS_Unlock:
+        TEST    ES:[DI.sf_flags],sf_isnet
+        JZ      LOCAL_UNLOCK
+;;      invoke  OWN_SHARE                        ;AN000;;MS. IFS owns share ?
+;;      JNZ     LOCAL_UNLOCK                     ;AN000;;MS. no
+
+        CallInstall Net_Xlock,multNet,10
+        JMP     SHORT ValChk
+LOCAL_UNLOCK:
+if installed
+        Call    JShare + 7 * 4
+else
+        Call    clr_block
+endif
+ValChk:
+        JNC     Lock_OK
+lockerror:
+        transfer SYS_RET_ERR
+Lock_OK:
+        MOV     AX,[Temp_VAR]                    ;AN000;;MS. AX= number of bytes
+        transfer SYS_Ret_OK
+DOS_Lock:
+        TEST    ES:[DI.sf_flags],sf_isnet
+        JZ      LOCAL_LOCK
+;;      invoke  OWN_SHARE                        ;AN000;;MS. IFS owns share ?
+;;      JNZ     LOCAL_LOCK                       ;AN000;;MS. no
+        CallInstall NET_XLock,multNet,10
+        JMP     ValChk
+LOCAL_LOCK:
+if installed
+        Call    JShare + 6 * 4
+else
+        Call    Set_Block
+endif
+        JMP     ValChk
+
+EndProc $LockOper
+
+BREAK <Set_Lock>
+
+;   Input:
+;          BP = Lock_Buffer addr
+;          CX = lock length
+;   Function:
+;          set the lock
+;   Output:
+;          carry clear ,Lock is set
+;                       DS:DX = addr of
+;          carry set Lock is not set
+;          DS,DX,CX preserved
+
+;       procedure   Set_Lock,NEAR                                               ;AN000;
+;ASSUME  DS:NOTHING,ES:NOTHING                                                   ;AN000;
+                                                                                ;AN000;
+;       PUSH    DS                          ;MS. save regs                      ;AN000;
+;       PUSH    DX                          ;MS.                                ;AN000;
+;       PUSH    CX                          ;MS.                                ;AN000;
+;                                                                               ;AN000;
+;       PUSH    CS                          ;MS.                                ;AN000;
+;       POP     DS                          ;MS. DS:DX poits to Lock_Buffer     ;AN000;
+;       MOV     DX,BP                       ;MS.                                ;AN000;
+;       PUSH    BX                          ;MS. save handle                    ;AN000;
+;       PUSH    AX                          ;MS. save functions                 ;AN000;
+;       MOV     CX,1                        ;MS. set one lock                   ;AN000;
+;if installed                                                                    ;AN000;
+;       Call    JShare + 6 * 4              ;MS. call share set block           ;AN000;
+;else                                                                            ;AN000;
+;       Call    Set_Block                   ;MS.                                ;AN000;
+;endif                                                                           ;AN000;
+;       POP     AX                          ;MS. restore regs                   ;AN000;
+;       POP     BX                          ;MS.                                ;AN000;
+;       POP     CX                          ;MS.                                ;AN000;
+;       POP     DX                          ;MS.                                ;AN000;
+;       POP     DS                          ;MS.                                ;AN000;
+;       return                              ;MS.                                ;AN000;
+;                                                                               ;AN000;
+;EndProc Set_Lock                                                                ;AN000;
+
+BREAK <Set_Lock_Buffer>
+
+;   Input:
+;          ES:DI = addr of SFT
+;          CX = lock length
+;   Function:
+;          set up the lock buffer
+;   Output:
+;          Lock_Buffer is filled with position and lock length
+;          BP = Lock_Buffer addr
+;
+
+;       procedure   Set_Lock_Buffer,NEAR
+;ASSUME  DS:NOTHING,ES:NOTHING
+;
+;       MOV     BP, OFFSET DOSGROUP:Lock_Buffer   ;MS. move file position       ;AN000;
+;       MOV     SI,WORD PTR ES:[DI.sf_position]   ;MS. to DOS lock_buffer       ;AN000;
+;       MOV     WORD PTR [BP.Lock_position],SI    ;MS.                          ;AN000;
+;       MOV     SI,WORD PTR ES:[DI.sf_position+2] ;MS.                          ;AN000;
+;       MOV     WORD PTR [BP.Lock_position+2],SI  ;MS.                          ;AN000;
+;       MOV     WORD PTR [BP.Lock_length],CX      ;MS. move cx to lock_buffer   ;AN000;
+;       MOV     WORD PTR [BP.Lock_length+2],0     ;MS.                          ;AN000;
+;       return                                    ;MS.                          ;AN000;
+;
+;EndProc Set_Lock_Buffer
+
+; Inputs:
+;       Outputs of SETUP
+;       [USER_ID] Set
+;       [PROC_ID] Set
+; Function:
+;       Check for lock violations on local I/O
+;       Retries are attempted with sleeps in between
+; Outputs:
+;    Carry clear
+;       Operation is OK
+;    Carry set
+;       A lock violation detected
+; Outputs of SETUP preserved
+
+        procedure   LOCK_CHECK,NEAR
+        DOSAssume   CS,<DS>,"Lock_Check"
+        ASSUME  ES:NOTHING
+
+        MOV     BX,RetryCount           ; Number retries
+LockRetry:
+        SaveReg <BX,AX>                 ; MS. save regs                         ;AN000;
+if installed
+        call    JShare + 8 * 4
+else
+        Call    chk_block
+endif
+        RestoreReg  <AX,BX>             ; MS. restrore regs                     ;AN000;
+        retnc                           ; There are no locks
+        Invoke  Idle                    ; wait a while
+        DEC     BX                      ; remember a retry
+        JNZ     LockRetry               ; more retries left...
+        STC
+        return
+EndProc LOCK_CHECK
+
+; Inputs:
+;       [THISDPB] set
+;       [READOP] indicates whether error on read or write
+; Function:
+;       Handle Lock violation on compatibility (FCB) mode SFTs
+; Outputs:
+;       Carry set if user says FAIL, causes error_lock_violation
+;       Carry clear if user wants a retry
+;
+; DS, ES, DI, CX preserved, others destroyed
+
+        procedure   LOCK_VIOLATION,NEAR
+        DOSAssume   CS,<DS>,"Lock_Violation"
+        ASSUME  ES:NOTHING
+
+        PUSH    DS
+        PUSH    ES
+        PUSH    DI
+        PUSH    CX
+        MOV     AX,error_lock_violation
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        LES     BP,[THISDPB]
+        MOV     DI,1                            ; Fake some registers
+        MOV     CX,DI
+        MOV     DX,ES:[BP.dpb_first_sector]
+        invoke  HARDERR
+        POP     CX
+        POP     DI
+        POP     ES
+        POP     DS
+        CMP     AL,1
+        retz                    ; 1 = retry, carry clear
+        STC
+        return
+
+EndProc LOCK_VIOLATION
+
+IF  INSTALLED
+;
+; do a retz to return error
+;
+Procedure   CheckShare,NEAR
+        ASSUME  CS:DOSGROUP,ES:NOTHING,DS:NOTHING,SS:NOTHING
+        CMP     fShare,0
+        return
+EndProc CheckShare
+ENDIF
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/MACRO.ASM b/v4.0/src/DOS/MACRO.ASM
new file mode 100644
index 0000000..dea0771
--- /dev/null
+++ b/v4.0/src/DOS/MACRO.ASM
@@ -0,0 +1,445 @@
+;       SCCSID = @(#)macro.asm  1.2 85/07/11
+TITLE   MACRO - Pathname and macro related internal routines
+NAME    MACRO
+;
+;   $AssignOper     written
+;   FIND_DPB        written
+;   InitCDS         written
+;   $UserOper       written
+;   GetVisDrv       written
+;   GetThisDrv      written
+;   GetCDSFromDrv   written
+;
+;   Revision history:
+;
+;       Created: MZ 4 April 1983
+;                MZ 18 April 1983   Make TransFCB handle extended FCBs
+;                AR 2 June 1983     Define/Delete macro for NET redir.
+;                MZ 3 Nov 83        Fix InitCDS to reset length to 2
+;                MZ 4 Nov 83        Fix NetAssign to use STRLEN only
+;                MZ 18 Nov 83       Rewrite string processing for subtree
+;                                   aliasing.
+;
+;   MSDOS performs several types of name translation.  First, we maintain for
+;   each valid drive letter the text of the current directory on that drive.
+;   For invalid drive letters, there is no current directory so we pretend to
+;   be at the root.  A current directory is either the raw local directory
+;   (consisting of drive:\path) or a local network directory (consisting of
+;   \\machine\path.  There is a limit on the point to which a ..  is allowed.
+;
+;   Given a path, MSDOS will transform this into a real from-the-root path
+;   without .  or ..  entries.  Any component that is > 8.3 is truncated to
+;   this and all * are expanded into ?'s.
+;
+;   The second part of name translation involves subtree aliasing.  A list of
+;   subtree pairs is maintained by the external utility SUBST.  The results of
+;   the previous 'canonicalization' are then examined to see if any of the
+;   subtree pairs is a prefix of the user path.  If so, then this prefix is
+;   replaced with the other subtree in the pair.
+;
+;   A third part involves mapping this "real" path into a "physical" path.  A
+;   list of drive/subtree pairs are maintained by the external utility JOIN.
+;   The output of the previous translation is examined to see if any of the
+;   subtrees in this list are a prefix of the string.  If so, then the prefix
+;   is replaced by the appropriate drive letter.  In this manner, we can
+;   'mount' one device under another.
+;
+;   The final form of name translation involves the mapping of a user's
+;   logical drive number into the internal physical drive.  This is
+;   accomplished by converting the drive number into letter:CON, performing
+;   the above translation and then converting the character back into a drive
+;   number.
+;
+;   curdir_list     STRUC
+;   curdir_text     DB      DIRSTRLEN DUP (?) ; text of assignment and curdir
+;   curdir_flags    DW      ?               ; various flags
+;   curdir_devptr   DD      ?               ; local pointer to DPB or net device
+;   curdir_ID       DW      ?               ; cluster of current dir (net ID)
+;                   DW      ?
+;   curdir_end      DW      ?               ; end of assignment
+;   curdir_list     ENDS
+;   curdir_netID    EQU     DWORD PTR curdir_ID
+;   ;Flag word masks
+;   curdir_isnet    EQU     1000000000000000B
+;   curdir_inuse    EQU     0100000000000000B
+;
+;   There are two main entry points:  TransPath and TransFCB.  TransPath will
+;   take a path and form the real text of the pathname with all .  and ..
+;   removed.  TransFCB will translate an FCB into a path and then invoke
+;   TransPath.
+;
+;   Implementation note:  CURDIR_End field points to the point in the text
+;   string where the user may back up to via ..  It is the location of a
+;   separator character.  For the root, it points at the leading /.  For net
+;   assignments it points at the end (nul) of the initial assignment:
+;   A:/     \\foo\bar       \\foo\bar\blech\bozo
+;     ^              ^               ^
+; A: -> d: /path/ path/ text
+;
+;   A000    version 4.00  Jan. 1988
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+.sall
+
+Installed = TRUE
+
+        I_need  ThisCDS,DWORD           ; pointer to CDS used
+        I_need  CDSAddr,DWORD           ; pointer to CDS table
+        I_need  CDSCount,BYTE           ; number of CDS entries
+        I_need  CurDrv,BYTE             ; current macro assignment (old
+                                        ; current drive)
+        I_need  NUMIO,BYTE              ; Number of physical drives
+        I_need  fSharing,BYTE           ; TRUE => no redirection allowed
+        I_need  DummyCDS,80h            ; buffer for dummy cds
+        I_need  DIFFNAM,BYTE            ; flag for MyName being set
+        I_need  MYNAME,16               ; machine name
+        I_need  MYNUM,WORD              ; machine number
+        I_need  DPBHEAD,DWORD           ; beginning of DPB chain
+        I_need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
+        I_need  DrvErr,BYTE             ; drive error
+
+BREAK <$AssignOper -- Set up a Macro>
+
+; Inputs:
+;       AL = 00 get assign mode                     (ReturnMode)
+;       AL = 01 set assign mode                     (SetMode)
+;       AL = 02 get attach list entry               (GetAsgList)
+;       AL = 03 Define Macro (attch start)
+;           BL = Macro type
+;              = 0 alias
+;              = 1 file/device
+;              = 2 drive
+;              = 3 Char device -> network
+;              = 4 File device -> network
+;           DS:SI -> ASCIZ source name
+;           ES:DI -> ASCIZ destination name
+;       AL = 04 Cancel Macro
+;           DS:SI -> ASCIZ source name
+;       AL = 05 Modified get attach list entry
+;       AL = 06 Get ifsfunc item
+;       AL = 07 set in_use of a drive's CDS
+;            DL = drive number, 0=default  0=A,,
+;       AL = 08 reset in_use of a drive's CDS
+;            DL = drive number, 0=A, 1=B,,,
+; Function:
+;       Do macro stuff
+; Returns:
+;       Std Xenix style error return
+
+        procedure   $AssignOper,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        CMP     AL,7                                  ; set in_use ?            ;AN000;
+        JNZ     chk08                                 ; no                      ;AN000;
+srinuse:                                                                        ;AN000;
+        PUSH    AX                                    ; save al                 ;AN000;
+        MOV     AL,DL                                 ; AL= drive id            ;AN000;
+        CALL    GetCDSFromDrv                         ; ds:si -> cds            ;AN000;
+        POP     AX                                    ;                         ;AN000;
+        JC      baddrv                                ; bad drive               ;AN000;
+        CMP     WORD PTR [SI.curdir_devptr],0         ; dpb ptr =0 ?            ;AN000;
+        JZ      baddrv                                ;     no                  ;AN000;
+        CMP     AL,7                                  ; set ?                   ;AN000;
+        JNZ     resetdrv                              ; no                      ;AN000;
+        OR      [SI.curdir_flags],curdir_inuse        ; set in_use              ;AN000;
+        JMP     SHORT okdone                          ;                         ;AN000;
+resetdrv:                                                                       ;AN000;
+        AND     [SI.curdir_flags],NOT curdir_inuse    ; reset in_use            ;AN000;
+        JMP     SHORT okdone                          ;                         ;AN000;
+baddrv:                                                                         ;AN000;
+        MOV     AX,error_invalid_drive                ; error                   ;AN000;
+        JMP     SHORT ASS_ERR                         ;                         ;AN000;
+chk08:                                                                          ;AN000;
+        CMP     AL,8                                  ; reset inuse ?           ;AN000;
+        JZ      srinuse                               ; yes                     ;AN000;
+
+        IF      NOT INSTALLED
+        transfer NET_ASSOPER
+        ELSE
+        PUSH    AX
+        MOV     AX,(multnet SHL 8) OR 30
+        INT     2FH
+        POP     BX                      ; Don't zap error code in AX
+        JC      ASS_ERR
+okdone:
+        transfer SYS_RET_OK
+
+ASS_ERR:
+        transfer SYS_RET_ERR
+        ENDIF
+
+EndProc $AssignOper
+
+Break <FIND_DPB - Find a DPB from a drive number>
+
+;   Inputs:     AL has drive number A = 0
+;   Outputs:    Carry Set
+;                   No DPB for this drive number
+;               Carry Clear
+;                   DS:SI points to DPB for drive
+;   registers modified: DS,SI
+Procedure FIND_DPB,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        LDS     SI,[DPBHEAD]
+DPB_LOOP:
+        CMP     SI,-1
+        JZ      NO_DPB
+        CMP     AL,[SI.dpb_drive]
+        retz                            ; Carry clear
+        LDS     SI,[SI.dpb_next_dpb]
+        JMP     DPB_LOOP
+
+NO_DPB:
+        STC
+        return
+EndProc FIND_DPB
+
+Break <InitCDS - set up an empty CDS>
+
+;   Inputs:     ThisCDS points to CDS
+;               AL has uppercase drive letter
+;   Outputs:    ThisCDS is now empty
+;               ES:DI point to CDS
+;               Carry set if no DPB associated with drive
+;   registers modified: AH,ES,DI
+Procedure InitCDS,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AH,':'
+        PUSH    AX
+        SUB     AL,"A"-1                ; A = 1
+        CMP     [NUMIO],AL
+        POP     AX
+        LES     DI,[THISCDS]
+        MOV     ES:[DI.curdir_flags],0  ; "free" CDS
+        JB      RET_OK                  ; Drive does not map a physical drive
+        MOV     WORD PTR ES:[DI.curdir_text],AX
+        PUSH    AX
+        MOV     AX,"\"
+        MOV     WORD PTR ES:[DI.curdir_text+2],AX   ; NUL terminate
+        POP     AX
+        OR      ES:[DI.curdir_flags],curdir_inuse
+        MOV     ES:[DI.curdir_END],2    ; MZ 3 Nov 83
+        MOV     ES:[DI.curdir_ID],0
+        MOV     ES:[DI.curdir_ID+2],0
+        PUSH    AX
+        PUSH    DS
+        PUSH    SI
+        SUB     AL,"A"                  ; A = 0
+        invoke  FIND_DPB
+        JC      PRET                    ; OOOOPPPPPSSSS!!!!
+        MOV     WORD PTR ES:[DI.curdir_devptr],SI
+        MOV     WORD PTR ES:[DI.curdir_devptr+2],DS
+PRET:
+        POP     SI
+        POP     DS
+        POP     AX
+RET_OK: return
+EndProc InitCDS
+
+Break <$UserOper - get/set current user ID (for net)>
+
+;
+;   $UserOper - retrieve or initiate a user id string.  MSDOS will only
+;       maintain this string and do no verifications.
+;
+;   Inputs:     AL has function type (0-get 1-set 2-printer-set 3-printer-get
+;                                     4-printer-set-flags,5-printer-get-flags)
+;               DS:DX is user string pointer (calls 1,2)
+;               ES:DI is user buffer (call 3)
+;               BX is assign index (calls 2,3,4,5)
+;               CX is user number (call 1)
+;               DX is flag word (call 4)
+;   Outputs:    If AL = 0 then the current user string is written to DS:DX
+;                       and user CX is set to the user number
+;               If AL = 3 then CX bytes have been put at input ES:DI
+;               If AL = 5 then DX is flag word
+
+Procedure   $UserOper,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        PUSH    AX
+        SUB     AL,1                    ; quick dispatch on 0,1
+        POP     AX
+        JB      UserGet                 ; return to user the string
+        JZ      UserSet                 ; set the current user
+        CMP     AL,5                    ; test for 2,3,4 or 5
+        JBE     UserPrint               ; yep
+        MOV     EXTERR_LOCUS,errLoc_Unk ; Extended Error Locus
+        error   error_Invalid_Function  ; not 0,1,2,3
+
+UserGet:
+; Transfer MYNAME to DS:DX
+; Set Return CX to MYNUM
+        PUSH    DS                      ; switch registers
+        POP     ES
+        MOV     DI,DX                   ; destination
+        MOV     CX,[MYNUM]              ; Get number
+        invoke  get_user_stack
+        MOV     [SI.User_CX],CX         ; Set number return
+        Context DS                      ; point to DOSGroup
+ASSUME  DS:DOSGROUP
+        MOV     SI,OFFSET DOSGroup:MyName   ; point source to user string
+UserMove:
+ASSUME  DS:NOTHING
+        MOV     CX,15
+        REP     MOVSB                   ; blam.
+        XOR     AX,AX                   ; 16th byte is 0
+        STOSB
+UserBye:
+        transfer    sys_ret_ok          ; no errors here
+
+UserSet:
+ASSUME  DS:NOTHING
+; Transfer DS:DX to MYNAME
+; CX to MYNUM
+        MOV     [MYNUM],CX
+        MOV     SI,DX                   ; user space has source
+        Context ES
+        MOV     DI,OFFSET DOSGroup:MyName   ; point dest to user string
+        INC     [DiffNam]                 ; signal change
+        JMP     UserMove
+
+UserPrint:
+        ASSUME  ES:NOTHING
+IF NOT Installed
+        transfer PRINTER_GETSET_STRING
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 31
+        INT     2FH
+        POP     DX                      ; Clean stack
+        JNC     OKPA
+        transfer SYS_RET_ERR
+
+OKPA:
+        transfer SYS_RET_OK
+ENDIF
+
+EndProc $UserOper
+
+Break   <GetVisDrv - return visible drive>
+
+;
+;   GetVisDrv - correctly map non-spliced inuse drives
+;
+;   Inputs:     AL has drive identifier (0=default)
+;   Outputs:    Carry Set - invalid drive/macro
+;               Carry Clear - AL has physical drive (0=A)
+;                   ThisCDS points to CDS
+;   Registers modified: AL
+
+Procedure   GetVisDrv,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        CALL    GetThisDrv              ; get inuse drive
+        retc
+        SaveReg <DS,SI>
+        LDS     SI,ThisCDS
+        TEST    [SI].curdir_flags,curdir_splice
+        RestoreReg  <SI,DS>
+        retz                            ; if not spliced, return OK
+        MOV     [DrvErr],error_invalid_drive ;IFS.                              ;AN000;
+        STC                             ; signal error
+        return
+EndProc GetVisDrv
+
+Break <Getthisdrv - map a drive designator (0=def, 1=A...)>
+
+;
+;   GetThisDrv - look through a set of macros and return the current drive and
+;       macro pointer
+;
+;   Inputs:     AL has drive identifier (1=A, 0=default)
+;   Outputs:
+;               Carry Set - invalid drive/macro
+;               Carry Clear - AL has physical drive (0=A)
+;                  ThisCDS points to macro
+;   Registers modified: AL
+
+Procedure   GetThisDrv,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        OR      AL,AL                   ; are we using default drive?
+        JNZ     GetMap                  ; no, go get the CDS pointers
+        MOV     AL,[CurDrv]             ; get the current drive
+        INC     AL                      ; Counteract next instruction
+GetMap:
+        DEC     AL                      ; 0 = A
+        SaveReg <DS,SI>                 ; save world
+        mov     [EXTERR_LOCUS],errLOC_Disk
+        TEST    fSharing,-1             ; Logical or Physical?
+        JZ      Not_SRVC                ; Logical
+        SaveReg <AX,ES,DI>
+        MOV     WORD PTR ThisCDS,OFFSET DOSGroup:DummyCDS
+        MOV     WORD PTR ThisCDS+2,CS   ;       ThisCDS = &DummyCDS;
+        ADD     AL,'A'
+        CALL    InitCDS                 ;       InitCDS(c);
+        TEST    ES:[DI.curdir_flags],curdir_inuse       ; Clears carry
+        RestoreReg  <DI,ES,AX>
+        JZ      GetBerr                 ; Not a physical drive.
+        JMP     SHORT GetBye            ; carry clear
+
+Not_SRVC:
+        invoke  GetCDSFromDrv
+        JC      GetBerr2                ; Unassigned CDS -> return error already set
+        TEST    [SI.curdir_flags],curdir_inuse  ; Clears Carry
+        JNZ     GetBye                  ; carry clear
+GetBerr:
+        MOV     AL,error_not_DOS_disk   ;AN000;IFS. Formatted IFS drive
+        CMP     WORD PTR [SI.curdir_devptr],0    ;AN000;IFS. dpb ptr =0 ?
+        JNZ     notfat                  ;AN000;IFS. no
+GetBerr2:
+        MOV     AL,error_invalid_drive  ;AN000;;IFS. invalid FAT drive
+notfat:                                 ;AN000;
+        MOV     [DrvErr],AL             ;AN000;;IFS. save this for IOCTL
+        mov     [EXTERR_LOCUS],errLOC_UNK
+        STC
+GetBye: RestoreReg  <SI,DS>             ; restore world
+        return
+EndProc GetThisDrv
+
+Break <GetCDSFromDrv - convert a drive number to a CDS pointer>
+
+;
+;   GetCDSFromDrv - given a physical drive number, convert it to a CDS
+;       pointer, returning an error if the drive number is greater than the
+;       number of CDS's
+;
+;   Inputs:     AL is physical unit # A=0...
+;   Outputs:    Carry Set if Bad Drive
+;               Carry Clear
+;                   DS:SI -> CDS
+;                   [THISCDS] = DS:SI
+;   Registers modified: DS,SI
+
+Procedure   GetCDSFromDrv,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        CMP     AL,[CDSCount]           ; is this a valid designator
+        JB      GetCDS                  ; yes, go get the macro
+        STC                             ; signal error
+        return                          ; bye
+GetCDS:
+        SaveReg <BX,AX>
+        LDS     SI,[CDSAddr]            ; get pointer to table
+        MOV     BL,SIZE CurDir_list     ; size in convenient spot
+        MUL     BL                      ; get net offset
+        ADD     SI,AX                   ; convert to true pointer
+        MOV     WORD PTR [ThisCDS],SI   ; store convenient offset
+        MOV     WORD PTR [ThisCDS+2],DS ; store convenient segment
+        RestoreReg  <AX,BX>
+        CLC                             ; no error
+        return                          ; bye!
+EndProc GetCDSFromDrv
+
+CODE ends
+END
diff --git a/v4.0/src/DOS/MACRO2.ASM b/v4.0/src/DOS/MACRO2.ASM
new file mode 100644
index 0000000..a3ff4cc
--- /dev/null
+++ b/v4.0/src/DOS/MACRO2.ASM
@@ -0,0 +1,1281 @@
+;       SCCSID = @(#)macro2.asm 1.2 85/07/23
+TITLE   MACRO2 - Pathname and macro related internal routines
+NAME    MACRO2
+;
+;   TransFCB        written
+;   TransPath       written
+;   TransPathSet    written
+;   TransPathNoSet  Written
+;   Canonicalize    written
+;   PathSep         written
+;   SkipBack        written
+;   CopyComponent   written
+;   Splice          written
+;   $NameTrans      written
+;   DriveFromText
+;   TextFromDrive
+;   PathPref
+;   ScanPathChar
+;
+;   Revision history:
+;
+;       Created: MZ 4 April 1983
+;                MZ 18 April 1983   Make TransFCB handle extended FCBs
+;                AR 2 June 1983     Define/Delete macro for NET redir.
+;                MZ 3 Nov 83        Fix InitCDS to reset length to 2
+;                MZ 4 Nov 83        Fix NetAssign to use STRLEN only
+;                MZ 18 Nov 83       Rewrite string processing for subtree
+;                                   aliasing.
+;                BAS 3 Jan 85       ScanPathChar to search for path separator
+;                                   in null terminated string.
+;
+;   MSDOS performs several types of name translation.  First, we maintain for
+;   each valid drive letter the text of the current directory on that drive.
+;   For invalid drive letters, there is no current directory so we pretend to
+;   be at the root.  A current directory is either the raw local directory
+;   (consisting of drive:\path) or a local network directory (consisting of
+;   \\machine\path.  There is a limit on the point to which a ..  is allowed.
+;
+;   Given a path, MSDOS will transform this into a real from-the-root path
+;   without .  or ..  entries.  Any component that is > 8.3 is truncated to
+;   this and all * are expanded into ?'s.
+;
+;   The second part of name translation involves subtree aliasing.  A list of
+;   subtree pairs is maintained by the external utility SUBST.  The results of
+;   the previous 'canonicalization' are then examined to see if any of the
+;   subtree pairs is a prefix of the user path.  If so, then this prefix is
+;   replaced with the other subtree in the pair.
+;
+;   A third part involves mapping this "real" path into a "physical" path.  A
+;   list of drive/subtree pairs are maintained by the external utility JOIN.
+;   The output of the previous translation is examined to see if any of the
+;   subtrees in this list are a prefix of the string.  If so, then the prefix
+;   is replaced by the appropriate drive letter.  In this manner, we can
+;   'mount' one device under another.
+;
+;   The final form of name translation involves the mapping of a user's
+;   logical drive number into the internal physical drive.  This is
+;   accomplished by converting the drive number into letter:CON, performing
+;   the above translation and then converting the character back into a drive
+;   number.
+;
+;   curdir_list     STRUC
+;   curdir_text     DB      DIRSTRLEN DUP (?) ; text of assignment and curdir
+;   curdir_flags    DW      ?               ; various flags
+;   curdir_devptr   DD      ?               ; local pointer to DPB or net device
+;   curdir_ID       DW      ?               ; cluster of current dir (net ID)
+;                   DW      ?
+;   curdir_end      DW      ?               ; end of assignment
+;   curdir_list     ENDS
+;   curdir_netID    EQU     DWORD PTR curdir_ID
+;   ;Flag word masks
+;   curdir_isnet    EQU     1000000000000000B
+;   curdir_inuse    EQU     0100000000000000B
+;
+;
+;   There are two main entry points:  TransPath and TransFCB.  TransPath will
+;   take a path and form the real text of the pathname with all .  and ..
+;   removed.  TransFCB will translate an FCB into a path and then invoke
+;   TransPath.
+;
+;   Implementation note:  CURDIR_End field points to the point in the text
+;   string where the user may back up to via ..  It is the location of a
+;   separator character.  For the root, it points at the leading /.  For net
+;   assignments it points at the end (nul) of the initial assignment:
+;   A:/     \\foo\bar       \\foo\bar\blech\bozo
+;     ^              ^               ^
+; A: -> d: /path/ path/ text
+;
+;   A000  version 4.00  Jan. 1988
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+.sall
+
+Installed = TRUE
+
+        I_need  Splices,BYTE            ; TRUE => splices are being done.
+        I_need  WFP_Start,WORD          ; pointer to beginning of expansion
+        I_need  Curr_Dir_End,WORD       ; offset to end of current dir
+        I_need  ThisCDS,DWORD           ; pointer to CDS used
+        I_need  ThisDPB,DWORD           ; pointer to DPB used
+        I_need  NAME1,11                ; Parse output of NameTrans
+        I_need  OpenBuf,128             ; ususal destination of strings
+        I_need  ExtFCB,BYTE             ; flag for extended FCBs
+        I_need  Sattrib,BYTE            ; attribute of search
+        I_need  fSplice,BYTE            ; TRUE => do splice after canonicalize
+        I_need  fSharing,BYTE           ; TRUE => no redirection allowed
+        I_Need  NoSetDir,BYTE           ; TRUE => syscall is interested in
+                                        ; entry, not contents.  We splice only
+                                        ; inexact matches
+        I_Need  cMeta,BYTE              ; count of meta chars in path
+        I_Need  Temp_Var,WORD           ;AN000; variable for temporary use 3/31/KK
+        I_Need  DOS34_FLAG,WORD         ;AN000; variable for dos34
+        I_Need  NO_FILTER_PATH,DWORD    ;AN000; pointer to orignal path
+Table   SEGMENT
+        EXTRN   CharType:BYTE
+Table   ENDS
+
+BREAK <TransFCB - convert an FCB into a path, doing substitution>
+
+;
+;   TransFCB - Copy an FCB from DS:DX into a reserved area doing all of the
+;       gritty substitution.
+;
+;   Inputs:     DS:DX - pointer to FCB
+;               ES:DI - point to destination
+;   Outputs:    Carry Set - invalid path in final map
+;               Carry Clear - FCB has been mapped into ES:DI
+;                   Sattrib is set from possibly extended FCB
+;                   ExtFCB set if extended FCB found
+;   Registers modified: most
+
+Procedure   TransFCB,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+PUBLIC MACRO001S,MACRO001E
+MACRO001S:
+        LocalVar    FCBTmp,15
+MACRO001E:
+        Enter
+        Context ES                      ; get DOSGroup addressability
+        SaveReg <ES,DI>                 ; save away final destination
+        LEA     DI,FCBTmp               ; point to FCB temp area
+        MOV     [ExtFCB],0              ; no extended FCB found
+        MOV     [Sattrib],0             ; default search attributes
+        invoke  GetExtended             ; get FCB, extended or not
+        JZ      GetDrive                ; not an extended FCB, get drive
+        MOV     AL,[SI-1]               ; get attributes
+        MOV     [SAttrib],AL            ; store search attributes
+        MOV     [ExtFCB],-1             ; signal extended FCB
+GetDrive:
+        LODSB                           ; get drive byte
+        invoke  GetThisDrv
+        jc      BadPack
+        CALL    TextFromDrive           ; convert 0-based drive to text
+;
+; Scan the source to see if there are any illegal chars
+;
+        MOV     BX,OFFSET DOSGroup:CharType
+ IF  DBCS                               ;AN000;
+;----------------------------- Start of DBCS 2/13/KK
+        SaveReg <SI>                    ;AN000;; back over name, ext
+        MOV     CX,8                    ;AN000;; 8 chars in main part of name
+FCBScan:LODSB                           ;AN000;; get a byte
+        invoke  testkanj                ;AN000;
+        jz      notkanj2                ;AN000;
+        DEC     CX                      ;AN000;
+        JCXZ    VolidChck               ;AN000;; Kanji half char screw up
+        LODSB                           ;AN000;; second kanji byte
+        jmp     short Nextch            ;AN000;
+VolidChck:                              ;AN000;
+        TEST    [SAttrib],attr_volume_id ;AN000;; volume id ?
+        JZ      Badpack                  ;AN000;; no, error
+        OR      [DOS34_FLAG],DBCS_VOLID  ;AN000;; no, error
+        DEC     CX                       ;AN000;; cx=-1
+        INC     SI                       ;AN000;; next char
+        JMP     SHORT FCBScango          ;AN000;
+notkanj2:                                ;AN000;
+        XLAT    ES:CharType              ;AN000;;get bits
+        TEST    AL,fFCB                  ;AN000;
+        JZ      BadPack                  ;AN000;
+NextCh:                                  ;AN000;
+        LOOP    FCBScan                  ;AN000;
+FCBScango:                               ;AN000;
+        ADD     CX,3                    ;AN000;; Three chars in extension
+FCBScanE:                               ;AN000;
+        LODSB                           ;AN000;
+        invoke  testkanj                ;AN000;
+        jz      notkanj3                ;AN000;
+        DEC     CX                      ;AN000;
+        JCXZ    BadPack                 ;AN000;; Kanji half char problem
+        LODSB                           ;AN000;; second kanji byte
+        jmp     short NextChE           ;AN000;
+notkanj3:                               ;AN000;
+        XLAT    ES:CharType             ;AN000;; get bits
+        TEST    AL,fFCB                 ;AN000;
+        JZ      BadPack                 ;AN000;
+NextChE:                                ;AN000;
+        LOOP    FCBScanE                ;AN000;
+;----------------------------- End of DBCS 2/13/KK
+ ELSE
+
+        MOV     CX,11
+        SaveReg <SI>                    ; back over name, ext
+FCBScan:LODSB                           ; get a byte
+        XLAT    ES:CharType             ; get bits
+        TEST    AL,fFCB
+        JZ      BadPack
+NextCh: LOOP    FCBScan
+ ENDIF
+        RestoreReg  <SI>
+        MOV     BX,DI
+        invoke  PackName                ; crunch the path
+        RestoreReg  <DI,ES>             ; get original destination
+        Context DS                      ; get DS addressability
+        LEA     SI,FCBTmp               ; point at new pathname
+        CMP     BYTE PTR [BX],0
+        JZ      BadPack
+        SaveReg <BP>
+        CALL    TransPathSet            ; convert the path
+        RestoreReg  <BP>
+        JNC     FCBRet                  ; bye with transPath error code
+BadPack:
+        STC
+        MOV     AL,error_path_not_found
+FCBRet: Leave
+        return
+EndProc TransFCB,NoCheck
+
+BREAK <TransPath - copy a path, do string sub and put in current dir>
+
+;
+;   TransPath - copy a path from DS:SI to ES:DI, performing component string
+;       substitution, insertion of current directory and fixing .  and ..
+;       entries.  Perform splicing.  Allow input string to match splice
+;       exactly.
+;
+;   TransPathSet - Same as above except No splicing is performed if input path
+;       matches splice.
+;
+;   TransPathNoSet - No splicing/local using is performed at all.
+;
+;   The following anomalous behaviour is required:
+;
+;       Drive letters on devices are ignored.  (set up DummyCDS)
+;       Paths on devices are ignored. (truncate to 0-length)
+;       Raw net I/O sets ThisCDS => NULL.
+;       fSharing => dummyCDS and no subst/splice.  Only canonicalize.
+;
+;   Other behaviour:
+;
+;       ThisCDS set up.
+;       FatRead done on local CDS.
+;       ValidateCDS done on local CDS.
+;
+;   Brief flowchart:
+;
+;       if fSharing then
+;           set up DummyCDS (ThisCDS)
+;           canonicalize (sets cMeta)
+;           splice
+;           fatRead
+;           return
+;       if \\ or d:\\ lead then
+;           set up null CDS (ThisCDS)
+;           canonicalize (sets cMeta)
+;           return
+;       if device then
+;           set up dummyCDS (ThisCDS)
+;           canonicalize (sets cMeta)
+;           return
+;       if file then
+;           getCDS (sets (ThisCDS) from name)
+;           validateCDS (may reset current dir)
+;           Copy current dir
+;           canonicalize (set cMeta)
+;           splice
+;           generate correct CDS (ThisCDS)
+;           if local then
+;               fatread
+;           return
+;
+;   Inputs:     DS:SI - point to ASCIZ string path
+;               DI - point to buffer in DOSGroup
+;   Outputs:    Carry Set - invalid path specification: too many .., bad
+;                   syntax, etc. or user FAILed to I 24.
+;               WFP_Start - points to beginning of buffer
+;               Curr_Dir_End - points to end of current dir in path
+;               DS - DOSGroup
+;   Registers modified: most
+
+Procedure   TransPath,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        XOR     AL,AL
+        JMP     SHORT SetSplice
+        Entry   TransPathSet
+        MOV     AL,-1
+SetSplice:
+        MOV     NoSetDir,AL             ;   NoSetDir = !fExact;
+        MOV     AL,-1
+        Entry   TransPathNoSet
+        MOV     WORD PTR [NO_FILTER_PATH],SI   ;AN000;;IFS. save old path for IFS
+        MOV     WORD PTR [NO_FILTER_PATH+2],DS ;AN000;;IFS.
+
+        MOV     fSplice,AL              ;   fSplice = TRUE;
+        MOV     cMeta,-1
+        MOV     WFP_Start,DI
+        MOV     Curr_Dir_End,-1         ; crack from start
+        Context ES
+        LEA     BP,[DI+TEMPLEN]         ; end of buffer
+;
+; if this is through the server dos call, fsharing is set.  We set up a
+; dummy cds and let the operation go.
+;
+        TEST    fSharing,-1             ; if no sharing
+        JZ      CheckUNC                ; skip to UNC check
+;
+; ES:DI point to buffer
+;
+        CALL    DriveFromText           ; get drive and advance DS:SI
+        invoke  GetThisDrv              ; Set ThisCDS and convert to 0-based
+        jc      NoPath
+        CALL    TextFromDrive           ; drop in new
+        LEA     BX,[DI+1]               ; backup limit
+        CALL    Canonicalize            ; copy and canonicalize
+        retc                            ; errors
+;
+; Perform splices for net guys.
+;
+        Context DS
+        MOV     SI,wfp_Start            ; point to name
+        TEST    fSplice,-1
+        JZ      NoServerSplice
+        CALL    Splice
+NoServerSplice:
+        Context DS                      ; for FATREAD
+        LES     DI,ThisCDS              ; for fatread
+        EnterCrit   critDisk
+        Invoke  FatRead_CDS
+        LeaveCrit   critDisk
+NoPath:
+        MOV     AL,error_path_not_found ; Set up for possible bad path error
+        return                          ; any errors are in Carry flag
+        ASSUME  DS:NOTHING
+;
+; Let the network decide if the name is for a spooled device.  It will map
+; the name if so.
+;
+CheckUnc:
+        MOV     WORD PTR ThisCDS,-1     ; NULL thisCDS
+        CallInstall NetSpoolCheck,multNet,35
+        JNC     UNCDone
+;
+; At this point the name is either a UNC-style name (prefixed with two leading
+; \\s) or is a local file/device.  Remember that if a net-spooled device was
+; input, then the name has been changed to the remote spooler by the above net
+; call.  Also, there may be a drive in front of the \\.
+;
+NO_CHECK:
+        CALL    DriveFromText           ; eat drive letter
+        PUSH    AX                      ; save it
+        MOV     AX,WORD PTR [SI]        ; get first two bytes of path
+        Invoke  PathChrCmp              ; convert to normal form
+        XCHG    AH,AL                   ; swap for second byte
+        Invoke  PathChrCmp              ; convert to normal form
+        JNZ     CheckDevice             ; not a path char
+        CMP     AH,AL                   ; are they same?
+        JNZ     CheckDevice             ; nope
+;
+; We have a UNC request.  We must copy the string up to the beginning of the
+; local machine root path
+;
+
+        POP     AX
+        MOVSW                           ; get the lead \\
+UNCCpy: LODSB                           ; get a byte
+ IF  DBCS                               ;AN000;
+;----------------------------- Start of DBCS 2/23/KK
+        invoke  testkanj                ;AN000;
+        jz      notkanj1                ;AN000;
+        STOSB                           ;AN000;
+        LODSB                           ;AN000;
+        OR      AL,AL                   ;AN000;
+        JZ      UNCTerm                 ;AN000;; Ignore half kanji error for now
+        STOSB                           ;AN000;
+        jmp     UNCCpy                  ;AN000;
+notkanj1:                               ;AN000;
+;----------------------------- End of DBCS 2/23/KK
+ ENDIF                                  ;AN000;
+        invoke  UCase                   ;AN000;; convert the char
+        OR      AL,AL
+        JZ      UNCTerm                 ; end of string.  All done.
+        Invoke  PathChrCmp              ; is it a path char?
+        MOV     BX,DI                   ; backup position
+        STOSB
+        JNZ     UNCCpy                  ; no, go copy
+        CALL    Canonicalize            ; wham (and set cMeta)
+UNCDone:
+        Context DS
+ IF  DBCS
+;----------------------------- Start of DBCS 2/23/KK
+        retc                            ;AN000; Return if error from Canonicalize
+
+; Although Cononicalize has done lots of good things for us it may also have
+; done e5 to 05 conversion on the fisrt char following a path sep char which is
+; not wanted on a UNC request as this should be left for the remote station.
+; The simplest thing to do is check for such conversions and convert them back
+; again.
+; This check loop is also called from the DoFile section of TransPath if the
+; file is a remote file. Entry point when called is TP_check05 with the
+; inputs/outputs as follows;
+;       Inputs : ES:DI = Buffer to check for re-conversion
+;       Outputs: None
+;       Used   : DI,AX
+
+
+        MOV     DI,WFP_start            ;AN000;; ES:DI points to converted string
+TP_check05:                             ;AN000;
+        MOV     AL,BYTE PTR ES:[DI]     ;AN000;; Get character from path
+        OR      AL,AL                   ;AN000;; End of null terminated path?
+        JZ      TP_end05                ;AN000;; Finished, CF =0 from OR (ret success)
+        invoke  testkanj                ;AN000;; Kanji lead character?
+        JZ      TP_notK                 ;AN000;; Check for path seperator if not
+        INC     DI                      ;AN000;; Bypass Kanji second byte
+        JMP     TP_nxt05                ;AN000;; Go to check next character
+TP_notK:                                ;AN000;
+        invoke  PathChrCmp              ;AN000;; Is it a path seperator char?
+        JNZ     TP_nxt05                ;AN000;; Check next character if not
+        CMP     BYTE PTR ES:[DI+1],05   ;AN000;; 05 following path sep char?
+        JNZ     TP_nxt05                ;AN000;; Check next character if not
+        MOV     BYTE PTR ES:[DI+1],0E5h ;AN000;; Convert 05 back to E5
+TP_nxt05:                               ;AN000;
+        INC     DI                      ;AN000;; Point to next char in path
+        JMP     TP_check05              ;AN000;; Test all chars in path
+TP_end05:
+;----------------------------- End of DBCS 2/23/KK
+ ENDIF                                  ;AN000;
+        return                          ; return error code
+
+        ASSUME  DS:NOTHING
+UNCTerm:
+        STOSB                           ;AN000;
+        JMP     UNCDone                 ;AN000;
+
+CheckDevice:
+;
+; Check DS:SI for device.  First eat any path stuff
+;
+        POP     AX                      ; retrieve drive info
+        CMP     BYTE PTR DS:[SI],0      ; check for null file
+        JNZ     CheckPath
+        MOV     AL,error_file_not_found ; bad file error
+        STC                             ; signal error on null input
+        RETURN                          ; bye!
+CheckPath:
+        SaveReg <AX,BP>                 ; save drive number
+        Invoke  CheckThisDevice         ; snoop for device
+        RestoreReg  <BP,AX>             ; get drive letter back
+        JNC     DoFile                  ; yes we have a file.
+;
+; We have a device.  AX has drive letter.  At this point we may fake a CDS ala
+; sharing DOS call.  We know by getting here that we are NOT in a sharing DOS
+; call.
+;
+        MOV     fSharing,-1             ; simulate sharing dos call
+        invoke  GetThisDrv              ; set ThisCDS and init DUMMYCDS
+        MOV     fSharing,0              ;
+;
+; Now that we have noted that we have a device, we put it into a form that
+; getpath can understand.  Normally getpath requires d:\ to begin the input
+; string.  We relax this to state that if the d:\ is present then the path
+; may be a file.  If D:/ (note the forward slash) is present then we have
+; a device.
+;
+        CALL    TextFromDrive
+        MOV     AL,'/'                  ; path sep.
+        STOSB
+        invoke  StrCpy                  ; move remainder of string
+        CLC                             ; everything OK.
+        Context DS                      ; remainder of OK stuff
+        return
+;
+; We have a file.  Get the raw CDS.
+;
+DoFile:
+        ASSUME  DS:NOTHING
+        invoke  GetVisDrv               ; get proper CDS
+        MOV     AL,error_path_not_found ; Set up for possible bad file error
+        retc                            ; CARRY set -> bogus drive/spliced
+;
+; ThisCDS has correct CDS.  DS:SI advanced to point to beginning of path/file.
+; Make sure that CDS has valid directory; ValidateCDS requires a temp buffer
+; Use the one that we are going to use (ES:DI).
+;
+        SaveReg <DS,SI,ES,DI>           ; save all string pointers.
+        invoke  ValidateCDS             ; poke CDS amd make everything OK
+        RestoreReg <DI,ES,SI,DS>        ; get back pointers
+        MOV     AL,error_path_not_found ; Set up for possible bad path error
+        retc                            ; someone failed an operation
+;
+; ThisCDS points to correct CDS.  It contains the correct text of the
+; current directory.  Copy it in.
+;
+        SaveReg <DS,SI>
+        LDS     SI,ThisCDS              ; point to CDS
+        MOV     BX,DI                   ; point to destination
+        ADD     BX,[SI].curdir_end      ; point to backup limit
+;       LEA     SI,[SI].curdir_text     ; point to text
+        LEA     BP,[DI+TEMPLEN]         ; regenerate end of buffer
+ IF  DBCS                               ;AN000;
+;------------------------ Start of DBCS 2/13/KK
+Kcpylp:                                 ;AN000;
+        LODSB                           ;AN000;
+        invoke  TestKanj                ;AN000;
+        jz      Notkanjf                ;AN000;
+        STOSB                           ;AN000;
+        MOVSB                           ;AN000;
+        CMP     BYTE PTR [SI],0         ;AN000;
+        JNZ     Kcpylp                  ;AN000;
+        MOV     AL, '\'                 ;AN000;
+        STOSB                           ;AN000;
+        JMP     SHORT GetOrig           ;AN000;
+Notkanjf:                               ;AN000;
+        STOSB                           ;AN000;
+        OR      AL,AL                   ;AN000;
+        JNZ     Kcpylp                  ;AN000;
+        DEC     DI                      ;AN000;; point to NUL byte
+
+;------------------------ End of DBCS 2/13/KK
+ ELSE                                   ;AN000;
+        invoke  FStrCpy                 ; copy string.  ES:DI point to end
+        DEC     DI                      ; point to NUL byte
+ ENDIF                                  ;AN000;
+;
+; Make sure that there is a path char at end.
+;
+        MOV     AL,'\'
+        CMP     ES:[DI-1],AL
+        JZ      GetOrig
+        STOSB
+;
+; Now get original string.
+;
+GetOrig:
+        DEC     DI                      ; point to path char
+        RestoreReg  <SI,DS>
+;
+; BX points to the end of the root part of the CDS (at where a path char
+; should be) .  Now, we decide whether we use this root or extend it with the
+; current directory.  See if the input string begins with a leading \
+;
+        CALL    PathSep                 ; is DS:SI a path sep?
+        JNZ     PathAssure              ; no, DI is correct. Assure a path char
+        OR      AL,AL                   ; end of string?
+        JZ      DoCanon                 ; yes, skip.
+;
+; The string does begin with a \.  Reset the beginning of the canonicalization
+; to this root.  Make sure that there is a path char there and advance the
+; source string over all leading \'s.
+;
+        MOV     DI,BX                   ; back up to root point.
+SkipPath:
+        LODSB
+        invoke PathChrCmp
+        JZ      SkipPath
+        DEC     SI
+        OR      AL,AL
+        JZ      DoCanon
+;
+; DS:SI start at some file name.  ES:DI points at some path char.  Drop one in
+; for yucks.
+;
+PathAssure:
+        MOV     AL,'\'
+        STOSB
+;
+; ES:DI point to the correct spot for canonicalization to begin.
+; BP is the max extent to advance DI
+; BX is the backup limit for ..
+;
+DoCanon:
+        CALL    Canonicalize            ; wham.
+        retc                            ; badly formatted path.
+ IF  DBCS                               ;AN000;
+;--------------------- Start of DBCS 2/13/KK
+; Although Cononicalize has done lots of good things for us it may also have
+; done e5 to 05 conversion on the fisrt char following a path sep char which is
+; not wanted if this a remote file as this should be left for the remote
+; station. Check for a leading \\ in the path buffer and call TP_check05 to
+; reconvert if found.
+
+        MOV     DI,WFP_start            ;AN000;; ES:DI points to string
+        MOV     AX,WORD PTR ES:[DI]     ;AN000;; Get leading 2 chars from path buffer
+        invoke  PathChrCmp              ;AN000;; First char a path char?
+        JNZ     TP_notremote            ;AN000;; Not remote if not.
+        invoke  PathChrCmp              ;AN000;; Second char a path char?
+        JNZ     TP_notremote            ;AN000;; Not remote if not
+        CALL    TP_check05              ;AN000;; Remote so convert 05 back to e5
+TP_notremote:                           ;AN000;
+;--------------------- End of DBCS 2/13/KK
+ ENDIF
+;
+; The string has been moved to ES:DI.  Reset world to DOS context, pointers
+; to wfp_start and do string substitution.  BP is still the max position in
+; buffer.
+;
+        Context DS
+        MOV     DI,wfp_start            ; DS:SI point to string
+        LDS     SI,ThisCDS              ; point to CDS
+        ASSUME  DS:NOTHING
+;       LEA     SI,[SI].curdir_text     ; point to text
+        CALL    PathPref                ; is there a prefix?
+        JNZ     DoSplice                ; no, do splice
+;
+; We have a match. Check to see if we ended in a path char.
+;
+ IF  DBCS                               ;AN000;
+;---------------------------- Start of DBCS 2/13/KK
+        PUSH    BX                      ;AN000;
+        MOV     BX,SI                   ;AN000;
+        MOV     SI,WORD PTR ThisCDS     ;AN000;; point to CDS
+LOOKDUAL:                               ;AN000;
+        MOV     AL,BYTE PTR [SI]        ;AN000;
+        invoke  TESTKANJ                ;AN000;
+        JZ      ONEINC                  ;AN000;
+        INC     SI                      ;AN000;
+        INC     SI                      ;AN000;
+        CMP     SI,BX                   ;AN000;
+        JB      LOOKDUAL                ;AN000;
+        POP     BX                      ;AN000;; Last char was KANJI, don't look back
+        JMP     SHORT Pathline          ;AN000;;  for path sep, there isn't one.
+                                        ;AN000;
+ONEINC:                                 ;AN000;
+        INC     SI                      ;AN000;
+        CMP     SI,BX                   ;AN000;
+        JB      LOOKDUAL                ;AN000;
+        POP     BX                      ;AN000;
+;------------------------ End of DBCS 2/13/KK
+ ENDIF                                  ;AN000;
+        MOV     AL,DS:[SI-1]            ; last char to match
+        Invoke  PathChrCmp              ; did we end on a path char? (root)
+        JZ      DoSplice                ; yes, no current dir here.
+Pathline:                               ; 2/13/KK
+        CMP     BYTE PTR ES:[DI],0      ; end at NUL?
+        JZ      DoSplice
+        INC     DI                      ; point to after current path char
+        MOV     Curr_Dir_End,DI         ; point to correct spot
+;
+; Splice the result.
+;
+DoSplice:
+        Context DS                      ; back to DOSGROUP
+        MOV     SI,wfp_Start            ; point to beginning of string
+        XOR     CX,CX
+        TEST    fSplice,-1
+        JZ      SkipSplice
+        CALL    Splice                  ; replaces in place.
+SkipSplice:
+        ASSUME  DS:NOTHING
+;
+; The final thing is to assure ourselves that a FATREAD is done on the local
+; device.
+;
+        Context DS
+        LES     DI,ThisCDS              ; point to correct drive
+        TEST    ES:[DI].curdir_flags,curdir_isnet
+        retnz                           ; net, no fatread necessary
+        JCXZ    Done
+        EnterCrit   critDisk
+        invoke  FatRead_CDS
+        LeaveCrit   critDisk
+        MOV     AL,error_path_not_found ; Set up for possible bad path error
+Done:   return                          ; any errors in carry flag.
+EndProc TransPath
+
+BREAK <Canonicalize - copy a path and remove . and .. entries>
+
+;
+;   Canonicalize - copy path removing . and .. entries.
+;
+;   Inputs:     DS:SI - point to ASCIZ string path
+;               ES:DI - point to buffer
+;               BX - backup limit (offset from ES) points to slash
+;               BP - end of buffer
+;   Outputs:    Carry Set - invalid path specification: too many .., bad
+;                   syntax, etc.
+;               Carry Clear -
+;                   DS:DI - advanced to end of string
+;                   ES:DI - advanced to end of canonicalized form after nul
+;   Registers modified: AX CX DX (in addition to those above)
+
+Procedure Canonicalize,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+;
+; We copy all leading path separators.
+;
+        LODSB                           ;   while (PathChr (*s))
+        Invoke  PathChrCmp
+ IF  DBCS
+        JNZ     CanonDec0               ; 2/19/KK
+ ELSE
+        JNZ     CanonDec
+ ENDIF
+        CMP     DI,BP                   ;       if (d > dlim)
+        JAE     CanonBad                ;           goto error;
+        STOSB
+        JMP     Canonicalize            ;           *d++ = *s++;
+ IF  DBCS                               ;AN000;
+CanonDec0:                              ;AN000; 2/19/KK
+;       mov     cs:Temp_Var,di          ;AN000; 3/31/KK
+ ENDIF                                  ;AN000;
+CanonDec:
+        DEC     SI
+;
+; Main canonicalization loop.  We come here with DS:SI pointing to a textual
+; component (no leading path separators) and ES:DI being the destination
+; buffer.
+;
+CanonLoop:
+;
+; If we are at the end of the source string, then we need to check to see that
+; a potential drive specifier is correctly terminated with a path sep char.
+; Otherwise, do nothing
+;
+        XOR     AX,AX
+        CMP     [SI],AL                 ;       if (*s == 0) {
+        JNZ     DoComponent
+ IF  DBCS                               ;AN000;
+        call    chk_last_colon          ;AN000; 2/18/KK
+ ELSE                                   ;AN000;
+        CMP     BYTE PTR ES:[DI-1],':'  ;           if (d[-1] == ':')
+ ENDIF                                  ;AN000;
+        JNZ     DoTerminate
+        MOV     AL,'\'                  ;               *d++ = '\';
+        STOSB
+        MOV     AL,AH
+DoTerminate:
+        STOSB                           ;           *d++ = 0;
+        CLC                             ;           return (0);
+        return
+ IF  DBCS                               ;AN000;
+;---------------- Start of DBCS 2/18/KK
+chk_last_colon  proc                    ;AN000;
+        push    si                      ;AN000;
+        push    ax                      ;AN000;
+        push    bx                      ;AN000;
+        mov     si,[WFP_START]          ;AN000;;PTM. for cd ..  use beginning of buf
+        cmp     si,di                   ;AN000;; no data stored ?
+        jb      CLC02                   ;AN000;;PTM. for cd ..
+        inc     si                      ;AN000;; make NZ flag
+        JMP     SHORT CLC09             ;AN000;
+CLC02:                                  ;AN000;
+        mov     bx,di                   ;AN000;
+        dec     bx                      ;AN000;
+CLC_lop:                                ;AN000;
+        cmp     si,bx                   ;AN000;
+        jb      CLC00                   ;AN000;
+        jne     CLC09                   ;AN000;
+CLC01:                                  ;AN000;
+        CMP     BYTE PTR ES:[DI-1],':'  ;AN000;;           if (d[-1] == ':')
+        jmp     CLC09                   ;AN000;
+CLC00:                                  ;AN000;
+        mov     al,es:[si]              ;AN000;
+        inc     si                      ;AN000;
+        invoke  testkanj                ;AN000;
+        je      CLC_lop                 ;AN000;
+        inc     si                      ;AN000;
+        jmp     CLC_lop                 ;AN000;
+CLC09:                                  ;AN000;
+        pop     bx                      ;AN000;
+        pop     ax                      ;AN000;
+        pop     si                      ;AN000;
+        ret                             ;AN000;
+chk_last_colon  endp                    ;AN000;
+;---------------- Endt of DBCS 2/18/KK
+ ENDIF                                  ;AN000;
+
+CanonBad:
+        CALL    ScanPathChar            ; check for path chars in rest of string
+        MOV     AL,error_path_not_found ; Set up for bad path error
+        JZ      PathEnc                 ; path character encountered in string
+        MOV     AL,error_file_not_found ; Set bad file error
+PathEnc:
+        STC
+        return
+;
+; We have a textual component that we must copy.  We uppercase it and truncate
+; it to 8.3
+;
+DoComponent:                            ;           }
+        CALL    CopyComponent           ;       if (!CopyComponent (s, d))
+        retc                            ;           return (-1);
+;
+; We special case the . and .. cases.  These will be backed up.
+;
+        CMP     WORD PTR ES:[DI],'.' + (0 SHL 8)
+        JZ      Skip1
+        CMP     WORD PTR ES:[DI],'..'
+        JNZ     CanonNormal
+        DEC     DI                      ;           d--;
+Skip1:  CALL    SkipBack                ;           SkipBack ();
+        MOV     AL,error_path_not_found ; Set up for possible bad path error
+        retc
+        JMP     CanonPath               ;           }
+;
+; We have a normal path.  Advance destination pointer over it.
+;
+CanonNormal:                            ;       else
+        ADD     DI,CX                   ;           d += ct;
+;
+; We have successfully copied a component.  We are now pointing at a path
+; sep char or are pointing at a nul or are pointing at something else.
+; If we point at something else, then we have an error.
+;
+CanonPath:
+        CALL    PathSep
+        JNZ     CanonBad                ; something else...
+;
+; Copy the first path char we see.
+;
+        LODSB                           ; get the char
+        Invoke  PathChrCmp              ; is it path char?
+        JNZ     CanonDec                ; no, go test for nul
+        CMP     DI,BP                   ; beyond buffer end?
+        JAE     CanonBad                ; yep, error.
+        STOSB                           ; copy the one byte
+;
+; Skip all remaining path chars
+;
+CanonPathLoop:
+        LODSB                           ; get next byte
+        Invoke  PathChrCmp              ; path char again?
+        JZ      CanonPathLoop           ; yep, grab another
+        DEC     SI                      ; back up
+        JMP     CanonLoop               ; go copy component
+EndProc Canonicalize
+
+BREAK <PathSep - determine if char is a path separator>
+
+;
+;   PathSep - look at DS:SI and see if char is / \ or NUL
+;   Inputs:     DS:SI - point to a char
+;   Outputs:    AL has char from DS:SI (/ => \)
+;               Zero set if AL is / \ or NUL
+;               Zero reset otherwise
+;   Registers modified: AL
+
+Procedure   PathSep,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     AL,[SI]                 ; get the character
+        entry   PathSepGotCh            ; already have character
+        OR      AL,AL                   ; test for zero
+        retz                            ; return if equal to zero (NUL)
+        invoke  PathChrCmp              ; check for path character
+        return                          ; and return HIS determination
+EndProc PathSep
+
+BREAK <SkipBack - move backwards to a path separator>
+
+;
+;   SkipBack - look at ES:DI and backup until it points to a / \
+;   Inputs:     ES:DI - point to a char
+;               BX has current directory back up limit (point to a / \)
+;   Outputs:    ES:DI backed up to point to a path char
+;               AL has char from output ES:DI (path sep if carry clear)
+;               Carry set if illegal backup
+;               Carry Clear if ok
+;   Registers modified: DI,AL
+
+Procedure   SkipBack,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+ IF  DBCS                      ;AN000;
+;-------------------------- Start of DBCS 2/13/KK
+        PUSH    DS              ;AN000;
+        PUSH    SI              ;AN000;
+        PUSH    CX              ;AN000;
+        PUSH    ES              ;AN000;
+        POP     DS              ;AN000;
+        MOV     SI,BX           ;AN000;; DS:SI -> start of ES:DI string
+        MOV     CX,DI           ;AN000;; Limit of forward scan is input DI
+        MOV     AL,[SI]         ;AN000;
+        invoke  PathChrCmp      ;AN000;
+        JNZ     SkipBadP        ;AN000;; Backup limit MUST be path char
+        CMP     DI,BX           ;AN000;
+        JBE     SkipBadP        ;AN000;
+        MOV     DI,BX           ;AN000;; Init backup point to backup limit
+Skiplp:                         ;AN000;
+        CMP     SI,CX           ;AN000;
+        JAE     SkipOK          ;AN000;; Done, DI is correct backup point
+        LODSB                   ;AN000;
+        invoke  Testkanj        ;AN000;
+        jz      Notkanjv        ;AN000;
+        lodsb                   ;AN000;; Skip over second kanji byte
+        JMP     Skiplp          ;AN000;
+NotKanjv:                       ;AN000;
+        invoke  PathChrCmp      ;AN000;
+        JNZ     Skiplp          ;AN000;; New backup point
+        MOV     DI,SI           ;AN000;; DI point to path sep
+        DEC     DI              ;AN000;
+        jmp     Skiplp          ;AN000;
+SkipOK:                         ;AN000;
+        MOV     AL,ES:[DI]      ;AN000;; Set output AL
+        CLC                     ;AN000;; return (0);
+        POP     CX              ;AN000;
+        POP     SI              ;AN000;
+        POP     DS              ;AN000;
+        return                  ;AN000;
+                                ;AN000;
+SkipBadP:                       ;AN000;
+        POP     CX              ;AN000;
+        POP     SI              ;AN000;
+        POP     DS              ;AN000;
+;-------------------------- End of DBCS 2/13/KK
+ ELSE                           ;AN000;
+        CMP     DI,BX                   ;   while (TRUE) {
+        JB      SkipBad                 ;       if (d < dlim)
+        DEC     DI                      ;           goto err;
+        MOV     AL,ES:[DI]              ;       if (pathchr (*--d))
+        invoke  PathChrCmp              ;           break;
+        JNZ     SkipBack                ;       }
+        CLC                             ;   return (0);
+        return                          ;
+ ENDIF                                  ;AN000;
+SkipBad:                                ;err:
+        MOV     AL,error_path_not_found ; bad path error
+        STC                             ;   return (-1);
+        return                          ;
+EndProc SkipBack
+
+Break <CopyComponent - copy out a file path component>
+
+;
+;   CopyComponent - copy a file component from a path string (DS:SI) into ES:DI
+;
+;   Inputs:     DS:SI - source path
+;               ES:DI - destination
+;               ES:BP - end of buffer
+;   Outputs:    Carry Set - too long
+;               Carry Clear - DS:SI moved past component
+;                   CX has length of destination
+;   Registers modified: AX,CX,DX
+
+Procedure   CopyComponent,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+CopyBP      EQU     WORD PTR [BP]
+CopyD       EQU     DWORD PTR [BP+2]
+CopyDoff    EQU     WORD PTR [BP+2]
+CopyS       EQU     DWORD PTR [BP+6]
+CopySoff    EQU     WORD PTR [BP+6]
+CopyTemp    EQU     BYTE PTR [BP+10]
+        SUB     SP,14                   ; room for temp buffer
+        SaveReg <DS,SI,ES,DI,BP>
+        MOV     BP,SP
+        MOV     AH,'.'
+        LODSB
+        STOSB
+        CMP     AL,AH                   ;   if ((*d++=*s++) == '.') {
+        JNZ     NormalComp
+        CALL    PathSep                 ;       if (!pathsep(*s))
+        JZ      NulTerm
+TryTwoDot:
+        LODSB                           ;           if ((*d++=*s++) != '.'
+        STOSB
+        CMP     AL,AH
+        JNZ     CopyBad
+        CALL    PathSep
+        JNZ     CopyBad                 ;               || !pathsep (*s))
+NulTerm:                                ;               return -1;
+        XOR     AL,AL                   ;       *d++ = 0;
+        STOSB
+        MOV     CopySoff,SI
+        JMP     SHORT GoodRet           ;       }
+NormalComp:                             ;   else {
+        MOV     SI,CopySoff
+        Invoke  NameTrans               ;       s = NameTrans (s, Name1);
+        CMP     SI,CopySOff             ;       if (s == CopySOff)
+        JZ      CopyBad                 ;           return (-1);
+        TEST    fSharing,-1             ;       if (!fSharing) {
+        JNZ     DoPack
+        AND     DL,1                    ;           cMeta += fMeta;
+        ADD     cMeta,DL                ;           if (cMeta > 0)
+        JG      CopyBad                 ;               return (-1);
+        JNZ     DoPack                  ;           else
+        OR      DL,DL                   ;           if (cMeta == 0 && fMeta == 0)
+        JZ      CopyBadPath             ;               return (-1);
+DoPack:                                 ;           }
+        MOV     CopySoff,SI
+        Context DS
+        MOV     SI,OFFSET DOSGroup:NAME1
+        LEA     DI,CopyTemp
+        SaveReg <DI>
+        Invoke  PackName                ;       PackName (Name1, temp);
+        RestoreReg  <DI>
+        Invoke  StrLen                  ;       if (strlen(temp)+d > bp)
+        DEC     CX
+        ADD     CX,CopyDoff
+        CMP     CX,CopyBP
+        JAE     CopyBad                 ;           return (-1);
+        MOV     SI,DI                   ;       strcpy (d, temp);
+        LES     DI,CopyD
+        Invoke  FStrCpy
+GoodRet:                                ;       }
+        CLC
+        JMP     SHORT CopyEnd           ;   return 0;
+CopyBad:
+        STC
+        CALL    ScanPathChar            ; check for path chars in rest of string
+        MOV     AL,error_file_not_found ; Set up for bad file error
+        JNZ     CopyEnd
+CopyBadPath:
+        STC
+        MOV     AL,error_path_not_found ; Set bad path error
+CopyEnd:
+        RestoreReg  <BP,DI,ES,SI,DS>
+        LAHF
+        ADD     SP,14                   ; reclaim temp buffer
+        Invoke  Strlen
+        DEC     CX
+        SAHF
+        return
+EndProc CopyComponent,NoCheck
+
+Break <Splice - pseudo mount by string substitution>
+
+;
+;   Splice - take a string and substitute a prefix if one exists.  Change
+;       ThisCDS to point to physical drive CDS.
+;   Inputs:     DS:SI point to string
+;               NoSetDir = TRUE => exact matches with splice fail
+;   Outputs:    DS:SI points to thisCDS
+;               ES:DI points to DPB
+;               String at DS:SI may be reduced in length by removing prefix
+;               and substituting drive letter.
+;               CX = 0 If no splice done
+;               CX <> 0 otherwise
+;               ThisCDS points to proper CDS if spliced, otherwise it is
+;                   left alone
+;               ThisDPB points to proper DPB
+;   Registers modified: DS:SI, ES:DI, BX,AX,CX
+
+Procedure   Splice,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        TEST    Splices,-1
+        JZ      AllDone
+        SaveReg <<WORD PTR ThisCDS>,<WORD PTR ThisCDS+2>>   ; TmpCDS = ThisCDS
+        SaveReg <DS,SI>
+        RestoreReg <DI,ES>
+        XOR     AX,AX                   ;   for (i=1; s = GetCDSFromDrv (i); i++)
+SpliceScan:
+        invoke  GetCDSFromDrv
+        JC      SpliceDone
+        INC     AL
+        TEST    [SI.curdir_flags],curdir_splice
+        JZ      SpliceScan              ;       if ( Spliced (i) ) {
+        SaveReg <DI>
+        CALL    PathPref                ;           if (!PathPref (s, d))
+        JZ      SpliceFound             ;
+SpliceSkip:
+        RestoreReg  <DI>
+        JMP     SpliceScan              ;               continue;
+SpliceFound:
+        CMP     BYTE PTR ES:[DI],0      ;           if (*s || NoSetDir) {
+        JNZ     SpliceDo
+        TEST    NoSetDir,-1
+        JNZ     SpliceSkip
+SpliceDo:
+        MOV     SI,DI                   ;               p = src + strlen (p);
+        SaveReg <ES>
+        RestoreReg  <DS,DI>
+        CALL    TextFromDrive1          ;               src = TextFromDrive1(src,i);
+        MOV     AX,Curr_Dir_End
+        OR      AX,AX
+        JS      NoPoke
+        ADD     AX,DI                   ;               curdirend += src-p;
+        SUB     AX,SI
+        MOV     Curr_Dir_End,AX
+NoPoke:
+        CMP     BYTE PTR [SI],0         ;               if (*p)
+        JNZ     SpliceCopy              ;                   *src++ = '\\';
+        MOV     AL,"\"
+        STOSB
+SpliceCopy:                             ;               strcpy (src, p);
+        invoke  FStrCpy
+        ADD     SP,4                    ; throw away saved stuff
+        OR      CL,1                    ; signal splice done.
+        JMP     SHORT DoSet             ;               return;
+SpliceDone:                             ;               }
+        ASSUME  DS:NOTHING              ;   ThisCDS = TmpCDS;
+        RestoreReg  <<WORD PTR ThisCDS+2>,<WORD PTR ThisCDS>>
+AllDone:
+        XOR     CX,CX
+DoSet:
+        LDS     SI,ThisCDS              ;   ThisDPB = ThisCDS->devptr;
+        LES     DI,[SI].curdir_devptr
+        MOV     WORD PTR ThisDPB,DI
+        MOV     WORD PTR ThisDPB+2,ES
+        return
+EndProc Splice
+
+Break <$NameTrans - partially process a name>
+
+;
+;   $NameTrans - allow users to see what names get mapped to.  This call
+;   performs only string substitution and canonicalization, not splicing.  Due
+;   to Transpath playing games with devices, we need to insure that the output
+;   has drive letter and :  in it.
+;
+;   Inputs:     DS:SI - source string for translation
+;               ES:DI - pointer to buffer
+;   Outputs:
+;       Carry Clear
+;               Buffer at ES:DI is filled in with data
+;               ES:DI point byte after nul byte at end of dest string in buffer
+;       Carry Set
+;               AX = error_path_not_found
+;   Registers modified: all
+
+Procedure   $NameTrans,Near
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        SaveReg <DS,SI,ES,DI>
+        MOV     DI,OFFSET DOSGroup:OpenBuf
+        CALL    TransPath               ; to translation (everything)
+        RestoreReg  <DI,ES,SI,DS>
+        JNC     TransOK
+        transfer    SYS_Ret_Err
+TransOK:
+        MOV     SI,OFFSET DOSGroup:OpenBuf
+        Context DS
+GotText:
+        Invoke  FStrCpy
+        Transfer    SYS_Ret_OK
+EndProc $NameTrans
+
+Break   <DriveFromText - return drive number from a text string>
+
+;
+;   DriveFromText - examine DS:SI and remove a drive letter, advancing the
+;   pointer.
+;
+;   Inputs:     DS:SI point to a text string
+;   Outputs:    AL has drive number
+;               DS:SI advanced
+;   Registers modified: AX,SI.
+
+Procedure   DriveFromText,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        XOR     AL,AL                   ;       drive = 0;
+        CMP     BYTE PTR [SI],0         ;       if (*s &&
+        retz
+        CMP     BYTE PTR [SI+1],':'     ;           s[1] == ':') {
+        retnz
+ IF  DBCS                               ;AN000;
+;--------------------- Start of DBCS 2/18/KK
+        push    ax                     ;AN000;
+        mov     al,[si]                ;AN000;
+        invoke  testkanj               ;AN000;
+        pop     ax                     ;AN000;
+        retnz                          ;AN000;
+;--------------------- End of DBCS 2/18/KK
+ ENDIF                                 ;AN000;
+        LODSW                           ;           drive = (*s | 020) - 'a'+1;
+        OR      AL,020h
+        SUB     AL,'a'-1                ;           s += 2;
+        retnz
+        MOV     AL,-1                   ; nuke AL...
+        return                          ;           }
+EndProc DriveFromText
+
+Break   <TextFromDrive - convert a drive number to a text string>
+
+;
+;   TextFromDrive - turn AL into a drive letter: and put it at es:di with
+;   trailing :. TextFromDrive1 takes a 1-based number.
+;
+;   Inputs:     AL has 0-based drive number
+;   Outputs:    ES:DI advanced
+;   Registers modified: AX
+
+Procedure TextFromDrive,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        INC     AL
+        Entry   TextFromDrive1
+        ADD     AL,'A'-1                ;   *d++ = drive-1+'A';
+        MOV     AH,":"                  ;   strcat (d, ":");
+        STOSW
+        return
+EndProc TextFromDrive
+
+Break   <PathPref - see if one path is a prefix of another>
+
+;
+;   PathPref - compare DS:SI with ES:DI to see if one is the prefix of the
+;   other.  Remember that only at a pathchar break are we allowed to have a
+;   prefix: A:\ and A:\FOO
+;
+;   Inputs:     DS:SI potential prefix
+;               ES:DI string
+;   Outputs:    Zero set => prefix found
+;                   DI/SI advanced past matching part
+;               Zero reset => no prefix, DS/SI garbage
+;   Registers modified: CX
+
+Procedure   PathPref,NEAR
+        Invoke  DStrLen                 ; get length
+        DEC     CX                      ; do not include nul byte
+ IF  DBCS                               ;AN000;
+;----------------------- Start of DBCS 2/13/KK
+        SaveReg <AX>                    ;AN000;; save char register
+CmpLp:                                  ;AN000;
+        MOV     AL,[SI]                 ;AN000;
+        invoke  Testkanj                ;AN000;
+        jz      NotKanj9                ;AN000;
+        CMPSW                           ;AN000;
+        JNZ     Prefix                  ;AN000;
+        DEC     CX                      ;AN000;
+        LOOP    CmpLp                   ;AN000;
+        JMP     SHORT NotSep            ;AN000;
+NotKanj9:                               ;AN000;
+        CMPSB                           ;AN000;
+        JNZ     Prefix                  ;AN000;
+        LOOP    CmpLp                   ;AN000;
+;----------------------- End of DBCS 2/13/KK
+ ELSE                                   ;AN000;
+        REPZ    CMPSB                   ; compare
+        retnz                           ; if NZ then return NZ
+        SaveReg <AX>                    ; save char register
+ ENDIF                                  ;AN000;
+        MOV     AL,[SI-1]               ; get last byte to match
+        Invoke  PathChrCmp              ; is it a path char (Root!)
+        JZ      Prefix                  ; yes, match root (I hope)
+NotSep:                                 ; 2/13/KK
+        MOV     AL,ES:[DI]              ; get next char to match
+        CALL    PathSepGotCh            ; was it a pathchar?
+Prefix:
+        RestoreReg  <AX>                ; get back original
+        return
+EndProc PathPref
+
+Break   <ScanPathChar - see if there is a path character in a string>
+
+;
+;     ScanPathChar - search through the string (pointed to by DS:SI) for
+;     a path separator.
+;
+;     Input:    DS:SI target string (null terminated)
+;     Output:   Zero set => path separator encountered in string
+;               Zero clear => null encountered
+;     Registers modified: SI
+
+Procedure     ScanPathChar,NEAR
+        LODSB                           ; fetch a character
+ IF  DBCS                               ;AN000;
+        invoke  TestKanj                ;AN000;; 2/13/KK
+        jz      NotKanjr                ;AN000;; 2/13/KK
+        LODSB                           ;AN000;; 2/13/KK
+        OR      AL,AL                   ;AN000;; 2/13/KK  3/31/removed
+        JNZ     ScanPathChar            ;AN000;; 2/13/KK  3/31/removed
+        INC     AL                      ;AN000;; 2/13/KK
+        return                          ;AN000;; 2/13/KK
+                                        ;AN000;
+NotKanjr:                               ;AN000;; 2/13/KK
+ ENDIF                                  ;AN000;
+        call    PathSepGotCh
+        JNZ     ScanPathChar            ; not \, / or NUL => go back for more
+        invoke  PathChrCmp              ; path separator?
+        return
+EndProc       ScanPathChar
+
+CODE ends
+END
diff --git a/v4.0/src/DOS/MAKEFILE b/v4.0/src/DOS/MAKEFILE
new file mode 100644
index 0000000..12912c4
--- /dev/null
+++ b/v4.0/src/DOS/MAKEFILE
@@ -0,0 +1,221 @@
+#*************************** Makefile for DOS ***************************
+
+msg     =..\messages
+inc     =..\inc
+hinc    =..\hinc
+make    =nmake -i
+dos     =.
+
+#
+###################### Dependencies begin here ##########################
+#
+
+all: msdos.sys
+
+msdos.cl1: msdos.skl \
+        $(msg)\$(COUNTRY).msg 
+
+dossym.inc: $(inc)\dosmac.inc $(inc)\bpb.inc \
+    $(inc)\buffer.inc $(inc)\sysvar.inc $(inc)\vector.inc \
+    $(inc)\mult.inc $(inc)\dirent.inc $(inc)\dpb.inc $(inc)\curdir.inc \
+    $(inc)\cpmfcb.inc $(inc)\find.inc $(inc)\pdb.inc $(inc)\exe.inc \
+    $(inc)\sf.inc $(inc)\arena.inc $(inc)\intnat.inc $(inc)\mi.inc \
+    $(inc)\filemode.inc $(inc)\error.inc $(inc)\syscall.inc
+        echo "touch dossym.inc; files that are in ..\inc"
+
+$(inc)\nibdos.obj: 
+        cd ..\inc
+        $(make)
+        cd ..\dos                  
+
+$(inc)\const2.obj: 
+        cd ..\inc
+        $(make)
+        cd ..\dos          
+
+$(inc)\msdata.obj: 
+        cd ..\inc
+        $(make)
+        cd ..\dos          
+                   
+$(inc)\mstable.obj:
+        cd ..\inc
+        $(make)
+        cd ..\dos          
+                   
+$(inc)\msdosme.obj:
+        cd ..\inc
+        $(make)
+        cd ..\dos
+
+msdisp.obj: msdisp.asm mssw.asm disp.asm \
+             $(inc)\dossym.inc $(inc)\dosseg.asm
+
+mscode.obj: mscode.asm mssw.asm ms_code.asm \
+             $(inc)\dossym.inc $(inc)\dosseg.asm $(inc)\devsym.inc
+
+time.obj: time.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+          $(inc)\devsym.inc
+
+getset.obj: getset.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+parse.obj: parse.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+misc.obj: misc.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\bugtyp.asm
+
+misc2.obj: misc2.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\bugtyp.asm
+
+crit.obj: crit.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\bugtyp.asm
+
+cpmio.obj: cpmio.asm $(inc)\dosseg.asm \
+    $(inc)\dossym.inc \
+    $(inc)\devsym.inc \
+    kstrin.asm strin.asm
+
+cpmio2.obj: cpmio2.asm $(inc)\dosseg.asm \
+    $(inc)\dossym.inc $(inc)\devsym.inc
+
+fcbio.obj: fcbio.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\sf.inc $(inc)\fastopen.inc
+
+fcbio2.obj: fcbio2.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+search.obj: search.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+path.obj: path.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+ioctl.obj: ioctl.asm $(inc)\ioctl.inc $(inc)\dosseg.asm \
+    $(inc)\dossym.inc $(inc)\devsym.inc
+
+delete.obj: delete.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\sf.inc $(inc)\fastxxxx.inc $(inc)\fastopen.inc
+
+rename.obj: rename.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\sf.inc
+
+finfo.obj: finfo.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+dup.obj: dup.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+create.obj: create.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+open.obj: open.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\fastopen.inc
+
+dinfo.obj: dinfo.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+   $(inc)\devsym.inc $(inc)\bugtyp.asm $(inc)\buffer.inc
+
+isearch.obj: isearch.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+abort.obj: abort.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\sf.inc
+
+close.obj: close.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\buffer.inc
+
+dircall.obj: dircall.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\buffer.inc $(inc)\fastopen.inc
+
+disk.obj: disk.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+disk2.obj: disk2.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\buffer.inc
+
+disk3.obj: disk3.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+dir.obj: dir.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+         $(inc)\buffer.inc $(inc)\fastopen.inc
+
+dir2.obj: dir2.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+          $(inc)\buffer.inc $(inc)\fastopen.inc
+
+dev.obj: dev.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+mknode.obj: mknode.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc  $(inc)\buffer.inc $(inc)\fastopen.inc \
+    $(inc)\filemode.inc
+
+rom.obj: rom.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc  $(inc)\buffer.inc
+
+fcb.obj: fcb.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+msctrlc.obj: msctrlc.asm mssw.asm ctrlc.asm \
+    $(inc)\dosseg.asm $(inc)\dossym.inc $(inc)\devsym.inc \
+    $(inc)\bugtyp.asm
+
+fat.obj: fat.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\buffer.inc $(inc)\curdir.inc
+
+buf.obj: buf.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\buffer.inc
+
+proc.obj: proc.asm \
+    $(inc)\dosseg.asm $(inc)\dossym.inc $(inc)\devsym.inc \
+    $(inc)\curdir.inc \
+    exec.asm
+
+alloc.obj: alloc.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+srvcall.obj: srvcall.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+util.obj: util.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+macro.obj: macro.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc  $(inc)\curdir.inc
+
+macro2.obj: macro2.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\curdir.inc
+
+handle.obj: handle.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\bugtyp.asm
+
+file.obj: file.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\bugtyp.asm $(inc)\fastopen.inc \
+    $(inc)\filemode.inc
+
+lock.obj: lock.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+share.obj: share.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc
+
+extattr.obj: extattr.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\ea.inc $(inc)\buffer.inc
+
+ifs.obj: ifs.asm $(inc)\dosseg.asm $(inc)\dossym.inc \
+    $(inc)\devsym.inc $(inc)\doscntry.inc $(inc)\buffer.inc
+
+msdos.sys: msdos.cl1 $(inc)\nibdos.obj $(inc)\const2.obj  \
+    $(inc)\msdata.obj mscode.obj $(inc)\msdosme.obj time.obj getset.obj \
+    parse.obj misc.obj misc2.obj crit.obj cpmio.obj cpmio2.obj \
+    $(inc)\mstable.obj msdisp.obj fcbio.obj fcbio2.obj \
+    search.obj path.obj ioctl.obj delete.obj rename.obj finfo.obj \
+    dup.obj create.obj open.obj dinfo.obj isearch.obj buf.obj \
+    abort.obj close.obj dircall.obj disk.obj disk2.obj disk3.obj dir.obj \
+    dir2.obj dev.obj mknode.obj rom.obj fcb.obj msctrlc.obj fat.obj \
+    proc.obj alloc.obj srvcall.obj util.obj macro.obj macro2.obj ifs.obj \
+    handle.obj file.obj lock.obj share.obj extattr.obj \
+    makefile msdos.lnk
+        link @msdos.lnk
+        exe2bin msdos.exe msdos.sys
+        del msdos.exe
diff --git a/v4.0/src/DOS/MISC.ASM b/v4.0/src/DOS/MISC.ASM
new file mode 100644
index 0000000..e169f32
--- /dev/null
+++ b/v4.0/src/DOS/MISC.ASM
@@ -0,0 +1,572 @@
+;       SCCSID = @(#)misc.asm   1.1 85/04/10
+TITLE MISC - Miscellanious routines for MS-DOS
+NAME  MISC
+;
+; Miscellaneous system calls most of which are CAVEAT
+;
+;   $SLEAZEFUNC
+;   $SLEAZEFUNCDL
+;   $GET_INDOS_FLAG
+;   $GET_IN_VARS
+;   $GET_DEFAULT_DPB
+;   $GET_DPB
+;   $DISK_RESET
+;   $SETDPB
+;   $Dup_PDB
+;   $CREATE_PROCESS_DATA_BLOCK
+;   SETMEM
+;   FETCHI_CHECK
+;   $GSetMediaID
+;
+;   Revision  history:
+;
+;       Created: ARR 30 March 1983
+;
+;       A000   version 4.00   Jan. 1988
+;       A001   D490 -- Change IOCTL subfunctions from 63h, 43h to 66h , 46h
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+ENTRYPOINTSEG   EQU     0CH
+MAXDIF          EQU     0FFFH
+SAVEXIT         EQU     10
+
+        i_need  LASTBUFFER,DWORD
+        i_need  BuffHead,DWORD
+        i_need  INDOS,BYTE
+        i_need  SYSINITVAR,BYTE
+        i_need  CurrentPDB,WORD
+        i_need  CreatePDB,BYTE
+        i_need  FATBYTE,BYTE
+        i_need  THISCDS,DWORD
+        i_need  THISSFT,DWORD
+        i_need  FETCHI_TAG,WORD                  ; for TAG CHECK
+        i_need  BUF_HASH_COUNT,WORD              ;AN000; number of Hash Entries
+        i_need  HIGH_SECTOR,WORD                 ;AN000; high word of sector #
+        i_need  DOS34_FLAG,WORD                  ;AN000;
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+BREAK <SleazeFunc -- get a pointer to media byte>
+
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+; Inputs:
+;       None
+; Function:
+;       Return Stuff sort of like old get fat call
+; Outputs:
+;       DS:BX = Points to FAT ID byte (IBM only)
+;               GOD help anyone who tries to do ANYTHING except
+;               READ this ONE byte.
+;       DX = Total Number of allocation units on disk
+;       CX = Sector size
+;       AL = Sectors per allocation unit
+;          = -1 if bad drive specified
+
+        procedure   $SLEAZEFUNC,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     DL,0
+
+entry   $SLEAZEFUNCDL
+;Same as above except drive passed in DL (0=default, 1=A, 2=B, ...)
+
+        context DS
+        MOV     AL,DL
+        invoke  GETTHISDRV              ; Get CDS structure
+SET_AL_RET:
+;       MOV     AL,error_invalid_drive  ; Assume error                          ;AC000;
+        JC      BADSLDRIVE
+        invoke  DISK_INFO
+        JC      SET_AL_RET              ; User FAILed to I 24
+        MOV     [FATBYTE],AH
+; NOTE THAT A FIXED MEMORY CELL IS USED --> THIS CALL IS NOT
+; RE-ENTRANT. USERS BETTER GET THE ID BYTE BEFORE THEY MAKE THE
+; CALL AGAIN
+        MOV     DI,OFFSET DOSGROUP:FATBYTE
+        XOR     AH,AH                   ; AL has sectors/cluster
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_CX],CX
+        MOV     [SI.user_DX],BX
+        MOV     [SI.user_BX],DI
+        MOV     [SI.user_DS],CS         ; stash correct pointer
+        return
+BADSLDRIVE:
+        transfer    FCB_Ret_ERR
+EndProc $SLEAZEFUNC
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+BREAK <$Get_INDOS_Flag -- Return location of DOS critical-section flag>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+; Inputs:
+;       None
+; Function:
+;       Returns location of DOS status for interrupt routines
+; Returns:
+;       Flag location in ES:BX
+
+        procedure   $GET_INDOS_FLAG,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        invoke  get_user_stack
+        MOV     [SI.user_BX],OFFSET DOSGROUP:INDOS
+        MOV     [SI.user_ES],SS
+        return
+EndProc $GET_INDOS_FLAG
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+BREAK <$Get_IN_VARS -- Return a pointer to DOS variables>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+; Return a pointer to interesting DOS variables This call is version
+; dependent and is subject to change without notice in future versions.
+; Use at risk.
+        procedure   $GET_IN_VARS,NEAR
+        invoke  get_user_stack
+        MOV     [SI.user_BX],OFFSET DOSGROUP:SYSINITVAR
+        MOV     [SI.user_ES],SS
+        return
+EndProc $GET_IN_VARS
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+
+BREAK <$Get_Default_DPB,$Get_DPB -- Return pointer to DPB>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+; Inputs:
+;       None
+; Function:
+;       Return pointer to drive parameter table for default drive
+; Returns:
+;       DS:BX points to the DPB
+;       AL = 0 If OK, = -1 if bad drive (call 50 only)
+
+        procedure   $GET_DEFAULT_DPB,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     DL,0
+
+        entry   $GET_DPB
+; Same as above only drive passed in DL (0=default, 1=A, 2=B, ...)
+
+        context DS
+        MOV     AL,DL
+        invoke  GETTHISDRV              ; Get CDS structure
+        JC      ISNODRV                 ; no valid drive
+        LES     DI,[THISCDS]            ; check for net CDS
+        TEST    ES:[DI.curdir_flags],curdir_isnet
+        JNZ     ISNODRV                 ; No DPB to point at on NET stuff
+        EnterCrit CritDisk
+        invoke  FATRead_CDS             ; Force Media Check and return DPB
+        LeaveCrit CritDisk
+        JC      ISNODRV                 ; User FAILed to I 24, only error we
+                                        ;   have.
+        invoke  get_user_stack
+ASSUME  DS:NOTHING
+        MOV     [SI.user_BX],BP
+        MOV     [SI.user_DS],ES
+        XOR     AL,AL
+        return
+
+ISNODRV:
+        MOV     AL,-1
+        return
+EndProc $GET_Default_dpb
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+
+BREAK <$Disk_Reset -- Flush out all dirty buffers>
+
+        procedure   $DISK_RESET,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Flush and invalidate all buffers
+; Returns:
+;       Nothing
+
+        MOV     AL,-1
+ entry $DISK_RESET2
+        context DS
+        EnterCrit   critDisk
+        OR      [DOS34_FLAG],FROM_DISK_RESET                                    ;AN000;
+        invoke  FLUSHBUF
+        AND     [DOS34_FLAG],NO_FROM_DISK_RESET                                 ;AN000;
+;
+; We will "ignore" any errors on the flush, and go ahead and invalidate.  This
+; call doesn't return any errors and it is supposed to FORCE a known state, so
+; let's do it.
+;
+; Invalidate 'last-buffer' used
+;
+        MOV     BX,-1
+        MOV     WORD PTR [LASTBUFFER+2],BX
+        MOV     WORD PTR [LASTBUFFER],BX
+;
+;       TEST    [DOS34_FLAG],IFS_DRIVE_RESET     ;AN000;;IFS. from ifs call back ?
+;       JZ      FreeDone                         ;AN000;;IFS. no
+;       AND     [DOS34_FLAG],NO_IFS_DRIVE_RESET  ;AN000;;IFS. clear the flag
+;       LeaveCrit   critDisk                     ;AN000;;IFS.
+;       return                                   ;AN000;;IFS. return
+FreeDone:
+        LeaveCrit   critDisk
+        MOV     AX,-1
+        CallInstall NetFlushBuf,multNET,32
+        return
+EndProc $DISK_RESET
+
+BREAK <$SetDPB - Create a valid DPB from a user-specified BPB>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        procedure   $SETDPB,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       ES:BP Points to DPB
+;       DS:SI Points to BPB
+; Function:
+;       Build a correct DPB from the BPB
+; Outputs:
+; ES:BP and DS preserved all others destroyed
+
+        MOV     DI,BP
+        ADD     DI,2                    ; Skip over dpb_drive and dpb_UNIT
+        LODSW
+        STOSW                           ; dpb_sector_size
+        CMP     BYTE PTR [SI.BPFTCNT-2],0     ; FAT file system drive           ;AN000;
+        JNZ     yesfat                        ; yes                             ;AN000;
+        MOV     BYTE PTR ES:[DI.dpb_FAT_count-4],0
+        JMP     setend                        ; NO                              ;AN000;
+yesfat:
+        MOV     DX,AX
+        LODSB
+        DEC     AL
+        STOSB                           ; dpb_cluster_mask
+        INC     AL
+        XOR     AH,AH
+LOG2LOOP:
+        TEST    AL,1
+        JNZ     SAVLOG
+        INC     AH
+        SHR     AL,1
+        JMP     SHORT LOG2LOOP
+SAVLOG:
+        MOV     AL,AH
+        STOSB                           ; dpb_cluster_shift
+        MOV     BL,AL
+        MOVSW                           ; dpb_first_FAT Start of FAT (# of reserved sectors)
+        LODSB
+        STOSB                           ; dpb_FAT_count Number of FATs
+;       OR      AL,AL                   ; NONFAT ?                              ;AN000;
+;       JZ      setend                  ; yes, don't do anything                ;AN000;
+        MOV     BH,AL
+        LODSW
+        STOSW                           ; dpb_root_entries Number of directory entries
+        MOV     CL,5
+        SHR     DX,CL                   ; Directory entries per sector
+        DEC     AX
+        ADD     AX,DX                   ; Cause Round Up
+        MOV     CX,DX
+        XOR     DX,DX
+        DIV     CX
+        MOV     CX,AX                   ; Number of directory sectors
+        INC     DI
+        INC     DI                      ; Skip dpb_first_sector
+        MOVSW                           ; Total number of sectors in DSKSIZ (temp as dpb_max_cluster)
+        LODSB
+        MOV     ES:[BP.dpb_media],AL    ; Media byte
+        LODSW                           ; Number of sectors in a FAT
+        STOSW                           ;AC000;;>32mb dpb_FAT_size
+        MOV     DL,BH                   ;AN000;;>32mb
+        XOR     DH,DH                   ;AN000;;>32mb
+        MUL     DX                      ;AC000;;>32mb Space occupied by all FATs
+        ADD     AX,ES:[BP.dpb_first_FAT]
+        STOSW                           ; dpb_dir_sector
+        ADD     AX,CX                   ; Add number of directory sectors
+        MOV     ES:[BP.dpb_first_sector],AX
+
+        MOV     CL,BL                  ;F.C. >32mb                              ;AN000;
+        CMP     WORD PTR ES:[BP.DSKSIZ],0       ;F.C. >32mb                     ;AN000;
+        JNZ     normal_dpb             ;F.C. >32mb                              ;AN000;
+        XOR     CH,CH                  ;F.C. >32mb                              ;AN000;
+        MOV     BX,WORD PTR [SI+BPB_BigTotalSectors-BPB_SectorsPerTrack]        ;AN000;
+        MOV     DX,WORD PTR [SI+BPB_BigTotalSectors-BPB_SectorsPerTrack+2]      ;AN000;
+        SUB     BX,AX                  ;AN000;;F.C. >32mb
+        SBB     DX,0                   ;AN000;;F.C. >32mb
+        OR      CX,CX                  ;AN000;;F.C. >32mb
+        JZ      norot                  ;AN000;;F.C. >32mb
+rott:                                  ;AN000;;F.C. >32mb
+        CLC                            ;AN000;;F.C. >32mb
+        RCR     DX,1                   ;AN000;;F.C. >32mb
+        RCR     BX,1                   ;AN000;;F.C. >32mb
+        LOOP    rott                   ;AN000;;F.C. >32mb
+norot:                                 ;AN000;
+        MOV     AX,BX                  ;AN000;;F.C. >32mb
+        JMP     setend                 ;AN000;;F.C. >32mb
+normal_dpb:
+        SUB     AX,ES:[BP.DSKSIZ]
+        NEG     AX                      ; Sectors in data area
+;;      MOV     CL,BL                   ; dpb_cluster_shift
+        SHR     AX,CL                   ; Div by sectors/cluster
+setend:
+        INC     AX
+        MOV     ES:[BP.dpb_max_cluster],AX
+        MOV     ES:[BP.dpb_next_free],0 ; Init so first ALLOC starts at
+                                        ; begining of FAT
+        MOV     ES:[BP.dpb_free_cnt],-1 ; current count is invalid.
+        return
+EndProc $SETDPB
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+BREAK <$Create_Process_Data_Block,SetMem -- Set up process data block>
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+;
+; Inputs:   DX is new segment address of process
+;           SI is end of new allocation block
+;
+        procedure   $Dup_PDB,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     CreatePDB,0FFH          ; indicate a new process
+        MOV     DS,CurrentPDB
+        PUSH    SI
+        JMP     SHORT   CreateCopy
+EndProc $Dup_PDB
+
+        procedure   $CREATE_PROCESS_DATA_BLOCK,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+; Inputs:
+;       DX = Segment number of new base
+; Function:
+;       Set up program base and copy term and ^C from int area
+; Returns:
+;       None
+; Called at DOS init
+
+        CALL    get_user_stack
+        MOV     DS,[SI.user_CS]
+        PUSH    DS:[PDB_Block_len]
+CreateCopy:
+        MOV     ES,DX
+        XOR     SI,SI                   ; copy all 80h bytes
+        MOV     DI,SI
+        MOV     CX,80H
+        REP     MOVSW
+; DOS 3.3 7/9/86
+
+        MOV     CX,FilPerProc           ; copy handles in case of
+        MOV     DI,PDB_JFN_Table        ; Set Handle Count has been issued
+        PUSH    DS
+        LDS     SI,DS:[PDB_JFN_Pointer]
+        REP     MOVSB
+        POP     DS
+
+; DOS 3.3 7/9/86
+        TEST    CreatePDB,0FFh          ; Shall we create a process?
+        JZ      Create_PDB_cont         ; nope, old style call
+;
+; Here we set up for a new process...
+;
+
+        PUSH    CS                      ; Called at DOSINIT time, NO SS
+        POP     DS
+        DOSAssume   CS,<DS>,"MISC/Create_Copy"
+        XOR     BX,BX                   ; dup all jfns
+        MOV     CX,FilPerProc           ; only 20 of them
+
+Create_dup_jfn:
+        PUSH    ES                      ; save new PDB
+        invoke  SFFromHandle            ; get sf pointer
+        MOV     AL,-1                   ; unassigned JFN
+        JC      CreateStash             ; file was not really open
+        TEST    ES:[DI].sf_flags,sf_no_inherit
+        JNZ     CreateStash             ; if no-inherit bit is set, skip dup.
+;
+; We do not inherit network file handles.
+;
+        MOV     AH,BYTE PTR ES:[DI].sf_mode
+        AND     AH,sharing_mask
+        CMP     AH,sharing_net_fcb
+        jz      CreateStash
+;
+; The handle we have found is duplicatable (and inheritable).  Perform
+; duplication operation.
+;
+        MOV     WORD PTR [THISSFT],DI
+        MOV     WORD PTR [THISSFT+2],ES
+        invoke  DOS_DUP                 ; signal duplication
+;
+; get the old sfn for copy
+;
+        invoke  pJFNFromHandle          ; ES:DI is jfn
+        MOV     AL,ES:[DI]              ; get sfn
+;
+; Take AL (old sfn or -1) and stash it into the new position
+;
+CreateStash:
+        POP     ES
+        MOV     ES:[BX].PDB_JFN_Table,AL; copy into new place!
+        INC     BX                      ; next jfn...
+        LOOP    create_dup_jfn
+
+        MOV     BX,CurrentPDB           ; get current process
+        MOV     ES:[PDB_Parent_PID],BX  ; stash in child
+        MOV     [CurrentPDB],ES
+        ASSUME  DS:NOTHING
+        MOV     DS,BX
+;
+; end of new process create
+;
+Create_PDB_cont:
+        MOV     BYTE PTR [CreatePDB],0h ; reset flag
+        POP     AX
+
+        entry   SETMEM
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+; Inputs:
+;       AX = Size of memory in paragraphs
+;       DX = Segment
+; Function:
+;       Completely prepares a program base at the
+;       specified segment.
+; Called at DOS init
+; Outputs:
+;       DS = DX
+;       ES = DX
+;       [0] has INT int_abort
+;       [2] = First unavailable segment
+;       [5] to [9] form a long call to the entry point
+;       [10] to [13] have exit address (from int_terminate)
+;       [14] to [17] have ctrl-C exit address (from int_ctrl_c)
+;       [18] to [21] have fatal error address (from int_fatal_abort)
+; DX,BP unchanged. All other registers destroyed.
+
+        XOR     CX,CX
+        MOV     DS,CX
+        MOV     ES,DX
+        MOV     SI,addr_int_terminate
+        MOV     DI,SAVEXIT
+        MOV     CX,6
+        REP     MOVSW
+        MOV     ES:[2],AX
+        SUB     AX,DX
+        CMP     AX,MAXDIF
+        JBE     HAVDIF
+        MOV     AX,MAXDIF
+HAVDIF:
+        SUB     AX,10H                  ; Allow for 100h byte "stack"
+        MOV     BX,ENTRYPOINTSEG        ;       in .COM files
+        SUB     BX,AX
+        MOV     CL,4
+        SHL     AX,CL
+        MOV     DS,DX
+        MOV     WORD PTR DS:[PDB_CPM_Call+1],AX
+        MOV     WORD PTR DS:[PDB_CPM_Call+3],BX
+        MOV     DS:[PDB_Exit_Call],(int_abort SHL 8) + mi_INT
+        MOV     BYTE PTR DS:[PDB_CPM_Call],mi_Long_CALL
+        MOV     WORD PTR DS:[PDB_Call_System],(int_command SHL 8) + mi_INT
+        MOV     BYTE PTR DS:[PDB_Call_System+2],mi_Long_RET
+        MOV     WORD PTR DS:[PDB_JFN_Pointer],PDB_JFN_Table
+        MOV     WORD PTR DS:[PDB_JFN_Pointer+2],DS
+        MOV     WORD PTR DS:[PDB_JFN_Length],FilPerProc
+;
+; The server runs several PDB's without creating them VIA EXEC.  We need to
+; enumerate all PDB's at CPS time in order to find all references to a
+; particular SFT.  We perform this by requiring that the server link together
+; for us all sub-PDB's that he creates.  The requirement for us, now, is to
+; initialize this pointer.
+;
+        MOV     word ptr DS:[PDB_Next_PDB],-1
+        MOV     word ptr DS:[PDB_Next_PDB+2],-1
+        return
+
+EndProc $CREATE_PROCESS_DATA_BLOCK
+
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        procedure   FETCHI_CHECK,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        PUSHF
+        CMP     CS:[FETCHI_TAG],22642
+        JZ      TAG_OK
+        invoke  DOSINIT               ; go to hell
+TAG_OK:
+        POPF
+        return
+EndProc FETCHI_CHECK
+
+BREAK <$GSetMediaID -- get set media ID>
+; Inputs:
+;       BL= drive number as defined in IOCTL
+;       AL= 0 get media ID
+;           1 set media ID
+;       DS:DX= buffer containing information
+;               DW  0  info level (set on input)
+;               DD  ?  serial #
+;               DB  11 dup(?)  volume id
+;               DB   8 dup(?)  file system type
+; Function:
+;       Get or set media ID
+; Returns:
+;       carry clear, DS:DX is filled
+;       carry set, error
+
+        procedure   $GSetMediaID,NEAR ;AN000;
+ASSUME  DS:NOTHING,ES:NOTHING         ;AN000;
+
+        MOV     CX,0866H              ;AN000;MS.; assume get  for IOCTL
+        CMP     AL,0                  ;AN001;MS.; get ?
+        JZ      doioctl               ;AN000;MS.; yes
+        CMP     AL,1                  ;AN000;MS.; set ?
+        JNZ     errorfunc             ;AN000;MS.; no
+        MOV     CX,0846H              ;AN001;MS.;
+doioctl:                              ;AN000;
+        MOV     AL,0DH                ;AN000;MS.; generic IOCTL
+        invoke  $IOCTL                ;AN000;MS.; let IOCTL take care of it
+        return                        ;AN000;MS.;
+errorfunc:                            ;AN000;
+        error   error_invalid_function;AN000;MS.        ; invalid function
+EndProc $GSetMediaID                  ;AN000;
+
+CODE    ENDS
+END
diff --git a/v4.0/src/DOS/MISC2.ASM b/v4.0/src/DOS/MISC2.ASM
new file mode 100644
index 0000000..c8860bb
--- /dev/null
+++ b/v4.0/src/DOS/MISC2.ASM
@@ -0,0 +1,594 @@
+;       SCCSID = @(#)misc2.asm  1.1 85/04/10
+TITLE MISC2 - Miscellanious routines for MS-DOS
+NAME  MISC2
+;
+; Miscellaneous useful routines
+;
+;   StrCpy
+;   StrCmp
+;   Ucase
+;   StrLen
+;   DStrLen
+;   Idle
+;   TableDispatch
+;   FastInit                      ; DOS 4.0
+;   FastRet                       ; DOS 4.0
+;   NLS_OPEN                      ; DOS 4.0
+;   NLS_LSEEK                     ; DOS 4.0
+;   Fake_User_Stack               ; DOS 4.0
+;   GetDevList                    ; DOS 4.0
+;   NLS_IOCTL                     ; DOS 4.0
+;   NLS_GETEXT                    ; DOS 4.0
+;   MSG_RETRIEVAL                 ; DOS 4.0
+;   Fake_Version                  ; DOS 4.0
+;
+;   Revision history:
+;
+;       Created: ARR 30 March 1983
+;
+;       A000   version 4.0   Jan. 1988
+;       A001   DCR 486 - Share installation for >32mb drives
+;       A006   DCR 503 - fake version number for IBMCACHE
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include fastseek.inc                   ;AN000;
+include fastxxxx.inc                   ;AN000;
+.cref
+.list
+
+        i_need  THISCDS,DWORD
+        I_Need  RetryLoop,WORD
+        I_need  fSharing,BYTE           ; TRUE => server-issued call
+        I_need  FastTable,BYTE          ;AN000;
+        I_need  FastFlg,BYTE            ;AN000;
+        I_need  User_SP_2F,WORD         ;AN000;
+        I_need  User_SP,WORD            ;AN000;
+        I_need  User_SS,WORD            ;AN000;
+        I_need  SysInitTable,BYTE       ;AN000;
+        I_need  EXTERR,WORD             ;AN000;
+        I_need  MSG_EXTERROR,DWORD      ;AN000;
+        I_need  fshare,byte             ;AN001;
+        I_need  Special_version,WORD    ;AN006;
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+Break <STRCMP - compare two ASCIZ strings DS:SI to ES:DI>
+
+;
+;   Strcmp - compare ASCIZ DS:SI to ES:DI. Case INSENSITIVE. '/' = '\'
+;               Strings of different lengths don't match.
+;   Inputs:     DS:SI - pointer to source string  ES:DI - pointer to dest string
+;   Outputs:    Z if strings same, NZ if different
+;   Registers modified: NONE
+
+Procedure   StrCmp,NEAR
+        ASSUME  CS:DOSGroup,SS:DOSGroup,DS:NOTHING,ES:NOTHING
+        SaveReg <SI,DI,AX>
+Cmplp:
+        LODSB
+ IF  DBCS                               ;AN000;
+        invoke  testkanj                ;AN000;; 2/13/KK
+        jz      notkanj1                ;AN000;; 2/13/KK
+        dec     si                      ;AN000;; Do source again 2/13/KK
+        cmpsb                           ;AN000;; First byte      2/13/KK
+        JNZ     PopRet                  ;AN000;; Strings dif     2/13/KK
+        cmpsb                           ;AN000;; Second byte of kanji char 2/13/KK
+        JNZ     PopRet                  ;AN000;; Strings dif     2/13/KK
+        mov     al,byte ptr [SI-1]      ;AN000;; Need last byte in AL  2/13/KK
+        jmp     short Tend              ;AN000;
+notkanj1:                               ;AN000;; 2/13/KK
+ ENDIF                                  ;AN000;
+        CALL    uCase                   ; convert to upper case
+        Invoke  PathChrCmp              ; convert / to \
+        MOV     AH,AL
+        MOV     AL,ES:[DI]
+        INC     DI
+        CALL    uCase                   ; convert to upper case
+        Invoke  PathChrCmp              ; convert / to \
+        CMP     AH,AL
+        JNZ     PopRet                  ; Strings dif
+Tend:
+        OR      AL,AL
+        JNZ     Cmplp                   ; More string
+PopRet:
+        RestoreReg  <AX,DI,SI>
+        return
+EndProc StrCmp
+
+Break <STRCPY - copy ASCIZ string from DS:SI to ES:DI>
+
+;
+;   Strcpy - copy an ASCIZ string from DS:SI to ES:DI and make uppercase
+;   FStrcpy - copy an ASCIZ string from DS:SI to ES:DI.  no modification of
+;       characters.
+;
+;   Inputs:     DS:SI - pointer to source string
+;               ES:DI - pointer to destination string
+;   Outputs:    ES:DI point byte after nul byte at end of dest string
+;               DS:SI point byte after nul byte at end of source string
+;   Registers modified: SI,DI
+
+Procedure   StrCpy,NEAR
+        ASSUME  CS:DOSGroup,SS:DOSGroup,DS:NOTHING,ES:NOTHING
+        SaveReg <AX>
+CPYLoop:
+        LODSB
+ IF  DBCS                       ;AN000;
+        invoke  testkanj        ;AN000;; 2/13/KK
+        jz      notkanj2        ;AN000;; 2/13/KK
+        STOSB                   ;AN000;; 2/13/KK
+        LODSB                   ;AN000;; 2/13/KK
+        STOSB                   ;AN000;; 2/13/KK
+        jmp     short CPYLoop   ;AN000;; 3/31/KK
+
+notkanj2:                       ;AN000;; 2/13/KK
+ ENDIF                          ;AN000;
+        CALL    uCase                   ; convert to upper case
+        Invoke  PathChrCmp              ; convert / to \
+        STOSB
+Tend2:
+        OR      AL,AL
+        JNZ     CPYLoop
+        RestoreReg  <AX>
+        return
+EndProc StrCpy
+
+Procedure   FStrCpy,NEAR
+        ASSUME  CS:DOSGroup,SS:DOSGroup,DS:NOTHING,ES:NOTHING
+        SaveReg <AX>
+FCPYLoop:
+        LODSB
+        STOSB
+        OR      AL,AL
+        JNZ     FCPYLoop
+        RestoreReg  <AX>
+        return
+EndProc FStrCpy
+
+;
+; Upper case the letter in AL.  Most chars are non lowercase.
+;
+Procedure   uCase,NEAR
+;       CMP     AL,'a'
+;       JAE     Maybe
+;       return
+;Maybe:
+;       CMP     AL,'z'
+;       JA      CaseRet
+;       ADD     AL,'A'-'a'
+;CaseRet:
+;;; 10/31/86 let's do file upper case for all DOS file names
+        invoke  GetLet2
+;;; 10/31/86 let's do file upper case for all DOS file names
+        return
+EndProc uCase
+
+Break <StrLen - compute length of string ES:DI>
+
+;
+;   StrLen  - Compute length of string ES:DI
+;   Inputs:     ES:DI - pointer to string
+;   Outputs:    CX is size of string INCLUDING the NUL
+;   Registers modified: CX
+
+Procedure   StrLen,NEAR
+        ASSUME  CS:DOSGroup,SS:DOSGroup,DS:NOTHING,ES:NOTHING
+        PUSH    DI
+        PUSH    AX
+        MOV     CX,-1
+        XOR     AL,AL
+        REPNE   SCASB
+        NOT     CX
+        POP     AX
+        POP     DI
+        return
+EndProc StrLen
+
+;
+;   DStrLen  - Compute length of string DS:SI
+;   Inputs:     DS:SI - pointer to string
+;   Outputs:    CX is size of string INCLUDING the NUL
+;   Registers modified: CX
+Procedure   DStrLen,NEAR
+        CALL    XCHGP
+        CALL    StrLen
+        CALL    XCHGP
+        return
+EndProc DStrLen
+
+Break   <XCHGP - exchange source and destination pointers>
+
+Procedure XCHGP,NEAR
+        SaveReg <DS,ES>
+        RestoreReg  <DS,ES>
+        XCHG    SI,DI
+        return
+EndProc XCHGP
+
+Break   <Idle - wait for a specified amount of time>
+
+;
+;   Idle - when retrying an operation due to a lock/sharing violation, we spin
+;   until RetryLoop is exhausted.
+;
+;   Inputs:     RetryLoop is the number of times we spin
+;   Outputs:    Wait
+;   Registers modified: none
+
+Procedure   Idle,NEAR
+        ASSUME  CS:DOSGroup,SS:DOSGROUP,DS:NOTHING,ES:NOTHING
+        TEST    fSharing,-1
+        retnz
+        SaveReg <CX>
+        MOV     CX,RetryLoop
+        JCXZ    Idle3
+Idle1:  PUSH    CX
+        XOR     CX,CX
+Idle2:  LOOP    Idle2
+        POP     CX
+        LOOP    Idle1
+Idle3:  RestoreReg  <CX>
+        return
+EndProc Idle
+
+Break   <TableDispatch - dispatch to a table>
+
+;
+;   TableDispatch - given a table and an index, jmp to the approptiate
+;   routine.  Preserve all input registers to the routine.
+;
+;   Inputs:     Push    return address
+;               Push    Table address
+;               Push    index (byte)
+;   Outputs:    appropriate routine gets jumped to.
+;               return indicates invalid index
+;   Registers modified: none.
+
+TableFrame  STRUC
+OldBP   DW  ?
+OldRet  DW  ?
+Index   DB  ?
+Pad     DB  ?
+Tab     DW  ?
+NewRet  DW  ?
+TableFrame  ENDS
+
+procedure   TableDispatch,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,SS:NOTHING,SS:NOTHING
+        PUSH    BP
+        MOV     BP,SP
+        PUSH    BX                      ; save BX
+        MOV     BX,[BP.Tab]             ; get pointer to table
+        MOV     BL,CS:[BX]              ; maximum index
+        CMP     [BP.Index],BL           ; table error?
+        JAE     TableError              ; yes
+        MOV     BL,[BP.Index]           ; get desired table index
+        XOR     BH,BH                   ; convert to word
+        SHL     BX,1                    ; convert to word pointer
+        INC     BX                      ; point past first length byte
+        ADD     BX,[BP.Tab]             ; get real offset
+        MOV     BX,CS:[BX]              ; get contents of table entry
+        MOV     [BP.Tab],BX             ; put table entry into return address
+        POP     BX                      ; restore BX
+        POP     BP                      ; restore BP
+        ADD     SP,4                    ; clean off Index and our return addr
+        return                          ; do operation
+TableError:
+        POP     BX                      ; restore BX
+        POP     BP                      ; restore BP
+        RET     6                       ; clean off Index, Table and RetAddr
+EndProc TableDispatch
+
+Break   <TestNet - determine if a CDS is for the network>
+
+;
+;   TestNet - examine CDS pointed to by ThisCDS and see if it indicates a
+;       network CDS.  This will handle NULL cds also.
+;
+;   Inputs:     ThisCDS points to CDS or NULL
+;   Outputs:    ES:DI = ThisCDS
+;               carry Set => network
+;               carry Clear => local
+;   Registers modified: none.
+
+Procedure   TestNet,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        LES     DI,ThisCDS
+        CMP     DI,-1
+        JZ      CMCRet                  ; UNC? carry is clear
+        TEST    ES:[DI].curdir_flags,curdir_isnet
+        JNZ     CMCret                  ; jump has carry clear
+        return                          ; carry is clear
+CMCRet: CMC
+        return
+
+EndProc TestNet
+
+Break   <IsSFTNet - see if an sft is for the network>
+
+;
+;   IsSFTNet - examine SF pointed to by ES:DI and see if it indicates a
+;       network file.
+;
+;   Inputs:     ES:DI point to SFT
+;   Outputs:    Zero set if not network sft
+;               zero reset otherwise
+;               Carry CLEAR!!!
+;   Registers modified: none.
+
+Procedure   IsSFTNet,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        TEST    ES:[DI].sf_flags,sf_isnet
+        return
+EndProc IsSFTNet
+
+Break   <FastInit - Initialize FastTable entries >
+
+;   DOS 4.00   2/9/87
+;   FastInit  - initialize the FASTXXX routine entry
+;                 in the FastTable
+;
+;   Inputs:     BX = FASTXXX ID ( 1=fastopen, 2=fastseek,,,,)
+;               DS:SI = address of FASTXXX routine entry
+;                  SI = -1 for query only
+;   Outputs:    Carry flag clear, if success
+;               Carry flag set,   if failure
+;
+;
+
+Procedure   FastInit,NEAR                                     ;AN000;
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING  ;AN000;
+
+        MOV     DI,OFFSET DOSGROUP:FastTable + 2   ;AN000;FO. points to fastxxx entry
+        DEC     BX                ;AN000;FO.;; decrement index
+        MOV     DX,BX             ;AN000;FO.;; save bx
+        SHL     BX,1              ;AN000;FO.;; times 4 , each entry is DWORD
+        SHL     BX,1              ;AN000;FO.
+        ADD     DI,BX             ;AN000;FO. index to the entry
+        MOV     AX,WORD PTR CS:[DI+2] ;AN000;FO. get entry segment
+fcheck:                               ;AN000;
+        MOV     CX,CS             ;AN000;FO.;; get DOS segment
+        CMP     AX,CX             ;AN000;FO.;; first time installed ?
+        JZ      ok_install        ;AN000;FO.;; yes
+        OR      AX,AX             ;AN000;FO.;
+        JZ      ok_install        ;AN000;FO.;
+        STC                       ;AN000;FO.;; already installed !
+        JMP     SHORT FSret       ;AN000;FO. set carry
+ok_install:                           ;AN000;
+        CMP     SI,-1                 ;AN000;FO.;  Query only ?
+        JZ      FSret                 ;AN000;FO.;  yes
+        MOV     CX,DS                 ;AN000;FO.;  get FASTXXX entry segment
+        MOV     CX,DS                 ;AN000;FO.;;  get FASTXXX entry segment
+        MOV     WORD PTR CS:[DI+2],CX ;AN000;FO.;;  initialize routine entry
+        MOV     WORD PTR CS:[DI],SI   ;AN000;FO.;;  initialize routine offset
+        MOV     DI,OFFSET DOSGROUP:FastFlg ;AN000;FO.; get addr of FASTXXX flags
+        ADD     DI,DX                      ;AN000;FO.;  index to a FASTXXX flag
+        OR      byte ptr CS:[DI],Fast_yes  ;AN000;FO.;  indicate installed
+
+FSret:                                       ;AN000;
+        return                               ;AN000;FO.
+EndProc FastInit                             ;AN000;FO.
+
+Break   <FastRet - initial routine in FastOpenTable >
+
+;   DOS 3.3   6/10/86
+;   FastRet     - indicate FASTXXXX  not in memory
+;
+;   Inputs:     None
+;   Outputs:    AX = -1 and carry flag set
+;
+;   Registers modified: none.
+
+Procedure   FastRet,FAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     AX,-1
+        STC
+        RET
+EndProc FastRet
+
+Break   <NLS_OPEN - do $open for NLSFUNC   >
+
+;   DOS 3.3   6/10/86
+;   NLS_OPEN    - call $OPEN for NLSFUNC
+;
+;   Inputs:     Same input as $OPEN except CL = mode
+;   Outputs:    same output as $OPEN
+;
+
+Procedure   NLS_OPEN,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+;       MOV     BL,[CPSWFLAG]    ; disable code page matching logic
+;       MOV     [CPSWFLAG],0
+;       PUSH    BX               ; save current state
+
+        MOV     AL,CL            ; set up correct interface for $OPEN
+        invoke  $OPEN
+
+ ;      POP     BX               ; restore current state
+ ;      MOV     [CPSWFLAG],BL
+        RET
+EndProc NLS_OPEN
+
+Break   <NLS_LSEEK - do $LSEEK for NLSFUNC   >
+
+;   DOS 3.3   6/10/86
+;   NLS_LSEEK   - call $LSEEK for NLSFUNC
+;
+;   Inputs:     BP = open mode
+;   Outputs:    same output as $LSEEK
+;
+
+Procedure   NLS_LSEEK,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        PUSH    [user_SP]        ; save user stack
+        PUSH    [user_SS]
+        CALL    Fake_User_Stack
+        MOV     AX,BP        ; set up correct interface for $LSEEK
+        invoke  $LSEEK
+        POP     [user_SS]        ; restore user stack
+        POP     [user_SP]
+        RET
+EndProc NLS_LSEEK
+
+
+Break   <Fake_User_Stack - save uesr stack >
+
+
+;   DOS 3.3   6/10/86
+;   Fake_User_Stack - save user stack pointer
+;
+
+Procedure   Fake_User_Stack,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        MOV     AX,[User_SP_2F]               ; replace with INT 2F stack
+        MOV     [user_SP],AX
+
+        MOV     AX,CS
+        MOV     [user_SS],AX                  ; DOSGROUP
+
+        RET
+EndProc Fake_User_Stack
+
+;
+Break   <GetDevList - get device header list pointer>
+
+
+;   DOS 3.3   7/25/86
+;   GetDevList - get device header list pointer
+;
+;   Output: AX:BX points to the device header list
+
+Procedure   GetDevList,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+
+        MOV     SI,OFFSET DOSGROUP:SysInitTable
+        LDS     SI,CS:[SI.SYSI_InitVars]
+
+        MOV     AX,WORD PTR DS:[SI.SYSI_DEV]
+        MOV     BX,WORD PTR DS:[SI.SYSI_DEV+2]
+
+        RET
+EndProc GetDevList
+
+Break   <NLS_IOCTL - do $IOCTL for NLSFUNC   >
+
+;   DOS 3.3   7/25/86
+;   NLS_IOCTL   - call $IOCTL for NLSFUNC
+;
+;   Inputs:     BP = function code 0CH
+;   Outputs:    same output as generic $IOCTL
+;
+
+Procedure   NLS_IOCTL,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        PUSH    [user_SP]        ; save user stack
+        PUSH    [user_SS]
+        CALL    Fake_User_Stack
+        MOV     AX,BP        ; set up correct interface for $LSEEK
+        invoke  $IOCTL
+        POP     [user_SS]        ; restore user stack
+        POP     [user_SP]
+        RET
+EndProc NLS_IOCTL
+
+Break   <NLS_GETEXT- get extended error for NLSFUNC>
+
+;   DOS 3.3   7/25/86
+;   NLS_GETEXT  -
+;
+;   Inputs:     none
+;   Outputs:    AX = extended error
+;
+
+Procedure   NLS_GETEXT,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        MOV     AX,CS:[EXTERR]   ; return extended error
+        RET
+EndProc NLS_GETEXT
+
+Break   <MSG_RETRIEVAL- get beginning addr of system and parser messages>
+
+;   DOS 4.00
+;
+;   Inputs:     DL=0 get extended error message addr
+;                 =1 set extended error message addr
+;                 =2 get parser error message addr
+;                 =3 set parser error message addr
+;                 =4 get critical error message addr
+;                 =5 set critical error message addr
+;                 =6 get file system error message addr
+;                 =7 set file system error message addr
+;                 =8 get address for code reduction
+;                 =9 set address for code reduction
+;   Function:   get/set message address
+;   Outputs:    ES:DI points to addr when get
+;
+
+Procedure   MSG_RETRIEVAL,NEAR                                    ;AN000;
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING      ;AN000;
+
+        PUSH    AX                  ;AN000;;MS. save regs
+        PUSH    SI                  ;AN000;;MS. save regs
+        MOV     AX,DX               ;AN000;;MS.
+        MOV     SI,OFFSET DOSGROUP:MSG_EXTERROR ;AN000;;MS.
+        TEST    AL,1                ;AN000;;MS. get ?
+        JZ      toget               ;AN000;;MS. yes
+        DEC     AL                  ;AN000;;MS.
+toget:                              ;AN000;
+        SHL     AL,1                ;AN000;;MS. times 2
+        XOR     AH,AH               ;AN000;;MS.
+        ADD     SI,AX               ;AN000;;MS. position to the entry
+        TEST    DL,1                ;AN000;;MS. get ?
+        JZ      getget                       ;AN000;;MS. yes
+        MOV     WORD PTR CS:[SI],DI    ;AN000;;MS. set MSG
+        MOV     WORD PTR CS:[SI+2],ES  ;AN000;;MS. address to ES:DI
+        JMP     SHORT MSGret                 ;AN000;;MS. exit
+getget:                                      ;AN000;
+        LES     DI,DWORD PTR CS:[SI]         ;AN000;;MS. get msg addr
+MSGret:                                      ;AN000;
+        POP     SI                           ;AN000;;MS.
+        POP     AX                           ;AN000;;MS.
+        return                               ;AN000;;MS. exit
+
+EndProc MSG_RETRIEVAL                        ;AN000;
+
+
+Break   <Fake_version - set/reset version flag>
+
+;
+;   Inputs:     DL=0 current version number
+;                 <>0  special version number
+;   Function:   set special version number
+;   Outputs:    version number is changed
+;
+
+Procedure   Fake_version,NEAR                                     ;AN000;
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING      ;AN000;
+
+        MOV     [Special_version],DX   ;AN006;MS.
+        return                         ;AN006;;MS. exit
+
+EndProc Fake_version                   ;AN006;;MS.
+
+
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/MKNODE.ASM b/v4.0/src/DOS/MKNODE.ASM
new file mode 100644
index 0000000..968c8eb
--- /dev/null
+++ b/v4.0/src/DOS/MKNODE.ASM
@@ -0,0 +1,890 @@
+;       SCCSID = @(#)mknode.asm 1.5 85/08/29
+TITLE   MKNODE - Node maker
+NAME    MKNODE
+; Low level routines for making a new local file system node
+;   and filling in an SFT from a directory entry
+;
+;   BUILDDIR
+;   SETDOTENT
+;   MakeNode
+;   NEWENTRY
+;   FREEENT
+;   NEWDIR
+;   DOOPEN
+;   RENAME_MAKE
+;   CHECK_VIRT_OPEN
+;
+;   Revision history:
+;
+;    AN000  version 4.0  Jan. 1988
+;    A004   PTM 3680  --- Make SFT NAME field offset same as 3.30
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+include fastopen.inc
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include devsym.inc
+.cref
+.list
+
+        i_need  EntFree,WORD
+        i_need  DirStart,WORD
+        i_need  LastEnt,WORD
+        i_need  ClusNum,WORD
+        i_need  CurBuf,DWORD
+        i_need  Attrib,BYTE
+        i_need  VolID,BYTE
+        i_need  Name1,BYTE
+        i_need  ThisDPB,DWORD
+        i_need  EntLast,WORD
+        i_need  Creating,BYTE
+        i_need  SecClusPos,BYTE
+        i_need  ClusFac,BYTE
+        i_need  NxtClusNum,WORD
+        i_need  DirSec,WORD
+        i_need  NoSetDir,BYTE
+        i_need  THISSFT,DWORD
+        i_need  SATTRIB,BYTE
+        i_need  ALLOWED,BYTE
+        i_need  FAILERR,BYTE
+        i_need  VIRTUAL_OPEN
+        I_need  FastOpen_Ext_info,BYTE        ; DOS 3.3
+        I_need  FastOpenFlg,BYTE              ; DOS 3.3
+        I_need  CPSWFLAG,BYTE                 ;FT. DOS 3.4                      ;AN000;
+        I_need  EXTOPEN_ON,BYTE               ;FT. DOS 3.4                      ;AN000;
+        I_need  EXTOPEN_FLAG,WORD             ;FT. DOS 3.4                      ;AN000;
+        I_need  EXTOPEN_IO_MODE,WORD          ;FT. DOS 3.4                      ;AN000;
+        I_need  HIGH_SECTOR,WORD              ;>32mb                            ;AN000;
+        I_need  ACT_PAGE,WORD                 ;>32mb                            ;AN000;
+
+Break   <BUILDDIR,NEWDIR -- ALLOCATE DIRECTORIES>
+
+; Inputs:
+;       ES:BP Points to DPB
+;       [THISSFT] Set if using NEWDIR entry point
+;               (used by ALLOCATE)
+;       [LASTENT] current last valid entry number in directory if no free
+;               entries
+;       [DIRSTART] Points to first cluster of dir (0 means root)
+; Function:
+;       Grow directory if no free entries and not root
+; Outputs:
+;       CARRY SET IF FAILURE
+;       ELSE
+;          AX entry number of new entry
+;          If a new dir [DIRSTART],[CLUSFAC],[CLUSNUM],[DIRSEC] set
+;               AX = first entry of new dir
+;       GETENT should be called to set [LASTENT]
+
+        procedure   BUILDDIR,NEAR
+        DOSAssume   CS,<DS>,"BuildDir"
+        ASSUME  ES:NOTHING
+
+        MOV     AX,[ENTFREE]
+        CMP     AX,-1
+        JZ      CHECK_IF_ROOT
+        CLC
+        return
+
+CHECK_IF_ROOT:
+        CMP     [DIRSTART],0
+        JNZ     NEWDIR
+        STC
+        return                  ; Can't grow root
+
+        entry   NEWDIR
+        MOV     BX,[DIRSTART]
+        OR      BX,BX
+        JZ      NULLDIR
+        invoke  GETEOF
+        retc                    ; Screw up
+NULLDIR:
+        MOV     CX,1
+        invoke  ALLOCATE
+        retc
+        MOV     DX,[DIRSTART]
+        OR      DX,DX
+        JNZ     ADDINGDIR
+        invoke  SETDIRSRCH
+        retc
+        MOV     [LASTENT],-1
+        JMP     SHORT GOTDIRREC
+ADDINGDIR:
+        PUSH    BX
+        MOV     BX,[ClusNum]
+        Invoke  IsEof
+        POP     BX
+        JB      NOTFIRSTGROW
+;;;; 10/17/86 update CLUSNUM in the fastopen cache
+        MOV     [CLUSNUM],BX
+        PUSH    CX
+        PUSH    AX
+        PUSH    BP
+        MOV     AH,1                       ; CLUSNUM update
+        MOV     DL,ES:[BP.dpb_drive]       ; drive #
+        MOV     CX,[DIRSTART]              ; first cluster #
+        MOV     BP,BX                      ; CLUSNUM
+        invoke  FastOpen_Update
+        POP     BP
+        POP     AX
+        POP     CX
+
+;;;; 10/17/86 update CLUSNUM in the fastopen cache
+NOTFIRSTGROW:
+        MOV     DX,BX
+        XOR     BL,BL
+        invoke  FIGREC
+GOTDIRREC:
+        MOV     CL,ES:[BP.dpb_cluster_mask]
+        INC     CL
+        XOR     CH,CH
+ZERODIR:
+        PUSH    CX
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        MOV     AL,0FFH
+        invoke  GETBUFFR
+        JNC     GET_SSIZE
+        POP     CX
+        return
+
+GET_SSIZE:
+        MOV     CX,ES:[BP.dpb_sector_size]
+        PUSH    ES
+        LES     DI,[CURBUF]
+        OR      ES:[DI.buf_flags],buf_isDIR
+        PUSH    DI
+        ADD     DI,BUFINSIZ
+        XOR     AX,AX
+        SHR     CX,1
+        REP     STOSW
+        JNC     EVENZ
+        STOSB
+EVENZ:
+        POP     DI
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI.buf_flags],buf_dirty
+yesdirty:
+        POP     ES
+        POP     CX
+        INC     DX
+        LOOP    ZERODIR
+        MOV     AX,[LASTENT]
+        INC     AX
+        CLC
+        return
+
+EndProc BUILDDIR
+
+;
+; set up a . or .. directory entry for a directory.
+;
+;   Inputs:     ES:DI point to the beginning of a directory entry.
+;               AX contains ". " or ".."
+;               DX contains first cluster of entry
+;
+        procedure   SETDOTENT,NEAR
+        DOSAssume   CS,<DS>,"SetDotEnt"
+;
+; Fill in name field
+;
+        STOSW
+        MOV     CX,4
+        MOV     AX,"  "
+        REP     STOSW
+        STOSB
+;
+; Set up attribute
+;
+        MOV     AL,attr_directory
+        errnz   dir_attr-(dir_name+11)
+        STOSB
+;
+; Initialize time and date of creation
+;
+        ADD     DI,10
+        MOV     SI,WORD PTR [THISSFT]
+        MOV     AX,[SI.sf_time]
+        errnz   dir_time-(dir_attr+1+10)
+        STOSW
+        MOV     AX,[SI.sf_date]
+        errnz   dir_date-(dir_time+2)
+        STOSW
+;
+; Set up first cluster field
+;
+        MOV     AX,DX
+        errnz   dir_first-(dir_date+2)
+        STOSW
+;
+; 0 file size
+;
+        XOR     AX,AX
+        errnz   dir_size_l-(dir_first+2)
+        STOSW
+        STOSW
+        errnz   <(size dir_entry)-(dir_size_l+4)>
+        return
+EndProc SETDOTENT
+
+Break   <MAKENODE -- CREATE A NEW NODE>
+
+; Inputs:
+;       AL - attribute to create
+;       AH = 0 if it is ok to truncate a file already by this name
+;       AH = Non 0 if this is an error
+;               (AH ignored on dirs and devices)
+;        NOTE: When making a DIR or volume ID, AH need not be set since
+;               a name already existant is ALWAYS an error in these cases.
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;       [THISSFT] Points to an empty SFT. EXCEPT sf_mode filled in.
+; Function:
+;       Make a new node
+; Outputs:
+;       Sets EXTERR_LOCUS = errLOC_Disk or errLOC_Unk via GetPathNoset
+;       CARRY SET IF ERROR
+;          AX = 1 A node by this name exists and is a directory
+;          AX = 2 A new node could not be created
+;          AX = 3 A node by this name exists and is a disk file
+;               (AH was NZ on input)
+;          AX = 4 Bad Path
+;               SI return from GetPath maintained
+;          AX = 5 Attribute mismatch
+;          AX = 6 Sharing Violation
+;               (INT 24 generated ALWAYS since create is always compat mode
+;          AX = 7 file not found for Extended Open (not exists and fails)
+;       ELSE
+;          AX = 0       Disk Node
+;          AX = 3       Device Node (error in some cases)
+;          [DIRSTART],[DIRSEC],[CLUSFAC],[CLUSNUM] set to directory
+;               containing new node.
+;          [CURBUF+2]:BX Points to entry
+;          [CURBUF+2]:SI Points to entry.dir_first
+;          [THISSFT] is filled in
+;               sf_mode = unchanged.
+;          Attribute byte in entry is input AL
+; DS preserved, others destroyed
+
+        procedure   MakeNode,NEAR
+        DOSAssume   CS,<DS>,"MakeNode"
+        ASSUME  ES:NOTHING
+
+        MOV     WORD PTR [CREATING],0E5FFH      ; Creating, not DEL *.*
+        PUSH    AX              ; Save AH value
+        MOV     [NoSetDir],0
+        MOV     [SATTRIB],AL
+        invoke  GetPathNoSet
+        MOV     DL,CL           ; Save CL info
+        MOV     CX,AX           ; Device ID to CH
+        POP     AX              ; Get back AH
+        JNC     make_exists     ; File existed
+        JNZ     make_err_4      ; Path bad
+        CMP     DL,80H          ; Check "CL" return from GETPATH
+        JZ      make_type       ; Name simply not found, and no metas
+make_err_4:
+        MOV     AL,4            ; case 1 bad path
+make_err_ret:
+        XOR     AH,AH
+        STC
+        return
+
+        entry   RENAME_MAKE     ; Used by DOS_RENAME to "copy" a node
+
+make_type:
+;Extended Open hooks
+        TEST   [EXTOPEN_ON],ext_open_on  ;FT. from extended open                ;AN000;
+        JZ     make_type2                ;FT. no                                ;AN000;
+        OR     [EXTOPEN_ON],ext_file_not_exists ;FT. set for extended open      ;AN000;
+        TEST   [EXTOPEN_FLAG],0F0H       ;FT. not exists and fails              ;AN000;
+        JNZ    make_type2                ;FT. no                                ;AN000;
+        STC                              ;FT. set carry                         ;AN000;
+        MOV    AX,7                      ;FT. file not found                    ;AN000;
+        return                           ;FT.                                   ;AN000;
+make_type2:
+;Extended Open hooks
+        LES     DI,[THISSFT]
+;       MOV     ES:[DI.sf_mode],sharing_compat + open_for_both
+        XOR     AX,AX           ; nothing exists Disk Node
+        STC                     ; Not found
+        JMP     make_new
+
+;
+; The node exists.  It may be either a device, directory or file:
+;   Zero set => directory
+;   High bit of CH on => device
+;   else => file
+make_exists:
+        JZ      make_exists_dir
+        MOV     AL,3            ; file exists type 3  (error or device node)
+        TEST    BYTE PTR [ATTRIB],(attr_volume_id+attr_directory)
+        JNZ     make_err_ret_5  ; Cannot already exist as Disk or Device Node
+                                ;       if making DIR or Volume ID
+        OR      CH,CH
+        JS      make_share      ; No further checks on attributes if device
+        OR      AH,AH
+        JNZ     make_err_ret    ; truncating NOT OK (AL = 3)
+        PUSH    CX              ; Save device ID
+        MOV     ES,WORD PTR [CURBUF+2]
+        MOV     CH,ES:[BX+dir_attr] ; Get file attributes
+        TEST    CH,attr_read_only
+        JNZ     make_err_ret_5P ; Cannot create on read only files
+        invoke  MatchAttributes
+        POP     CX              ; Devid back in CH
+        JNZ     make_err_ret_5  ; Attributes not ok
+        XOR     AL,AL           ; AL = 0, Disk Node
+make_share:
+        XOR     AH,AH
+        PUSH    AX              ; Save Disk or Device node
+        PUSH    CX              ; Save Device ID
+        MOV     AH,CH           ; Device ID to AH
+        CALL    DOOPEN          ; Fill in SFT for share check
+        LES     DI,[THISSFT]
+;       MOV     ES:[DI.sf_mode],sharing_compat + open_for_both
+        SaveReg <SI,BX>         ; Save CURBUF pointers
+        invoke  ShareEnter
+        jnc     MakeEndShare
+;
+; User failed request.
+;
+        RestoreReg  <BX,SI,CX,AX>
+Make_Share_ret:
+        MOV     AL,6
+        JMP     make_err_ret
+
+make_err_ret_5P:
+        POP     CX              ; Get back device ID
+make_err_ret_5:
+        MOV     AL,5            ; Attribute mismatch
+        JMP     make_err_ret
+
+make_exists_dir:
+        MOV     AL,1            ; exists as directory, always an error
+        JMP     make_err_ret
+
+make_save:
+        PUSH    AX              ; Save whether Disk or File
+        MOV     AX,CX           ; Device ID to AH
+        CALL    NewEntry
+        POP     AX              ; 0 if Disk, 3 if File
+        retnc
+        MOV     AL,2            ; create failed case 2
+        return
+
+make_new:
+        call    make_save
+        retc                    ; case 2 fail
+        TEST    BYTE PTR [ATTRIB],attr_directory
+        retnz                   ; Don't "open" directories, so don't
+                                ;   tell the sharer about them
+        SaveReg <AX,BX,SI>      ; Save AL code
+        invoke  ShareEnter
+        RestoreReg  <SI,BX,AX>
+        retnc
+;
+; We get here by having the user FAIL a share problem.  Typically a failure of
+; this nature is an out-of-space or an internal error.  We clean up as best as
+; possible:  delete the newly created directory entry and return share_error.
+;
+        PUSH    AX
+        LES     DI,CurBuf
+        MOV     BYTE PTR ES:[BX],0E5H   ; nuke newly created entry.
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty2                 ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI].buf_flags,buf_dirty ; flag buffer as dirty
+yesdirty2:
+        LES     BP,ThisDPB
+        MOV     AL,ES:[BP].DPB_Drive    ; get drive for flush
+        Invoke  FlushBuf                ; write out buffer.
+        POP     AX
+        jmp     make_Share_ret
+;
+; We have found an existing file.  We have also entered it into the share set.
+; At this point we need to call newentry to correctly address the problem of
+; getting rid of old data (create an existing file) or creating a new
+; directory entry (create a new file).  Unfortunately, this operation may
+; result in an INT 24 that the user doesn't return from, thus locking the file
+; irretrievably into the share set.  The correct solution is for us to LEAVE
+; the share set now, do the operation and then reassert the share access.
+;
+; We are allowed to do this!  There is no window!  After all, we are in
+; critDisk here and for someone else to get in, they must enter critDisk also.
+;
+MakeEndShare:
+        LES     DI,ThisSFT              ; grab SFT
+        XOR     AX,AX
+        EnterCrit   critSFT
+        XCHG    AX,ES:[DI].sf_ref_count
+        SaveReg <AX,DI,ES>
+        PUSHF
+        invoke  ShareEnd                ; remove sharing
+        POPF
+        RestoreReg  <ES,DI,ES:[DI].sf_ref_count>
+        LeaveCrit   critSFT
+        RestoreReg  <BX,SI,CX,AX>
+        CALL    make_save
+;
+; If the user failed, we do not reenter into the sharing set.
+;
+        retc                            ; bye if error
+        SaveReg <AX,BX,SI>
+        PUSHF
+        invoke  ShareEnter
+        POPF
+        RestoreReg  <SI,BX,AX>
+;
+; If Share_check fails, then we have an internal ERROR!!!!!
+;
+        return
+EndProc MakeNode
+
+; Inputs:
+;       [THISSFT] set
+;       [THISDPB] set
+;       [LASTENT] current last valid entry number in directory if no free
+;               entries
+;       [VOLID] set if a volume ID was found during search
+;       [ATTRIB] Contains attributes for new file
+;       [DIRSTART] Points to first cluster of dir (0 means root)
+;       CARRY FLAG INDICATES STATUS OF SEARCH FOR FILE
+;               NC means file existed (device)
+;               C  means file did not exist
+;       AH = Device ID byte
+;       If FILE
+;           [CURBUF+2]:BX points to start of directory entry
+;           [CURBUF+2]:SI points to dir_first of directory entry
+;       If device
+;           DS:BX points to start of "fake" directory entry
+;           DS:SI points to dir_first of "fake" directory entry
+;               (has DWORD pointer to device header)
+; Function:
+;       Make a new directory entry
+;       If an old one existed it is truncated first
+; Outputs:
+;       Carry set if error
+;               Can't grow dir, atts didn't match, attempt to make 2nd
+;               vol ID, user FAILed to I 24
+;       else
+;               outputs of DOOPEN
+; DS, BX, SI preserved (meaning on SI BX, not value), others destroyed
+
+        procedure NEWENTRY,NEAR
+        DOSAssume   CS,<DS>,"NewEntry"
+        ASSUME  ES:NOTHING
+
+        LES     BP,[THISDPB]
+ASSUME  ES:NOTHING
+        JNC     EXISTENT
+        CMP     [FAILERR],0
+        STC
+        retnz                   ; User FAILed, node might exist
+        CALL    BUILDDIR        ; Try to build dir
+        retc                    ; Failed
+        invoke  GETENT          ; Point at that free entry
+        retc                    ; Failed
+        JMP     SHORT FREESPOT
+
+ERRRET3:
+        STC
+        return
+
+EXISTENT:
+        DOSAssume   CS,<DS>,"MKNODE/ExistEnt"
+        OR      AH,AH           ; Check if file is I/O device
+        JNS     NOT_DEV1
+        JMP     DOOPEN          ; If so, proceed with open
+
+NOT_DEV1:
+        invoke  FREEENT         ; Free cluster chain
+        retc                    ; Failed
+FREESPOT:
+        TEST    BYTE PTR [ATTRIB],attr_volume_id
+        JZ      NOTVOLID
+        CMP     BYTE PTR [VOLID],0
+        JNZ     ERRRET3         ; Can't create a second volume ID
+NOTVOLID:
+        MOV     ES,WORD PTR [CURBUF+2]
+        MOV     DI,BX
+        MOV     SI,OFFSET DOSGROUP:NAME1
+        MOV     CX,5
+        REP     MOVSW
+        MOVSB                   ; Move name into dir entry
+        MOV     AL,[ATTRIB]
+        errnz   dir_attr-(dir_name+11)
+        STOSB                   ; Attributes
+;; File Tagging for Create DOS 4.00
+        MOV     CL,5            ;FT. assume normal                              ;AN000;
+;       CMP     [CPSWFLAG],0    ;FT. code page matching on                      ;AN000;
+;       JZ      NORMFT          ;FT. no, make null code page                    ;AN000;
+;       invoke  Get_Global_CdPg ;FT. get global code page                       ;AN000;
+;       STOSW                   ;FT. tag this file with global code page        ;AN000;
+;       DEC     CL              ;FT. only 4                                     ;AN000;
+;NORMFT:                        ;FT.                                            ;AN000;
+
+;; File Tagging for Create DOS 4.00
+        XOR     AX,AX
+        REP     STOSW           ; Zero pad
+        invoke  DATE16
+        XCHG    AX,DX
+        errnz   dir_time-(dir_attr+1+2*5)
+        STOSW                   ; dir_time
+        XCHG    AX,DX
+        errnz   dir_date-(dir_time+2)
+        STOSW                   ; dir_date
+        XOR     AX,AX
+        PUSH    DI              ; Correct SI input value (recomputed for new buffer)
+
+        errnz   dir_first-(dir_date+2)
+        STOSW                   ; Zero dir_first and size
+        errnz   dir_size_l-(dir_first+2)
+        STOSW
+        STOSW
+updnxt:
+        errnz   <(size dir_entry)-(dir_size_l+4)>
+        MOV     SI,WORD PTR [CURBUF]
+
+        TEST    ES:[SI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty3                 ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[SI.buf_flags],buf_dirty
+yesdirty3:
+        LES     BP,[THISDPB]
+        MOV     AL,ES:[BP.dpb_drive]    ; Sets AH value again (in AL)
+        PUSH    AX
+        PUSH    BX
+; If we have a file, we need to increment the open ref. count so that
+; we have some protection against invalid media changes if an Int 24
+; error occurs.
+; Do nothing for a device.
+        SaveReg <ES,DI>
+        LES     DI,[THISSFT]
+        test    es:[di.sf_flags],devid_device
+        jnz     GotADevice
+        SaveReg <DS,BX>
+        LDS     BX,[THISDPB]
+        MOV     word ptr ES:[DI.sf_devptr],BX
+        MOV     BX,DS
+        MOV     word ptr ES:[DI.sf_devptr+2],BX
+        RestoreReg <BX,DS>      ; need to use DS for segment later on
+        invoke  Dev_Open_SFT    ; increment ref. count
+        mov     [VIRTUAL_OPEN],1; set flag
+GotADevice:
+        RestoreReg <DI,ES>
+
+        PUSH    [ACT_PAGE]      ;LB. save EMS page for curbuf                   ;AN000;
+        invoke  FLUSHBUF
+        POP     BX              ;LB. restore EMS page for curbuf                ;AN000;
+        PUSHF                   ;LB. save flushbuf falg                         ;AN000;
+        CMP     BX,-1           ;BL-NETWORK PTM #-?
+        JE      Page_ok         ;BL-NETWORK PTM #-?
+        invoke  SET_MAP_PAGE    ;LB. remap curbuf                               ;AN000;
+Page_ok:                        ;BL-NETWORK PTM #-?
+        POPF                    ;LB. restore flush flag                         ;AN000;
+        Call    CHECK_VIRT_OPEN ; decrement ref. count                          ;AN000;
+        POP     BX
+        POP     AX
+        POP     SI              ; Get SI input back
+        MOV     AH,AL           ; Get I/O driver number back
+        retc                    ; Failed
+
+
+;NOTE FALL THROUGH
+
+; Inputs:
+;       [THISDPB] points to DPB if file
+;       [THISSFT] points to SFT being used
+;       AH = Device ID byte
+;       If FILE
+;           [CURBUF+2]:BX points to start of directory entry
+;           [CURBUF+2]:SI points to dir_first of directory entry
+;       If device
+;           DS:BX points to start of "fake" directory entry
+;           DS:SI points to dir_first of "fake" directory entry
+;               (has DWORD pointer to device header)
+; Function:
+;       Fill in SFT from dir entry
+; Outputs:
+;       CARRY CLEAR
+;       sf_ref_count and sf_mode fields not altered
+;       sf_flags high byte = 0
+;       sf_flags low byte = AH except
+;       sf_flags Bit 6 set (not dirty or not EOF)
+;       sf_attr sf_date sf_time sf_name set from entry
+;       sf_position = 0
+;       If device
+;           sf_devptr = dword at dir_first (pointer to device header)
+;           sf_size = 0
+;       If file
+;           sf_firclus sf_size set from entry
+;           sf_devptr = [THISDPB]
+;           sf_cluspos = 0
+;           sf_lstclus = sf_firclus
+;           sf_dirsec sf_dirpos set
+; DS,SI,BX preserved, others destroyed
+
+    entry   DOOPEN
+        DOSAssume   CS,<DS>,"DoOpen"
+        ASSUME  ES:NOTHING
+
+;
+; Generate and store attribute
+;
+        MOV     DH,AH           ; AH to different place
+        LES     DI,[THISSFT]
+        ADD     DI,sf_attr      ; Skip ref_count and mode fields
+        XOR     AL,AL           ; Assume it's a device, devices have an
+                                ;   attribute of 0 (for R/O testing etc).
+        OR      DH,DH           ; See if our assumption good.
+        JS      DEV_SFT1        ; If device DS=DOSGROUP
+        MOV     DS,WORD PTR [CURBUF+2]
+ASSUME  DS:NOTHING
+        MOV     AL,[BX.dir_attr] ; If file, get attrib from dir entry
+DEV_SFT1:
+        STOSB                   ; sf_attr, ES:DI -> sf_flags
+;
+; Generate and store flags word
+;
+        XOR     AX,AX
+        MOV     AL,DH
+        OR      AL,devid_file_clean
+        STOSW                   ; sf_flags, ES:DI -> sf_devptr
+;
+; Generate and store device pointer
+;
+        PUSH    DS
+        LDS     AX,DWORD PTR [BX.dir_first]       ; Assume device
+        OR      DH,DH
+        JS      DEV_SFT2
+        LDS     AX,[THISDPB]            ; Was file
+DEV_SFT2:
+        STOSW                           ; store offset
+        MOV     AX,DS
+        POP     DS
+        STOSW                           ; store segment
+                                        ; ES:DI -> sf_firclus
+;
+; Generate pointer to, generate and store first cluster (irrelevant  for
+; devices)
+;
+        PUSH    SI              ; Save pointer to dir_first
+        MOVSW                   ; dir_first -> sf_firclus
+                                ; DS:SI -> dir_size_l, ES:DI -> sf_time
+;
+; Copy time/date of last modification
+;
+        SUB     SI,dir_size_l - dir_time        ; DS:SI->dir_time
+        MOVSW                   ; dir_time -> sf_time
+                                ; DS:SI -> dir_date, ES:DI -> sf_date
+        MOVSW                   ; dir_date -> sf_date
+                                ; DS:SI -> dir_first, ES:DI -> sf_size
+;
+; Generate and store file size (0 for devices)
+;
+        LODSW                   ; skip dir_first, DS:SI -> dir_size_l
+        LODSW                   ; dir_size_l in AX , DS:SI -> dir_size_h
+        MOV     CX,AX           ; dir_size_l in CX
+        LODSW                   ; dir_size_h (size AX:CX), DS:SI -> ????
+        OR      DH,DH
+        JNS     FILE_SFT1
+        XOR     AX,AX
+        MOV     CX,AX           ; Devices are open ended
+FILE_SFT1:
+        XCHG    AX,CX
+        STOSW                   ; Low word of sf_size
+        XCHG    AX,CX
+        STOSW                   ; High word of sf_size
+                                ; ES:DI -> sf_position
+;
+; Initialize position to 0
+;
+        XOR     AX,AX
+        STOSW
+        STOSW                   ; sf_position
+                                ; ES:DI -> sf_cluspos
+;
+; Generate cluster optimizations for files
+;
+        OR      DH,DH
+        JS      DEV_SFT3
+        STOSW                   ; sf_cluspos
+        MOV     AX,[BX.dir_first]
+;;;;    STOSW                   ; sf_lstclus
+        PUSH    DI              ;AN004; save dirsec offset
+        SUB     DI,sf_dirsec    ;AN004; es:di -> SFT
+        MOV     ES:[DI.sf_lstclus],AX  ;AN004; save it
+        POP     DI              ;AN004; restore dirsec offset
+
+
+
+; DOS 3.3  FastOpen  6/13/86
+
+        PUSH   DS
+        context DS
+        TEST   [FastOpenFlg],Special_Fill_Set
+        JZ     Not_FastOpen
+        MOV     SI,OFFSET DOSGROUP:FastOpen_Ext_Info
+        MOV     AX,WORD PTR [SI.FEI_dirsec]
+        STOSW                   ; sf_dirsec
+        MOV     AX,WORD PTR [SI.FEI_dirsec+2]  ;;; changed for >32mb
+        STOSW                   ; sf_dirsec
+        MOV     AL,[SI.FEI_dirpos]
+        STOSB                   ; sf_dirpos
+        POP     DS
+        JMP     Next_Name
+
+; DOS 3.3  FastOpen  6/13/86
+
+Not_FastOpen:
+        POP     DS                      ; normal path
+ASSUME  DS:NOTHING
+        MOV     SI,WORD PTR [CURBUF]    ; DS:SI->buffer header
+        MOV     AX,WORD PTR [SI.buf_sector]     ;F.C. >32mb                        ;AN000;
+        STOSW                   ; sf_dirsec     ;F.C. >32mb                        ;AN000;
+        MOV     AX,WORD PTR [SI.buf_sector+2]   ;F.C. >32mb                        ;AN000;
+        STOSW                   ; sf_dirsec     ;F.C. >32mb                        ;AN000;
+        MOV     AX,BX
+        ADD     SI,BUFINSIZ     ; DS:SI-> start of data in buffer
+        SUB     AX,SI           ; AX = BX relative to start of sector
+        MOV     CL,SIZE dir_entry
+        DIV     CL
+        STOSB                   ; sf_dirpos
+
+Next_Name:
+        errnz   sf_name-(sf_dirpos+1)
+        JMP     SHORT FILE_SFT2
+
+DEV_SFT3:
+        ADD     DI,sf_name - sf_cluspos
+FILE_SFT2:
+;
+; Copy in the object's name
+;
+        MOV     SI,BX           ; DS:SI points to dir_name
+        MOV     CX,11
+        REP     MOVSB           ; sf_name
+        POP     SI              ; recover DS:SI -> dir_first
+;; File tagging , code page and XA cluster must be after name
+;       MOV     AX,[BX.dir_CODEPG]       ;FT. set file's code page                 ;AN000;
+;       STOSW                            ;FT.                                      ;AN000;
+;       MOV     AX,[BX.dir_EXTCLUSTER]   ;FT. set XA cluster                       ;AN000;
+;       STOSW                            ;FT.                                      ;AN000;
+;       MOV     AX,[EXTOPEN_IO_MODE]     ;FT. extended open                        ;AN000;
+;       STOSW                            ;FT.                                      ;AN000;
+;       MOV     AL,[BX.dir_attr2]        ;FT. high attribute                       ;AN000;
+;       STOSB                            ;FT.                                      ;AN000;
+
+;; File tagging , code page and XA cluster must be after name
+
+        context DS
+        CLC
+        return
+
+EndProc NEWENTRY
+
+; Inputs:
+;       ES:BP -> DPB
+;       [CURBUF] Set
+;       [CURBUF+2]:BX points to directory entry
+;       [CURBUF+2]:SI points to above dir_first
+; Function:
+;       Free the cluster chain for the entry if present
+; Outputs:
+;       Carry set if error (currently user FAILed to I 24)
+;       (NOTE dir_firclus and dir_size_l/h are wrong)
+; DS BX SI ES BP preserved (BX,SI in meaning, not value) others destroyed
+
+        procedure FREEENT,NEAR
+        DOSAssume   CS,<DS>,"FreeEnt"
+        ASSUME  ES:NOTHING
+
+        PUSH    DS
+        LDS     DI,[CURBUF]
+ASSUME  DS:NOTHING
+        MOV     CX,[SI]         ; Get pointer to clusters
+        MOV     DX,WORD PTR [DI.buf_sector+2]  ;F.C. >32mb                      ;AN000;
+        MOV     [HIGH_SECTOR],DX               ;F.C. >32mb                      ;AN000;
+        MOV     DX,WORD PTR [DI.buf_sector]
+        POP     DS
+        DOSAssume   CS,<DS>,"MKNODE/FreeEnt"
+        CMP     CX,2
+        JB      RET1            ; Was 0 length file (or mucked Firclus if CX=1)
+        CMP     CX,ES:[BP.dpb_max_cluster]
+        JA      RET1            ; Treat like zero length file (firclus mucked)
+        SUB     BX,DI
+        PUSH    BX              ; Save offset
+        PUSH    [HIGH_SECTOR]                  ;F.C. >32mb                      ;AN000;
+        PUSH    DX              ; Save sector number
+
+        MOV     BX,CX
+        invoke  Delete_FSeek    ; FS. delete Fastseek Clusters                  ;AN000;
+        invoke  RELEASE         ; Free any data allocated
+        POP     DX
+        POP     [HIGH_SECTOR]                  ;F.C. >32mb                      ;AN000;
+        JNC     GET_BUF_BACK
+        POP     BX
+        return                  ; Screw up
+
+GET_BUF_BACK:
+
+        MOV     [ALLOWED],allowed_RETRY + allowed_FAIL
+        XOR     AL,AL
+        invoke  GETBUFFR        ; Get sector back
+        POP     BX              ; Get offset back
+        retc
+        invoke  SET_BUF_AS_DIR
+        ADD     BX,WORD PTR [CURBUF]    ; Correct it for new buffer
+        MOV     SI,BX
+        ADD     SI,dir_first    ; Get corrected SI
+RET1:
+        CLC
+        return
+EndProc FREEENT
+
+;
+; CHECK_VIRT_OPEN checks to see if we had performed a "virtual open" (by
+; examining the flag [VIRTUAL_OPEN] to see if it is 1). If we did, then
+; it calls Dev_Close_SFT to decrement the ref. count. It also resets the
+; flag [VIRTUAL_OPEN].
+; No registers affected (including flags).
+; On input, [THISSFT] points to current SFT.
+;
+        Procedure CHECK_VIRT_OPEN,NEAR
+        DOSAssume   CS,<DS>,"Check_Virt_Open"
+
+        PUSH    AX
+        lahf                    ; preserve flags
+        CMP     [VIRTUAL_OPEN],0
+        JZ      ALL_CLOSED
+        mov     [VIRTUAL_OPEN],0        ; reset flag
+        SaveReg <ES,DI>
+        LES     DI,[THISSFT]
+        INVOKE  DEV_CLOSE_SFT
+        RestoreReg <DI,ES>
+
+ALL_CLOSED:
+        sahf                    ; restore flags
+        POP     AX
+        return
+
+EndProc CHECK_VIRT_OPEN
+
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSCODE.ASM b/v4.0/src/DOS/MSCODE.ASM
new file mode 100644
index 0000000..74668c9
--- /dev/null
+++ b/v4.0/src/DOS/MSCODE.ASM
@@ -0,0 +1,16 @@
+;       SCCSID = @(#)ibmcode.asm        1.1 85/04/10
+TITLE   MISC DOS ROUTINES - Int 25 and 26 handlers and other
+NAME    IBMCODE
+
+;
+; System call dispatch code.
+;
+
+.xlist
+.xcref
+include mssw.asm
+.cref
+.list
+
+include ms_code.asm
+        END
diff --git a/v4.0/src/DOS/MSCONST.ASM b/v4.0/src/DOS/MSCONST.ASM
new file mode 100644
index 0000000..126f322
--- /dev/null
+++ b/v4.0/src/DOS/MSCONST.ASM
@@ -0,0 +1,153 @@
+;       SCCSID = @(#)msconst.asm        1.4 85/09/12
+;   Revision history
+;      AN000  version 4.00  Jan. 1988
+;      AN007  fake version check for IBMCACHE.COM
+include mshead.asm
+include version.inc
+
+CODE            SEGMENT BYTE PUBLIC 'CODE'
+        Extrn   LeaveDOS:NEAR
+        Extrn   BadCall:FAR, OKCall:FAR
+CODE            ENDS
+
+Break <Initialized data and data used at DOS initialization>
+
+;
+; We need to identify the parts of the data area that are relevant to tasks
+; and those that are relevant to the system as a whole.  Under 3.0, the system
+; data will be gathered with the system code.  The process data under 2.x will
+; be available for swapping and under 3.0 it will be allocated per-process.
+;
+; The data that is system data will be identified by [SYSTEM] in the comments
+; describing that data item.
+;
+
+        AsmVars <Kanji, Debug, Redirector, ShareF>
+
+CONSTANTS       SEGMENT WORD PUBLIC 'CONST'
+
+        extrn   sfTabl:DWORD
+
+        ORG     0
+
+        EVEN
+;
+; WANGO!!!  The following word is used by SHARE and REDIR to determin data
+; area compatability.  This location must be incremented EACH TIME the data
+; area here gets mucked with.
+;
+; Also, do NOT change this position relative to DOSGROUP:0.
+;
+Public MSCT001S,MSCT001E
+MSCT001S:
+        I_am    DataVersion,WORD,<1>    ;AC000; [SYSTEM] version number for DOS DATA
+
+%out WARNING!!! Debug fields are being included!!!
+        DB      "BUG "                  ; THIS FIELD MUST BE EVEN # OF BYTES
+        I_am    BugTyp,WORD,<0>
+        I_am    BugLev,WORD,<0>
+include bugtyp.asm
+
+        I_am    MYNUM,WORD,<0>          ; [SYSTEM] A number that goes with MYNAME
+        I_am    FCBLRU,WORD,<0>         ; [SYSTEM] LRU count for FCB cache
+        I_am    OpenLRU,WORD,<0>        ; [SYSTEM] LRU count for FCB cache opens
+; NOTE: We include the decl of OEM_HANDLER in IBM DOS even though it is not used.
+;       This allows the REDIRector to work on either IBM or MS-DOS.
+        PUBLIC  OEM_HANDLER
+OEM_HANDLER     DD      -1              ; [SYSTEM] Pointer to OEM handler code
+        I_am    LeaveAddr,WORD,<<OFFSET DOSGroup:LeaveDOS>> ; [SYSTEM]
+        I_am    RetryCount,WORD,<3>     ; [SYSTEM] Share retries
+        I_am    RetryLoop,WORD,<1>      ; [SYSTEM] Share retries
+        I_am    LastBuffer,DWORD,<-1,-1>; [SYSTEM] Buffer queue recency pointer
+        I_am    CONTPOS,WORD            ; [SYSTEM] location in buffer of next read
+        I_am    arena_head,WORD         ; [SYSTEM] Segment # of first arena in memory
+; The following block of data is used by SYSINIT.  Do not change the order or
+; size of this block
+        PUBLIC  SYSINITVAR              ; [SYSTEM]
+SYSINITVAR  LABEL   WORD                ; [SYSTEM]
+        I_am    DPBHEAD,DWORD           ; [SYSTEM] Pointer to head of DPB-FAT list
+        I_am    sft_addr,DWORD,<<OFFSET DosGroup:sfTabl>,?> ; [SYSTEM] Pointer to first SFT table
+        I_am    BCLOCK,DWORD            ; [SYSTEM] The CLOCK device
+        I_am    BCON,DWORD              ; [SYSTEM] Console device entry points
+        I_am    MAXSEC,WORD,<128>       ; [SYSTEM] Maximum allowed sector size
+        I_am    BUFFHEAD,DWORD          ; [SYSTEM] Pointer to head of buffer queue
+        I_am    CDSADDR,DWORD           ; [SYSTEM] Pointer to curdir structure table
+        I_am    sftFCB,DWORD            ; [SYSTEM] pointer to FCB cache table
+        I_am    KeepCount,WORD          ; [SYSTEM] count of FCB opens to keep
+        I_am    NUMIO,BYTE              ; [SYSTEM] Number of disk tables
+        I_am    CDSCOUNT,BYTE           ; [SYSTEM] Number of CDS structures in above
+; A fake header for the NUL device
+        I_am    NULDEV,DWORD            ; [SYSTEM] Link to rest of device list
+        DW      DEVTYP OR ISNULL        ; [SYSTEM] Null device attributes
+        short_addr  SNULDEV             ; [SYSTEM] Strategy entry point
+        short_addr  INULDEV             ; [SYSTEM] Interrupt entry point
+        DB      "NUL     "              ; [SYSTEM] Name of null device
+        I_am    Splices,BYTE,<0>        ; [SYSTEM] TRUE => splices being done
+        I_am    Special_Entries,WORD,<0>; [SYSTEM] address of specail entries   ;AN000;
+        I_am    IFS_DOS_CALL,DWORD      ; [SYSTEM] entry for IFS DOS service    ;AN000;
+        I_am    IFS_HEADER,DWORD        ; [SYSTEM] IFS header chain             ;AN000;
+        I_am    BUFFERS_PARM1,WORD,<0>  ; [SYSTEM] value of BUFFERS= ,m         ;AN000;
+        I_am    BUFFERS_PARM2,WORD,<0>  ; [SYSTEM] value of BUFFERS= ,n         ;AN000;
+        I_am    BOOTDRIVE,BYTE          ; [SYSTEM] the boot drive               ;AN000;
+        I_am    DDMOVE,BYTE,<0>         ; [SYSTEM] 1 if we need DWORD move      ;AN000;
+        I_am    EXT_MEM_SIZE,WORD,<0>   ; [SYSTEM] extended memory size         ;AN000;
+
+        PUBLIC  HASHINITVAR             ; [SYSTEM]                              ;AN000;
+HASHINITVAR  LABEL   WORD               ; [SYSTEM]                              ;AN000;
+        I_am    BUF_HASH_PTR,DWORD      ; [SYSTEM] buffer Hash table addr       ;AN000;
+        I_am    BUF_HASH_COUNT,WORD,<1> ; [SYSTEM] number of Hash entries       ;AN000;
+        I_am    SC_CACHE_PTR,DWORD      ; [SYSTEM] secondary cache pointer      ;AN000;
+        I_am    SC_CACHE_COUNT,WORD,<0> ; [SYSTEM] secondary cache count        ;AN000;
+
+IF      BUFFERFLAG
+
+        I_am    BUF_EMS_SAFE_FLAG,BYTE,<1>      ; indicates whether the page used by buffers is safe or not
+        I_am    BUF_EMS_LAST_PAGE,4,<0,0,0,0>   ; holds the last page above 640k
+        I_am    BUF_EMS_FIRST_PAGE,4,<0,0,0,0>  ; holds the first page above 640K
+        I_am    BUF_EMS_NPA640,WORD,<0>         ; holds the number of pages above 640K
+
+ENDIF
+
+        I_am    BUF_EMS_MODE,BYTE,<-1>  ; [SYSTEM] EMS mode                     ;AN000;
+        I_am    BUF_EMS_HANDLE,WORD     ; [SYSTEM] buffer EMS handle            ;AN000;
+        I_am    BUF_EMS_PAGE_FRAME,WORD ,<-1>;[SYSTEM] EMS page frame number    ;AN000;
+        I_am    BUF_EMS_SEG_CNT,WORD,<1>; [SYSTEM] EMS seg count                ;AN000;
+        I_am    BUF_EMS_PFRAME,WORD     ; [SYSTEM] EMS page frame seg address   ;AN000;
+        I_am    BUF_EMS_RESERV,WORD,<0> ; [SYSTEM] reserved                     ;AN000;
+
+IF      BUFFERFLAG
+        I_am    BUF_EMS_MAP_BUFF,1,<0>  ; this is not used to save the state of the 
+                                        ; of the buffers page. this one byte is
+                                        ; retained to keep the size of this data 
+                                        ; block the same.
+ELSE
+        I_am    BUF_EMS_MAP_BUFF,12,<0,0,0,0,0,0,0,0,0,0,0,0>   ; map buufer    ;AN000;
+ENDIF
+
+; End of SYSINITVar block
+
+;
+; Sharer jump table
+;
+PUBLIC  JShare
+        EVEN
+JShare  LABEL   DWORD
+        DW      OFFSET DOSGROUP:BadCall, 0
+        DW      OFFSET DOSGROUP:OKCall,  0  ;   1   MFT_enter
+        DW      OFFSET DOSGROUP:OKCall,  0  ;   2   MFTClose
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   3   MFTclU
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   4   MFTCloseP
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   5   MFTCloN
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   6   set_block
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   7   clr_block
+        DW      OFFSET DOSGROUP:OKCall,  0  ;   8   chk_block
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   9   MFT_get
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   10  ShSave
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   11  ShChk
+        DW      OFFSET DOSGROUP:OKCall , 0  ;   12  ShCol
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   13  ShCloseFile
+        DW      OFFSET DOSGROUP:BadCall, 0  ;   14  ShSU
+
+MSCT001E:
+CONSTANTS       ENDS
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSCPMIO.ASM b/v4.0/src/DOS/MSCPMIO.ASM
new file mode 100644
index 0000000..53656ff
--- /dev/null
+++ b/v4.0/src/DOS/MSCPMIO.ASM
@@ -0,0 +1,17 @@
+;       SCCSID = @(#)ibmcpmio.asm       1.1 85/04/10
+;
+; Standard device IO for MSDOS (first 12 function calls)
+;
+
+.xlist
+.xcref
+include mssw.asm
+include dosseg.asm
+.cref
+.list
+
+TITLE   IBMCPMIO - device IO for MSDOS
+NAME    IBMCPMIO
+
+include cpmio.asm
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSCTRLC.ASM b/v4.0/src/DOS/MSCTRLC.ASM
new file mode 100644
index 0000000..8343b08
--- /dev/null
+++ b/v4.0/src/DOS/MSCTRLC.ASM
@@ -0,0 +1,16 @@
+;       SCCSID = @(#)ibmctrlc.asm       1.1 85/04/10
+;
+; ^C and error handler for MSDOS
+;
+
+.xlist
+.xcref
+include mssw.asm
+.cref
+.list
+
+TITLE   Control C detection, Hard error and EXIT routines
+NAME    IBMCTRLC
+
+include ctrlc.asm
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSDISP.ASM b/v4.0/src/DOS/MSDISP.ASM
new file mode 100644
index 0000000..a0f069e
--- /dev/null
+++ b/v4.0/src/DOS/MSDISP.ASM
@@ -0,0 +1,17 @@
+;       SCCSID = @(#)ibmdisp.asm        1.1 85/04/10
+TITLE   IBM DOS DISPATCHER - System call dispatch code
+NAME    DISP
+
+;
+; System call dispatch code
+;
+
+.xlist
+.xcref
+include mssw.asm
+.cref
+.list
+
+include disp.asm
+        END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSDOS.LNK b/v4.0/src/DOS/MSDOS.LNK
new file mode 100644
index 0000000..2d43bdb
--- /dev/null
+++ b/v4.0/src/DOS/MSDOS.LNK
@@ -0,0 +1,59 @@
+..\inc\nibdos.obj    +
+..\inc\const2.obj   +
+..\inc\msdata.obj  +
+..\inc\mstable.obj +
+ msdisp.obj          +
+ mscode.obj          +
+..\inc\msdosme.obj +
+ time.obj             +
+ getset.obj           +
+ parse.obj            +
+ misc.obj             +
+ misc2.obj            +
+ crit.obj             +
+ cpmio.obj            +
+ cpmio2.obj           +
+ fcbio.obj            +
+ fcbio2.obj           +
+ search.obj           +
+ path.obj             +
+ ioctl.obj            +
+ delete.obj           +
+ rename.obj           +
+ finfo.obj            +
+ dup.obj              +
+ create.obj           +
+ open.obj             +
+ dinfo.obj            +
+ isearch.obj          +
+ abort.obj            +
+ close.obj            +
+ dircall.obj          +
+ disk.obj             +
+ disk2.obj            +
+ disk3.obj            +
+ dir.obj              +
+ dir2.obj             +
+ dev.obj              +
+ mknode.obj           +
+ rom.obj              +
+ fcb.obj              +
+ msctrlc.obj         +
+ fat.obj              +
+ buf.obj              +
+ proc.obj             +
+ alloc.obj            +
+ srvcall.obj          +
+ util.obj             +
+ handle.obj           +
+ macro.obj            +
+ macro2.obj           +
+ file.obj             +
+ lock.obj             +
+ share.obj            +
+ extattr.obj          +
+ ifs.obj
+MSDOS.EXE
+MSDOS.MAP /M
+;
+
diff --git a/v4.0/src/DOS/MSDOS.SKL b/v4.0/src/DOS/MSDOS.SKL
new file mode 100644
index 0000000..c76c224
--- /dev/null
+++ b/v4.0/src/DOS/MSDOS.SKL
@@ -0,0 +1,17 @@
+
+:class 1
+; This was taken from DEVMES.INC IN G:USA\ ...
+;      DIVMES  DB      13,10,"Divide overflow",13,10
+
+:use 001 msdos DIVMES
+
+:class 3
+
+;This is for Yes No check
+:use 205 command NLS_YES
+:use 206 command NLS_NO
+:use 002 msdos  NLS_yes2
+:use 003 msdos  NLS_no2
+
+:end
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MSHALO.ASM b/v4.0/src/DOS/MSHALO.ASM
new file mode 100644
index 0000000..dc6c64a
--- /dev/null
+++ b/v4.0/src/DOS/MSHALO.ASM
@@ -0,0 +1,247 @@
+;       SCCSID = @(#)ibmhalo.asm        1.1 85/04/10
+;   On 2K (800h) boundaries beginning at address C0000h and ending at EF800h
+;   there is a header that describes a block of rom program.  This header
+;   contains information needed to initialize a module and to provide PCDOS
+;   with a set of reserved names for execution.
+;
+;   This header has the following format:
+;
+;   rom_header  STRUC
+;       Signature1  DB  55h
+;       Signature2  DB  AAh
+;       rom_length  DB  ?               ; number of 512 byte pieces
+;       init_jmp    DB  3 dup (?)
+;       name_list   name_struc <>
+;   rom_header  ENDS
+;
+;   name_struc  STRUC
+;       name_len    DB  ?
+;       name_text   DB  ? DUP (?)
+;       name_jmp    DB  3 DUP (?)
+;   name_struc  ENDS
+;
+;   The name list is a list of names that are reserved by a particular section
+;   of a module.  This list of names is terminated by a null name (length
+;   is zero).
+;
+;   Consider now, the PCDOS action when a user enters a command:
+;
+;       COMMAND.COM has control.
+;       o   If location FFFFEh has FDh then
+;       o       Start scanning at C0000h, every 800h for a byte 55h followed
+;                   by AAh, stop scan if we get above or = F0000H
+;       o       When we've found one, compare the name entered by the user
+;                   with the one found in the rom.  If we have a match, then
+;                   set up the environment for execution and do a long jump
+;                   to the near jump after the found name.
+;       o       If no more names in the list, then continue scanning the module
+;                   for more 55h followed by AAh.
+;       o   We get to this point only if there is no matching name in the
+;               rom.  We now look on disk for the command.
+;
+;   This gives us the flexibility to execute any rom cartridge without having
+;   to 'hard-code' the name of the cartridge into PCDOS.  Rom modules that
+;   want to be invisible to the DOS should not have any names in their lists
+;   (i.e. they have a single null name).
+;
+;   Consider a new release of BASIC, say, that patches bugs in the ROM version.
+;   Clearly this version will be available on disk.  How does a user actually
+;   invoke this new BASIC??  He cannot call it BASIC on the disk because the
+;   EXEC loader will execute the ROM before it even looks at the disk!  Only
+;   solution:
+;
+;   o   Keep things consistent and force the user to have his software named
+;       differently from the ROM names (BASIC1, BASIC2, etc).
+
+rom_header  STRUC
+    Signature1  DB  ?
+    Signature2  DB  ?
+    rom_length  DB  ?
+    init_jmp    DB  3 dup (?)
+    name_list   DB  ?
+rom_header  ENDS
+
+name_struc  STRUC
+    name_len    DB  ?
+    name_text   DB  1 DUP (?)
+    name_jmp    DB  3 DUP (?)
+name_struc  ENDS
+
+ASSUME  CS:TRANGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+;
+; Check for IBM HALO rom cartrides. DS:DX is a pointer to name
+;
+ROM_SCAN:
+        PUSH    ES
+        PUSH    SI
+        PUSH    DI
+        PUSH    CX
+        PUSH    AX
+        PUSH    BX
+;
+; check for halo signature in rom
+;
+        MOV     AX,0F000h
+        MOV     ES,AX
+        CMP     BYTE PTR ES:[0FFFEh],0FDh
+        JZ      SCAN_IT
+NO_ROM:
+        CLC
+ROM_RET:
+        POP     BX
+        POP     AX
+        POP     CX
+        POP     DI
+        POP     SI
+        POP     ES
+        RET
+SCAN_IT:
+;
+; start scanning at C000
+;
+        MOV     AX,0C000h
+SCAN_ONE:
+        MOV     ES,AX
+        XOR     DI,DI
+SCAN_MODULE:
+;
+; check for a valid header
+;
+        CMP     WORD PTR ES:[DI],0AA55h
+        JZ      SCAN_LIST
+        ADD     AX,080h
+SCAN_END:
+        CMP     AX,0F000h
+        JB      SCAN_ONE
+        JMP     NO_ROM
+;
+; trundle down list of names
+;
+SCAN_LIST:
+        MOV     BL,ES:[DI].rom_length   ; number of 512-byte jobbers
+        XOR     BH,BH                   ; nothing in the high byte
+        SHL     BX,1
+        SHL     BX,1                    ; number of paragraphs
+        ADD     BX,7Fh
+        AND     BX,0FF80h               ; round to 2k
+
+        MOV     DI,name_list
+SCAN_NAME:
+        MOV     CL,ES:[DI]              ; length of name
+        INC     DI                      ; point to name
+        XOR     CH,CH
+        OR      CX,CX                   ; zero length name
+        JNZ     SCAN_TEST               ; nope... compare
+        ADD     AX,BX                   ; yep, skip to next block
+        JMP     SCAN_END
+;
+; compare a single name
+;
+SCAN_TEST:
+        MOV     SI,DX
+        INC     SI
+        REPE    CMPSB                   ; compare name
+        JZ      SCAN_FOUND              ; success!
+SCAN_NEXT:
+        ADD     DI,CX                   ; failure, next name piece
+        ADD     DI,3
+        JMP     SCAN_NAME
+;
+; found a name. save entry location
+;
+SCAN_FOUND:
+        CMP     BYTE PTR DS:[SI],'?'
+        JZ      SCAN_SAVE
+        CMP     BYTE PTR DS:[SI],' '
+        JNZ     SCAN_NEXT
+SCAN_SAVE:
+        MOV     [rom_cs],ES
+        MOV     [ROM_ip],DI
+        STC
+        JMP     ROM_RET
+
+;
+; execute a rom-placed body of code. allocate largest block
+;
+ROM_EXEC:
+        MOV     BX,0FFFFh
+        MOV     AH,ALLOC
+        INT     int_command
+        MOV     AH,ALLOC
+        INT     int_command
+        PUSH    BX
+        PUSH    AX
+;
+; set terminate addresses
+;
+        MOV     AX,(set_interrupt_vector SHL 8) + int_terminate
+        PUSH    DS
+        MOV     DS,[RESSEG]
+        ASSUME  DS:RESGROUP
+        MOV     DX,OFFSET RESGROUP:EXEC_WAIT
+        INT     int_command
+        MOV     DX,DS
+        MOV     ES,DX
+        ASSUME  ES:RESGROUP
+        POP     DS
+        ASSUME  DS:NOTHING
+;
+; and create program header and dup all jfn's
+;
+        POP     DX
+        MOV     AH,DUP_PDB
+        INT     int_command
+;
+; set up dma address
+;
+        MOV     DS,DX
+        MOV     DX,080h
+        MOV     AH,SET_DMA
+        INT     int_command
+;
+; copy in environment info
+;
+        MOV     AX,[ENVIRSEG]
+        MOV     DS:[PDB_environ],AX
+;
+; set up correct size of block
+;
+        POP     BX                      ; BX has size, DS has segment
+        MOV     DX,DS
+        ADD     DX,BX
+        MOV     DS:[PDB_block_len],DX
+;
+; change ownership of block
+;
+        MOV     DX,DS
+        DEC     DX
+        MOV     DS,DX
+        INC     DX
+        MOV     DS:[arena_owner],DX
+        MOV     DS,DX
+;
+; set up correct stack
+;
+        CMP     BX,1000h
+        JB      GOT_STACK
+        XOR     BX,BX
+GOT_STACK:
+        MOV     CL,4
+        SHL     BX,CL
+        MOV     DX,DS
+        MOV     SS,DX
+        MOV     SP,BX
+        XOR     AX,AX
+        PUSH    AX
+;
+; set up initial registers and go to the guy
+;
+        NOT     AX
+        PUSH    [ROM_CS]
+        PUSH    [ROM_IP]
+        MOV     ES,DX
+ASSUME ES:NOTHING
+FOOBAR  PROC    FAR
+        RET
+FOOBAR  ENDP
diff --git a/v4.0/src/DOS/MSINIT.ASM b/v4.0/src/DOS/MSINIT.ASM
new file mode 100644
index 0000000..cbd9eaf
--- /dev/null
+++ b/v4.0/src/DOS/MSINIT.ASM
@@ -0,0 +1,667 @@
+;       SCCSID = @(#)msinit.asm 1.2 85/07/23
+; TITLE MSINIT.ASM -- MS-DOS INITIALIZATION CODE
+; AN000 version 4.0 Jan. 1988
+; AN007 PTM 3957 - fake version for IBMCACHE.COM
+; AN008 PTM 4070 - fake version for MS WINDOWS
+include sysvar.inc
+include doscntry.inc
+include fastopen.inc
+
+        I_need  DMAAdd,DWORD            ; current dma address
+        I_need  DPBHead,DWORD           ; long pointer to DPB chain
+        I_need  SFT_Addr,DWORD          ; pointer to open file list
+        I_need  NumIO,BYTE              ; number of physical drives
+        I_need  BuffHead,DWORD          ; pointer to buffer chain
+        I_need  EndMem,WORD             ; first unavailable address in memory
+        I_need  CurrentPDB,WORD         ; current process ID
+        I_need  CreatePDB,BYTE          ; TRUE => create a new PDB
+        I_need  Arena_Head,WORD         ; paragraph address of head of arena
+        I_need  sfTabl,BYTE             ; internal file table
+        I_need  SysInitVar,BYTE         ; label for internal structures
+        I_need  NulDev,DWORD            ; long pointer to device chain
+        I_need  BCon,DWORD              ; pointer to console device
+        I_need  BClock,DWORD            ; pointer to clock device
+        I_need  CallUnit,BYTE           ; unit field in dd packet
+        I_need  CallBPB,DWORD           ; returned BPB from DD
+        I_need  Maxsec,WORD
+        I_need  Dskchret,BYTE
+        I_need  Devcall,BYTE
+        i_need  Header,BYTE
+        I_need  JShare,DWORD
+        I_need  COUNTRY_CDPG,BYTE        ; country info table, DOS 3.3
+        I_need  SysInitTable,BYTE        ; sys init table for SYSINIT
+        I_need  FastOpenTable,BYTE       ; table for FASTOPEN
+        I_need  FETCHI_TAG,WORD          ; TAG CHECK
+        I_need  Special_Entries,WORD     ; address of special entries ;AN007;
+        I_need  IFS_DOS_CALL,DWORD       ; IFS IBMDOS CALL entry      ;AN000;
+        I_need  HASHINITVAR,WORD         ; hash table variables       ;AN000;
+        I_need  Packet_Temp,WORD         ; used for initial Hash table;AN000;
+        I_need  BUF_HASH_PTR,DWORD       ; used for initial Hash table;AN000;
+        I_need  SWAP_ALWAYS_AREA,DWORD   ; swap always area addr    ;AN000;
+        I_need  SWAP_ALWAYS_AREA_LEN,WORD; swap always area length  ;AN000;
+        I_need  SWAP_IN_DOS,DWORD        ; swap in dos area         ;AN000;
+        I_need  SWAP_IN_DOS_LEN,WORD     ; swap in dos area length  ;AN000;
+        I_need  SWAP_AREA_LEN,WORD       ; swap area length         ;AN000;
+        I_need  SWAP_START,BYTE          ; swap start addr          ;AN000;
+        I_need  SWAP_ALWAYS,BYTE         ; swap always addr         ;AN000;
+        I_need  Hash_Temp,WORD           ; temporary Hash table     ;AN000;
+
+CODE            SEGMENT BYTE PUBLIC 'CODE'
+        Extrn   IRETT:NEAR,INT2F:NEAR,CALL_ENTRY:NEAR,QUIT:NEAR,IFS_DOSCALL:FAR
+        Extrn   COMMAND:NEAR,ABSDRD:NEAR,ABSDWRT:NEAR
+CODE            ENDS
+
+DATA    SEGMENT WORD PUBLIC 'DATA'
+        ORG     0                       ; reset to beginning of data segment
+
+Public MSINI001S,MSINI001E
+MSINI001S label byte
+INITBLOCK DB    110H DUP(0)     ; Allow for segment round up
+
+INITSP  DW      ?
+INITSS  DW      ?
+MSINI001E label byte
+
+ASSUME  CS:DOSGROUP,SS:NOTHING
+
+MOVDPB:
+        DOSAssume   CS,<DS,ES>,"MovDPB"
+; This section of code is safe from being overwritten by block move
+        MOV     SS,CS:[INITSS]
+        MOV     SP,CS:[INITSP]
+        REP     MOVS    BYTE PTR [DI],[SI]
+        CLD
+        MOV     WORD PTR ES:[DMAADD+2],DX
+        MOV     SI,WORD PTR [DPBHEAD]   ; Address of first DPB
+        MOV     WORD PTR ES:[DPBHEAD+2],ES
+        MOV     WORD PTR ES:[sft_addr+2],ES
+        MOV     CL,[NUMIO]      ; Number of DPBs
+        XOR     CH,CH
+SETFINDPB:
+        MOV     WORD PTR ES:[SI.dpb_next_dpb+2],ES
+        MOV     ES:[SI.dpb_first_access],-1      ; Never accessed before
+        ADD     SI,DPBSIZ       ; Point to next DPB
+        LOOP    SETFINDPB
+        SUB     SI,DPBSIZ
+        MOV     WORD PTR ES:[SI.dpb_next_dpb+2],-1
+
+;;      PUSH    ES
+;;      MOV     DI,OFFSET DOSGroup:SYSBUF + 0Fh
+;;      RCR     DI,1
+;;      SHR     DI,1
+;;      SHR     DI,1
+;;      SHR     DI,1
+;;      MOV     AX,ES
+;;      ADD     AX,DI
+;;      MOV     ES,AX
+;;      ASSUME  ES:NOTHING
+;;      XOR     DI,DI
+
+;       MOV     DI,OFFSET DOSGroup:SYSBUF       ; Set up one default buffer
+;       MOV     WORD PTR [BUFFHEAD+2],ES
+;       MOV     WORD PTR [BUFFHEAD],DI
+;;      MOV     WORD PTR [Hash_Temp+4],ES   ;LB. intitialize one Hash entry   ;AN000;
+;;      MOV     WORD PTR [Hash_Temp+2],DI   ;LB.                              ;AN000;
+;;      MOV     WORD PTR [Hash_Temp+6],0    ;LB. dirty count =0               ;AN000;
+;;      MOV     WORD PTR ES:[DI.buf_ID],00FFH
+;;      MOV     WORD PTR ES:[DI.buf_next],DI  ;;;1/19/88
+;;      MOV     WORD PTR ES:[DI.buf_prev],DI  ;;;1/19/88
+
+;;      POP     ES
+        MOV     SI,OFFSET DOSGROUP:Version_Fake_Table ;MS.;AN007;move special
+        MOV     DI,ES:[Special_Entries]               ;MS.;AN007;entries
+        MOV     CX,ES:[Temp_Var]                      ;MS.;AN007;
+        REP     MOVSB                                 ;MS.;AN007;
+
+        ASSUME  ES:DOSGroup
+
+        PUSH    ES
+        INC     DX                          ; Leave enough room for the ARENA
+        MOV     SI,EndMem
+        invoke  $Dup_PDB
+;       MOV     BYTE PTR [CreatePDB],0FFh   ; create jfns and set CurrentPDB
+;       invoke  $CREATE_PROCESS_DATA_BLOCK     ; Set up segment
+ASSUME  DS:NOTHING,ES:NOTHING
+        POP     ES
+        DOSAssume   CS,<ES>,"INIT/CreateProcess"
+;
+; set up memory arena
+;SPECIAL NOTE FOR HIGHMEM VERSION
+; At this point a process header has been built where the start of the CONSTANTS
+; segment as refed by CS is. From this point until the return below be careful
+; about references off of CS.
+;
+        MOV     AX,[CurrentPDB]
+        MOV     ES:[CurrentPDB],AX         ; Put it in the REAL location
+        MOV     BYTE PTR ES:[CreatePDB],0h ; reset flag in REAL location
+        DEC     AX
+        MOV     ES:[arena_head],AX
+        PUSH    DS
+        MOV     DS,AX
+        MOV     DS:[arena_signature],arena_signature_end
+        MOV     DS:[arena_owner],arena_owner_system
+        SUB     AX,ES:[ENDMEM]
+        NEG     AX
+        DEC     AX
+        MOV     DS:[arena_size],AX
+        POP     DS
+
+        MOV     DI,OFFSET DOSGROUP:sftabl + SFTable   ; Point to sft 0
+        MOV     AX,3
+        STOSW           ; Adjust Refcount
+        MOV     DI,OFFSET DOSGROUP:SySInitTable
+
+        IF      NOT Installed
+        invoke  NETWINIT
+;       ELSE
+;       invoke  NETWINIT
+;       %OUT Random NETWINIT done at install
+        ENDIF
+
+procedure XXX,FAR
+        RET
+EndProc XXX
+DATA    ENDS
+
+; the next segment defines a new class that MUST appear last in the link map.
+; This defines several important locations for the initialization process that
+; must be the first available locations of free memory.
+
+LAST    SEGMENT PARA PUBLIC 'LAST'
+        PUBLIC  SYSBUF
+        PUBLIC  MEMSTRT
+
+SYSBUF  LABEL   WORD
+ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+INITIRET:                       ; Temp IRET instruction
+        IRET
+
+        entry   DOSINIT
+        CLI
+        CLD
+        MOV     [ENDMEM],DX
+        MOV     [INITSP],SP
+        MOV     [INITSS],SS
+        MOV     AX,CS
+        MOV     SS,AX
+ASSUME  SS:DOSGROUP
+        MOV     SP,OFFSET DOSGROUP:INITSTACK
+        MOV     WORD PTR [NULDEV+2],DS
+        MOV     WORD PTR [NULDEV],SI   ; DS:SI Points to CONSOLE Device
+
+        PUSH    DS              ; Need Crit vector inited to use DEVIOCALL
+        XOR     AX,AX
+        MOV     DS,AX
+        MOV     AX,OFFSET DOSGROUP:INITIRET
+        MOV     DS:[addr_int_IBM],AX
+        MOV     AX,CS
+        MOV     DS:[addr_int_IBM+2],AX
+        POP     DS
+
+        CALL    CHARINIT
+        PUSH    SI                      ; Save pointer to header
+        PUSH    CS
+        POP     ES
+        ASSUME  ES:DOSGROUP
+        MOV     DI,OFFSET DOSGROUP:sftabl + SFTable   ; Point to sft 0
+        MOV     AX,3
+        STOSW           ; Refcount
+        DEC     AL
+        errnz   sf_mode-(sf_ref_count+2)
+        STOSW           ; Access rd/wr, compatibility
+        XOR     AL,AL
+        errnz   sf_attr-(sf_mode+2)
+        STOSB           ; attribute
+        MOV     AL,devid_device_EOF OR devid_device OR ISCIN OR ISCOUT
+        errnz   sf_flags-(sf_attr+1)
+        STOSW           ; Flags
+        MOV     AX,SI
+        errnz   sf_devptr-(sf_flags+2)
+        STOSW                   ; Device pointer in devptr
+        MOV     AX,DS
+        STOSW
+        XOR     AX,AX
+        errnz   sf_firclus-(sf_devptr+4)
+        STOSW                   ; firclus
+        errnz   sf_time-(sf_firclus+2)
+        STOSW                   ; time
+        errnz   sf_date-(sf_time+2)
+        STOSW                   ; date
+        DEC     AX
+        errnz   sf_size-(sf_date+2)
+        STOSW                   ; size
+        STOSW
+        INC     AX
+        errnz   sf_position-(sf_size+4)
+        STOSW                   ; position
+        STOSW
+        ADD     DI,sf_name - sf_cluspos ;Point at name
+        ADD     SI,SDEVNAME             ; Point to name
+        MOV     CX,4
+        REP     MOVSW   ; Name
+        MOV     CL,3
+        MOV     AL," "
+        REP     STOSB   ; Extension
+        POP     SI      ; Get back pointer to header
+        OR      BYTE PTR [SI.SDEVATT],ISCIN OR ISCOUT
+        MOV     WORD PTR [BCON],SI
+        MOV     WORD PTR [BCON+2],DS
+CHAR_INIT_LOOP:
+        LDS     SI,DWORD PTR [SI]               ; AUX device
+        CALL    CHARINIT
+        TEST    BYTE PTR [SI.SDEVATT],ISCLOCK
+        JZ      CHAR_INIT_LOOP
+        MOV     WORD PTR [BCLOCK],SI
+        MOV     WORD PTR [BCLOCK+2],DS
+        MOV     BP,OFFSET DOSGROUP:MEMSTRT      ; ES:BP points to DPB
+PERDRV:
+        LDS     SI,DWORD PTR [SI]               ; Next device
+        CMP     SI,-1
+        JZ      CONTINIT
+        CALL    CHARINIT
+        TEST    [SI.SDEVATT],DEVTYP
+        JNZ     PERDRV                          ; Skip any other character devs
+        MOV     CL,[CALLUNIT]
+        XOR     CH,CH
+        MOV     [SI.SDEVNAME],CL                ; Number of units in name field
+        MOV     DL,[NUMIO]
+        XOR     DH,DH
+        ADD     [NUMIO],CL
+        PUSH    DS
+        PUSH    SI
+        LDS     BX,[CALLBPB]
+PERUNIT:
+        MOV     SI,[BX]                 ; DS:SI Points to BPB
+        INC     BX
+        INC     BX                      ; On to next BPB
+        MOV     ES:[BP.dpb_drive],DL
+        MOV     ES:[BP.dpb_UNIT],DH
+        PUSH    BX
+        PUSH    CX
+        PUSH    DX
+        invoke  $SETDPB
+        MOV     AX,ES:[BP.dpb_sector_size]
+        CMP     AX,[MAXSEC]
+        JBE     NOTMAX
+        MOV     [MAXSEC],AX
+NOTMAX:
+
+        POP     DX
+        POP     CX
+        POP     BX
+        MOV     AX,DS                   ; Save DS
+        POP     SI
+        POP     DS
+        MOV     WORD PTR ES:[BP.dpb_driver_addr],SI
+        MOV     WORD PTR ES:[BP.dpb_driver_addr+2],DS
+        PUSH    DS
+        PUSH    SI
+        INC     DH
+        INC     DL
+        MOV     DS,AX
+        ADD     BP,DPBSIZ
+        LOOP    PERUNIT
+        POP     SI
+        POP     DS
+        JMP     PERDRV
+
+CONTINIT:
+        PUSH    CS
+        POP     DS
+ASSUME  DS:DOSGROUP
+;
+; BP has the current offset to the allocated DPBs.  Calculate true address of
+; buffers, FATs, free space
+;
+        MOV     DI,BP                   ; First byte after current DPBs
+;
+; Compute location of first buffer.  If we are to make buffers paragraph
+; aligned, change this code to make sure that AX = 0 mod 16 and change the
+; setting of the segment address part of BuffHead to make sure that the offset
+; is zero.  Alternatively, this may be done by making segment LAST paragraph
+; aligned.
+;
+;;;     MOV     BP,[MAXSEC]             ; get size of buffer
+        MOV     AX,OFFSET DOSGROUP:SYSBUF
+;
+; Compute location of DPBs
+;
+;;;     ADD     AX,BP                   ; One I/O buffer
+;;;     ADD     AX,BUFINSIZ
+        MOV     WORD PTR [DPBHEAD],AX   ; True start of DPBs
+        MOV     DX,AX
+        SUB     DX,OFFSET DOSGROUP:SYSBUF
+        MOV     BP,DX
+        ADD     BP,DI                   ; Allocate buffer space
+        SUB     BP,ADJFAC               ; True address of free memory
+        PUSH    BP
+        MOV     DI,OFFSET DOSGROUP:MEMSTRT    ; Current start of DPBs
+        ADD     DI,dpb_next_dpb         ; Point at dpb_next_dpb field
+        MOV     CL,[NUMIO]
+        XOR     CH,CH
+TRUEDPBAD:
+        ADD     AX,DPBSIZ       ; Compute address of next DPB
+        STOSW                   ; Set the link to next DPB
+        ADD     DI,DPBSIZ-2     ; Point at next address
+        LOOP    TRUEDPBAD
+        SUB     DI,DPBSIZ       ; Point at last dpb_next_dpb field
+        MOV     AX,-1
+        STOSW                   ; End of list
+
+        MOV     [Special_Entries],BP ;MS.;AN007 save starting address of Special entries
+        MOV     SI,OFFSET DOSGROUP:Version_Fake_Table   ;MS.;AN007
+        MOV     DX,SI                ;MS.;AN007
+        XOR     AH,AH                ;MS.;AN007
+NextEntry:                           ;MS.;AN007
+        LODSB                        ;MS.;AN007  get name length
+        OR      AL,AL                ;MS.;AN007  end of list
+        JZ      endlist              ;MS.;AN007  yes
+        ADD     SI,AX                ;MS.;AN007  position to
+        ADD     SI,3                 ;MS.;AN007  next entry
+        JMP     NextEntry            ;MS.;AN007
+endlist:                             ;MS.;AN007
+        SUB     SI,DX                ;MS.;AN007
+        MOV     [Temp_Var],SI        ;MS.;AN007  si = total table length
+        ADD     BP,SI                ;MS.;AN007
+
+
+        ADD     BP,15           ; True start of free space (round up to segment)
+        RCR     BP,1
+        MOV     CL,3
+        SHR     BP,CL           ; Number of segments for DOS resources
+;;;;;;  MOV     [IBMDOS_SIZE],BP ;MS. save it for information
+        MOV     DX,CS
+        ADD     DX,BP           ; First free segment
+        MOV     BX,0FH
+        MOV     CX,[ENDMEM]
+
+        IF      HIGHMEM
+        SUB     CX,BP
+        MOV     BP,CX           ; Segment of DOS
+        MOV     DX,CS           ; Program segment
+        ENDIF
+
+        IF      NOT HIGHMEM
+        MOV     BP,CS
+        ENDIF
+
+; BP has segment of DOS (whether to load high or run in place)
+; DX has program segment (whether after DOS or overlaying DOS)
+; CX has size of memory in paragraphs (reduced by DOS size if HIGHMEM)
+        MOV     [ENDMEM],CX
+        MOV     ES,BP
+ASSUME  ES:DOSGROUP
+
+        IF      HIGHMEM
+        XOR     SI,SI
+        MOV     DI,SI
+        MOV     CX,OFFSET DOSGROUP:SYSBUF  ;# bytes to move
+        SHR     CX,1            ;# words to move (carry set if odd)
+        REP MOVSW               ; Move DOS to high memory
+        JNC     NOTODD
+        MOVSB
+NOTODD:
+        ENDIF
+
+        MOV     WORD PTR ES:[DSKCHRET+3],ES
+        XOR     AX,AX
+        MOV     DS,AX
+        MOV     ES,AX
+ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     DI,INTBASE+2
+        MOV     AX,BP           ; Final DOS segment to AX
+
+        EXTRN   DIVOV:near
+        MOV     WORD PTR DS:[0],OFFSET DOSGROUP:DIVOV   ; Set default divide trap address
+        MOV     DS:[2],AX
+
+; Set vectors 20-28 and 2A-3F to point to IRET.
+
+        MOV     CX,17
+        REP     STOSW           ; Set 9 segments
+                                ;   Sets segs for INTs 20H-28H
+        ADD     DI,6            ; Skip INT 29H vector (FAST CON) as it may
+                                ;   already be set.
+        MOV     CX,43
+        REP     STOSW           ; Set 22 segments
+                                ;   Sets segs for vectors 2AH-3FH
+
+        MOV     DI,INTBASE
+        MOV     AX,OFFSET DOSGROUP:IRETT
+        MOV     CX,9            ; Set 9 offsets (skip 2 between each)
+                                ;   Sets offsets for INTs 20H-28H
+
+ISET1:
+        STOSW
+        ADD     DI,2
+        LOOP    ISET1
+
+        ADD     DI,4            ; Skip vector 29H
+
+        MOV     CX,22           ; Set 22 offsets (skip 2 between each)
+                                ;   Sets offsets for INTs 2AH-3FH
+
+ISET2:
+        STOSW
+        ADD     DI,2
+        LOOP    ISET2
+
+        MOV     AX,BP           ; Final DOS segment to AX
+
+IF installed
+; the following two are in the Code segment, thus the CS
+; overrides
+        MOV     WORD PTR DS:[02FH * 4],OFFSET DOSGROUP:INT2F
+ENDIF
+
+; Set up entry point call at vectors 30-31H
+        MOV     BYTE PTR DS:[ENTRYPOINT],mi_Long_JMP
+        MOV     WORD PTR DS:[ENTRYPOINT+1],OFFSET DOSGROUP:CALL_ENTRY
+        MOV     WORD PTR DS:[ENTRYPOINT+3],AX
+
+        IF      ALTVECT
+        MOV     DI,ALTBASE+2
+        MOV     CX,15
+        REP     STOSW           ; Set 8 segments (skip 2 between each)
+        ENDIF
+
+        MOV     WORD PTR DS:[addr_int_abort],OFFSET DOSGROUP:QUIT
+        MOV     WORD PTR DS:[addr_int_command],OFFSET DOSGROUP:COMMAND
+        MOV     WORD PTR DS:[addr_int_terminate],100H
+        MOV     WORD PTR DS:[addr_int_terminate+2],DX
+        MOV     WORD PTR DS:[addr_int_disk_read],OFFSET DOSGROUP:ABSDRD   ; INT 25
+        MOV     WORD PTR DS:[addr_int_disk_write],OFFSET DOSGROUP:ABSDWRT  ; INT 26
+        EXTRN   Stay_resident:NEAR
+        MOV     WORD PTR DS:[addr_int_keep_process],OFFSET DOSGROUP:Stay_resident
+
+        PUSH    CS
+        POP     DS
+        PUSH    CS
+        POP     ES
+ASSUME  DS:DOSGROUP,ES:DOSGROUP
+;
+; Initialize the jump table for the sharer...
+;
+        MOV     DI,OFFSET DOSGroup:JShare
+        MOV     AX,CS
+        MOV     CX,15
+JumpTabLoop:
+        ADD     DI,2                    ; skip offset
+        STOSW                           ; drop in segment
+        LOOP    JumpTabLoop
+
+        MOV     AX,OFFSET DOSGROUP:INITBLOCK
+        ADD     AX,0Fh                  ; round to a paragraph
+        MOV     CL,4
+        SHR     AX,CL
+        MOV     DI,DS
+        ADD     DI,AX
+        INC     DI
+        MOV     [CurrentPDB],DI
+        PUSH    BP
+        PUSH    DX              ; Save COMMAND address
+        MOV     AX,[ENDMEM]
+        MOV     DX,DI
+
+        invoke  SETMEM          ; Basic Header
+ASSUME  DS:NOTHING,ES:NOTHING
+        PUSH    CS
+        POP     DS
+ASSUME  DS:DOSGROUP
+        MOV     DI,PDB_JFN_Table
+        XOR     AX,AX
+        STOSW
+        STOSB                   ; 0,1 and 2 are CON device
+        MOV     AL,0FFH
+        MOV     CX,FilPerProc - 3
+        REP     STOSB           ; Rest are unused
+        PUSH    CS
+        POP     ES
+ASSUME  ES:DOSGROUP
+        MOV     WORD PTR [sft_addr+2],DS     ; Must be set to print messages
+
+; After this points the char device functions for CON will work for
+; printing messages
+
+        IF      (NOT IBM) OR (DEBUG)
+        IF      NOT ALTVECT
+        MOV     SI,OFFSET DOSGROUP:HEADER
+OUTMES:
+        LODS    CS:BYTE PTR [SI]
+        CMP     AL,"$"
+        JZ      OUTDONE
+        invoke  OUT
+        JMP     SHORT OUTMES
+OUTDONE:
+        PUSH    CS                      ; OUT stomps on segments
+        POP     DS
+        PUSH    CS
+        POP     ES
+        ENDIF
+        ENDIF
+
+;F.C Modification start  DOS 3.3
+        MOV     SI,OFFSET DOSGROUP:COUNTRY_CDPG  ;F.C. for DOS 3.3 country info
+                                                 ; table address
+        MOV     WORD PTR ES:[SI.ccUcase_ptr + 2],ES    ; initialize double word
+        MOV     WORD PTR ES:[SI.ccFileUcase_ptr + 2],ES ; pointers with DOSGROUP
+        MOV     WORD PTR ES:[SI.ccFileChar_ptr + 2],ES
+        MOV     WORD PTR ES:[SI.ccCollate_ptr + 2],ES
+        MOV     WORD PTR ES:[SI.ccMono_ptr + 2],ES
+        MOV     WORD PTR ES:[SI.ccDBCS_ptr + 2],ES      ; 2/16/KK
+
+        MOV     SI,OFFSET DOSGROUP:SysInitTable
+        MOV     WORD PTR ES:[SI.SYSI_Country_Tab + 2],ES
+        MOV     WORD PTR ES:[SI.SYSI_InitVars + 2],ES
+
+        MOV     WORD PTR ES:[BUFFHEAD+2],ES       ;LB. DOS 4.00 buffer head pointer ;AN000;
+        MOV     SI,OFFSET DOSGROUP:HASHINITVAR    ;LB. points to Hashinitvar       ;AN000;
+        MOV     WORD PTR ES:[BUFFHEAD],SI         ;LB.                             ;AN000;
+        MOV     WORD PTR ES:[BUF_HASH_PTR+2],ES   ;LB.                             ;AN000;
+        MOV     SI,OFFSET DOSGROUP:Hash_Temp      ;LB.                             ;AN000;
+        MOV     WORD PTR ES:[BUF_HASH_PTR],SI     ;LB.                             ;AN000;
+
+        MOV     SI,OFFSET DOSGROUP:FastOpenTable
+        MOV     WORD PTR ES:[SI.FASTOPEN_NAME_CACHING + 2],ES
+        MOV     ES:[FETCHI_TAG],22642     ; TAG for IBM,
+                                          ; Fetchi's serial # = 822642
+        MOV     WORD PTR ES:[IFS_DOS_CALL+2],ES   ;IFS.                         ;AN000;
+        MOV     SI,OFFSET DOSGROUP:IFS_DOSCALL    ;IFS.                         ;AN000;
+        MOV     WORD PTR ES:[IFS_DOS_CALL],SI     ;IFS.                         ;AN000;
+
+        MOV     DI,OFFSET DOSGROUP:SWAP_START     ;IFS.                         ;AN000;
+        MOV     CX,OFFSET DOSGROUP:SWAP_END       ;IFS.                         ;AN000;
+        MOV     DX,OFFSET DOSGroup:Swap_Always    ;IFS.                         ;AN000;
+        MOV     BP,CX                   ;IFS.                                   ;AN000;
+        SUB     BP,DI                   ;IFS.                                   ;AN000;
+        SHR     BP,1                    ;IFS. div by 2, remainder in carry      ;AN000;
+        ADC     BP,0                    ;IFS. div by 2 + round up               ;AN000;
+        SHL     BP,1                    ;IFS. round up to 2 boundary.           ;AN000;
+        MOV     ES:[SWAP_AREA_LEN],BP   ;IFS.                                   ;AN000;
+
+        SUB     CX,DX                   ;IFS.                                   ;AN000;
+        SUB     DX,DI                   ;IFS.                                   ;AN000;
+        SHR     CX,1                    ;IFS. div by 2, remainder in carry      ;AN000;
+        ADC     CX,0                    ;IFS. div by 2 + round up               ;AN000;
+        SHL     CX,1                    ;IFS. round up to 2 boundary.           ;AN000;
+        MOV     ES:[SWAP_IN_DOS_LEN],CX             ;IFS.                       ;AN000;
+        MOV     WORD PTR ES:[SWAP_ALWAYS_AREA],DI   ;IFS.                       ;AN000;
+        MOV     WORD PTR ES:[SWAP_ALWAYS_AREA+2],ES ;IFS.                       ;AN000;
+        OR      DX,8000H                            ;IFS.                       ;AN000;
+        MOV     ES:[SWAP_ALWAYS_AREA_LEN],DX        ;IFS.                       ;AN000;
+        MOV     DI,OFFSET DOSGroup:Swap_Always      ;IFS.                       ;AN000;
+        MOV     WORD PTR ES:[SWAP_IN_DOS],DI        ;IFS.                       ;AN000;
+        MOV     WORD PTR ES:[SWAP_IN_DOS+2],ES      ;IFS.                       ;AN000;
+
+
+
+;F.C Modification end    DOS 3.3
+
+; Move the FATs into position
+        POP     DX                      ; Restore COMMAND address
+        POP     BP
+        POP     CX                      ; True address of free memory
+        MOV     SI,OFFSET DOSGROUP:MEMSTRT      ; Place to move DPBs from
+        MOV     DI,WORD PTR [DPBHEAD]   ; Place to move DPBs to
+        SUB     CX,DI                   ; Total length of DPBs
+        CMP     DI,SI
+        JBE     MOVJMP                  ; Are we moving to higher or lower memory?
+        DEC     CX                      ; Move backwards to higher memory
+        ADD     DI,CX
+        ADD     SI,CX
+        INC     CX
+        STD
+MOVJMP:
+        MOV     ES,BP
+ASSUME  ES:DOSGROUP
+        JMP     MOVDPB
+
+CHARINIT:
+ASSUME  DS:NOTHING,ES:NOTHING
+; DS:SI Points to device header
+        MOV     [DEVCALL.REQLEN],DINITHL
+        MOV     [DEVCALL.REQUNIT],0
+        MOV     [DEVCALL.REQFUNC],DEVINIT
+        MOV     [DEVCALL.REQSTAT],0
+        PUSH    ES
+        PUSH    BX
+        PUSH    AX
+        MOV     BX,OFFSET DOSGROUP:DEVCALL
+        PUSH    CS
+        POP     ES
+        invoke  DEVIOCALL2
+        POP     AX
+        POP     BX
+        POP     ES
+        RET
+
+Public MSINI002S,MSINI002E
+MSINI002S label byte
+
+        DB      100H DUP(?)
+INITSTACK LABEL BYTE
+        DW      ?
+        DB      "ADD SPECIAL ENTRIES",0     ;AN007  tiltle
+;The following entries don't expect version 4.0
+;The entry format: name_length, name, expected version, fake count
+;fake_count: ff means the version will be reset when Abort or Exec is encountered
+;            n means the version will be reset after n DOS version calls are issued
+;
+Version_Fake_Table:                         ;AN007  starting address for special
+        DB      12,"IBMCACHE.COM",3,40,255  ;AN007  ibmcache     1
+        DB      12,"IBMCACHE.SYS",3,40,255  ;AN007  ibmcache     2
+        DB      12,"DXMA0MOD.SYS",3,40,255  ;AN007  lan support  3
+        DB      10,"WIN200.BIN"  ,3,40,4    ;AN008  windows      4
+        DB       9,"PSCPG.COM"   ,3,40,255  ;AN008  vittoria     5
+        DB      11,"DCJSS02.EXE" ,3,40,255  ;AN008  netview      6
+        DB       8,"ISAM.EXE"    ,3,40,255  ;AN008  basic        7
+        DB       9,"ISAM2.EXE"   ,3,40,255  ;AN008  basic        8
+        DB      12,"DFIA0MOD.SYS",3,40,255  ;AN008  lan support  9
+        DB      20  dup(0)                  ;AN007
+
+MEMSTRT LABEL   WORD
+MSINI002E label byte
+ADJFAC  EQU     MEMSTRT-SYSBUF
+
+LAST    ENDS
diff --git a/v4.0/src/DOS/MSIOCTL.ASM b/v4.0/src/DOS/MSIOCTL.ASM
new file mode 100644
index 0000000..2117f41
--- /dev/null
+++ b/v4.0/src/DOS/MSIOCTL.ASM
@@ -0,0 +1,5 @@
+;       SCCSID = @(#)IBMIOCTL.INC       1.1 85/04/10

+IBM     EQU     0FFFFH          ;TRUE

+

+INCLUDE IOCTL.INC

+       SCCSID = @(#)IBMIOCTL.INC       1.1 85/04/10

diff --git a/v4.0/src/DOS/MSPROC.ASM b/v4.0/src/DOS/MSPROC.ASM
new file mode 100644
index 0000000..542874f
--- /dev/null
+++ b/v4.0/src/DOS/MSPROC.ASM
@@ -0,0 +1,15 @@
+;       SCCSID = @(#)ibmproc.asm        1.1 85/04/10
+;
+; Pseudo EXEC system call for DOS
+;
+
+.xlist
+.xcref
+include mssw.asm
+.cref
+.list
+
+TITLE   IBMPROC - process maintenance
+NAME    IBMPROC
+
+include proc.asm
diff --git a/v4.0/src/DOS/MSSW.ASM b/v4.0/src/DOS/MSSW.ASM
new file mode 100644
index 0000000..db8eb11
--- /dev/null
+++ b/v4.0/src/DOS/MSSW.ASM
@@ -0,0 +1,27 @@
+;       SCCSID = @(#)ibmsw.asm  1.1 85/04/10
+
+include version.inc
+
+IBM             EQU     ibmver
+WANG            EQU     FALSE
+
+; Set this switch to cause DOS to move itself to the end of memory
+HIGHMEM EQU     FALSE
+
+; Turn on switch below to allow testing disk code with DEBUG. It sets
+; up a different stack for disk I/O (functions > 11) than that used for
+; character I/O which effectively makes the DOS re-entrant.
+
+        IF      IBM
+ESCCH   EQU     0                       ; character to begin escape seq.
+CANCEL  EQU     27                      ;Cancel with escape
+TOGLPRN EQU     TRUE                    ;One key toggles printer echo
+ZEROEXT EQU     TRUE
+        ELSE
+ESCCH   EQU     1BH
+CANCEL  EQU     "X"-"@"                 ;Cancel with Ctrl-X
+TOGLPRN EQU     FALSE                   ;Separate keys for printer echo on
+                                        ;and off
+ZEROEXT EQU     TRUE
+        ENDIF
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MS_CODE.ASM b/v4.0/src/DOS/MS_CODE.ASM
new file mode 100644
index 0000000..1bdd4af
--- /dev/null
+++ b/v4.0/src/DOS/MS_CODE.ASM
@@ -0,0 +1,614 @@
+;       SCCSID = @(#)mscode.asm 1.2 85/07/23
+;
+; MSCODE.ASM -- MSDOS code
+;
+
+.xlist
+.xcref
+include dossym.inc
+include devsym.inc
+include dosseg.asm
+include ifssym.inc
+include fastopen.inc
+include fastxxxx.inc
+.cref
+.list
+
+AsmVars <Kanji, Debug>
+
+CODE    SEGMENT BYTE PUBLIC 'CODE'
+
+ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+    I_need  InDos,BYTE                  ; TRUE => we are in dos, no interrupt
+    I_need  OpenBuf,128                 ; temp name buffer
+    I_need  ExtErr,WORD                 ; extended error code
+    I_need  User_SS,WORD                ; stack segment from user
+    I_need  User_SP,WORD                ; stack pointer from user
+    I_need  DskStack,BYTE               ; stack segment inside DOS
+    I_need  ThisCDS,DWORD               ; Currently referenced CDS pointer
+    I_need  ThisDPB,DWORD               ; Currently referenced DPB pointer
+    I_need  Err_Table_21                ; allowed return map table for errors
+    I_need  FailErr,BYTE                ; TRUE => system call is being failed
+    I_need  ExtErr_Action,BYTE          ; recommended action
+    I_need  ExtErr_Class,BYTE           ; error classification
+    I_need  ExtErr_Locus,BYTE           ; error location
+    I_need  I21_Map_E_Tab,BYTE          ; mapping extended error table
+    I_need  User_In_AX,WORD             ; initial input user AX
+    I_need  FOO,WORD                    ; return address for dos 2f dispatch
+    I_need  DTAB,WORD                   ; dos 2f dispatch table
+    I_need  HIGH_SECTOR,WORD            ; >32mb
+    I_need  IFS_DRIVER_ERR,WORD         ; >32mb
+    I_need  FastOpenFlg,BYTE            ;
+    I_need  FastSeekFlg,BYTE            ;
+    I_need  CURSC_DRIVE,BYTE            ;
+
+BREAK <NullDev -- Driver for null device>
+
+procedure   SNULDEV,FAR
+ASSUME DS:NOTHING,ES:NOTHING,SS:NOTHING
+        OR      ES:[BX.REQSTAT],STDON   ; Set done bit
+entry INULDEV
+        RET                             ; MUST NOT BE A RETURN!
+EndProc SNULDEV
+
+BREAK <AbsDRD, AbsDWRT -- INT int_disk_read, int_disk_write handlers>
+
+
+TABLE   SEGMENT
+Public MSC001S,MSC001E
+MSC001S label byte
+        IF      IBM
+; Codes returned by BIOS
+ERRIN:
+        DB      2                       ; NO RESPONSE
+        DB      6                       ; SEEK FAILURE
+        DB      12                      ; GENERAL ERROR
+        DB      4                       ; BAD CRC
+        DB      8                       ; SECTOR NOT FOUND
+        DB      0                       ; WRITE ATTEMPT ON WRITE-PROTECT DISK
+ERROUT:
+; DISK ERRORS RETURNED FROM INT 25 and 26
+        DB      80H                     ; NO RESPONSE
+        DB      40H                     ; Seek failure
+        DB      2                       ; Address Mark not found
+        DB      10H                     ; BAD CRC
+        DB      4                       ; SECTOR NOT FOUND
+        DB      3                       ; WRITE ATTEMPT TO WRITE-PROTECT DISK
+
+NUMERR  EQU     $-ERROUT
+        ENDIF
+MSC001E label byte
+
+TABLE   ENDS
+
+;   AbsSetup - setup for abs disk functions
+
+Procedure   AbsSetup,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        INC     INDOS
+        STI
+        CLD
+        PUSH    DS
+        Context DS
+        CALL    GETBP
+        JC      errdriv                 ;PM. error drive                        ;AN000;
+        MOV     ES:[BP.dpb_free_cnt],-1 ; do not trust user at all.
+errdriv:
+        POP     DS
+ASSUME  DS:NOTHING
+        retc
+
+        MOV     [HIGH_SECTOR],0         ;>32mb  from API                        ;AN000;
+        CALL    RW32_CONVERT            ;>32mb convert 32bit format to 16bit    ;AN000;
+        retc
+
+        invoke  SET_RQ_SC_PARMS         ;LB. set up SC parms                    ;AN000;
+        PUSH    DS
+        PUSH    SI
+        PUSH    AX
+        Context DS
+        MOV     SI,OFFSET DOSGROUP:OPENBUF
+        MOV     [SI],AL
+        ADD     BYTE PTR [SI],"A"
+        MOV     WORD PTR [SI+1],003AH   ; ":",0
+        MOV     AX,0300H
+        CLC
+        INT     int_IBM                 ; Will set carry if shared
+        POP     AX
+        POP     SI
+        POP     DS
+ASSUME  DS:NOTHING
+        retnc
+        MOV     ExtErr,error_not_supported
+        return
+EndProc AbsSetup
+
+; Interrupt 25 handler.  Performs absolute disk read.
+; Inputs:       AL - 0-based drive number
+;               DS:BX point to destination buffer
+;               CX number of logical sectors to read
+;               DX starting  logical sector number (0-based)
+; Outputs:      Original flags still on stack
+;               Carry set
+;                   AH error from BIOS
+;                   AL same as low byte of DI from INT 24
+
+        procedure   ABSDRD,FAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        CLI
+        MOV     [user_SS],SS
+        MOV     [user_SP],SP
+        PUSH    CS
+        POP     SS
+ASSUME  SS:DOSGROUP
+        MOV     SP,OFFSET DOSGROUP:DSKSTACK
+        invoke  Save_World                    ;>32mb save all regs              ;AN000;
+        PUSH    ES
+        CALL    AbsSetup
+        JC      ILEAVE
+if not ibmcopyright
+; Here is a gross temporary fix to get around a serious design flaw in
+;  the secondary cache.  The secondary cache does not check for media
+;  changed (it should).  Hence, you can change disks, do an absolute
+;  read, and get data from the previous disk.  To get around this,
+;  we just won't use the secondary cache for absolute disk reads.
+;                                                      -mw 8/5/88
+        EnterCrit   critDisk
+        MOV     [CURSC_DRIVE],-1              ; invalidate SC                   ;AN000;
+        LeaveCrit   critDisk
+endif
+        invoke  DSKREAD
+TLEAVE:
+        JZ      ILEAVE
+
+        IF      IBM
+; Translate the error code to ancient 1.1 codes
+        PUSH    ES
+        PUSH    CS
+        POP     ES
+        XOR     AH,AH                   ; Nul error code
+        MOV     CX,NUMERR               ; Number of possible error conditions
+        MOV     DI,OFFSET DOSGROUP:ERRIN    ; Point to error conditions
+        REPNE   SCASB
+        JNZ     LEAVECODE               ; Not found
+        MOV     AH,ES:[DI+NUMERR-1]     ; Get translation
+LEAVECODE:
+        POP     ES
+        ENDIF
+        MOV     [IFS_DRIVER_ERR],AX     ;>32mb save error
+        STC
+ILEAVE:
+        POP     ES
+        invoke  Restore_World                ;>32mb                             ;AN000;
+        CLI
+        DEC     INDOS
+        MOV     SS,[user_SS]
+ASSUME  SS:NOTHING
+        MOV     SP,[user_SP]
+        MOV     AX,[IFS_DRIVER_ERR]          ;>32mb restore error               ;AN000;
+        STI
+        RET                             ; This must not be a RETURN!
+EndProc ABSDRD
+
+; Interrupt 26 handler.  Performs absolute disk write.
+; Inputs:       AL - 0-based drive number
+;               DS:BX point to source buffer
+;               CX number of logical sectors to write
+;               DX starting  logical sector number (0-based)
+; Outputs:      Original flags still on stack
+;               Carry set
+;                   AH error from BIOS
+;                   AL same as low byte of DI from INT 24
+
+        procedure   ABSDWRT,FAR
+ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+
+        CLI
+        MOV     [user_SS],SS
+        MOV     [user_SP],SP
+        PUSH    CS
+        POP     SS
+ASSUME  SS:DOSGROUP
+        MOV     SP,OFFSET DOSGROUP:DSKSTACK
+        invoke  Save_World                    ;>32mb save all regs              ;AN000;
+
+        PUSH    ES
+        CALL    AbsSetup
+        JC      ILEAVE
+
+        EnterCrit   critDisk
+        MOV     [CURSC_DRIVE],-1              ; invalidate SC                   ;AN000;
+        CALL    Fastxxx_Purge                 ; purge fatopen                   ;AN000;
+        LeaveCrit   critDisk
+
+        invoke  DSKWRITE
+        JMP     TLEAVE
+EndProc ABSDWRT
+
+; Inputs:
+;       AL = Logical unit number (A = 0)
+; Function:
+;       Find Drive Parameter Block
+; Outputs:
+;       ES:BP points to DPB
+;       [THISDPB] = ES:BP
+;       Carry set if unit number bad or unit is a NET device.
+;               Later case sets extended error error_I24_not_supported
+; No other registers altered
+
+Procedure GETBP,NEAR
+        DOSAssume   CS,<DS>,"GetBP"
+        ASSUME  ES:NOTHING
+
+        PUSH    AX
+        ADD     AL,1                    ; No increment; need carry flag
+        JC      SkipGet
+        invoke  GetThisDrv
+        JNC     SkipGet                    ;PM. good drive                      ;AN000;
+        XOR     AH,AH                      ;DCR. ax= error code                 ;AN000;
+        CMP     AX,error_not_dos_disk      ;DCR. is unknown media ?             ;AN000;
+        JZ      SkipGet                    ;DCR. yes, let it go                 ;AN000;
+        STC                                ;DCR.                                ;AN000;
+        MOV     ExtErr,AX                  ;PM. invalid drive or Non DOS drive  ;AN000;
+        MOV     [IFS_DRIVER_ERR],0201H     ;PM. other errors/unknown unit       ;AN000;
+SkipGet:
+        POP     AX
+        retc
+        LES     BP,[THISCDS]
+        TEST    ES:[BP.curdir_flags],curdir_isnet   ; Clears carry
+        JZ      GETBP_CDS
+        LES     BP,ES:[BP.curdir_ifs_hdr]           ;IFS. if remote file        ;AN000;
+        TEST    ES:[BP.ifs_attribute],IFSREMOTE     ;IFS.                       ;AN000;
+        LES     BP,[THISCDS]
+        JZ      GETBP_CDS                           ;IFS. then error            ;AN000;
+        MOV     ExtErr,error_not_supported
+        STC
+        return
+
+GETBP_CDS:
+        LES     BP,ES:[BP.curdir_devptr]
+
+        entry   GOTDPB
+        DOSAssume   CS,<DS>,"GotDPB"
+; Load THISDPB from ES:BP
+
+        MOV     WORD PTR [THISDPB],BP
+        MOV     WORD PTR [THISDPB+2],ES
+        return
+EndProc GetBP
+
+BREAK <SYS_RET_OK SYS_RET_ERR CAL_LK ETAB_LK set system call returns>
+
+ASSUME  SS:DOSGROUP
+
+;
+; These are the general system call exit mechanisms.  All internal system
+; calls will transfer (jump) to one of these at the end.  Their sole purpose
+; is to set the user's flags and set his AX register for return.
+;
+
+procedure   SYS_RETURN,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+entry   SYS_RET_OK
+        invoke  FETCHI_CHECK            ; TAG checking for FETCHI
+        invoke  get_user_stack
+        AND     [SI.user_F],NOT f_Carry ; turn off user's carry flag
+        JMP     SHORT DO_RET            ; carry is now clear
+
+entry   SYS_RET_ERR
+        XOR     AH,AH                   ; hack to allow for smaller error rets
+        invoke  ETAB_LK                 ; Make sure code is OK, EXTERR gets set
+        CALL    ErrorMap
+entry   From_GetSet
+        invoke  get_user_stack
+        OR      [SI.user_F],f_Carry     ; signal carry to user
+        STC                             ; also, signal internal error
+DO_RET:
+        MOV     [SI.user_AX],AX         ; Really only sets AH
+        return
+
+        entry   FCB_RET_OK
+        entry   CPMFunc
+        XOR     AL,AL
+        return
+
+        entry   FCB_RET_ERR
+        XOR     AH,AH
+        mov     exterr,AX
+        CALL    ErrorMap
+        MOV     AL,-1
+        return
+
+        entry   errorMap
+        PUSH    SI
+        MOV     SI,OFFSET DOSGROUP:ERR_TABLE_21
+        CMP     [FAILERR],0             ; Check for SPECIAL case.
+        JZ      EXTENDED_NORMAL         ; All is OK.
+        MOV     [EXTERR],error_FAIL_I24 ; Ooops, this is the REAL reason
+        MOV     SI,OFFSET DOSGROUP:ERR_TABLE_21
+EXTENDED_NORMAL:
+        invoke  CAL_LK                  ; Set CLASS,ACTION,LOCUS for EXTERR
+        POP     SI
+        return
+
+EndProc SYS_RETURN
+
+; Inputs:
+;       SI is OFFSET in DOSGROUP of CLASS,ACTION,LOCUS Table to use
+;               (DS NEED not be DOSGROUP)
+;       [EXTERR] is set with error
+; Function:
+;       Look up and set CLASS ACTION and LOCUS values for GetExtendedError
+; Outputs:
+;       [EXTERR_CLASS] set
+;       [EXTERR_ACTION] set
+;       [EXTERR_LOCUS] set  (EXCEPT on certain errors as determined by table)
+; Destroys SI, FLAGS
+
+        procedure   CAL_LK,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS
+        PUSH    AX
+        PUSH    BX
+        Context DS              ; DS:SI -> Table
+        MOV     BX,[EXTERR]     ; Get error in BL
+TABLK1:
+        LODSB
+        CMP     AL,0FFH
+        JZ      GOT_VALS        ; End of table
+        CMP     AL,BL
+        JZ      GOT_VALS        ; Got entry
+        ADD     SI,3            ; Next table entry
+        JMP     TABLK1
+
+GOT_VALS:
+        LODSW                   ; AL is CLASS, AH is ACTION
+        CMP     AH,0FFH
+        JZ      NO_SET_ACT
+        MOV     [EXTERR_ACTION],AH     ; Set ACTION
+NO_SET_ACT:
+        CMP     AL,0FFH
+        JZ      NO_SET_CLS
+        MOV     [EXTERR_CLASS],AL      ; Set CLASS
+NO_SET_CLS:
+        LODSB                   ; Get LOCUS
+        CMP     AL,0FFH
+        JZ      NO_SET_LOC
+        MOV     [EXTERR_LOCUS],AL
+NO_SET_LOC:
+        POP     BX
+        POP     AX
+        POP     DS
+        return
+EndProc CAL_LK
+
+; Inputs:
+;       AX is error code
+;       [USER_IN_AX] has AH value of system call involved
+; Function:
+;       Make sure error code is appropriate to this call.
+; Outputs:
+;       AX MAY be mapped error code
+;       [EXTERR] = Input AX
+; Destroys ONLY AX and FLAGS
+
+        procedure   ETAB_LK,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        PUSH    DS
+        PUSH    SI
+        PUSH    CX
+        PUSH    BX
+        Context DS
+        MOV     [EXTERR],AX             ; Set EXTERR with "real" error
+        MOV     SI,OFFSET DOSGROUP:I21_MAP_E_TAB
+        MOV     BH,AL                   ; Real code to BH
+        MOV     BL,BYTE PTR [USER_IN_AX + 1]    ; Sys call to BL
+TABLK2:
+        LODSW
+        CMP     AL,0FFH                 ; End of table?
+        JZ      NOT_IN_TABLE            ; Yes
+        CMP     AL,BL                   ; Found call?
+        JZ      GOT_CALL                ; Yes
+        XCHG    AH,AL                   ; Count to AL
+        XOR     AH,AH                   ; Make word for add
+        ADD     SI,AX                   ; Next table entry
+        JMP     TABLK2
+
+NOT_IN_TABLE:
+        MOV     AL,BH                   ; Restore original code
+        JMP     SHORT NO_MAP
+
+GOT_CALL:
+        MOV     CL,AH
+        XOR     CH,CH                   ; Count of valid err codes to CX
+CHECK_CODE:
+        LODSB
+        CMP     AL,BH                   ; Code OK?
+        JZ      NO_MAP                  ; Yes
+        LOOP    CHECK_CODE
+NO_MAP:
+        XOR     AH,AH                   ; AX is now valid code
+        POP     BX
+        POP     CX
+        POP     SI
+        POP     DS
+        return
+
+EndProc ETAB_LK
+
+BREAK <DOS 2F Handler and default NET 2F handler>
+
+IF installed
+
+;
+; SetBad sets up info for bad functions
+;
+Procedure   SetBad,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     AX,error_invalid_function       ; ALL NET REQUESTS get inv func
+        MOV     ExtErr_LOCUS,errLoc_UNK
+        STC
+        ret
+EndProc SetBad
+;
+; BadCall is the initial routine for bad function calls
+;
+procedure   BadCall,FAR
+        call    SetBad
+        ret
+EndProc BadCall
+;
+; OKCall always sets carry to off.
+;
+Procedure   OKCall,FAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        CLC
+        ret
+EndProc OKCall
+
+; INT 2F handler works as follows:
+;   PUSH    AX
+;   MOV     AX,multiplex:function
+;   INT     2F
+;   POP     ...
+; The handler itself needs to make the AX available for the various routines.
+
+PUBLIC  Int2F
+INT2F   PROC    FAR
+
+INT2FNT:
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        STI
+        CMP     AH,multNET
+        JNZ     INT2FSHR
+TestInstall:
+        OR      AL,AL
+        JZ      Leave2F
+BadFunc:
+        CALL    SetBad
+        entry   Leave2F
+        RET     2                       ; long return + clear flags off stack
+
+INT2FSHR:
+        CMP     AH,multSHARE            ; is this a share request
+        JZ      TestInstall             ; yes, check for installation
+
+INT2FNLS:
+        CMP     AH,NLSFUNC              ; is this a DOS 3.3 NLSFUNC request
+        JZ      TestInstall             ; yes check for installation
+
+INT2FDOS:
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        CMP     AH,multDOS
+        JZ      DispatchDOS
+        IRET                            ; This assume that we are at the head
+                                        ; of the list
+INT2F   ENDP
+
+DispatchDOS:
+        PUSH    FOO                     ; push return address
+        PUSH    DTab                    ; push table address
+        PUSH    AX                      ; push index
+        PUSH    BP
+        MOV     BP,SP
+; stack looks like:
+;   0   BP
+;   2   DISPATCH
+;   4   TABLE
+;   6   RETURN
+;   8   LONG-RETURN
+;   c   FLAGS
+;   e   AX
+
+        MOV     AX,[BP+0Eh]             ; get AX value
+        POP     BP
+        Invoke  TableDispatch
+        JMP     BadFunc                 ; return indicates invalid function
+
+Procedure   INT2F_etcetera,NEAR
+        entry   DosGetGroup
+        PUSH    CS
+        POP     DS
+        return
+
+        entry   DOSInstall
+        MOV     AL,0FFh
+        return
+EndProc INT2F_etcetera
+
+ENDIF
+;Input: same as ABSDRD and ABSDWRT
+;        ES:BP -> DPB
+;Functions: convert 32bit absolute RW input parms to 16bit input parms
+;Output: carry set when CX=-1 and drive is less then 32mb
+;        carry clear, parms ok
+;
+Procedure   RW32_CONVERT,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        CMP     CX,-1                        ;>32mb  new format ?               ;AN000;
+        JZ      new32format                  ;>32mb  yes                        ;AN000;
+        PUSH    AX                           ;>32mb  save ax                    ;AN000;
+        PUSH    DX                           ;>32mb  save dx                    ;AN000;
+        MOV     AX,ES:[BP.dpb_max_cluster]   ;>32mb  get max cluster #          ;AN000;
+        MOV     DL,ES:[BP.dpb_cluster_mask]  ;>32mb                             ;AN000;
+        CMP     DL,0FEH                      ;>32mb  removable ?                ;AN000;
+        JZ      letold                       ;>32mb  yes                        ;AN000;
+        INC     DL                           ;>32mb                             ;AN000;
+        XOR     DH,DH                        ;>32mb  dx = sector/cluster        ;AN000;
+        MUL     DX                           ;>32mb  dx:ax= max sector #        ;AN000;
+        OR      DX,DX                        ;>32mb  > 32mb ?                   ;AN000;
+letold:
+        POP     DX                           ;>32mb  retore dx                  ;AN000;
+        POP     AX                           ;>32mb  restore ax                 ;AN000;
+        JZ      old_style                    ;>32mb  no                         ;AN000;
+        MOV     [IFS_DRIVER_ERR],0207H       ;>32mb  error                      ;AN000;
+        STC                                  ;>32mb                             ;AN000;
+        return                               ;>32mb                             ;AN000;
+new32format:
+        MOV     DX,WORD PTR [BX.SECTOR_RBA+2];>32mb                             ;AN000;
+        MOV     [HIGH_SECTOR],DX             ;>32mb                             ;AN000;
+        MOV     DX,WORD PTR [BX.SECTOR_RBA]  ;>32mb                             ;AN000;
+        MOV     CX,[BX.ABS_RW_COUNT]         ;>32mb                             ;AN000;
+        LDS     BX,[BX.BUFFER_ADDR]          ;>32mb                             ;AN000;
+old_style:                                   ;>32mb                             ;AN000;
+        CLC                                  ;>32mb                             ;AN000;
+        return                               ;>32mb                             ;AN000;
+EndProc RW32_CONVERT
+
+
+;Input: None
+;Functions: Purge Fastopen/seek Cache Buffers
+;Output: None
+;
+;
+Procedure   Fastxxx_Purge,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        PUSH    AX                            ; save regs.                      ;AN000;
+        PUSH    SI                                                              ;AN000;
+        PUSH    DX                                                              ;AN000;
+        TEST    FastSeekflg,Fast_yes          ; fastseek installed ?            ;AN000;
+        JZ      topen                         ; no                              ;AN000;
+        MOV     AH,FastSeek_ID                ; set fastseek id                 ;AN000;
+        JMP     SHORT dofast                  ;                                 ;AN000;
+topen:
+        TEST    FastOpenflg,Fast_yes          ; fastopen installed ?            ;AN000;
+        JZ      nofast                        ; no                              ;AN000;
+        MOV     AH,FastOpen_ID                ; set fastseek installed          ;AN000;
+dofast:
+        MOV     AL,FONC_purge                 ; purge                           ;AN000;
+        MOV     DL,ES:[BP.dpb_drive]          ; set up drive number             ;AN000;
+        invoke  Fast_Dispatch                 ; call fastopen/seek              ;AN000;
+nofast:
+        POP     DX                                                              ;AN000;
+        POP     SI                            ; restore regs                    ;AN000;
+        POP     AX                            ;                                 ;AN000;
+
+        return                                ; exit                            ;AN000;
+EndProc Fastxxx_Purge
+
+CODE    ENDS
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/MS_TABLE.ASM b/v4.0/src/DOS/MS_TABLE.ASM
new file mode 100644
index 0000000..b5ffac7
--- /dev/null
+++ b/v4.0/src/DOS/MS_TABLE.ASM
@@ -0,0 +1,710 @@
+;       SCCSID = @(#)mstable.asm        1.3 85/07/25
+;       Revision history:
+;         A000   version 4.0  Jan. 1988
+;         A001   DCR 486 - Share installation for >32mb drives
+;         A006   DCR 503 - fake version for IBMCACHE
+;         A008   PTM 4070 - fake version for MS WINDOWS
+.xlist
+.xcref
+include dosseg.asm
+include EA.inc                           ;AN000;; for Extended Attributes
+include fastopen.inc                     ;AN000;; for Extended Attributes
+include dossym.inc
+.cref
+.list
+
+        AsmVars <Kanji, Debug, Redirector, ShareF>
+
+TABLE           SEGMENT BYTE PUBLIC 'TABLE'
+TableZero   LABEL   BYTE
+
+        PUBLIC  MSVERS
+PUBLIC MSTAB001s,MSTAB001e
+MSTAB001S       label byte
+
+MSVERS  EQU     THIS WORD               ; MS-DOS version in hex for $GET_VERSION
+MSMAJOR DB      MAJOR_VERSION
+MSMINOR DB      MINOR_VERSION
+
+        I_am    YRTAB,8,<200,166,200,165,200,165,200,165>   ; [SYSTEM]
+        I_am    MONTAB,12,<31,28,31,30,31,30,31,31,30,31,30,31> ; [SYSTEM]
+
+;
+; This is the error code mapping table for INT 21 errors.  This table defines
+; those error codes which are "allowed" for each system call.  If the error
+; code ABOUT to be returned is not "allowed" for the call, the correct action
+; is to return the "real" error via Extended error, and one of the allowed
+; errors on the actual call.
+;
+; The table is organized as follows:
+;
+;    Each entry in the table is of variable size, but the first
+;       two bytes are always:
+;
+;       Call#,Cnt of bytes following this byte
+;
+; EXAMPLE:
+;       Call 61 (OPEN)
+;
+;       DB      61,5,12,3,2,4,5
+;
+;       61 is the AH INT 21 call value for OPEN.
+;        5 indicates that there are 5 bytes after this byte (12,3,2,4,5).
+;       Next five bytes are those error codes which are "allowed" on OPEN.
+;       The order of these values is not important EXCEPT FOR THE LAST ONE (in
+;       this case 5).  The last value will be the one returned on the call if
+;       the "real" error is not one of the allowed ones.
+;
+; There are a number of calls (for instance all of the FCB calls) for which
+;   there is NO entry.  This means that NO error codes are returned on this
+;   call, so set up an Extended error and leave the current error code alone.
+;
+; The table is terminated by a call value of 0FFh
+
+PUBLIC  I21_MAP_E_TAB
+I21_MAP_E_TAB   LABEL   BYTE
+    DB  International,2,error_invalid_function,error_file_not_found
+    DB  MKDir,3,error_path_not_found,error_file_not_found,error_access_denied
+    DB  RMDir,4,error_current_directory,error_path_not_found
+    DB          error_file_not_found,error_access_denied
+    DB  CHDir,2,error_file_not_found,error_path_not_found
+    DB  Creat,4,error_path_not_found,error_file_not_found
+    DB          error_too_many_open_files
+    DB          error_access_denied
+    DB  Open,6,error_path_not_found,error_file_not_found,error_invalid_access
+    DB          error_too_many_open_files
+    DB          error_not_dos_disk,error_access_denied
+    DB  Close,1,error_invalid_handle
+    DB  Read,2,error_invalid_handle,error_access_denied
+    DB  Write,2,error_invalid_handle,error_access_denied
+    DB  Unlink,3,error_path_not_found,error_file_not_found,error_access_denied
+    DB  LSeek,2,error_invalid_handle,error_invalid_function
+    DB  CHMod,4,error_path_not_found,error_file_not_found,error_invalid_function
+    DB          error_access_denied
+    DB  IOCtl,5,error_invalid_drive,error_invalid_data,error_invalid_function
+    DB          error_invalid_handle,error_access_denied
+    DB  XDup,2,error_invalid_handle,error_too_many_open_files
+    DB  XDup2,2,error_invalid_handle,error_too_many_open_files
+    DB  Current_Dir,2,error_not_DOS_disk,error_invalid_drive
+    DB  Alloc,2,error_arena_trashed,error_not_enough_memory
+    DB  Dealloc,2,error_arena_trashed,error_invalid_block
+    DB  Setblock,3,error_arena_trashed,error_invalid_block,error_not_enough_memory
+    DB  Exec,8,error_path_not_found,error_invalid_function,error_file_not_found
+    DB          error_too_many_open_files,error_bad_format,error_bad_environment
+    DB          error_not_enough_memory,error_access_denied
+    DB  Find_First,3,error_path_not_found,error_file_not_found,error_no_more_files
+    DB  Find_Next,1,error_no_more_files
+    DB  Rename,5,error_not_same_device,error_path_not_found,error_file_not_found
+    DB          error_current_directory,error_access_denied
+    DB  File_Times,4,error_invalid_handle,error_not_enough_memory
+    DB               error_invalid_data,error_invalid_function
+    DB  AllocOper,1,error_invalid_function
+    DB  CreateTempFile,4,error_path_not_found,error_file_not_found
+    DB          error_too_many_open_files,error_access_denied
+    DB  CreateNewFile,5,error_file_exists,error_path_not_found
+    DB          error_file_not_found,error_too_many_open_files,error_access_denied
+    DB  LockOper,4,error_invalid_handle,error_invalid_function
+    DB          error_sharing_buffer_exceeded,error_lock_violation
+    DB  GetExtCntry,2,error_invalid_function,error_file_not_found       ;DOS 3.3
+    DB  GetSetCdPg,2,error_invalid_function,error_file_not_found        ;DOS 3.3
+    DB  Commit,1,error_invalid_handle                                   ;DOS 3.3
+    DB  ExtHandle,3,error_too_many_open_files,error_not_enough_memory
+    DB              error_invalid_function
+    DB  ExtOpen,10
+    DB    error_path_not_found,error_file_not_found,error_invalid_access
+    DB          error_too_many_open_files,error_file_exists,error_not_enough_memory
+    DB          error_not_dos_disk,error_invalid_data
+    DB              error_invalid_function,error_access_denied
+    DB  GetSetMediaID,4,error_invalid_drive,error_invalid_data
+    DB          error_invalid_function,error_access_denied
+    DB  0FFh
+
+;
+; The following table defines CLASS ACTION and LOCUS info for the INT 21H
+; errors.  Each entry is 4 bytes long:
+;
+;       Err#,Class,Action,Locus
+;
+; A value of 0FFh indicates a call specific value (ie.  should already
+; be set).  AN ERROR CODE NOT IN THE TABLE FALLS THROUGH TO THE CATCH ALL AT
+; THE END, IT IS ASSUMES THAT CLASS, ACTION, LOCUS IS ALREADY SET.
+ErrTab  Macro   err,class,action,locus
+ifidn <locus>,<0FFh>
+    DB  error_&err,errCLASS_&class,errACT_&action,0FFh
+ELSE
+    DB  error_&err,errCLASS_&class,errACT_&action,errLOC_&locus
+ENDIF
+ENDM
+
+PUBLIC  ERR_TABLE_21
+ERR_TABLE_21    LABEL   BYTE
+    ErrTab  invalid_function,       Apperr,     Abort,      0FFh
+    ErrTab  file_not_found,         NotFnd,     User,       Disk
+    ErrTab  path_not_found,         NotFnd,     User,       Disk
+    ErrTab  too_many_open_files,    OutRes,     Abort,      Unk
+    ErrTab  access_denied,          Auth,       User,       0FFh
+    ErrTab  invalid_handle,         Apperr,     Abort,      Unk
+    ErrTab  arena_trashed,          Apperr,     Panic,      Mem
+    ErrTab  not_enough_memory,      OutRes,     Abort,      Mem
+    ErrTab  invalid_block,          Apperr,     Abort,      Mem
+    ErrTab  bad_environment,        Apperr,     Abort,      Mem
+    ErrTab  bad_format,             BadFmt,     User,       Unk
+    ErrTab  invalid_access,         Apperr,     Abort,      Unk
+    ErrTab  invalid_data,           BadFmt,     Abort,      Unk
+    ErrTab  invalid_drive,          NotFnd,     User,       Disk
+    ErrTab  current_directory,      Auth,       User,       Disk
+    ErrTab  not_same_device,        Unk,        User,       Disk
+    ErrTab  no_more_files,          NotFnd,     User,       Disk
+    ErrTab  file_exists,            Already,    User,       Disk
+    ErrTab  sharing_violation,      Locked,     DlyRet,     Disk
+    ErrTab  lock_violation,         Locked,     DlyRet,     Disk
+    ErrTab  out_of_structures,      OutRes,     Abort,      0FFh
+    ErrTab  invalid_password,       Auth,       User,       Unk
+    ErrTab  cannot_make,            OutRes,     Abort,      Disk
+    ErrTab  Not_supported,          BadFmt,     User,       Net
+    ErrTab  Already_assigned,       Already,    User,       Net
+    ErrTab  Invalid_Parameter,      BadFmt,     User,       Unk
+    ErrTab  FAIL_I24,               Unk,        Abort,      Unk
+    ErrTab  Sharing_buffer_exceeded,OutRes,     Abort,      Mem
+    ErrTab  Handle_EOF,             OutRes,     Abort,      Unk     ;AN000;
+    ErrTab  Handle_DISK_FULL,       OutRes,     Abort,      Unk     ;AN000;
+    ErrTab  sys_comp_not_loaded,    Unk,        Abort,      Disk    ;AN001;
+    DB      0FFh,                   0FFH,       0FFH,       0FFh
+
+;
+; The following table defines CLASS ACTION and LOCUS info for the INT 24H
+; errors.  Each entry is 4 bytes long:
+;
+;       Err#,Class,Action,Locus
+;
+; A Locus value of 0FFh indicates a call specific value (ie.  should already
+; be set).  AN ERROR CODE NOT IN THE TABLE FALLS THROUGH TO THE CATCH ALL AT
+; THE END.
+
+PUBLIC  ERR_TABLE_24
+ERR_TABLE_24    LABEL   BYTE
+    ErrTab  write_protect,          Media,      IntRet,     Disk
+    ErrTab  bad_unit,               Intrn,      Panic,      Unk
+    ErrTab  not_ready,              HrdFail,    IntRet,     0FFh
+    ErrTab  bad_command,            Intrn,      Panic,      Unk
+    ErrTab  CRC,                    Media,      Abort,      Disk
+    ErrTab  bad_length,             Intrn,      Panic,      Unk
+    ErrTab  Seek,                   HrdFail,    Retry,      Disk
+    ErrTab  not_DOS_disk,           Media,      IntRet,     Disk
+    ErrTab  sector_not_found,       Media,      Abort,      Disk
+    ErrTab  out_of_paper,           TempSit,    IntRet,     SerDev
+    ErrTab  write_fault,            HrdFail,    Abort,      0FFh
+    ErrTab  read_fault,             HrdFail,    Abort,      0FFh
+    ErrTab  gen_failure,            Unk,        Abort,      0FFh
+    ErrTab  sharing_violation,      Locked,     DlyRet,     Disk
+    ErrTab  lock_violation,         Locked,     DlyRet,     Disk
+    ErrTab  wrong_disk,             Media,      IntRet,     Disk
+    ErrTab  not_supported,          BadFmt,     User,       Net
+    ErrTab  FCB_unavailable,        Apperr,     Abort,      Unk
+    ErrTab  Sharing_buffer_exceeded,OutRes,     Abort,      Mem
+    DB      0FFh,                   errCLASS_Unk, errACT_Panic, 0FFh
+
+;
+; We need to map old int 24 errors and device driver errors into the new set
+; of errors.  The following table is indexed by the new errors
+;
+Public  ErrMap24
+ErrMap24    Label   BYTE
+    DB  error_write_protect             ;   0
+    DB  error_bad_unit                  ;   1
+    DB  error_not_ready                 ;   2
+    DB  error_bad_command               ;   3
+    DB  error_CRC                       ;   4
+    DB  error_bad_length                ;   5
+    DB  error_Seek                      ;   6
+    DB  error_not_DOS_disk              ;   7
+    DB  error_sector_not_found          ;   8
+    DB  error_out_of_paper              ;   9
+    DB  error_write_fault               ;   A
+    DB  error_read_fault                ;   B
+    DB  error_gen_failure               ;   C
+    DB  error_gen_failure               ;   D   RESERVED
+    DB  error_gen_failure               ;   E   RESERVED
+    DB  error_wrong_disk                ;   F
+
+Public  ErrMap24End
+ErrMap24End LABEL   BYTE
+
+
+        PUBLIC  DISPATCH,MAXCALL,MAXCOM
+
+MAXCALL DB      VAL1
+MAXCOM  DB      VAL2
+
+; Standard Functions
+DISPATCH    LABEL WORD
+        short_addr  $ABORT                          ;  0      0
+        short_addr  $STD_CON_INPUT                  ;  1      1
+        short_addr  $STD_CON_OUTPUT                 ;  2      2
+        short_addr  $STD_AUX_INPUT                  ;  3      3
+        short_addr  $STD_AUX_OUTPUT                 ;  4      4
+        short_addr  $STD_PRINTER_OUTPUT             ;  5      5
+        short_addr  $RAW_CON_IO                     ;  6      6
+        short_addr  $RAW_CON_INPUT                  ;  7      7
+        short_addr  $STD_CON_INPUT_NO_ECHO          ;  8      8
+        short_addr  $STD_CON_STRING_OUTPUT          ;  9      9
+        short_addr  $STD_CON_STRING_INPUT           ; 10      A
+        short_addr  $STD_CON_INPUT_STATUS           ; 11      B
+        short_addr  $STD_CON_INPUT_FLUSH            ; 12      C
+        short_addr  $DISK_RESET                     ; 13      D
+        short_addr  $SET_DEFAULT_DRIVE              ; 14      E
+        short_addr  $FCB_OPEN                       ; 15      F
+        short_addr  $FCB_CLOSE                      ; 16     10
+        short_addr  $DIR_SEARCH_FIRST               ; 17     11
+        short_addr  $DIR_SEARCH_NEXT                ; 18     12
+        short_addr  $FCB_DELETE                     ; 19     13
+        short_addr  $FCB_SEQ_READ                   ; 20     14
+        short_addr  $FCB_SEQ_WRITE                  ; 21     15
+        short_addr  $FCB_CREATE                     ; 22     16
+        short_addr  $FCB_RENAME                     ; 23     17
+        short_addr  CPMFUNC                         ; 24     18
+        short_addr  $GET_DEFAULT_DRIVE              ; 25     19
+        short_addr  $SET_DMA                        ; 26     1A
+
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $SLEAZEFUNC                     ; 27     1B
+        short_addr  $SLEAZEFUNCDL                   ; 28     1C
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+
+        short_addr  CPMFUNC                         ; 29     1D
+        short_addr  CPMFUNC                         ; 30     1E
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $GET_DEFAULT_DPB                ; 31     1F
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  CPMFUNC                         ; 32     20
+        short_addr  $FCB_RANDOM_READ                ; 33     21
+        short_addr  $FCB_RANDOM_WRITE               ; 34     22
+        short_addr  $GET_FCB_FILE_LENGTH            ; 35     23
+        short_addr  $GET_FCB_POSITION               ; 36     24
+VAL1    =       ($-DISPATCH)/2 - 1
+
+; Extended Functions
+        short_addr  $SET_INTERRUPT_VECTOR           ; 37     25
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $CREATE_PROCESS_DATA_BLOCK      ; 38     26
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  $FCB_RANDOM_READ_BLOCK          ; 39     27
+        short_addr  $FCB_RANDOM_WRITE_BLOCK         ; 40     28
+        short_addr  $PARSE_FILE_DESCRIPTOR          ; 41     29
+        short_addr  $GET_DATE                       ; 42     2A
+        short_addr  $SET_DATE                       ; 43     2B
+        short_addr  $GET_TIME                       ; 44     2C
+        short_addr  $SET_TIME                       ; 45     2D
+        short_addr  $SET_VERIFY_ON_WRITE            ; 46     2E
+
+; Extended functionality group
+        short_addr  $GET_DMA                        ; 47     2F
+        short_addr  $GET_VERSION                    ; 48     30
+        short_addr  $Keep_Process                   ; 49     31
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $GET_DPB                        ; 50     32
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  $SET_CTRL_C_TRAPPING            ; 51     33
+        short_addr  $GET_INDOS_FLAG                 ; 52     34
+        short_addr  $GET_INTERRUPT_VECTOR           ; 53     35
+        short_addr  $GET_DRIVE_FREESPACE            ; 54     36
+        short_addr  $CHAR_OPER                      ; 55     37
+        short_addr  $INTERNATIONAL                  ; 56     38
+; XENIX CALLS
+;   Directory Group
+        short_addr  $MKDIR                          ; 57     39
+        short_addr  $RMDIR                          ; 58     3A
+        short_addr  $CHDIR                          ; 59     3B
+;   File Group
+        short_addr  $CREAT                          ; 60     3C
+        short_addr  $OPEN                           ; 61     3D
+        short_addr  $CLOSE                          ; 62     3E
+        short_addr  $READ                           ; 63     3F
+        short_addr  $WRITE                          ; 64     40
+        short_addr  $UNLINK                         ; 65     41
+        short_addr  $LSEEK                          ; 66     42
+        short_addr  $CHMOD                          ; 67     43
+        short_addr  $IOCTL                          ; 68     44
+        short_addr  $DUP                            ; 69     45
+        short_addr  $DUP2                           ; 70     46
+        short_addr  $CURRENT_DIR                    ; 71     47
+;    Memory Group
+        short_addr  $ALLOC                          ; 72     48
+        short_addr  $DEALLOC                        ; 73     49
+        short_addr  $SETBLOCK                       ; 74     4A
+;    Process Group
+        short_addr  $EXEC                           ; 75     4B
+        short_addr  $EXIT                           ; 76     4C
+        short_addr  $WAIT                           ; 77     4D
+        short_addr  $FIND_FIRST                     ; 78     4E
+;   Special Group
+        short_addr  $FIND_NEXT                      ; 79     4F
+; SPECIAL SYSTEM GROUP
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $SET_CURRENT_PDB                ; 80     50
+        short_addr  $GET_CURRENT_PDB                ; 81     51
+        short_addr  $GET_IN_VARS                    ; 82     52
+        short_addr  $SETDPB                         ; 83     53
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  $GET_VERIFY_ON_WRITE            ; 84     54
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $DUP_PDB                        ; 85     55
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  $RENAME                         ; 86     56
+        short_addr  $FILE_TIMES                     ; 87     57
+        short_addr  $AllocOper                      ; 88     58
+; Network extention system calls
+        short_addr  $GetExtendedError               ; 89     59
+        short_addr  $CreateTempFile                 ; 90     5A
+        short_addr  $CreateNewFile                  ; 91     5B
+        short_addr  $LockOper                       ; 92     5C
+        short_addr  $ServerCall                     ; 93     5D
+        short_addr  $UserOper                       ; 94     5E
+        short_addr  $AssignOper                     ; 95     5F
+        short_addr  $NameTrans                      ; 96     60
+        short_addr  CPMFunc                         ; 97     61
+        short_addr  $Get_Current_PDB                ; 98     62
+; the next call is reserved for hangool sys call
+        short_addr  $ECS_Call                       ; 99     63
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;                                                                          ;
+        short_addr  $Set_Printer_Flag               ; 100    64
+;                                                                          ;
+;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+        short_addr  $GetExtCntry                    ; 101    65
+        short_addr  $GetSetCdPg                     ; 102    66
+        short_addr  $ExtHandle                      ; 103    67
+        short_addr  $Commit                         ; 104    68
+        short_addr  $GSetMediaID                    ; 105    69   ;AN000;
+        short_addr  $Commit                         ; 106    6A   ;AN000;
+        short_addr  $IFS_IOCTL                      ; 107    6B   ;AN000;
+        short_addr  $Extended_Open                  ; 108    6C   ;AN000;
+;
+VAL2    =       ($-DISPATCH)/2 - 1
+
+
+        If      Installed
+
+PUBLIC FOO
+FOO     LABEL WORD
+        Short_addr  Leave2F
+DTab    DW  OFFSET  DOSGroup:DOSTable
+        PUBLIC FOO,DTAB
+
+DOSTable    LABEL   WORD
+        DB      (DOSTableEnd-DOSTable-1)/2
+        Short_addr  DOSInstall          ;   0 install check
+        Short_addr  DOS_CLOSE           ;   1   DOS_CLOSE
+        Short_addr  RECSET              ;   2   RECSET
+        Short_addr  DOSGetGroup         ;   3   Get DOSGROUP
+        Short_addr  PATHCHRCMP          ;   4   PATHCHRCMP
+        Short_addr  OUTT                ;   5   OUT
+        Short_addr  NET_I24_ENTRY       ;   6   NET_I24_ENTRY
+        Short_addr  PLACEBUF            ;   7   PLACEBUF
+        Short_addr  FREE_SFT            ;   8   FREE_SFT
+        Short_addr  BUFWRITE            ;   9   BUFWRITE
+        Short_addr  SHARE_VIOLATION     ;   10  SHARE_VIOLATION
+        Short_addr  SHARE_ERROR         ;   11  SHARE_ERROR
+        Short_addr  SET_SFT_MODE        ;   12  SET_SFT_MODE
+        Short_addr  DATE16              ;   13  DATE16
+        Short_addr  idle                ;   14      empty slot
+        Short_addr  SCANPLACE           ;   15  SCANPLACE
+        Short_addr  idle                ;   16      empty slot
+        Short_addr  StrCpy              ;   17  StrCpy
+        Short_addr  StrLen              ;   18  StrLen
+        Short_addr  Ucase               ;   19  Ucase
+        Short_addr  POINTCOMP           ;   20  POINTCOMP
+        Short_addr  CHECKFLUSH          ;   21  CHECKFLUSH
+        Short_addr  SFFromSFN           ;   22  SFFromSFN
+        Short_addr  GetCDSFromDrv       ;   23  GetCDSFromDrv
+        Short_addr  Get_User_Stack      ;   24  Get_User_Stack
+        Short_addr  GetThisDrv          ;   25  GetThisDrv
+        Short_addr  DriveFromText       ;   26  DriveFromText
+        Short_addr  SETYEAR             ;   27  SETYEAR
+        Short_addr  DSUM                ;   28  DSUM
+        Short_addr  DSLIDE              ;   29  DSLIDE
+        Short_addr  StrCmp              ;   30  StrCmp
+        Short_addr  InitCDS             ;   31  initcds
+        Short_addr  pJFNFromHandle      ;   32  pJfnFromHandle
+        Short_addr  $NameTrans          ;   33  $NameTrans
+        Short_addr  CAL_LK              ;   34  CAL_LK
+        Short_addr  DEVNAME             ;   35  DEVNAME
+        Short_addr  Idle                ;   36  Idle
+        Short_addr  DStrLen             ;   37  DStrLen
+        Short_addr  NLS_OPEN            ;   38  NLS_OPEN      DOS 3.3
+        Short_addr  $CLOSE              ;   39  $CLOSE        DOS 3.3
+        Short_addr  NLS_LSEEK           ;   40  NLS_LSEEK     DOS 3.3
+        Short_addr  $READ               ;   41  $READ         DOS 3.3
+        Short_addr  FastInit            ;   42  FastInit      DOS 3.4  ;AN000;
+        Short_addr  NLS_IOCTL           ;   43  NLS_IOCTL     DOS 3.3
+        Short_addr  GetDevList          ;   44  GetDevList    DOS 3.3
+        Short_addr  NLS_GETEXT          ;   45  NLS_GETEXT    DOS 3.3
+        Short_addr  MSG_RETRIEVAL       ;   46  MSG_RETRIEVAL DOS 4.0  ;AN000;
+        Short_addr  Fake_Version        ;   47  Fake_Version  DOS 4.0  ;AN006;
+
+DOSTableEnd LABEL   BYTE
+
+        ENDIF
+
+; NOTE WARNING: This declaration of HEADER must be THE LAST thing in this
+;       module. The reason is so that the data alignments are the same in
+;       IBM-DOS and MS-DOS up through header.
+;---------------------------------------Start of Korean support  2/11/KK
+;
+; The varialbes for ECS version are moved here for the same data alignments
+; as IBM-DOS and MS-DOS.
+;
+
+        I_AM    InterChar, byte         ; Interim character flag ( 1= interim)  ;AN000;
+                                                                                ;AN000;
+;------- NOTE: NEXT TWO BYTES SOMETIMES USED AS A WORD !! ---------------------
+DUMMY   LABEL   WORD                                                            ;AN000;
+        PUBLIC  InterCon                ; Console in Interim mode ( 1= interim) ;AN000;
+InterCon        db      0                                                       ;AN000;
+        PUBLIC  SaveCurFlg              ; Print, do not advance cursor flag     ;AN000;
+SaveCurFlg      db      0                                                       ;AN000;
+;-----------------------------------------End of Korean support  2/11/KK
+
+
+        PUBLIC  HEADER
+Header  LABEL   BYTE
+        IF      DEBUG
+        DB      13,10,"Debugging DOS version "
+        DB      MAJOR_VERSION + "0"
+        DB      "."
+        DB      (MINOR_VERSION / 10) + "0"
+        DB      (MINOR_VERSION MOD 10) + "0"
+        ENDIF
+
+        IF      NOT IBM
+        DB      13,10,"MS-DOS version "
+        DB      MAJOR_VERSION + "0"
+        DB      "."
+        DB      (MINOR_VERSION / 10) + "0"
+        DB      (MINOR_VERSION MOD 10) + "0"
+
+        IF      HIGHMEM
+        DB      "H"
+        ENDIF
+
+        DB      13,10, "Copyright 1981,82,83,84,88 Microsoft Corp.",13,10,"$"
+        ENDIF
+
+IF DEBUG
+        DB      13,10,"$"
+ENDIF
+
+MSTAB001E       label byte
+
+include copyrigh.inc                                                            ;AN000;
+
+; SYS init extended table,   DOS 3.3   F.C. 5/29/86
+;
+       PUBLIC   SysInitTable
+       I_need   COUNTRY_CDPG,BYTE
+       I_need   SYSINITVAR,BYTE
+
+SysInitTable  label  byte
+               dw      OFFSET DOSGROUP:SYSINITVAR    ; pointer to sysinit var
+               dw      0                             ; segment
+               dw      OFFSET DOSGROUP:COUNTRY_CDPG  ; pointer to country table
+               dw      0                             ; segment of pointer
+; DOS 3.3 F.C. 6/12/86
+
+; FASTOPEN communications area DOS 3.3   F.C. 5/29/86
+;
+       PUBLIC   FastOpenTable
+       PUBLIC   FastTable                            ; a better name
+       EXTRN    FastRet:FAR                          ; defined in misc2.asm
+
+FastTable      label  byte                           ; a better name
+FastOpenTable  label  byte
+               dw      2                             ; number of entries
+               dw      OFFSET DOSGROUP:FastRet       ; pointer to ret instr.
+               dw      0                             ; and will be modified by
+               dw      OFFSET DOSGROUP:FastRet       ; FASTxxx when loaded in
+               dw      0                             ;
+; DOS 3.3 F.C. 6/12/86
+      PUBLIC   FastFlg                  ;AN000; flags
+FastFlg        label  byte              ;AN000; don't change the following order
+        I_am   FastOpenFlg,BYTE,<0>     ;AN000;
+        I_am   FastSeekFlg,BYTE,<0>     ;AN000;
+
+       PUBLIC   FastOpen_Ext_Info
+
+; FastOpen_Ext_Info is used as a temporary storage for saving dirpos,dirsec
+; and clusnum  which are filled by DOS 3.3 when calling FastOpen Insert
+; or filled by FastOPen when calling FastOpen Lookup
+
+FastOpen_Ext_Info  label  byte
+               db   SIZE FASTOPEN_EXTENDED_INFO dup(0) ;dirpos
+
+; Dir_Info_Buff is a dir entry buffer which is filled by FastOPen
+; when calling FastOpen Lookup
+
+       PUBLIC  Dir_Info_Buff
+
+Dir_Info_Buff  label  byte
+               db   SIZE dir_entry dup (0)
+
+
+      I_am     Next_Element_Start,WORD  ; save next element start offset
+
+; Following 4 variables moved to MSDATA.asm  (P4986)
+;     I_am     FSeek_drive,BYTE         ;AN000; fastseek drive #
+;     I_am     FSeek_firclus,WORD       ;AN000; fastseek first cluster #
+;     I_am     FSeek_logclus,WORD       ;AN000; fastseek logical cluster #
+;     I_am     FSeek_logsave,WORD       ;AN000; fastseek returned log clus #
+
+; The following is a stack and its pointer for interrupt 2F which is uesd
+; by NLSFUNC.  There is no significant use of this stack, we are just trying
+; not to destroy the INT 21 stack saved for the user.
+
+
+       PUBLIC   User_SP_2F
+
+USER_SP_2F       LABEL  WORD
+                dw    OFFSET DOSGROUP:FAKE_STACK_2F
+
+       PUBLIC   Packet_Temp
+Packet_Temp      label  word             ; temporary packet used by readtime
+       PUBLIC   DOS_TEMP                 ; temporary word
+DOS_TEMP         label  word
+FAKE_STACK_2F   dw   14 dup (0)          ; 12 register temporary storage
+
+       PUBLIC   Hash_Temp                ;AN000; temporary word
+Hash_Temp        label  word             ;AN000;
+                dw    4 dup (0)          ;AN000; temporary hash table during config.sys
+
+      PUBLIC   SCAN_FLAG                 ; flag to indicate key ALT_Q
+SCAN_FLAG      label  byte
+               db     0
+;;; The following  2 words must be adjacent for IBMDOS reasons
+
+      PUBLIC   DATE_FLAG
+DATE_FLAG      label  word               ; flag to
+               dw     0                  ; to update the date
+;;;; special tag for IBMDOS
+      PUBLIC   FETCHI_TAG
+FETCHI_TAG     label  word               ; TAG to make DOS 3.3 work
+               dw     0                  ; must be 22642
+;;; The above  2 words must be adjacent for IBMDOS reasons
+; DOS 3.3 F.C. 6/12/86
+      I_am     Del_ExtCluster,WORD       ; for dos_delete                       ;AN000;
+
+      PUBLIC   MSG_EXTERROR              ; for system message addr              ;AN000;
+MSG_EXTERROR   label  DWORD                                                     ;AN000;
+               dd     0                  ; for extended error                   ;AN000;
+               dd     0                  ; for parser                           ;AN000;
+               dd     0                  ; for critical errror                  ;AN000;
+               dd     0                  ; for IFS                              ;AN000;
+               dd     0                  ; for code reduction                   ;AN000;
+
+      PUBLIC   SEQ_SECTOR                ; last sector read                     ;AN000;
+SEQ_SECTOR     label  DWORD                                                     ;AN000;
+               dd     -1                                                        ;AN000;
+
+      I_am     XA_CONDITION,BYTE,<0>     ; for Extended Attributes              ;AN000;
+;     I_am     XA_ES,WORD                ; for extended find                    ;AN000;
+;     I_am     XA_BP,WORD                ; for extended find                    ;AN000;
+;     I_am     XA_handle,WORD            ; for get/set EA                       ;AN000;
+      I_am     XA_type,BYTE              ; for get/set EA                       ;AN000;
+;     I_am     XA_device,BYTE            ; for get/set EA                       ;AN000;
+      I_am     XA_from,BYTE              ; for get/set EA                       ;AN000;
+;     I_am     XA_VAR,WORD               ; for get/set EA                       ;AN000;
+;     I_am     XA_TEMP,WORD              ; for get/set EA                       ;AN000;
+;     I_am     XA_TEMP2,WORD             ; for get/set EA                       ;AN000;
+;
+
+;     I_am     MAX_EA_SIZE,WORD,<29>     ; max EA list size                     ;AN000;
+;     I_am     MAX_EANAME_SIZE,WORD,<20> ; max EA name list size                ;AN000;
+;     I_am     XA_COUNT,WORD,<2>         ; number of EA entries                 ;AN000;
+
+
+;     PUBLIC   XA_TABLE                       ; for get/set EA                  ;AN000;
+;
+;XA_TABLE       label  byte                                                      ;AN000;
+;              db EAISBINARY                                       ;Code Page   ;AN000;
+;              dw EASYSTEM                                                      ;AN000;
+;              db 0,2                                                           ;AN000;
+;              dw 2                                                             ;AN000;
+;              db 'CP'                                                          ;AN000;
+;
+;              db EAISBINARY                                       ;File Type   ;AN000;
+;              dw EASYSTEM                                                      ;AN000;
+;              db 0,8                                                           ;AN000;
+;              dw 1                                                             ;AN000;
+;              db 'FILETYPE'                                                    ;AN000;
+;
+
+;         PUBLIC XA_PACKET                                                            ;AN000;
+;XA_PACKET        label byte                                                           ;AN000;
+;IF  DBCS                                                                             ;AN000;
+;                dw   18                                                              ;AN000;
+;                db   18 dup(0)                                                       ;AN000;
+;         PUBLIC DBCS_PACKET                                                          ;AN000;
+;DBCS_PACKET      label byte                                                           ;AN000;
+;                db   5 dup(0)
+;ELSE
+;                dw   2, 0                       ; get/set device code page           ;AN000;
+;ENDIF
+        I_am    CurHashEntry,DWORD               ; current hash buffer entry          ;AN000;
+;;      I_am    ACT_PAGE,WORD,<-1>               ;BL ; active EMS page                       ;AN000;
+        I_am    SC_SECTOR_SIZE,WORD              ; sector size for SC                 ;AN000;
+        I_am    SC_DRIVE,BYTE                    ; drive # for secondary cache        ;AN000;
+        I_am    CurSC_DRIVE,BYTE,<-1>            ; current SC drive                   ;AN000;
+        I_am    CurSC_SECTOR,DWORD               ; current SC starting sector         ;AN000;
+        I_am    SC_STATUS,WORD,<0>               ; SC status word                     ;AN000;
+        I_am    SC_FLAG,BYTE,<0>                 ; SC flag                            ;AN000;
+        I_am    IFS_DRIVER_ERR,WORD,<0>          ; driver error for IFS               ;AN000;
+
+          PUBLIC NO_NAME_ID                                                           ;AN000;
+NO_NAME_ID       label byte                                                           ;AN000;
+                 db   'NO NAME    '              ; null media id                      ;AN000;
+
+          PUBLIC SWAP_AREA_TABLE                                                      ;AN000;
+SWAP_AREA_TABLE  label byte                                                           ;AN000;
+        I_am    NUM_SWAP_AREA,WORD,<2>           ; number of swap areas               ;AN000;
+        I_am    SWAP_IN_DOS,DWORD                ; swap in dos area                   ;AN000;
+        I_am    SWAP_IN_DOS_LEN,WORD             ; swap in dos area length            ;AN000;
+        I_am    SWAP_ALWAYS_AREA,DWORD           ; swap always area                   ;AN000;
+        I_am    SWAP_ALWAYS_AREA_LEN,WORD        ; swap always area length            ;AN000;
+        I_am    IFSFUNC_SWAP_IN_DOS,DWORD        ; ifsfunc swap in dos area           ;AN000;
+        I_am    IFSFUNC_SWAP_IN_DOS_LEN,WORD     ; ifsfunc swap in dos area length    ;AN000;
+
+        I_am    SWAP_AREA_LEN,WORD               ; swap area length                   ;AN000;
+        I_am    FIRST_BUFF_ADDR,WORD             ; first buffer address               ;AN000;
+        I_am    SPECIAL_VERSION,WORD,<0>         ;AN006; used by INT 2F 47H
+        I_am    FAKE_COUNT,<255>                 ;AN008; fake version count
+        I_am    OLD_FIRSTCLUS,WORD               ;AN011; save old first cluster for fastopen
+
+TABLE   ENDS
+
+
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/NSTDOS.ASM b/v4.0/src/DOS/NSTDOS.ASM
new file mode 100644
index 0000000..f35055f
--- /dev/null
+++ b/v4.0/src/DOS/NSTDOS.ASM
@@ -0,0 +1,7 @@
+;       SCCSID = @(#)nstdos.asm 1.1 85/04/10
+TITLE   MS-DOS
+NAME    MSDOS_3
+
+include stdsw.asm
+include msconst.asm
+        END
diff --git a/v4.0/src/DOS/OPEN.ASM b/v4.0/src/DOS/OPEN.ASM
new file mode 100644
index 0000000..ab9b4c1
--- /dev/null
+++ b/v4.0/src/DOS/OPEN.ASM
@@ -0,0 +1,569 @@
+;       SCCSID = @(#)open.asm   1.1 85/04/10
+TITLE   DOS_OPEN - Internal OPEN call for MS-DOS
+NAME    DOS_OPEN
+; Low level routines for openning a file from a file spec.
+;   Also misc routines for sharing errors
+;
+;   DOS_Open
+;   Check_Access_AX
+;   SHARE_ERROR
+;   SET_SFT_MODE
+;   Code_Page_Mismatched_Error             ; DOS 4.00
+;
+;   Revision history:
+;
+;       Created: ARR 30 March 1983
+;       A000    version 4.00   Jan. 1988
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+include dossym.inc
+include devsym.inc
+include fastopen.inc
+include fastxxxx.inc                   ;AN000;
+include ifssym.inc                     ;AN000;
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  NoSetDir,BYTE
+        i_need  THISSFT,DWORD
+        i_need  THISCDS,DWORD
+        i_need  CURBUF,DWORD
+        i_need  CurrentPDB,WORD
+        i_need  CURR_DIR_END,WORD
+        I_need  RetryCount,WORD
+        I_need  Open_Access,BYTE
+        I_need  fSharing,BYTE
+        i_need  JShare,DWORD
+        I_need  FastOpenFlg,byte
+        I_need  EXTOPEN_ON,BYTE                   ;AN000;; DOS 4.00
+        I_need  ALLOWED,BYTE                      ;AN000;; DOS 4.00
+        I_need  EXTERR,WORD                       ;AN000;; DOS 4.00
+        I_need  EXTERR_LOCUS,BYTE                 ;AN000;; DOS 4.00
+        I_need  EXTERR_ACTION,BYTE                ;AN000;; DOS 4.00
+        I_need  EXTERR_CLASS,BYTE                 ;AN000;; DOS 4.00
+        I_need  CPSWFLAG,BYTE                     ;AN000;; DOS 4.00
+        I_need  EXITHOLD,DWORD                    ;AN000;; DOS 4.00
+        I_need  THISDPB,DWORD                     ;AN000;; DOS 4.00
+        I_need  SAVE_CX,WORD                      ;AN000;; DOS 4.00
+
+Break   <DOS_Open - internal file access>
+
+; Inputs:
+;       [WFP_START] Points to WFP string ("d:/" must be first 3 chars, NUL
+;               terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [THISSFT] Points to SFT to fill in if file found
+;               (sf_mode field set so that FCB may be detected)
+;       [SATTRIB] Is attribute of search, determines what files can be found
+;       AX is Access and Sharing mode
+;         High NIBBLE of AL (Sharing Mode)
+;               sharing_compat     file is opened in compatibility mode
+;               sharing_deny_none  file is opened Multi reader, Multi writer
+;               sharing_deny_read  file is opened Only reader, Multi writer
+;               sharing_deny_write file is opened Multi reader, Only writer
+;               sharing_deny_both  file is opened Only reader, Only writer
+;         Low NIBBLE of AL (Access Mode)
+;               open_for_read   file is opened for reading
+;               open_for_write  file is opened for writing
+;               open_for_both   file is opened for both reading and writing.
+;
+;         For FCB SFTs AL should = sharing_compat + open_for_both
+;               (not checked)
+; Function:
+;       Try to open the specified file
+; Outputs:
+;       sf_ref_count is NOT altered
+;       CARRY CLEAR
+;           THISSFT filled in.
+;       CARRY SET
+;           AX is error code
+;               error_file_not_found
+;                       Last element of path not found
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;               error_invalid_access
+;                       Bad sharing mode or bad access mode or bad combination
+;               error_access_denied
+;                       Attempt to open read only file for writting, or
+;                       open a directory
+;               error_sharing_violation
+;                       The sharing mode was correct but not allowed
+;                       generates an INT 24 on compatibility mode SFTs
+; DS preserved, others destroyed
+
+        procedure   DOS_Open,NEAR
+        DOSAssume   CS,<DS>,"DOS_Open"
+        ASSUME  ES:NOTHING
+
+        MOV     [NoSetDir],0
+        CALL    Check_Access_AX
+        retc
+        LES     DI,[THISSFT]
+        XOR     AH,AH
+; sleaze! move only access/sharing mode in.  Leave sf_isFCB unchanged
+        MOV     BYTE PTR ES:[DI.sf_mode],AL ; For moment do this on FCBs too
+        PUSH    ES
+        LES     SI,[THISCDS]
+        CMP     SI,-1
+        JNZ     TEST_RE_NET
+        POP     ES
+;Extended open hooks
+
+        TEST    [EXTOPEN_ON],ext_open_on    ;FT. from extnded open              ;AN000;
+        JZ      NOEXTOP                     ;FT. no, do normal                  ;AN000;
+IFS_extopen:                                                                    ;AN000;
+        MOV     AL,byte ptr [SAVE_CX]       ;FT. al= create attribute           ;AN000;
+        PUSH    AX                          ;FT. pass create attr to IFS        ;AN000;
+        MOV     AX,(multNET SHL 8) OR 46    ;FT. issue extended open verb       ;AN000;
+        INT     2FH                         ;FT.                                ;AN000;
+        POP     BX                          ;FT. trash bx                       ;AN000;
+        MOV     [EXTOPEN_ON],0              ;FT.                                ;AN000;
+        JNC     update_size                 ;IFS. file may be opened            ;AN000;
+        return                              ;FT.                                ;AN000;
+NOEXTOP:
+;Extended open hooks
+
+
+IF NOT Installed
+        transfer NET_SEQ_OPEN
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 22
+        INT     2FH
+        POP     BX                      ; clean stack
+        return
+ENDIF
+
+TEST_RE_NET:
+        TEST    ES:[SI.curdir_flags],curdir_isnet
+        POP     ES
+        JZ      LOCAL_OPEN
+;       CALL    IFS_SHARE_CHECK         ;IFS. check IFS share,may create share  ;AN000;
+;       JC      nomore                  ;IFS. share violation                   ;AN000;
+;Extended open hooks
+
+        TEST    [EXTOPEN_ON],ext_open_on    ;FT. from extnded open              ;AN000;
+        JNZ     IFS_extopen                 ;FT. isuue extended open            ;AN000;
+;Extended open hooks
+
+IF NOT Installed
+        transfer NET_OPEN
+ELSE
+        PUSH    AX
+        MOV     AX,(multNET SHL 8) OR 22
+        INT     2FH
+        POP     BX                      ; clean stack
+;       JC      nomore                  ;IFS. error                             ;AN000;
+update_size:                                                                    ;AN000;
+;       CALL    OWN_SHARE               ;IFS. IFS owns share ?                  ;AN000;
+;       JZ      nomore2                 ;IFS. yes                               ;AN000;
+;       MOV     AX,3                    ;IFS. update file size for all SFT      ;AN000;
+;       LES     DI,ThisSFT              ;IFS.                                   ;AN000;
+;       call    JShare + 14 * 4         ;IFS. call ShSu                         ;AN000;
+nomore2:
+;       CLC
+nomore:
+        return
+ENDIF
+
+LOCAL_OPEN:
+        EnterCrit   critDisk
+
+; DOS 3.3 FastOPen 6/16/86
+
+        OR      [FastOpenFlg],FastOpen_Set+Special_Fill_Set   ;  only open can
+        invoke  GetPath
+
+
+; DOS 3.3 FastOPen 6/16/86
+
+        JNC     Open_found
+        JNZ     bad_path
+        OR      CL,CL
+        JZ      bad_path
+OpenFNF:
+        MOV     AX,error_file_not_found
+OpenBadRet:
+        AND     BYTE PTR CS:[FastOpenFlg],Fast_yes    ;; DOS 3.3
+        STC
+        LeaveCrit   critDisk
+        JMP     Clear_FastOpen
+
+bad_path:
+        MOV     AX,error_path_not_found
+        JMP     OpenBadRet
+
+open_bad_access:
+        MOV     AX,error_access_denied
+        JMP     OpenBadRet
+
+Open_found:
+        JZ      Open_Bad_Access         ; test for directories
+        OR      AH,AH
+        JS      open_ok                 ; Devices don't have attributes
+        MOV     ES,WORD PTR [CURBUF+2]  ; get buffer location
+        MOV     AL,ES:[BX].dir_attr
+        TEST    AL,attr_volume_id       ; can't open volume ids
+        JNZ     open_bad_access
+        TEST    AL,attr_read_only       ; check write on read only
+        JZ      open_ok
+;
+; The file is marked READ-ONLY.  We verify that the open mode allows access to
+; the read-only file.  Unfortunately, with FCB's and net-FCB's we cannot
+; determine at the OPEN time if such access is allowed.  Thus, we defer such
+; processing until the actual write operation:
+;
+; If FCB, then we change the mode to be read_only.
+; If net_FCB, then we change the mode to be read_only.
+; If not open for read then error.
+;
+        SaveReg <DS,SI>
+        LDS     SI,[THISSFT]
+        MOV     CX,[SI].sf_mode
+        TEST    CX,sf_isFCB             ; is it FCB?
+        JNZ     ResetAccess             ; yes, reset the access
+        MOV     DL,CL
+        AND     DL,sharing_mask
+        CMP     DL,sharing_net_FCB      ; is it net FCB?
+        JNZ     NormalOpen              ; no
+ResetAccess:
+        AND     CX,NOT access_mask      ; clear access
+        errnz   open_for_read
+;       OR      CX,open_for_read        ; stick in open_for_read
+        MOV     [SI].sf_mode,CX
+        JMP     SHORT FillSFT
+;
+; The SFT is normal.  See if the requested access is open_for_read
+;
+NormalOpen:
+        AND     CL,access_mask          ; remove extras
+        CMP     CL,open_for_read        ; is it open for read?
+        JZ      FillSFT
+        RestoreReg  <SI,DS>
+        JMP     short open_bad_access
+;
+; All done, restore registers and fill the SFT.
+;
+FillSFT:
+        RestoreReg  <SI,DS>
+open_ok:
+;;; File Tagging DOS 4.00
+;       OR      AH,AH                  ;FT. device ?                            ;AN000;
+;       JS      NORM0                  ;FT. yes, don't do code page matching    ;AN000;
+;       CMP     [CPSWFLAG],0           ;FT. code page matching on               ;AN000;
+;       JZ      NORM0                  ;FT. no                                  ;AN000;
+;       CMP     ES:[BX].dir_CODEPG,0   ;FT. code page 0                         ;AN000;
+;       JZ      NORM0                  ;FT. yes do nothing                      ;AN000;
+;       PUSH    AX                     ;FT.                                     ;AN000;
+;       invoke  Get_Global_CdPg        ;FT. get global code page                ;AN000;
+;       CMP     ES:[BX].dir_CODEPG,AX  ;FT. equal to global code page           ;AN000;
+;       JZ      NORM1                  ;FT. yes                                 ;AN000;
+;       call    Code_Page_Mismatched_Error ;FT.                                 ;AN000;
+;       CMP     AL,0                   ;FT. ignore ?                            ;AN000;
+;       JZ      NORM1                  ;FT.                                     ;AN000;
+;       POP     AX                     ;FT.                                     ;AN000;
+;       JMP     open_bad_access        ;FT. set carry and return                ;AN000;
+NORM1:                                                                          ;AN000;
+;       POP     AX                     ;FT.                                     ;AN000;
+NORM0:
+
+;;; File Tagging DOS 4.00
+        invoke  DOOPEN                  ; Fill in SFT
+        AND     BYTE PTR CS:[FastOpenFlg],Fast_yes    ;; DOS 3.3
+        CALL    DO_SHARE_CHECK          ;
+        JNC     Share_Ok
+        LeaveCrit   critDisk
+        JMP     Clear_FastOPen
+
+SHARE_OK:
+        MOV     AX,3
+        LES     DI,ThisSFT
+if installed
+        call    JShare + 14 * 4
+else
+        Call    ShSU
+endif
+;; DOS 4.00 10/27/86
+        LES     DI,ThisSFT                         ; if this is a newly         ;AN000;
+        CMP     ES:[DI.sf_firclus],0               ; created file then          ;AN000;
+        JZ      no_fastseek                        ; do nothing                 ;AN000;
+        MOV     CX,ES:[DI.sf_firclus]              ; first cluster #            ;AN000;
+        LES     DI,ES:[DI.sf_devptr]               ; pointer to DPB             ;AN000;
+        MOV     DL,ES:[DI.dpb_drive]               ; drive #                    ;AN000;
+        invoke  FastSeek_Open                      ; call fastseek              ;AN000;
+no_fastseek:
+
+;; DOS 4.00 10/27/86
+
+        LeaveCrit   critDisk
+
+;
+; Finish SFT initialization for new reference.  Set the correct mode.
+;
+;   Inputs:
+;       ThisSFT points to SFT
+;
+;   Outputs:
+;       Carry clear
+;   Registers modified: AX.
+
+        entry   SET_SFT_MODE
+        DOSAssume   CS,<DS>,"Set_SFT_Mode"
+        ASSUME  ES:NOTHING
+
+        LES     DI,ThisSFT
+        invoke  DEV_OPEN_SFT
+        TEST    ES:[DI.sf_mode],sf_isfcb; Clears carry
+        retz                            ; sf_mode correct
+        MOV     AX,[CurrentPDB]
+        MOV     ES:[DI.sf_PID],AX       ; For FCB sf_PID=PID
+
+Clear_FastOpen:
+        return                         ;;;;; DOS 3.3
+
+EndProc DOS_Open
+
+; Called on sharing violations. ES:DI points to SFT. AX has error code
+; If SFT is FCB or compatibility mode gens INT 24 error.
+; Returns carry set AX=error_sharing_violation if user says ignore (can't
+; really ignore).  Carry clear
+; if user wants a retry. ES, DI, DS preserved
+
+procedure SHARE_ERROR,NEAR
+        DOSAssume   CS,<DS>,"Share_Error"
+        ASSUME  ES:NOTHING
+        TEST    ES:[DI.sf_mode],sf_isfcb
+        JNZ     HARD_ERR
+        MOV     CL,BYTE PTR ES:[DI.sf_mode]
+        AND     CL,sharing_mask
+        CMP     CL,sharing_compat
+        JNE     NO_HARD_ERR
+HARD_ERR:
+        invoke  SHARE_VIOLATION
+        retnc                           ; User wants retry
+NO_HARD_ERR:
+        MOV     AX,error_sharing_violation
+        STC
+        return
+
+EndProc SHARE_ERROR
+
+
+; Input: THISDPB, WFP_Start, THISSFT set
+; Functions: check file sharing mode is valid
+; Output: carry set, error
+;         carry clear, share ok
+
+procedure DO_SHARE_CHECK,NEAR
+        DOSAssume   CS,<DS>,"DO_SHARE__CHECK"
+        ASSUME  ES:NOTHING
+        EnterCrit   critDisk            ; enter critical section
+
+OPN_RETRY:
+        MOV     CX,RetryCount           ; Get # tries to do
+OpenShareRetry:
+        SaveReg <CX>                    ; Save number left to do
+        invoke  SHARE_CHECK             ; Final Check
+        RestoreReg  <CX>                ; CX = # left
+        JNC     Share_Ok2               ; No problem with access
+        Invoke  Idle
+        LOOP    OpenShareRetry          ; One more retry used up
+OpenShareFail:
+        LES     DI,[ThisSft]
+        invoke  SHARE_ERROR
+        JNC     OPN_RETRY               ; User wants more retry
+Share_Ok2:
+        LeaveCrit   critDisk            ; leave critical section
+        return
+
+EndProc DO_SHARE_CHECK
+
+
+; Input: ES:DI -> SFT
+; Functions: check if IFS owns SHARE
+; Output: Zero set, use IFS SHARE
+;         otherwise, use DOS SHARE
+
+procedure OWN_SHARE,NEAR                ;AN000;
+        DOSAssume   CS,<DS>,"OWN_SHARE" ;AN000;
+        ASSUME  ES:NOTHING              ;AN000;
+
+;       PUSH    DS                      ;IFS. save reg                          ;AN000;
+;       PUSH    SI                      ;IFS. save reg                          ;AN000;
+;       LDS     SI,ES:[DI.sf_IFS_HDR]   ;IFS. ds:si-> IFS header                ;AN000;
+;       TEST    [SI.IFS_ATTRIBUTE],IFSUSESHARE  ;IFS. save reg                  ;AN000;
+;       POP     SI                      ;IFS. retore reg                        ;AN000;
+;       POP     DS                      ;IFS. restore reg                       ;AN000;
+        return                          ;IFS. return                            ;AN000;
+
+EndProc OWN_SHARE                       ;AN000;
+
+
+; Input: THISCDS -> CDS
+; Functions: check if IFS owns SHARE
+; Output: Zero set, use IFS SHARE
+;         otherwise, use DOS SHARE
+
+procedure OWN_SHARE2,NEAR                 ;AN000;
+        DOSAssume   CS,<DS>,"OWN_SHARE2"  ;AN000;
+        ASSUME  ES:NOTHING                ;AN000;
+
+;       CMP     WORD PTR [THISCDS],-1   ;IFS. UNC ?                             ;AN000;
+;       JZ      ifs_hasit               ;IFS. yes                               ;AN000;
+;       PUSH    DS                      ;IFS. save reg                          ;AN000;
+;       PUSH    SI                      ;IFS. save reg                          ;AN000;
+;       LDS     SI,[THISCDS]            ;IFS. DS:SI -> ThisCDS                  ;AN000;
+;       LDS     SI,[SI.curdir_IFS_HDR]  ;IFS. ds:si-> IFS header                ;AN000;
+;       TEST    [SI.IFS_ATTRIBUTE],IFSUSESHARE  ;IFS.                           ;AN000;
+;       POP     SI                      ;IFS. retore reg                        ;AN000;
+;       POP     DS                      ;IFS. restore reg                       ;AN000;
+ifs_hasit:                              ;AN000;
+        return                          ;IFS. return                            ;AN000;
+
+EndProc OWN_SHARE2                      ;AN000;
+
+
+; Input: ES:DI -> SFT
+; Functions: set THISDPB
+; Output: none
+
+procedure SET_THISDPB,NEAR                     ;AN000;
+        DOSAssume   CS,<DS>,"SET_THISDPB"      ;AN000;
+        ASSUME  ES:NOTHING                     ;AN000;
+
+;       PUSH    DS                      ;IFS. save reg                          ;AN000;
+;       PUSH    SI                      ;IFS. save reg                          ;AN000;
+;       LDS     SI,[THISCDS]            ;IFS. ds:si-> CDS                       ;AN000;
+;       LDS     SI,[SI.CURDIR_DEVPTR]   ;IFS. ds:si-> DPB                       ;AN000;
+;       MOV     WORD PTR [THISDPB],SI   ;IFS. set THISDPB                       ;AN000;
+;       MOV     WORD PTR [THISDPB+2],DS ;IFS.                                   ;AN000;
+;       POP     SI                      ;IFS. retore reg                        ;AN000;
+;       POP     DS                      ;IFS. restore reg                       ;AN000;
+        return                          ;IFS. return                            ;AN000;
+
+EndProc SET_THISDPB                     ;AN000;
+
+
+; Input: ES:DI -> SFT
+; Functions: check IFS share
+; Output: none
+
+procedure IFS_SHARE_CHECK,NEAR                     ;AN000;
+        DOSAssume   CS,<DS>,"IFS_SHARE_CHECK"      ;AN000;
+        ASSUME  ES:NOTHING                         ;AN000;
+
+
+;       CALL    OWN_SHARE               ;IFS. IFS owns share                    ;AN000;
+;       JZ      IFSSHARE                ;IFS. yes                               ;AN000;
+;       PUSH    AX                      ;IFS. save mode                         ;AN000;
+;       CALL    SET_THISDPB             ;IFS. set THISDPB for SHARE_VIOLATION   ;AN000;
+;       CALL    DO_SHARE_CHECK          ;IFS. check share                       ;AN000;
+;       POP     AX                      ;IFS. restore mode and share ok         ;AN000;
+IFSSHARE:                               ;AN000;
+        return                          ;IFS. return                            ;AN000;
+
+EndProc IFS_SHARE_CHECK                 ;AN000;
+
+; Inputs:
+;       AX is mode
+;         High NIBBLE of AL (Sharing Mode)
+;               sharing_compat     file is opened in compatibility mode
+;               sharing_deny_none  file is opened Multi reader, Multi writer
+;               sharing_deny_read  file is opened Only reader, Multi writer
+;               sharing_deny_write file is opened Multi reader, Only writer
+;               sharing_deny_both  file is opened Only reader, Only writer
+;         Low NIBBLE of AL (Access Mode)
+;               open_for_read   file is opened for reading
+;               open_for_write  file is opened for writing
+;               open_for_both   file is opened for both reading and writing.
+; Function:
+;       Check this access mode for correctness
+; Outputs:
+;       [open_access] = AL input
+;       Carry Clear
+;               Mode is correct
+;               AX unchanged
+;       Carry Set
+;               Mode is bad
+;               AX = error_invalid_access
+; No other registers effected
+
+        procedure Check_Access_AX
+        DOSAssume   CS,<DS>,"Check_Access"
+        ASSUME  ES:NOTHING
+
+        MOV     Open_Access,AL
+        PUSH    BX
+;
+; If sharing, then test for special sharing mode for FCBs
+;
+        MOV     BL,AL
+        AND     BL,sharing_mask
+        CMP     fSharing,-1
+        JNZ     CheckShareMode          ; not through server call, must be ok
+        CMP     BL,sharing_NET_FCB
+        JZ      CheckAccessMode         ; yes, we have an FCB
+CheckShareMode:
+        CMP     BL,40h                  ; is this a good sharing mode?
+        JA      Make_Bad_Access
+CheckAccessMode:
+        MOV     BL,AL
+        AND     BL,access_mask
+        CMP     BL,2
+        JA      Make_Bad_Access
+        POP     BX
+        CLC
+        return
+
+make_bad_access:
+        MOV     AX,error_invalid_access
+        POP     BX
+        STC
+        return
+
+EndProc Check_Access_AX
+
+; Input: none
+; Function: Issue Code Page Mismatched INT 24 Critical Error
+; OutPut: AL =0    ignore
+;            =3    fail
+
+procedure Code_Page_Mismatched_Error,NEAR                ;AN000;
+        DOSAssume   CS,<DS>,"Code_Page_Mismatched_Error" ;AN000;
+        ASSUME  ES:NOTHING                               ;AN000;
+
+;       PUSH    DS                     ;FT.                                     ;AN000;
+;       Context DS                     ;FT. ds=cs                               ;AN000;
+;       MOV     AH,0A9H                ;FT. fail,ignore,device,write            ;AN000;
+;       MOV     DI,error_I24_gen_failure                 ;FT. set error         ;AN000;
+;       MOV     [EXTERR],error_Code_Page_Mismatched      ;FT.                   ;AN000;
+;       MOV     [EXTERR_CLASS],errCLASS_NotFnd           ;FT.                   ;AN000;
+;       MOV     [EXTERR_ACTION],errACT_Abort             ;FT.                   ;AN000;
+;       MOV     [EXTERR_LOCUS],errLOC_Unk                ;FT.                   ;AN000;
+;       MOV     word ptr [EXITHOLD + 2],ES               ;FT. save es:bp        ;AN000;
+;       MOV     word ptr [EXITHOLD],BP                   ;FT.                   ;AN000;
+;       invoke  NET_I24_ENTRY                            ;FT. issue int 24H     ;AN000;
+;       POP     DS                                       ;FT.                   ;AN000;
+;       return                                           ;FT.                   ;AN000;
+
+EndProc Code_Page_Mismatched_Error                       ;AN000;
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/PARSE.ASM b/v4.0/src/DOS/PARSE.ASM
new file mode 100644
index 0000000..f8de345
--- /dev/null
+++ b/v4.0/src/DOS/PARSE.ASM
@@ -0,0 +1,447 @@
+;       SCCSID = @(#)parse.asm  1.2 85/07/23
+TITLE PARSE - Parsing system calls for MS-DOS
+NAME  PARSE
+;
+; System calls for parsing command lines
+;
+;   $PARSE_FILE_DESCRIPTOR
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;               EE PathParse 10 Sept 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+BOGUS =FALSE
+.lall
+        I_Need  chSwitch,BYTE
+
+BREAK <$Parse_File_Descriptor -- Parse an arbitrary string into an FCB>
+
+; Inputs:
+;       DS:SI Points to a command line
+;       ES:DI Points to an empty FCB
+;       Bit 0 of AL = 1 At most one leading separator scanned off
+;                   = 0 Parse stops if separator encountered
+;       Bit 1 of AL = 1 If drive field blank in command line - leave FCB
+;                   = 0  "    "    "     "         "      "  - put 0 in FCB
+;       Bit 2 of AL = 1 If filename field blank - leave FCB
+;                   = 0  "       "      "       - put blanks in FCB
+;       Bit 3 of AL = 1 If extension field blank - leave FCB
+;                   = 0  "       "      "        - put blanks in FCB
+; Function:
+;       Parse command line into FCB
+; Returns:
+;       AL = 1 if '*' or '?' in filename or extension, 0 otherwise
+;       DS:SI points to first character after filename
+
+        procedure   $PARSE_FILE_DESCRIPTOR,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        invoke  MAKEFCB
+        PUSH    SI
+        invoke  get_user_stack
+        POP     [SI.user_SI]
+        return
+EndProc $PARSE_FILE_DESCRIPTOR
+
+
+IF BOGUS
+BREAK <$PathParse - Parse a string>
+
+;------------------------------------------------------------------------------
+;
+; Parse is a string parser.  It copies the next token into a buffer, updates
+; the string pointer, and builds a flag word which describes the token.
+;
+; ENTRY
+;       DS:SI - Points to the beginning of the string to be parsed
+;       ES:DI - Points to the buffer which will hold the new token
+;
+; EXIT
+;       AX - Flag word
+;       DS:SI - String pointer updated to point past the token just found
+;       All other registers are unchanged.
+;
+; All of the isXXXX procedures called by the main routine test a character
+; to see if it is of a particular type.  If it is, they store the character
+; and return with the ZF set.
+;
+; CALLS
+;       isswit issep ispchr ispsep isinval isdot ischrnull dirdot pasep
+;
+;
+; INTERNAL REGISTER USAGE
+;       AH - FF/00  to indicate whether a path token can terminated with a
+;            slash or not.
+;       AL - Used with lodsb/stosb to transfer and test chars from DS:SI
+;       BX - Holds flag word
+;       CX - Used with loop/rep and as a work var
+;       DX - Used to test the length of names and extensions
+;
+; EFFECTS
+;       The memory pointed to by DI has the next token copied into it.
+;
+; WARNINGS
+;       It is the caller's responsibility to make sure DS:SI does not point
+;       to a null string.  If it does, SI is incremented, a null byte is
+;       stored at ES:DI, and the routine returns.
+;
+;------------------------------------------------------------------------------
+ParseClassMask          equ     1110000000000000b       ; Token class mask
+ParseSwitch             equ     1000000000000000b       ; Switch class
+ParseSeparators         equ     0100000000000000b       ; Separator class
+ParsePathName           equ     0010000000000000b       ; Path class
+ParsePathNameData       equ     0000000000001111b       ; Path token data mask
+ParsePathSynErr         equ     0000000000000001b       ; Path has syntax error
+ParsePathWild           equ     0000000000000010b       ; Path has wildcards
+ParsePathSeparators     equ     0000000000000100b       ; Path has pseparators
+ParseInvalidDrive       equ     0000000000001000b       ; Path has invald drive
+
+
+; Sepchars is a string containing all of the token separator characters
+; and is used to test for separators.
+
+Table   segment
+Public PRS001S,PRS001E
+PRS001S label byte
+sepchrs db      9,10,13,' ','+',',',';','='     ; tab cr lf sp + , ; =
+seplen  equ     $-sepchrs
+PRS001E label byte
+table   ends
+
+Procedure $PathParse,NEAR
+        assume  ds:nothing,es:nothing
+        xor     ah,ah           ; initialize registers and flags
+        xor     bx,bx
+        cld
+        lodsb                   ; used the first byte of the token to
+        call    isswit          ; determine its type and call the routine to
+        je      switch          ; parse it
+        call    issep
+        je      separ
+        call    ispchr
+        je      path
+        call    ispsep
+        je      path
+        call    isdot
+        je      path
+        call    isinval
+        je      inval
+        stosb
+        jmp     done
+
+inval:  or      bx,ParsePathName        ; an invalid character/path token
+        or      bx,ParsePathSynErr      ; was found, set the appropriate
+        call    issep                   ; flag bits and parse the rest of
+        jne     icont                   ; the token
+        dec     di
+icont:  dec     si
+        jmp     ptosep
+
+switch: mov     bx,ParseSwitch          ; found a switch, set flag and parse
+        jmp     ptosep                  ; the rest of it
+
+separ:  mov     bx,ParseSeparators      ; found separator, set flag and parse
+seloop: lodsb                           ; everything up to the next non
+        call    issep                   ; separator character
+        je      seloop
+        jmp     bksi
+
+path:   or      bx,ParsePathName        ; found path, set flag
+        mov     cx,8                    ; set up to parse a file name
+        mov     dx,8
+        call    pasep                   ; if the token began with a path
+        jne     pcont1                  ; separator or . call rcont which
+        not     ah                      ; handles checksfor . and ..
+        jmp     rcont
+pcont1: cmp     al,'.'
+        jne     pcont2
+        dec     si
+        dec     di
+        jmp     rcont
+pcont2: cmp     al,'A'                  ; if token may start with a drive
+        jge     drive                   ; designator, go to drive. otherwise
+        jmp     name1                   ; parse a file name.
+
+drive:  cmp     byte ptr [si],':'       ; if there is a drive designator, parse
+        jne     name1                   ; and verify it. otherwise parse a file
+        not     ah                      ; name.
+        cmp     al,'Z'
+        jle     dcont1
+        sub     al,' '
+dcont1: sub     al,'@'
+        invoke  GetthisDrv
+        lodsb
+        stosb
+        jc      dcont2
+        jmp     dcont3
+dcont2: or      bx,ParseInvalidDrive
+dcont3: dec     cx
+        lodsb
+        call    ispsep
+        je      rcont
+        dec     si
+
+repeat: mov     al,byte ptr [si-2]      ; repeat and rcont test for //, \\, .,
+        call    pasep                   ; and .. and repeatedly calls name
+        jne     rcont                   ; and ext until a path token has
+        inc     si                      ; been completely parsed.
+        jmp     inval
+rcont:  call    dirdot
+        je      done
+        jc      inval
+        mov     cx,8
+        mov     dx,8
+        jmp     name
+
+name1:  dec     cx
+name:   lodsb                           ; parse and verify a file name
+        call    ispchr
+        jne     ncheck
+        xor     ah,ah
+nloop:  loop    name
+        lodsb
+
+ncheck: cmp     ah,0
+        jne     ncont
+        cmp     cx,dx
+        jne     ncont
+        jmp     inval
+ncont:  call    isdot
+        je      ext
+        jmp     dcheck
+
+ext:    mov     cx,3                    ; parse and verify a file extension
+        mov     dx,3
+extl:   lodsb
+        call    ispchr
+        jne     echeck
+eloop:  loop    extl
+        lodsb
+
+echeck: cmp     cx,dx
+        jne     dcheck
+        jmp     inval
+
+dcheck: call    ispsep                  ; do the checks need to make sure
+        je      repeat                  ; a file name or extension ended
+        call    issep                   ; correctly and checks to see if
+        je      bkboth                  ; we're done
+        call    ischrnull
+        je      done
+        jmp     inval
+
+ptosep: lodsb                           ; parse everything to the next separator
+        call    issep
+        je      bkboth
+        call    ischrnull
+        je      done
+        call    isinval
+        jne     ptcont
+        or      bx,ParsePathSynErr
+ptcont: stosb
+        jmp     ptosep
+
+bkboth: dec     di                      ; clean up when the end of the token
+bksi:   dec     si                      ; is found, stick a terminating null
+done:   xor     al,al                   ; byte at the end of buf, and exit
+        stosb
+        push    si
+        invoke  Get_user_stack
+        mov     [si].user_AX,bx
+        pop     [si].user_SI
+        Transfer sys_ret_ok
+
+Endproc $PathParse
+
+; Is current character the beginning of a switch?
+
+isswit  proc    near
+        cmp     al,[chSwitch]
+        jne     swret
+        stosb
+swret:  ret
+isswit  endp
+
+
+; Is the current character a separator?
+
+issep   proc    near
+        push    cx
+        push    di
+        push    es
+        mov     cx,cs
+        mov     es,cx
+        mov     cx,seplen
+        mov     di,offset dosgroup:sepchrs
+        repne   scasb
+        pop     es
+        pop     di
+        jne     sepret
+sepyes: stosb
+sepret: pop     cx
+        ret
+issep   endp
+
+
+; Is the current character a path character?  If it is a wildcard char too,
+;  set that flag.
+
+ispchr  proc    near
+        cmp     al,'!'
+        je      pcyes
+        cmp     al,'#'
+        jl      pcret
+        cmp     al,'*'
+        je      pcwild
+        jl      pcyes
+        cmp     al,'-'
+        je      pcyes
+        cmp     al,'0'
+        jl      pcret
+        cmp     al,'9'
+        jle     pcyes
+        cmp     al,'?'
+        je      pcwild
+        jl      pcret
+        cmp     al,'Z'
+        jle     pcyes
+        cmp     al,'^'
+        jl      pcret
+        cmp     al,'{'
+        jle     pcyes
+        cmp     al,'}'
+        je      pcyes
+        cmp     al,'~'
+        je      pcyes
+        jmp     pcret
+pcwild: or      bx,ParsePathWild
+pcyes:  stosb
+        cmp     al,al
+pcret:  ret
+ispchr  endp
+
+
+; Is the current character a path separator?  If so, set that flag after
+; storing the byte.
+
+ispsep  proc    near
+        call    pasep
+        jne     psret
+        stosb
+        or      bx,ParsePathSeparators
+        cmp     al,al
+psret:  ret
+ispsep  endp
+
+
+; Set ZF if the character in AL is a path separator.
+
+pasep   proc    near
+        cmp     chSwitch,'/'
+        je      bkslash
+        cmp     al,'/'
+        retz
+bkslash:cmp     al,'\'
+        ret
+pasep   endp
+
+
+; Is the current character invalid?
+
+isinval proc    near
+        cmp     al,1
+        jl      inret
+        cmp     al,8
+        jle     inyes
+        cmp     al,11
+        jl      inret
+        cmp     al,13
+        jne     incont
+        cmp     al,0
+        ret
+incont: cmp     al,31
+        jle     inyes
+        cmp     al,'['
+        je      inyes
+        cmp     al,']'
+        je      inyes
+        ret
+inyes:  cmp     al,al
+inret:  ret
+isinval endp
+
+
+; Is the current character a dot?
+
+isdot   proc    near
+        cmp     al,'.'
+        jne     dotret
+        stosb
+dotret: ret
+isdot   endp
+
+
+; Is the current character null?  If so, update SI for exiting.
+
+ischrnull  proc    near
+        cmp     al,0
+        jne     nulret
+        dec     si
+        cmp     al,al
+nulret: ret
+ischrnull  endp
+
+
+; Check for . and ..  Before returning, CF and ZF are set to indicate whether
+; the token is invalid (found . or .. followed by an invalid char - CF on),
+; we're done (found . or .. followed by null or a separator - ZF on), or the
+; token continues (. and .. not found or found and followed by a path
+; separator - both flags off).
+
+dirdot  proc    near
+        cmp     byte ptr [si], '.'
+        jne     diretc
+        lodsb
+        stosb
+        cmp     byte ptr [si],'.'
+        jne     dicont
+        lodsb
+        stosb
+dicont: lodsb
+        call    ispsep
+        je      diretc
+        call    issep
+        je      dibk
+        call    ischrnull
+        je      diretd
+direti: stc                             ; Invalid return
+        ret
+dibk:   dec     si
+        dec     di
+diretd: cmp     al,al                   ; Done return
+        ret
+diretc: cmp     ah,1                    ; Continue return
+        clc
+        ret
+dirdot  endp
+ENDIF
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/PATH.ASM b/v4.0/src/DOS/PATH.ASM
new file mode 100644
index 0000000..5deed6c
--- /dev/null
+++ b/v4.0/src/DOS/PATH.ASM
@@ -0,0 +1,363 @@
+;       SCCSID = @(#)path.asm   1.1 85/04/10
+TITLE   PATH - Directory related system calls
+NAME    PATH
+
+;
+; Directory related system calls.  These will be passed direct text of the
+; pathname from the user.  They will need to be passed through the macro
+; expander prior to being sent through the low-level stuff.  I/O specs are
+; defined in DISPATCH.  The system calls are:
+;
+;   $CURRENT_DIR  Written
+;   $RMDIR        Written
+;   $CHDIR        Written
+;   $MKDIR        Written
+;
+;
+;   Modification history:
+;
+;       Created: ARR 4 April 1983
+;                MZ 10 May 1983     CurrentDir implemented
+;                MZ 11 May 1983     RmDir, ChDir, MkDir implemented
+;                EE 19 Oct 1983     RmDir no longer allows you to delete a
+;                                   current directory.
+;                MZ 19 Jan 1983     Brain damaged applications rely on success
+;                                   values of AL.
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+        EXTRN   DOS_MkDir:NEAR,DOS_RmDir:NEAR
+
+        I_Need  ThisCDS,DWORD           ; pointer to Current CDS
+        I_Need  WFP_Start,WORD          ; pointer to beginning of directory text
+        I_Need  Curr_Dir_End,WORD       ; offset to end of directory part
+        I_Need  OpenBuf,128             ; temp spot for translated name
+        I_need  fSplice,BYTE            ; TRUE => do splice
+        I_Need  NoSetDir,BYTE           ; TRUE => no exact match on splice
+        I_Need  cMeta,BYTE
+        I_Need  DrvErr,BYTE                                                     ;AN000;
+
+BREAK <$CURRENT_DIR - dump the current directory into user space>
+;
+;   Assembler usage:
+;               LDS     SI,area
+;               MOV     DL,drive
+;               INT     21h
+;           ; DS:SI is a pointer to 64 byte area that contains drive
+;           ; current directory.
+;   Error returns:
+;           AX = error_invalid_drive
+;
+
+        procedure $CURRENT_DIR,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        EnterCrit   critDisk
+        MOV     AL,DL                   ; get drive number (0=def, 1=A)
+        Invoke  GetVisDrv               ; grab it
+        JNC     CurrentValidate         ; no error -> go and validate dir
+CurdirErr:
+        LeaveCrit   critDisk
+        MOV     AL,[DrvErr]             ;IFS.                                   ;AN000;
+        transfer SYS_RET_ERR            ;IFS. make noise                        ;AN000;
+CurrentValidate:
+        SaveReg <DS,SI>                 ; save destination
+        LDS     SI,ThisCDS
+        TEST    [SI].curdir_flags,curdir_isnet
+        JNZ     DoCheck
+; Random optimization nuked due to some utilities using GetCurrentDir to do
+; media check.
+;       CMP     [SI].curdir_id,0
+;       JZ      GetDst
+DoCheck:
+        MOV     NoSetDir,0              ; interested only in contents
+        MOV     DI,OFFSET DOSGroup:OpenBuf
+        Invoke  ValidateCDS             ; output is ES:DI -> CDS
+        SaveReg <ES,DI>                 ; swap source and destination
+        RestoreReg  <SI,DS>
+GetDst:
+        RestoreReg  <DI,ES>             ; get real destination
+        JC      CurdirErr
+        ADD     SI,curdir_text
+        ADD     SI,[SI.curdir_END]
+        CMP     BYTE PTR [SI],'\'       ; root or subdirs present?
+        JNZ     CurrentCopy
+        INC     SI
+CurrentCopy:
+;       Invoke  FStrCpy
+;; 10/29/86 E5 char
+        PUSH    AX
+        LODSB                         ; get char
+        OR      AL,AL
+        JZ      FOK
+        CMP     AL,05
+        JZ      FCHANGE
+        JMP     FFF
+FCPYNEXT:
+        LODSB                         ; get char
+FFF:
+        CMP     AL,'\'                ; beginning of directory
+        JNZ     FOK                   ; no
+        STOSB                         ; put into user's buffer
+        LODSB                         ; 1st char of dir is 05?
+        CMP     AL,05H
+        JNZ     FOK                   ; no
+FCHANGE:
+        MOV     AL,0E5H               ; make it E5
+FOK:
+        STOSB                         ; put into user's buffer
+        OR      AL,AL                 ; final char
+        JNZ     FCPYNEXT              ; no
+        POP     AX
+
+;; 10/29/86 E5 char
+        xor     AL,AL                   ; MZ 19 Jan 84
+        LeaveCrit   critDisk
+        transfer    Sys_Ret_OK          ; no more, bye!
+EndProc $Current_Dir
+
+BREAK <$RmDir -- Remove a directory>
+
+; Inputs:
+;       DS:DX Points to asciz name
+; Function:
+;       Delete directory if empty
+; Returns:
+;       STD XENIX Return
+;       AX = error_path_not_found If path bad
+;       AX = error_access_denied If
+;               Directory not empty
+;               Path not directory
+;               Root directory specified
+;               Directory malformed (. and .. not first two entries)
+;               User tries to delete a current directory
+;       AX = error_current_directory
+
+        procedure $RMDIR,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+        push    dx                      ; Save ptr to name
+        push    ds
+        mov     si,dx                   ; Load ptr into si
+        mov     di,offset DOSGroup:OpenBuf      ; di = ptr to buf for trans name
+        push    di
+        Invoke  TransPathNoSet          ; Translate the name
+        pop     di                      ; di = ptr to buf for trans name
+        jnc     rmlset                  ; If transpath succeeded, continue
+        pop     ds
+        pop     dx                      ; Restore the    name
+        error   error_path_not_found    ; Otherwise, return an error
+
+rmlset:
+        CMP     cMeta,-1                ;   if (cMeta >= 0)
+        Jnz     rmerr                   ;       return (-1);
+        Context ES
+        xor     al,al                   ; al = 0 , ie drive a:
+rmloop: Invoke  GetCDSFromDrv           ; Get curdir for drive in al
+        jc      rmcont                  ; If error, exit loop & cont normally
+        Invoke  StrCmp                  ; Are the 2 paths the same?
+        jz      rmerr                   ; Yes, report error.
+        inc     al                      ; No, inc al to next drive number
+        jmp     rmloop                  ; Go check next drive.
+
+rmerr:
+        pop     ds
+        pop     dx                      ; Restore the    name
+        error   error_current_directory ;  error
+
+rmcont:
+        pop     ds
+        pop     dx                      ; Restore the    name
+        MOV     SI,OFFSET DOSGroup:DOS_RmDIR
+        JMP     DoDirCall
+EndProc $RMDIR
+
+BREAK <$ChDir -- Change current directory on a drive>
+
+;
+; $ChDir - Top-level change directory system call.  This call is responsible
+; for setting up the CDS for the specified drive appropriately.  There are
+; several cases to consider:
+;
+;   o   Local, simple CDS.  In this case, we take the input path and convert
+;       it into a WFP.  We verify the existance of this directory and then
+;       copy the WFP into the CDS and set up the ID field to point to the
+;       directory cluster.
+;   o   Net CDS.  We form the path from the root (including network prefix)
+;       and verify its existance (via DOS_Chdir).  If successful, we copy the
+;       WFP back into the CDS.
+;   o   SUBST'ed CDS.  This is no different than the local, simple CDS.
+;   o   JOIN'ed CDS.  This is trouble as there are two CDS's at work.  If we
+;       call TransPath, we will get the PHYSICAL CDS that the path refers to
+;       and the PHYSICAL WFP that the input path refers to.  This is perfectly
+;       good for the validation but not for currency.  We call TransPathNoSet
+;       to process the path but to return the logical CDS and the logical
+;       path.  We then copy the logical path into the logical CDS.
+;
+; Inputs:
+;       DS:DX Points to asciz name
+; Returns:
+;       STD XENIX Return
+;       AX = chdir_path_not_found if error
+
+        procedure $CHDIR,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; spot for translated name
+        MOV     SI,DX                   ; get source
+        Invoke  TransPath               ; go munge the path and get real CDS
+        JNC     ChDirCrack              ; no errors, try path
+ChDirErrP:
+        MOV     AL,error_path_not_found
+ChdirErr:
+        transfer    SYS_Ret_Err         ; oops!
+
+ChDirCrack:
+        Assume  DS:DOSGroup
+        CMP     cMeta,-1                ; No meta chars allowed.
+        JNZ     ChDirErrP
+;
+; We cannot do a ChDir (yet) on a raw CDS.  This is treated as a path not
+; found.
+;
+        LES     DI,ThisCDS
+        CMP     DI,-1                   ;   if (ThisCDS == NULL)
+        JZ      ChDirErrP               ;       error ();
+ ;
+ ; Find out if the directory exists.
+ ;
+        Invoke  DOS_ChDir
+        JC      ChDirErr
+;
+; Get back CDS to see if a join as seen.  Set the currency pointer (only if
+; not network).  If one was seen, all we need to do is copy in the text
+;
+        LES     DI,ThisCDS
+        TEST    ES:[DI].curdir_flags,curdir_splice
+        JZ      GotCDS
+;
+; The CDS was joined.  Let's go back and grab the logical CDS.
+;
+        SaveReg <ES,DI,CX>              ; save CDS and cluster...
+        Invoke  Get_User_Stack          ; get original text
+        ASSUME  DS:NOTHING
+        MOV     DI,[SI.User_DX]
+        MOV     DS,[SI.User_DS]
+        MOV     SI,OFFSET DOSGroup:OpenBuf  ; spot for translated name
+        XCHG    SI,DI
+        XOR     AL,AL                   ; do no splicing
+        SaveReg <DI>
+        Invoke  TransPathNoSet          ; Munge path
+        RestoreReg  <SI>
+        Assume  DS:DOSGroup
+;
+; There should NEVER be an error here.
+;
+IF FALSE
+        JNC SKipErr
+        fmt <>,<>,<"$p: Internal CHDIR error\n">
+SkipErr:
+ENDIF
+        LES     DI,ThisCDS              ; get new CDS
+        MOV     ES:[DI].curdir_ID,-1    ; no valid cluster here...
+        RestoreReg  <CX,DI,ES>
+;
+; ES:DI point to the physical CDS, CX is the ID (local only)
+;
+GotCDS:
+;
+; wfp_start points to the text.  See if it is long enough
+;
+        CALL    Check_PathLen           ;PTM.                                   ;AN000;
+        JA      ChDirErrP
+        TEST    ES:[DI].curdir_flags,curdir_isnet
+        JNZ     SkipRecency
+        TEST    ES:[DI].curdir_flags,curdir_splice   ;PTM. for Join and Subst   ;AN000;
+        JZ      setdirclus                           ;PTM.                      ;AN000;
+        MOV     CX,-1                                ;PTM.                      ;AN000;
+setdirclus:
+        MOV     ES:[DI].curdir_id,CX
+        LES     DI,ThisCDS              ; get logical CDS
+SkipRecency:
+        invoke  FStrCpy
+        XOR     AL,AL
+        transfer    Sys_Ret_OK
+EndProc $CHDIR
+
+BREAK <$MkDir - Make a directory entry>
+; Inputs:
+;       DS:DX Points to asciz name
+; Function:
+;       Make a new directory
+; Returns:
+;       STD XENIX Return
+;       AX = mkdir_path_not_found if path bad
+;       AX = mkdir_access_denied  If
+;               Directory cannot be created
+;               Node already exists
+;               Device name given
+;               Disk or directory(root) full
+
+        procedure $MKDIR,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     SI,OFFSET DOSGroup:DOS_MkDir
+DoDirCall:
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; spot for translated name
+        SaveReg <SI>
+        MOV     SI,DX                   ; get source
+        Invoke  TransPath               ; go munge the path
+        RestoreReg  <SI>
+        JNC     MkDirCrack              ; no errors, try path
+MkErrP:
+        MOV     AL,error_Path_Not_Found    ; oops!
+MkErr:
+        transfer    Sys_Ret_Err
+MkDirCrack:
+        CMP     cMeta,-1
+        JNZ     MkErrP
+
+        PUSH    SI                      ;PTM.                                   ;AN000;
+        CALL    Check_PathLen           ;PTM.  check path len > 67 ?            ;AN000;
+        POP     SI                      ;PTM.                                   ;AN000;
+        JBE     pathok                  ;PTM.                                   ;AN000;
+        MOV     AL,error_Access_Denied  ;PTM. ops!
+        transfer Sys_Ret_Err            ;PTM.
+pathok:
+        CALL    SI                      ; go get file
+        ASSUME  ES:NOTHING
+        JC      MkErr                   ; no errors
+        transfer    Sys_Ret_OK
+EndProc $MKDIR
+
+; Inputs:
+;       nothing
+; Function:
+;       check if final path length greater than 67
+; Returns:
+;       Above flag set if > 67
+
+        procedure Check_PathLen,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+        MOV     SI,Wfp_Start
+  entry Check_PathLen2
+        Context <DS>
+        SaveReg <CX>
+        invoke  DStrLen
+        CMP     CX,DirStrLen
+        RestoreReg  <CX>
+        ret
+EndProc Check_PathLen
+CODE ENDS
+END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/PRINT.ASM b/v4.0/src/DOS/PRINT.ASM
new file mode 100644
index 0000000..c2bbe55
--- /dev/null
+++ b/v4.0/src/DOS/PRINT.ASM
@@ -0,0 +1,199 @@
+;       SCCSID = @(#)print.asm  1.1 85/04/10
+;
+; PFMT - formatted output.  Calling sequence:
+;   PUSH    BP
+;   PUSH    fmtstr
+;   MOV     BP,SP
+;   PUSH    args
+;   CALL    PFMT
+;   ADD     SP,n
+;   POP     BP
+;
+; The format string contains format directives and normal output characters
+; much like the PRINTF for C.  We utilize NO format widths.  Special chars
+; and strings are:
+;
+;       $x      output a hex number
+;       $s      output an offset string
+;       $c      output a character
+;       $S      output a segmented string
+;       $p      output userid/processid
+;       \t      output a tab
+;       \n      output a CRLF
+;
+; The format string must be addressable via CS
+;
+
+Procedure PFMT,NEAR
+        SaveReg <AX,BX,DS,SI>
+        MOV     AX,8007h
+        INT     2Ah
+        PUSH    CS
+        POP     DS
+        SUB     BP,2
+        Call    FMTGetArg
+        MOV     SI,AX
+FmtLoop:
+        LODSB
+        OR      AL,AL
+        JZ      FmtDone
+        CMP     AL,'$'
+        JZ      FmtOpt
+        CMP     AL,'\'
+        JZ      FmtChr
+FmtOut:
+        CALL    Out
+        JMP     FmtLoop
+Out:
+        SaveReg <SI,DI,BP>
+        INT     29h
+        RestoreReg  <BP,DI,SI>
+        return
+FmtDone:
+        MOV     AX,8107h
+        INT     2Ah
+        RestoreReg  <SI,DS,BX,AX>
+        RET
+;
+; \ leads in a special character. See what the next char is.
+;
+FmtChr: LODSB
+        OR      AL,AL                   ; end of string
+        JZ      fmtDone
+        CMP     AL,'n'                  ; newline
+        JZ      FmtCRLF
+        CMP     AL,'t'                  ; tab
+        JNZ     FmtOut
+        MOV     AL,9
+        JMP     FmtOut
+FmtCRLF:MOV     AL,13
+        CALL    Out
+        MOV     AL,10
+        JMP     FmtOut
+;
+; $ leads in a format specifier.
+;
+FmtOpt: LODSB
+        CMP     AL,'x'                  ; hex number
+        JZ      FmtX
+        CMP     AL,'c'                  ; single character
+        JZ      FmtC
+        CMP     AL,'s'                  ; offset string
+        JZ      FmtSoff
+        CMP     AL,'S'                  ; segmented string
+        JZ      FmtSseg
+        CMP     AL,'p'
+        JZ      FmtUPID
+        JMP     FmtOut
+FmtX:
+        Call    FMTGetArg
+        MOV     BX,AX
+        CALL    MNUM
+        JMP     FmtLoop
+FmtC:
+        Call    FmtGetArg
+        CALL    Out
+        JMP     FmtLoop
+FmtSoff:
+        SaveReg <SI>
+        Call    FmtGetArg
+        MOV     SI,AX
+        CALL    fmtsout
+        RestoreReg  <SI>
+        JMP     FmtLoop
+FmtSSeg:
+        SaveReg <DS,SI>
+        CALL    FMTGetArg
+        MOV     DS,AX
+        CALL    FMTGetArg
+        MOV     SI,AX
+        CALL    fmtsout
+        RestoreReg  <SI,DS>
+        JMP     FmtLoop
+FmtUPID:
+        SaveReg <DS>
+        MOV     BX,0
+        MOV     DS,BX
+        MOV     DS,DS:[82h]
+        ASSUME  DS:DOSGroup
+        MOV     BX,User_ID
+        CALL    MNUM
+        MOV     AL,':'
+        CALL    OUT
+        MOV     BX,Proc_ID
+        CALL    MNUM
+        RestoreReg  <DS>
+        Assume  DS:NOTHING
+        JMP     FmtLoop
+EndProc PFMT
+
+Procedure   FMTGetArg,NEAR
+        MOV     AX,[BP]
+        SUB     BP,2
+        return
+EndProc FMTGetArg
+
+Procedure   FmtSOut,NEAR
+        LODSB
+        OR      AL,AL
+        retz
+        CALL    OUT
+        JMP     FmtSOut
+EndProc FMTSout
+
+;
+;   MOut - output a message via INT 29h
+;   Inputs:     BX points to bytes to output relative to CS
+;   Outputs:    message
+;   Registers modified: BX
+Procedure   MOut,Near
+        ASSUME  DS:NOTHING,SS:NOTHING,ES:NOTHING
+        PUSHF
+        SaveReg <DS,SI,AX>
+        PUSH    CS
+        POP     DS
+        MOV     SI,BX
+        Call    FMTSout
+        RestoreReg  <AX,SI,DS>
+        POPF
+        return
+EndProc MOut
+
+;   MNum - output a number in BX
+;   Inputs:     BX contains a number
+;   Outputs:    number in hex appears on screen
+;   Registers modified: BX
+
+Procedure   MNum,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        PUSHF
+        SaveReg <ES,DI,AX,BX,CX,SI,DS>
+        PUSH    SS
+        POP     ES
+        SUB     SP,6
+        MOV     DI,SP                   ;   p = MNumBuf;
+        SaveReg <DI>
+        MOV     CX,4                    ;   for (i=0; i < 4; i++)
+DLoop:  SaveReg <CX>
+        MOV     CX,4                    ;       rotate(n, 4);
+        ROL     BX,CL
+        RestoreReg  <CX>
+        MOV     AL,BL
+        AND     AL,0Fh
+        ADD     AL,'0'
+        CMP     AL,'9'
+        JBE     Nok
+        ADD     AL,'A'-'0'-10
+Nok:    STOSB                           ;       *p++ = "0123456789ABCDEF"[n];
+        LOOP    DLoop
+        XOR     AL,AL
+        STOSB                           ;   *p++ = 0;
+        RestoreReg  <SI>
+        PUSH    ES
+        POP     DS
+        CALL    FMTSOUT                 ;   mout (mNumBuf);
+        ADD     SP,6
+        RestoreReg  <DS,SI,CX,BX,AX,DI,ES>
+        POPF
+        return
+EndProc MNum
diff --git a/v4.0/src/DOS/PROC.ASM b/v4.0/src/DOS/PROC.ASM
new file mode 100644
index 0000000..1e54034
--- /dev/null
+++ b/v4.0/src/DOS/PROC.ASM
@@ -0,0 +1,187 @@
+;       SCCSID = @(#)proc.asm   1.1 85/04/10
+TITLE   IBMPROC - process maintenance
+NAME    IBMPROC
+
+;
+; Process related system calls and low level routines for DOS 2.X.
+; I/O specs are defined in DISPATCH.
+;
+;   $WAIT
+;   $EXEC
+;   $Keep_process
+;   Stay_resident
+;   $EXIT
+;   $ABORT
+;   abort_inner
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+SAVEXIT         EQU     10
+
+    i_need  CurrentPDB,WORD
+    i_need  CreatePDB,BYTE
+    i_need  Exit_type,BYTE
+    i_need  INDOS,BYTE
+    i_need  DMAADD,DWORD
+    i_need  DidCTRLC,BYTE
+    i_need  exit_type,BYTE
+    i_need  exit_code,WORD
+    i_need  OpenBuf,128
+    I_need  EXTERR_LOCUS,BYTE           ; Extended Error Locus
+
+SUBTTL $WAIT - return previous process error code
+PAGE
+;
+; process control data
+;
+        i_need  exit_code,WORD          ; code of exit
+
+;
+;   Assembler usage:
+;           MOV     AH, WaitProcess
+;           INT     int_command
+;         AX has the exit code
+        procedure   $WAIT,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+        XOR     AX,AX
+        XCHG    AX,exit_code
+        transfer    SYS_RET_OK
+EndProc $WAIT
+
+include exec.asm
+
+SUBTTL Terminate and stay resident handler
+PAGE
+;
+; Input:    DX is  an  offset  from  CurrentPDB  at which to
+;           truncate the current block.
+;
+; output:   The current block is truncated (expanded) to be [DX+15]/16
+;           paragraphs long.  An exit is simulated via resetting CurrentPDB
+;           and restoring the vectors.
+;
+        procedure   $Keep_process,NEAR
+        ASSUME DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+
+        PUSH    AX                      ; keep exit code around
+        MOV     BYTE PTR [Exit_type],Exit_keep_process
+        MOV     ES,[CurrentPDB]
+        CMP     DX,6h                   ; keep enough space around for system
+        JAE     Keep_shrink             ; info
+        MOV     DX,6h
+keep_shrink:
+        MOV     BX,DX
+        PUSH    BX
+        PUSH    ES
+        invoke  $SETBLOCK               ; ignore return codes.
+        POP     DS
+        POP     BX
+        JC      keep_done               ; failed on modification
+        MOV     AX,DS
+        ADD     AX,BX
+        MOV     DS:[PDB_block_len],AX
+
+keep_done:
+        POP     AX
+        JMP     SHORT exit_inner        ; and let abort take care of the rest
+
+EndProc $Keep_process
+
+        procedure   Stay_resident,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     AX,(Keep_process SHL 8) + 0 ; Lower part is return code
+        ADD     DX,15
+        RCR     DX,1
+        MOV     CL,3
+        SHR     DX,CL
+
+        transfer    COMMAND
+EndProc Stay_resident
+
+SUBTTL $EXIT - return to parent process
+PAGE
+;
+;   Assembler usage:
+;           MOV     AL, code
+;           MOV     AH, Exit
+;           INT     int_command
+;   Error return:
+;           None.
+;
+        procedure   $EXIT,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        XOR     AH,AH
+        XCHG    AH,BYTE PTR [DidCTRLC]
+        OR      AH,AH
+        MOV     BYTE PTR [Exit_type],exit_terminate
+        JZ      exit_inner
+        MOV     BYTE PTR [Exit_type],exit_ctrl_c
+
+        entry   Exit_inner
+
+        invoke  get_user_stack
+        PUSH    [CurrentPDB]
+        POP     [SI.user_CS]
+        JMP     SHORT abort_inner
+EndProc $EXIT
+
+BREAK <$ABORT -- Terminate a process>
+
+; Inputs:
+;       user_CS:00 must point to valid program header block
+; Function:
+;       Restore terminate and Cntrl-C addresses, flush buffers and transfer to
+;       the terminate address
+; Returns:
+;       TO THE TERMINATE ADDRESS
+
+        procedure   $ABORT,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        XOR     AL,AL
+        MOV     [exit_type],exit_abort
+
+;
+; abort_inner must have AL set as the exit code!  The exit type is retrieved
+; from exit_type.  Also, the PDB at user_CS needs to be correct as the one
+; that is terminating.
+;
+        entry   abort_inner
+
+        MOV     AH,[exit_type]
+        MOV     [exit_code],AX
+        invoke  Get_user_stack
+        MOV     DS,[SI.user_CS]         ; set up old interrupts
+        XOR     AX,AX
+        MOV     ES,AX
+        MOV     SI,SAVEXIT
+        MOV     DI,addr_int_terminate
+        MOVSW
+        MOVSW
+        MOVSW
+        MOVSW
+        MOVSW
+        MOVSW
+        transfer    reset_environment
+EndProc $ABORT
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/RENAME.ASM b/v4.0/src/DOS/RENAME.ASM
new file mode 100644
index 0000000..c7d6caf
--- /dev/null
+++ b/v4.0/src/DOS/RENAME.ASM
@@ -0,0 +1,434 @@
+;       SCCSID = @(#)rename.asm 1.1 85/04/10
+TITLE   DOS_RENAME - Internal RENAME call for MS-DOS
+NAME    DOS_RENAME
+; Low level routine for renaming files
+;
+;   DOS_RENAME
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+Installed = TRUE
+
+        i_need  RENAMEDMA,BYTE
+        i_need  AUXSTACK,BYTE
+        i_need  DESTSTART,WORD
+        i_need  DIRSTART,WORD
+        i_need  CURBUF,DWORD
+        I_need  NAME1,BYTE
+        i_need  NAME2,BYTE
+        i_need  WFP_START,WORD
+        i_need  REN_WFP,WORD
+        i_need  CURR_DIR_END,WORD
+        i_need  DMAADD,DWORD
+        i_need  THISCDS,DWORD
+        i_need  THISDPB,DWORD
+        i_need  THISSFT,DWORD
+        i_need  CREATING,BYTE
+        i_need  THISDRV,BYTE
+        i_need  ATTRIB,BYTE
+        i_need  FOUND_DEV,BYTE
+        i_need  FAILERR,BYTE
+        i_need  EXTERR_LOCUS,BYTE
+        i_need  SAVE_BX,WORD
+
+; Inputs:
+;       [WFP_START] Points to SOURCE WFP string ("d:/" must be first 3
+;               chars, NUL terminated)
+;       [CURR_DIR_END] Points to end of Current dir part of string [SOURCE]
+;               ( = -1 if current dir not involved, else
+;                Points to first char after last "/" of current dir part)
+;       [REN_WFP] Points to DEST WFP string ("d:/" must be first 3
+;               chars, NUL terminated)
+;       [THISCDS] Points to CDS being used
+;               (Low word = -1 if NUL CDS (Net direct request))
+;       [SATTRIB] Is attribute of search, determines what files can be found
+; Function:
+;       Rename the specified file(s)
+;       NOTE: This routine uses most of AUXSTACK as a temp buffer.
+; Outputs:
+;       CARRY CLEAR
+;           OK
+;       CARRY SET
+;           AX is error code
+;               error_file_not_found
+;                       No match for source, or dest path invalid
+;               error_not_same_device
+;                       Source and dest are on different devices
+;               error_access_denied
+;                       Directory specified (not simple rename),
+;                       Device name given, Destination exists.
+;                       NOTE: In third case some renames may have
+;                        been done if metas.
+;               error_path_not_found
+;                       Bad path (not in curr dir part if present)
+;                       SOURCE ONLY
+;               error_bad_curr_dir
+;                       Bad path in current directory part of path
+;                       SOURCE ONLY
+;               error_sharing_violation
+;                       Deny both access required, generates an INT 24.
+; DS preserved, others destroyed
+
+        procedure   DOS_RENAME,NEAR
+        DOSAssume   CS,<DS>,"DOS_Rename"
+        ASSUME  ES:NOTHING
+
+        Invoke  TestNet
+        JNC     LOCAL_RENAME
+;       invoke  OWN_SHARE2                     ;IFS.  IFS owns share ?          ;AN000;
+;       JZ      ifsshare                       ;IFS.  yes                       ;AN000;
+;       PUSH    WORD PTR [DMAADD+2]            ;IFS.  save DMAADD               ;AN000;
+;       PUSH    WORD PTR [DMAADD]              ;IFS.                            ;AN000;
+;
+;       invoke  IFS_SEARCH_FIRST               ;IFS.  search source name        ;AN000;
+;       JC      nofiles                        ;IFS.  not found                 ;AN000;
+rename_next_file:
+;       invoke  IFS_REN_DEL_CHECK              ;IFS.  do share check            ;AN000;
+;       JNC     share_okok                     ;IFS.  share ok                  ;AN000;
+;       MOV     AX,error_sharing_violation     ;IFS.  share error               ;AN000;
+;       JMP     SHORT nofiles                  ;IFS.                            ;AN000;
+share_okok:
+;       PUSH    CS                             ;IFS.                            ;AN000;
+;       POP     ES                             ;IFS.                            ;AN000;
+;       MOV     SI,[REN_WFP]                   ;IFS. ds:si -> destination name  ;AN000;
+;       MOV     BX,SI                          ;IFS.                            ;AN000;
+fndnxt:                                        ;IFS.                            ;AN000;
+;       LODSB                                  ;IFS.                            ;AN000;
+;       CMP     AL,0                           ;IFS.                            ;AN000;
+;       JNZ     fndnxt                         ;IFS.                            ;AN000;
+;       MOV     DI,SI                          ;IFS. es:di -> end of destinatio ;AN000;
+;       ADD     BX,2                           ;IFS.                            ;AN000;
+;       invoke  SkipBack                       ;IFS.                            ;AN000;
+;       INC     DI                             ;IFS. es:di -> last component of ;AN000;
+;       MOV     SI,DI                          ;IFS.          dstination        ;AN000;
+;       MOV     BX,[SAVE_BX]                   ;IFS. ds:bx -> last component of ;AN000;
+;       CALL    NEW_RENAME                     ;IFS.          source            ;AN000;
+;       MOV     AX,(multNET SHL 8) OR 17       ;IFS.  replace ? chars with      ;AN000;
+;       INT     2FH                            ;IFS.  source and issue RENAME   ;AN000;
+;       JC      nofiles                        ;IFS.  error                     ;AN000;
+;       invoke  DOS_SEARCH_NEXT                ;IFS.  serch next source         ;AN000;
+;       JNC     rename_next_file               ;IFS.  rename next               ;AN000;
+;       CLC                                    ;IFS.  no more files             ;AN000;
+nofiles:
+;       POP     WORD PTR [DMAADD]              ;IFS. restore DMAADD             ;AN000;
+;       POP     WORD PTR [DMAADD+2]            ;IFS.                            ;AN000;
+;       ret                                    ;IFS. return                     ;AN000;
+ifsshare:
+
+IF NOT Installed
+        transfer NET_RENAME
+ELSE
+        MOV     AX,(multNET SHL 8) OR 17
+        INT     2FH
+        return
+ENDIF
+
+LOCAL_RENAME:
+        MOV     [EXTERR_LOCUS],errLOC_Disk
+        MOV     SI,[WFP_START]
+        MOV     DI,[REN_WFP]
+        MOV     AL,BYTE PTR [SI]
+        MOV     AH,BYTE PTR [DI]
+        OR      AX,2020H                ; Lower case
+        CMP     AL,AH
+        JZ      SAMEDRV
+        MOV     AX,error_not_same_device
+        STC
+        return
+
+SAMEDRV:
+        PUSH    WORD PTR [DMAADD+2]
+        PUSH    WORD PTR [DMAADD]
+        MOV     WORD PTR [DMAADD+2],DS
+        MOV     WORD PTR [DMAADD],OFFSET DOSGROUP:RENAMEDMA
+        MOV     [Found_dev],0           ; Rename fails on DEVS, assume not a dev
+        EnterCrit   critDisk
+        invoke  DOS_SEARCH_FIRST        ; Sets [NoSetDir] to 1, [CURBUF+2]:BX
+                                        ;    points to entry
+        JNC     Check_Dev
+        CMP     AX,error_no_more_files
+        JNZ     GOTERR
+        MOV     AX,error_file_not_found
+GOTERR:
+        STC
+RENAME_POP:
+        POP     WORD PTR [DMAADD]
+        POP     WORD PTR [DMAADD+2]
+        LeaveCrit   critDisk
+        return
+
+Check_dev:
+        MOV     AX,error_access_denied  ; Assume error
+
+        PUSH    DS                            ;PTM.                             ;AN000;
+        LDS     SI,[DMAADD]                   ;PTM.  chek if source a dir       ;AN000;
+        ADD     SI,find_buf_attr              ;PTM.                             ;AN000;
+        TEST    [SI.dir_attr],attr_directory  ;PTM.                             ;AN000;
+        JZ      notdir                        ;PTM.                             ;AN000;
+        MOV     SI,[REN_WFP]                  ;PTM.  if yes, make sure path     ;AN000;
+        invoke  Check_Pathlen2                ;PTM.   length < 67               ;AN000;
+notdir:
+        POP     DS                            ;PTM.                             ;AN000;
+        JA      GOTERR                        ;PTM.                             ;AN000;
+
+        CMP     [Found_dev],0
+        JNZ     GOTERR
+; At this point a source has been found.  There is search continuation info (a
+; la DOS_SEARCH_NEXT) for the source at RENAMEDMA, together with the first
+; directory entry found.
+; [THISCDS], [THISDPB], and [THISDRV] are set and will remain correct
+; throughout the RENAME since it is known at this point that the source and
+; destination are both on the same device.
+; [SATTRIB] is also set.
+        MOV     SI,BX
+        ADD     SI,dir_first
+        invoke  REN_DEL_Check
+        JNC     REN_OK1
+        MOV     AX,error_sharing_violation
+        JMP     RENAME_POP
+
+REN_OK1:                                ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+        invoke  FastOpen_Delete         ; delete dir info in fastopen DOS 3.3
+        MOV     SI,[REN_WFP]            ; Swap source and destination
+        MOV     [WFP_START],SI
+        MOV     [CURR_DIR_END],-1       ; No current dir on dest
+        MOV     WORD PTR [CREATING],0E5FFH  ; Creating, not DEL *.*
+                                        ; A rename is like a CREATE_NEW as far
+                                        ; as the destination is concerned.
+        invoke  GetPathNoSet
+;   If this Getpath fails due to file not found, we know all renames will work
+;   since no files match the destination name.  If it fails for any other
+;   reason, the rename fails on a path not found, or whatever (also fails if
+;   we find a device or directory).  If the Getpath succeeds, we aren't sure
+;   if the rename should fail because we haven't built an explicit name by
+;   substituting for the meta chars in it.  In this case the destination file
+;   spec with metas is in [NAME1] and the explicit source name is at RENAMEDMA
+;   in the directory entry part.
+        JC      NODEST
+;;      JZ      BAD_ACC                 ; Dest string is a directory            ;AC000;
+        OR      AH,AH                   ; Device?
+        JNS     SAVEDEST                ; No, continue
+BAD_ACC:
+        MOV     AX,error_access_denied
+        STC
+RENAME_CLEAN:
+        PUSHF                           ; Save carry state
+        PUSH    AX                      ; and error code (if carry set)
+        MOV     AL,[THISDRV]
+        invoke  FLUSHBUF
+        POP     AX
+        CMP     [FAILERR],0
+        JNZ     BAD_ERR                 ; User FAILed to I 24
+        POPF
+        JMP     RENAME_POP
+
+BAD_ERR:
+        POP     AX                      ; Saved flags
+        MOV     AX,error_path_not_found
+        JMP     GOTERR
+
+NODEST:
+        JNZ     BAD_PATH
+        CMP     [FAILERR],0
+        JNZ     BAD_PATH        ; Search for dest failed because user FAILed on
+                                ;       I 24
+        OR      CL,CL
+        JNZ     SAVEDEST
+BAD_PATH:
+        MOV     AX,error_path_not_found
+        STC
+        JMP     RENAME_POP
+
+SAVEDEST:
+        Context ES
+        MOV     DI,OFFSET DOSGROUP:NAME2
+        MOV     SI,OFFSET DOSGROUP:NAME1
+        MOV     CX,11
+        REP     MOVSB                   ; Save dest with metas at NAME2
+        MOV     AX,[DIRSTART]
+        MOV     [DESTSTART],AX
+BUILDDEST:
+        Context ES                      ; needed due to JMP BUILDDEST below
+        MOV     BX,OFFSET DOSGROUP:RENAMEDMA + 21   ; Source of replace chars
+        MOV     DI,OFFSET DOSGROUP:NAME1    ; Real dest name goes here
+        MOV     SI,OFFSET DOSGROUP:NAME2    ; Raw dest
+        MOV     CX,11
+        CALL    NEW_RENAME                  ;IFS. replace ? chars               ;AN000;
+
+        MOV     [ATTRIB],attr_all       ; Stop duplicates with any attributes
+        MOV     [CREATING],0FFH
+        invoke  DEVNAME                 ; Check if we built a device name
+        ASSUME  ES:NOTHING
+        JNC     BAD_ACC
+        MOV     BX,[DESTSTART]
+        LES     BP,[THISDPB]
+        invoke  SetDirSrch              ; Reset search to start of dir
+        JC      BAD_ACC                 ; Screw up
+        invoke  FINDENTRY               ; See if new name already exists
+        JNC     BAD_ACC                 ; Error if found
+        CMP     [FAILERR],0
+        JNZ     BAD_ACCJ                ; Find failed because user FAILed to I 24
+        MOV     AX,[DESTSTART]          ; DIRSTART of dest
+        CMP     AX,WORD PTR [RENAMEDMA + 15]    ; DIRSTART of source
+        JZ      SIMPLE_RENAME           ; If =, just give new name
+
+        MOV     AL,[RENAMEDMA + 21 + dir_attr]
+        TEST    AL,attr_directory
+        JNZ     BAD_ACCJ                ; Can only do a simple rename on dirs,
+                                        ; otherwise the .  and ..  entries get
+                                        ; wiped.
+        MOV     [ATTRIB],AL
+        MOV     WORD PTR [THISSFT+2],DS
+        MOV     SI,OFFSET DOSGROUP:AUXSTACK - SIZE SF_ENTRY
+        MOV     WORD PTR [THISSFT],SI
+        MOV     [SI].sf_mode,sharing_compat+open_for_both
+        XOR     CX,CX                   ; Set "device ID" for call into makenode
+        invoke  RENAME_MAKE             ; This is in mknode
+        JNC     GOT_DEST
+BAD_ACCJ:
+        JMP     BAD_ACC
+
+GOT_DEST:
+        SaveReg <BX>
+        LES     DI,ThisSFT              ; Rename_make entered this into sharing
+        Invoke  ShareEnd                ; we need to remove it.
+        RestoreReg  <BX>
+; A zero length entry with the correct new name has now been made at
+;   [CURBUF+2]:BX.
+        LES     DI,[CURBUF]
+        Assert  ISBUF,<ES,DI>,"Got_Dest"
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI.buf_flags],buf_dirty
+yesdirty:
+        MOV     DI,BX
+        ADD     DI,dir_attr             ; Skip name
+        MOV     SI,OFFSET DOSGROUP:RENAMEDMA + 21 + dir_attr
+        MOV     CX,(SIZE dir_entry) - dir_attr
+        REP     MOVSB
+        CALL    GET_SOURCE
+        JC      RENAME_OVER
+        MOV     DI,BX
+        MOV     ES,WORD PTR [CURBUF+2]
+        MOV     AL,0E5H
+        STOSB                           ; "free" the source
+        JMP     SHORT DIRTY_IT
+
+SIMPLE_RENAME:
+        CALL    GET_SOURCE              ; Get the source back
+        JC      RENAME_OVER
+        MOV     DI,BX
+        MOV     ES,WORD PTR [CURBUF+2]
+        MOV     SI,OFFSET DOSGROUP:NAME1    ; New Name
+        MOV     CX,11
+        REP     MOVSB
+DIRTY_IT:
+        MOV     DI,WORD PTR [CURBUF]
+
+        TEST    ES:[DI.buf_flags],buf_dirty  ;LB. if already dirty              ;AN000;
+        JNZ     yesdirty2                 ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      ES:[DI.buf_flags],buf_dirty
+yesdirty2:
+        Assert  ISBUF,<ES,DI>,"Dirty_it"
+NEXT_SOURCE:
+        MOV     SI,OFFSET DOSGROUP:RENAMEDMA + 1    ;Name
+;
+; WARNING!  Rename_Next leaves the disk critical section *ALWAYS*.  We need
+; to enter it before going to RENAME_Next.
+;
+        EnterCrit   critDisk
+        MOV     [CREATING],0    ; Correct setting for search (we changed it
+                                ;   to FF when we made the prev new file).
+        invoke  RENAME_NEXT
+;
+; Note, now, that we have exited the previous ENTER and so are back to where
+; we were before.
+;
+        JC      RENAME_OVER
+        LEA     SI,[BX].dir_First
+        invoke  REN_DEL_Check
+        JNC     REN_OK2
+        MOV     AX,error_sharing_violation
+        JMP     RENAME_CLEAN
+
+REN_OK2:                                ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+        invoke  FastOpen_Delete         ; delete dir info in fastopen DOS 3.3
+        JMP     BUILDDEST
+
+RENAME_OVER:
+        CLC
+        JMP     RENAME_CLEAN
+
+; Inputs:
+;       RENAMEDMA has source info
+; Function:
+;       Re-find the source
+; Output:
+;       [CURBUF] set
+;       [CURBUF+2]:BX points to entry
+;       Carry set if error (currently user FAILed to I 24)
+; DS preserved, others destroyed
+
+GET_SOURCE:
+        DOSAssume   CS,<DS>,"Get_Source"
+        ASSUME  ES:NOTHING
+
+        MOV     BX,WORD PTR [RENAMEDMA + 15]    ; DirStart
+        LES     BP,ThisDPB
+        invoke  SetDirSrch
+        retc
+        invoke  StartSrch
+        MOV     AX,WORD PTR [RENAMEDMA + 13]    ; Lastent
+        invoke  GetEnt
+        return
+
+EndProc DOS_RENAME
+
+;Input: DS:SI -> raw string with ?
+;       ES:DI -> destination string
+;       DS:BX -> source string
+;Function: replace ? chars of raw string with chars in source string and
+;          put in destination string
+;Output: ES:DI-> new string
+
+
+
+        procedure   NEW_RENAME,NEAR
+        DOSAssume   CS,<DS>,"DOS_Rename"
+        ASSUME  ES:NOTHING
+NEWNAM:
+        LODSB
+        CMP     AL,"?"
+        JNZ     NOCHG
+        MOV     AL,[BX]                 ; Get replace char
+NOCHG:
+        STOSB
+        INC     BX                      ; Next replace char
+        LOOP    NEWNAM
+        return
+
+EndProc NEW_RENAME
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/ROM.ASM b/v4.0/src/DOS/ROM.ASM
new file mode 100644
index 0000000..ca34409
--- /dev/null
+++ b/v4.0/src/DOS/ROM.ASM
@@ -0,0 +1,938 @@
+;       SCCSID = @(#)rom.asm    1.1 85/04/10
+TITLE   ROM - Miscellaneous routines
+NAME    ROM
+; Misc Low level routines for doing simple FCB computations, Cache
+;       reads and writes, I/O optimization, and FAT allocation/deallocation
+;
+;   SKPCLP
+;   FNDCLUS
+;   BUFSEC
+;   BUFRD
+;   BUFWRT
+;   NEXTSEC
+;   OPTIMIZE
+;   FIGREC
+;   ALLOCATE
+;   RESTFATBYT
+;   RELEASE
+;   RELBLKS
+;   GETEOF
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+;
+; get the appropriate segment definitions
+;
+.xlist
+include dosseg.asm
+include fastseek.inc                           ; DOS 4.00
+include fastxxxx.inc                           ; DOS 4.00
+include version.inc
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+include EA.inc
+.cref
+.list
+
+        i_need  CLUSNUM,WORD
+        i_need  NEXTADD,WORD
+        i_need  LASTPOS,WORD
+        i_need  SECCLUSPOS,BYTE
+        i_need  FATBYT,WORD
+        i_need  THISSFT,DWORD
+        i_need  TRANS,BYTE
+        i_need  BYTCNT1,WORD
+        i_need  CURBUF,DWORD
+        i_need  BYTSECPOS,WORD
+        i_need  DMAADD,WORD
+        i_need  SECPOS,DWORD                         ;F.C. >32mb
+        i_need  VALSEC,DWORD                         ;F.C. >32mb
+        i_need  ALLOWED,BYTE
+        i_need  FSeek_drive,BYTE                     ; DOS 3.4
+        i_need  FSeek_firclus,WORD                   ; DOS 3.4
+        i_need  FSeek_logclus,WORD                   ; DOS 3.4
+        i_need  FSeek_logsave,WORD                   ; DOS 3.4
+        i_need  FastSeekFlg,BYTE                     ; DOS 3.4
+        i_need  XA_condition,BYTE                    ; DOS 3.4
+        i_need  HIGH_SECTOR,WORD                     ; DOS 3.4
+        i_need  DISK_FULL,BYTE                       ; DOS 3.4
+        i_need  Temp_VAR2,WORD                       ; DOS 3.4
+
+
+
+Break   <FNDCLUS -- Skip over allocation units>
+
+; Inputs:
+;       CX = No. of clusters to skip
+;       ES:BP = Base of drive parameters
+;       [THISSFT] point to SFT
+; Outputs:
+;       BX = Last cluster skipped to
+;       CX = No. of clusters remaining (0 unless EOF)
+;       DX = Position of last cluster
+;       Carry set if error (currently user FAILed to I 24)
+; DI destroyed. No other registers affected.
+
+        procedure   FNDCLUS,NEAR
+        DOSAssume   CS,<DS>,"FndClus"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"FndCLus"
+;; 10/31/86 FastSeek
+        PUSH    ES
+        LES     DI,[THISSFT]
+        Assert      ISSFT,<ES,DI>,"FndClus"
+        MOV     [FSeek_logclus],CX                ; presume CX is the position  ;AN000;
+        MOV     BX,ES:[DI.sf_lstclus]
+        MOV     DX,ES:[DI.sf_cluspos]
+;; 10/31/86 FastSeek
+        OR      BX,BX
+        JNZ     YCLUS
+        JMP     NOCLUS
+YCLUS:
+        SUB     CX,DX
+        JNB     FINDIT
+        ADD     CX,DX
+        XOR     DX,DX
+        MOV     BX,ES:[DI.sf_firclus]
+FINDIT:
+;; 10/31/86 FastSeek
+
+
+        POP     ES
+        OR      CX,CX
+        JNZ     skpclp
+        JMP     RET10
+
+entry   SKPCLP
+        TEST    [FastSeekflg],Fast_yes            ; fastseek installed?         ;AN000;
+        JZ      do_norm                           ; no                          ;AN000;
+        TEST    [FastSeekflg],FS_begin            ; do fastseek                 ;AN000;
+        JZ      do_norm                           ; no                          ;AN000;
+        TEST    [FastSeekflg],FS_insert           ; is in insert mode ?         ;AN000;
+        JNZ     do_norm                           ; yes                         ;AN000;
+        MOV     [Temp_Var2],BX                    ; save physical cluster       ;AN000;
+                                                  ; PTR P005079
+SKPCLP2:
+        invoke  FastSeek_Lookup                   ; ask for next cluster #      ;AN000;
+        JNC     clusfound                         ; yes, we got it              ;AN000;
+        CMP     DI,1                              ; valid drive ,e.g. C,D...    ;AN000;
+        JNZ     par_found                         ; yes,                        ;AN000;
+        AND     [FastSeekflg],Fast_yes            ; no more, fastseek           ;AN000;
+        JMP     SHORT do_norm                                                   ;AN000;
+                                                                                ;AN000;
+par_found:
+        CALL    FS_Trunc_EOF                      ; check EOF and truncate      ;AN000;
+        JNC     SKPCLP2                           ; redo lookup                 ;AN000;
+noteof:
+        OR      [FastSeekflg],FS_insert           ; no, start to insert         ;AN000;
+        CMP     DX,[FSeek_logsave]                ; is current better than new? ;AN000;
+        JBE     OnCache                           ; no, let's use new           ;AN000;
+        MOV     [FSeek_logclus],DX                ; use current                 ;AN000;
+        MOV     BX,[Temp_Var2]                    ; retore pysical cluster      ;AN000;
+        MOV     DI,BX                             ; insert cureent cluster      ;AN000;
+        invoke  FastSeek_Insert                   ; insert cluster # to         ;AN000;
+        INC     [FSeek_logclus]                   ; get next inserted position  ;AN000;
+        JMP     SHORT do_norm
+OnCache:
+        MOV     CX,[FSeek_logclus]                ; get the number of clusters  ;AN000;
+        SUB     CX,[FSeek_logsave]                ; we need to skip             ;AN000;
+        MOV     DX,[FSeek_logsave]                ; cluster position            ;AN000;
+dodo:
+        INC     [FSeek_logsave]                   ; get next inserted position  ;AN000;
+        PUSH    [FSeek_logsave]                   ; logclus=logsave             ;AN000;
+        POP     [FSeek_logclus]                                                 ;AN000;
+
+do_norm:
+
+        invoke  UNPACK
+        retc
+
+        invoke  FastSeek_Insert                   ; insert cluster # to         ;AN000;
+cluss:                                                                          ;AN000;
+        PUSH    BX                                ; FastSeek                    ;AN000;
+        MOV     BX,DI
+        Invoke  IsEOF
+        POP     BX
+        JAE     RET10
+        XCHG    BX,DI
+        INC     DX
+        INC     [FSeek_logclus]                  ; increment for next inserted  ;AN000;
+        LOOP    SKPCLPX
+        JMP     short  RET10
+SKPCLPX:
+        JMP     SKPCLP
+RET10:                                                                          ;AN000;
+        AND     [FastSeekflg],FS_no_insert       ; clear insert mode
+        CLC
+        return
+NOCLUS:
+        POP     ES
+        INC     CX
+        DEC     DX
+        CLC
+        return
+clusfound:
+        MOV     DX,[FSeek_logclus]                ; get cluster position        ;AN000;
+        MOV     BX,[FSeek_logsave]                ; bx=previous cluster # PTM   ;AN000;
+        DEC     DX                                                              ;AN000;
+        MOV     CX,1                              ; we found it                 ;AN000;
+        JMP     cluss                                                           ;AN000;
+
+EndProc FNDCLUS
+
+Break  <BUFSEC -- BUFFER A SECTOR AND SET UP A TRANSFER>
+
+; Inputs:
+;       AH = priority of buffer
+;       AL = 0 if buffer must be read, 1 if no pre-read needed
+;       ES:BP = Base of drive parameters
+;       [CLUSNUM] = Physical cluster number
+;       [SECCLUSPOS] = Sector position of transfer within cluster
+;       [BYTCNT1] = Size of transfer
+; Function:
+;       Insure specified sector is in buffer, flushing buffer before
+;       read if necessary.
+; Outputs:
+;       ES:DI = Pointer to buffer
+;       SI = Pointer to transfer address
+;       CX = Number of bytes
+;       [NEXTADD] updated
+;       [TRANS] set to indicate a transfer will occur
+;       Carry set if error (user FAILed to I 24)
+
+        procedure   BUFSEC,NEAR
+        DOSAssume   CS,<DS>,"BufSec"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"BufSec"
+        MOV     DX,[CLUSNUM]
+        MOV     BL,[SECCLUSPOS]
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY + allowed_IGNORE
+        CALL    FIGREC
+        invoke  GETBUFFR
+        retc
+        MOV     BYTE PTR [TRANS],1      ; A transfer is taking place
+        MOV     SI,[NEXTADD]
+        MOV     DI,SI
+        MOV     CX,[BYTCNT1]
+        ADD     DI,CX
+        MOV     [NEXTADD],DI
+        LES     DI,[CURBUF]
+        Assert  ISBUF,<ES,DI>,"BufSec"
+        OR      ES:[DI.buf_flags],buf_isDATA
+        LEA     DI,[DI].BUFINSIZ        ; Point to buffer
+        ADD     DI,[BYTSECPOS]
+        CLC
+        return
+EndProc BUFSEC
+
+Break   <BUFRD, BUFWRT -- PERFORM BUFFERED READ AND WRITE>
+
+; Do a partial sector read via one of the system buffers
+; ES:BP Points to DPB
+; Carry set if error (currently user FAILed to I 24)
+
+        procedure   BUFRD,NEAR
+        DOSAssume   CS,<DS>,"BufRd"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"BufRd"
+        PUSH    ES
+        MOV     AX,0
+        CALL    BUFSEC
+        JNC     BUF_OK
+BUF_IO_FAIL:
+        POP     ES
+        JMP     SHORT RBUFPLACED
+
+BUF_OK:
+        MOV     BX,ES
+        MOV     ES,[DMAADD+2]
+        MOV     DS,BX
+ASSUME  DS:NOTHING
+        XCHG    DI,SI
+        SHR     CX,1
+        JNC     EVENRD
+        MOVSB
+EVENRD:
+        REP     MOVSW
+        POP     ES
+        LDS     DI,[CURBUF]
+        Assert  ISBUF,<DS,DI>,"BufRD/EvenRD"
+        LEA     BX,[DI.BufInSiz]
+        SUB     SI,BX                   ; Position in buffer
+        invoke  PLACEBUF
+        Assert  ISDPB,<ES,BP>,"BufRD/EvenRD"
+        CMP     SI,ES:[BP.dpb_sector_size] ; Read Last byte?
+        JB      RBUFPLACEDC             ; No, leave buf where it is
+        invoke  PLACEHEAD               ; Make it prime candidate for chucking
+                                        ;  even though it is MRU.
+RBUFPLACEDC:
+        CLC
+RBUFPLACED:
+        PUSH    SS
+        POP     DS
+        return
+EndProc BUFRD
+
+; Do a partial sector write via one of the system buffers
+; ES:BP Points to DPB
+; Carry set if error (currently user FAILed to I 24)
+
+        procedure   BUFWRT,NEAR
+        DOSAssume   CS,<DS>,"BufWrt"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"BufWrt"
+        MOV     AX,WORD PTR [SECPOS]
+        ADD     AX,1            ; Set for next sector
+        MOV     WORD PTR [SECPOS],AX      ;F.C. >32mb                           ;AN000;
+        ADC     WORD PTR [SECPOS+2],0     ;F.C. >32mb                           ;AN000;
+        MOV     AX,WORD PTR [SECPOS+2]    ;F.C. >32mb                           ;AN000;
+        CMP     AX,WORD PTR [VALSEC+2]    ;F.C. >32mb                           ;AN000;
+        MOV     AL,1                      ;F.C. >32mb                           ;AN000;
+        JA      NOREAD                    ;F.C. >32mb                           ;AN000;
+        JB      doread                    ;F.C. >32mb                           ;AN000;
+        MOV     AX,WORD PTR [SECPOS]      ;F.C. >32mb                           ;AN000;
+        CMP     AX,WORD PTR [VALSEC]     ; Has sector been written before?
+        MOV     AL,1
+        JA      NOREAD          ; Skip preread if SECPOS>VALSEC
+doread:
+        XOR     AL,AL
+NOREAD:
+        PUSH    ES
+        CALL    BUFSEC
+        JC      BUF_IO_FAIL
+        MOV     DS,[DMAADD+2]
+ASSUME  DS:NOTHING
+        SHR     CX,1
+        JNC     EVENWRT
+        MOVSB
+EVENWRT:
+        REP     MOVSW
+        POP     ES
+        LDS     BX,[CURBUF]
+        Assert  ISBUF,<DS,BX>,"BufWrt/EvenWrt"
+
+        TEST    [BX.buf_flags],buf_dirty  ;LB. if already dirty                 ;AN000;
+        JNZ     yesdirty                  ;LB.    don't increment dirty count   ;AN000;
+        invoke  INC_DIRTY_COUNT           ;LB.                                  ;AN000;
+        OR      [BX.buf_flags],buf_dirty
+yesdirty:
+        LEA     SI,[BX.BufInSiz]
+        SUB     DI,SI                   ; Position in buffer
+        MOV     SI,DI
+        MOV     DI,BX
+        invoke  PLACEBUF
+        Assert  ISDPB,<ES,BP>,"BufWrt/EvenWrt"
+        CMP     SI,ES:[BP.dpb_sector_size]  ; Written last byte?
+        JB      WBUFPLACED              ; No, leave buf where it is
+        invoke  PLACEHEAD               ; Make it prime candidate for chucking
+                                        ;  even though it is MRU.
+WBUFPLACED:
+        CLC
+        PUSH    SS
+        POP     DS
+        return
+EndProc BUFWRT
+
+Break   <NEXTSEC -- Compute next sector to read or write>
+
+; Compute the next sector to read or write
+; ES:BP Points to DPB
+
+        procedure   NEXTSEC,NEAR
+        DOSAssume   CS,<DS>,"NextSec"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"NextSec"
+        TEST    BYTE PTR [TRANS],-1
+        JZ      CLRET
+        MOV     AL,[SECCLUSPOS]
+        INC     AL
+        CMP     AL,ES:[BP.dpb_cluster_mask]
+        JBE     SAVPOS
+        MOV     BX,[CLUSNUM]
+        Invoke  IsEOF
+        JAE     NONEXT
+;; 11/5/86 FastSeek
+        TEST    [FastSeekflg],Fast_yes            ; fastseek installed?         ;AN000;
+        JZ      do_norm2                          ; no                          ;AN000;
+        PUSH    [LASTPOS]               ; save logical cluster #                ;AN000;
+        POP     [FSeek_logclus]                                                 ;AN000;
+        INC     [FSeek_logclus]         ; get next cluster                      ;AN000;
+                                                                                ;AN000;
+        TEST    [FastSeekflg],FS_begin  ; from R/W                              ;AN000;
+        JZ      do_norm2                ; no                                    ;AN000;
+look2:                                                                          ;AN000;
+        invoke  FastSeek_Lookup         ; call lookup                           ;AN000;
+        JNC     clusgot                 ; found one                             ;AN000;
+
+        CMP     DI,1                              ; valid drive ,e.g. C,D...    ;AN000;
+        JNZ     parfound2                         ; yes,                        ;AN000;
+        AND     [FastSeekflg],Fast_yes            ; no more, fastseek           ;AN000;
+        JMP     SHORT do_norm2                                                  ;AN000;
+parfound2:
+        CALL    FS_TRUNC_EOF            ; check EOF                             ;AN000;
+        MOV     BX,[CLUSNUM]            ; don't need partially found cluster
+        OR      [FastSeekflg],FS_insert ; prepared for cluster insertion        ;AN000;
+                                        ; use the old bx                        ;AN000;
+                                                                                ;AN000;
+do_norm2:
+        invoke  UNPACK
+        JC      NONEXT
+        invoke  FastSeek_Insert         ; call insert                           ;AN000;
+        AND     [FastSeekflg],FS_no_insert  ; clear insert flag                 ;AN000;
+                                                                                ;AN000;
+clusgot:
+;; 11/5/86 FastSeek
+        MOV     [CLUSNUM],DI
+        INC     [LASTPOS]
+        MOV     AL,0
+SAVPOS:
+        MOV     [SECCLUSPOS],AL
+CLRET:
+        CLC
+        return
+NONEXT:
+        STC
+        return
+EndProc NEXTSEC
+
+Break   <OPTIMIZE -- DO A USER DISK REQUEST WELL>
+
+; Inputs:
+;       BX = Physical cluster
+;       CX = No. of records
+;       DL = sector within cluster
+;       ES:BP = Base of drives parameters
+;       [NEXTADD] = transfer address
+; Outputs:
+;       AX = No. of records remaining
+;       BX = Transfer address
+;       CX = No. or records to be transferred
+;       DX = Physical sector address            (LOW)
+;       [HIGH_SECTOR] = Physical sector address (HIGH)
+;       DI = Next cluster
+;       [CLUSNUM] = Last cluster accessed
+;       [NEXTADD] updated
+;       Carry set if error (currently user FAILed to I 24)
+; ES:BP unchanged. Note that segment of transfer not set.
+
+        procedure   OPTIMIZE,NEAR
+        DOSAssume   CS,<DS>,"Optimize"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"Optimize"
+        PUSH    DX
+        PUSH    BX
+        MOV     AL,ES:[BP.dpb_cluster_mask]
+        INC     AL              ; Number of sectors per cluster
+        MOV     AH,AL
+        SUB     AL,DL           ; AL = Number of sectors left in first cluster
+        MOV     DX,CX
+        MOV     CX,0
+;;; 11/5/86 FastSeek
+        PUSH    [LASTPOS]               ; save logical cluster #                ;AN000;
+        POP     [FSeek_logclus]                                                 ;AN000;
+        INC     [FSeek_logclus]         ; get next cluster                      ;AN000;
+                                                                                ;AN000;
+OPTCLUS:
+; AL has number of sectors available in current cluster
+; AH has number of sectors available in next cluster
+; BX has current physical cluster
+; CX has number of sequential sectors found so far
+; DX has number of sectors left to transfer
+; ES:BP Points to DPB
+; ES:SI has FAT pointer
+
+        TEST    [FastSeekflg],Fast_yes            ; fastseek installed?         ;AN000;
+        JZ      do_norm3                          ; no                          ;AN000;
+        TEST    [FastSeekflg],FS_begin            ; from R/W                    ;AN000;
+        JZ      do_norm3                          ; no                          ;AN000;
+        TEST    [FastSeekflg],FS_insert           ; is in insert mode ?         ;AN000;
+        JNZ     do_norm3                          ; yes                         ;AN000;
+        invoke  FastSeek_Lookup                   ; call lookup                 ;AN000;
+        JNC     clusgot2                          ; found one                   ;AN000;
+
+        CMP     DI,1                              ; valid drive ,e.g. C,D...    ;AN000;
+        JNZ     par_found3                        ; yes,                        ;AN000;
+        AND     [FastSeekflg],Fast_yes            ; no more, fastseek           ;AN000;
+        JMP     SHORT do_norm3                                                  ;AN000;
+par_found3:
+        PUSH    BX
+        CALL    FS_TRUNC_EOF                      ; file entry not existing     ;AN000;
+        POP     BX                                                              ;AN000;
+        OR      [FastSeekflg],FS_insert           ; prepare for insertion       ;AN000;
+                                                  ; use old bx                  ;AN000;
+do_norm3:
+        invoke  UNPACK
+        JC      OP_ERR
+clusgot2:
+        invoke  FastSeek_Insert         ; call insert                           ;AN000;
+        INC     [FSeek_logclus]         ; insert to next position               ;AN000;
+;;; 11/5/86 FastSeek                                                            ;AN000;
+        ADD     CL,AL
+        ADC     CH,0
+        CMP     CX,DX
+        JAE     BLKDON
+        MOV     AL,AH
+        INC     BX
+        CMP     DI,BX
+        JZ      OPTCLUS
+        DEC     BX
+FINCLUS:
+        MOV     [CLUSNUM],BX    ; Last cluster accessed
+        SUB     DX,CX           ; Number of sectors still needed
+        PUSH    DX
+        MOV     AX,CX
+        MUL     ES:[BP.dpb_sector_size]  ; Number of sectors times sector size
+        MOV     SI,[NEXTADD]
+        ADD     AX,SI           ; Adjust by size of transfer
+        MOV     [NEXTADD],AX
+        POP     AX              ; Number of sectors still needed
+        POP     DX              ; Starting cluster
+        SUB     BX,DX           ; Number of new clusters accessed
+        ADD     [LASTPOS],BX
+        POP     BX              ; BL = sector postion within cluster
+        invoke  FIGREC
+        MOV     BX,SI
+        AND     [FastSeekflg],FS_no_insert  ; clear insert flag
+        CLC
+        return
+
+OP_ERR:
+        ADD     SP,4
+        AND     [FastSeekflg],FS_no_insert  ; clear insert flag
+        STC
+        return
+
+BLKDON:
+        SUB     CX,DX           ; Number of sectors in cluster we don't want
+        SUB     AH,CL           ; Number of sectors in cluster we accepted
+        DEC     AH              ; Adjust to mean position within cluster
+        MOV     [SECCLUSPOS],AH
+        MOV     CX,DX           ; Anyway, make the total equal to the request
+        JMP     SHORT FINCLUS
+EndProc OPTIMIZE
+
+Break   <FIGREC -- Figure sector in allocation unit>
+
+; Inputs:
+;       DX = Physical cluster number
+;       BL = Sector postion within cluster
+;       ES:BP = Base of drive parameters
+; Outputs:
+;       DX = physical sector number           (LOW)
+;       [HIGH_SECTOR] Physical sector address (HIGH)
+; No other registers affected.
+
+        procedure   FIGREC,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"FigRec"
+        PUSH    CX
+        MOV     CL,ES:[BP.dpb_cluster_shift]
+        DEC     DX
+        DEC     DX
+        MOV     [HIGH_SECTOR],0              ;F.C. >32mb
+        OR      CL,CL                        ;F.C. >32mb
+        JZ      noshift                      ;F.C. >32mb
+        XOR     CH,CH                        ;F.C. >32mb
+rotleft:                                     ;F.C. >32mb
+        CLC                                  ;F.C. >32mb
+        RCL     DX,1                         ;F.C. >32mb
+        RCL     [HIGH_SECTOR],1              ;F.C. >32mb
+        LOOP    rotleft                      ;F.C. >32mb
+noshift:
+
+;       SHL     DX,CL
+        OR      DL,BL
+        ADD     DX,ES:[BP.dpb_first_sector]
+        ADC     [HIGH_SECTOR],0              ;F.C. >32mb
+        POP     CX
+        return
+EndProc FIGREC
+
+Break   <ALLOCATE -- Assign disk space>
+
+;***    ALLOCATE - Allocate Disk Space
+;
+;   ALLOCATE is called to allocate disk clusters.  The new clusters are
+;   FAT-chained onto the end of the existing file.
+;
+;   The DPB contains the cluster # of the last free cluster allocated
+;   (dpb_next_free).  We start at this cluster and scan towards higher
+;   numbered clusters, looking for the necessary free blocks.
+;
+;   Once again, fancy terminology gets in the way of corrct coding.  When
+;   using next_free, start scanning AT THAT POINT and not the one following it.
+;   This fixes the boundary condition bug when only free = next_free = 2.
+;
+;       If we get to the end of the disk without satisfaction:
+;
+;           if (dpb_next_free == 2) then we've scanned the whole disk.
+;               return (insufficient_disk_space)
+;           ELSE
+;               dpb_next_free = 2; start scan over from the beginning.
+;
+;   Note that there is no multitasking interlock.  There is no race when
+;   examining the entrys in an in-core FAT block since there will be no
+;   context switch.  When UNPACK context switches while waiting for a FAT read
+;   we are done with any in-core FAT blocks, so again there is no race.  The
+;   only special concern is that V2 and V3 MSDOS left the last allocated
+;   cluster as "00"; marking it EOF only when the entire alloc request was
+;   satisfied.  We can't allow another activation to think this cluster is
+;   free, so we give it a special temporary mark to show that it is, indeed,
+;   allocated.
+;
+;   Note that when we run out of space this algorithem will scan from
+;   dpb_next_free to the end, then scan from cluster 2 through the end,
+;   redundantly scanning the later part of the disk.  This only happens when
+;   we run out of space, so sue me.
+;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;            C  A  V  E  A  T     P  A  T  T  E  R  S  O  N                ;
+;                                                                          ;
+;   The use of FATBYT and RESTFATBYT is somewhat mysterious.  Here is the
+;   explanation:
+;
+;   In the NUL file case (sf_firclus currently 0) ALLOCATE is called with
+;   entry BX = 0.  What needs to be done in this case is to stuff the cluster
+;   number of the first cluster allocated in sf_firclus when the ALLOCATE is
+;   complete.  THIS VALUE IS SAVED TEMPORARILY IN CLUSTER 0, HENCE THE CURRENT
+;   VALUE IN CLUSTER 0 MUST BE SAVED AND RESTORED.  This is a side effect of
+;   the fact that PACK and UNPACK don't treat requests for clusters 0 and 1 as
+;   errors.  This "stuff" is done by the call to PACK which is right before
+;   the
+;           LOOP    findfre         ; alloc more if needed
+;   instruction when the first cluster is allocated to the nul file.  The
+;   value is recalled from cluster 0 and stored at sf_firclus at ads4:
+;
+;   This method is obviously useless (because it is non-reentrant) for
+;   multitasking, and will have to be changed.  Storing the required value on
+;   the stack is recommended.  Setting sf_firclus at the PACK of cluster 0
+;   (instead of actually doing the PACK) is BAD because it doesn't handle
+;   problems with INT 24 well.
+;
+;            C  A  V  E  A  T     P  A  T  T  E  R  S  O  N                ;
+;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
+;                                                                          ;
+;       ENTRY   BX = Last cluster of file (0 if null file)
+;               CX = No. of clusters to allocate
+;               ES:BP = Base of drive parameters
+;               [THISSFT] = Points to SFT
+;
+;       EXIT    'C' set if insufficient space
+;                 [FAILERR] can be tested to see the reason for failure
+;                 CX = max. no. of clusters that could be added to file
+;               'C' clear if space allocated
+;                 BX = First cluster allocated
+;                 FAT is fully updated
+;                 sf_FIRCLUS field of SFT set if file was null
+;
+;       USES    ALL but SI, BP
+
+        PROCEDURE   ALLOCATE,NEAR
+
+        DOSAssume   CS,<DS>,"Allocate"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"Allocate"
+        PUSH    BX                      ; save (bx)
+        XOR     BX,BX
+        invoke  UNPACK
+        MOV     [FATBYT],DI             ; save correct cluster 0 value
+        POP     BX
+        retc                            ; abort if error   [INTERR?]
+
+        PUSH    CX
+        PUSH    BX
+
+        MOV     DX,BX
+        Assert      ISDPB,<ES,BP>,"Allocate/Unpack"
+        mov     bx,es:[bp.dpb_next_free]
+        cmp     bx,2
+        ja      findfre
+
+;   couldn't find enough free space beyond dpb_next_free, or dpb_next_free is
+;   <2 or >dpb_max_clus.  Reset it and restart the scan
+
+ads1:
+        Assert      ISDPB,<ES,BP>,"Alloc/ads1"
+        mov     es:[bp.dpb_next_free],2
+        mov     bx,1                    ; Counter next instruction so first
+                                        ;       cluster examined is 2
+
+;   Scanning both forwards and backwards for a free cluster
+;
+;       (BX) = forwards scan pointer
+;       (CX) = clusters remaining to be allocated
+;       (DX) = current last cluster in file
+;       (TOS) = last cluster of file
+
+FINDFRE:
+        INC     BX
+        Assert      ISDPB,<ES,BP>,"Alloc/findfre"
+        CMP     BX,ES:[BP.dpb_max_cluster]
+        JBE     aupk
+        jmp     ads7            ; at end of disk
+aupk:
+        invoke  UNPACK          ; check out this cluster
+        jc      ads4            ; FAT error             [INTERR?]
+        jnz     findfre         ; not free, keep on truckin
+
+;   Have found a free cluster.  Chain it to the file
+;
+;       (BX) = found free cluster #
+;       (DX) = current last cluster in file
+
+        mov     es:[bp.dpb_next_free],bx        ; next time start search here
+        xchg    ax,dx           ; save (dx) in ax
+        mov     dx,1            ; mark this free guy as "1"
+        invoke  PACK            ; set special "temporary" mark
+        jc      ads4            ; FAT error             [INTERR?]
+        CMP     ES:[BP.dpb_free_cnt],-1 ; Free count valid?
+        JZ      NO_ALLOC                ; No
+        DEC     ES:[BP.dpb_free_cnt]    ; Reduce free count by 1
+NO_ALLOC:
+        xchg    ax,dx           ; (dx) = current last cluster in file
+        XCHG    BX,DX
+        MOV     AX,DX
+        invoke  PACK            ; link free cluster onto file
+                                ;  CAVEAT.. On Nul file, first pass stuffs
+                                ;    cluster 0 with FIRCLUS value.
+        jc      ads4            ; FAT error             [INTERR?]
+        xchg    BX,AX           ; (BX) = last one we looked at
+        mov     dx,bx           ; (dx) = current end of file
+        LOOP    findfre         ; alloc more if needed
+
+;   We've successfully extended the file.  Clean up and exit
+;
+;       (BX) = last cluster in file
+
+        MOV     DX,0FFFFH
+        invoke  PACK            ; mark last cluster EOF
+
+;   Note that FAT errors jump here to clean the stack and exit.  this saves us
+;   2 whole bytes.  Hope its worth it...
+;
+;       'C' set iff error
+;       calling (BX) and (CX) pushed on stack
+
+ads4:   POP     BX
+        POP     CX              ; Don't need this stuff since we're successful
+        retc
+        invoke  UNPACK          ; Get first cluster allocated for return
+                                ; CAVEAT... In nul file case, UNPACKs cluster 0.
+        retc
+        invoke  RESTFATBYT      ; Restore correct cluster 0 value
+        retc
+        XCHG    BX,DI           ; (DI) = last cluster in file upon our entry
+        OR      DI,DI           ; clear 'C'
+        retnz                   ; we were extending an existing file
+
+;   We were doing the first allocation for a new file.  Update the SFT cluster
+;   info
+;; Extended Attributes
+;       TEST    [XA_condition],XA_No_SFT      ;FT. don't update SFT when from   ;AN000;
+;       JZ      dofastk                       ;FT. GetSet_XA                    ;AN000;
+;       AND     [XA_condition],not XA_No_SFT  ;FT. clear the bit                ;AN000;
+;       CLC                                   ;FT.                              ;AN000;
+;       ret                                   ;FT.                              ;AN000;
+;; 11/6/86 FastSeek
+dofastk:
+        PUSH    DX
+        MOV     DL,ES:[BP.dpb_drive]              ; get drive #
+
+        PUSH    ES
+        LES     DI,[THISSFT]
+        Assert  ISSFT,<ES,DI>,"Allocate/ads4"
+        MOV     ES:[DI.sf_firclus],BX
+        MOV     ES:[DI.sf_lstclus],BX
+
+        TEST    [FastSeekflg],Fast_yes           ; fastseek installed
+        JZ      do_norm5                         ; no
+        TEST    [FastSeekflg],FS_begin           ; do fastseek
+        JZ      do_norm5                          ; no
+        PUSH    CX
+        MOV     CX,BX                             ; set up firclus #
+        MOV     [FSeek_firclus],BX                ; update firclus varible
+        invoke  FastSeek_Open                     ; create this file entry
+        POP     CX
+do_norm5:
+        POP     ES
+;; 11/6/86 FastSeek
+        POP     DX
+        return
+
+
+;** we're at the end of the disk, and not satisfied.  See if we've scanned ALL
+;   of the disk...
+
+ads7:   cmp     es:[bp.dpb_next_free],2
+if not debug
+        jz      tmplab2         ;
+        jmp     ads1            ; start scan from front of disk
+tmplab2:
+else
+        jz      tmplab
+        jmp     ads1
+tmplab:
+endif
+
+;   Sorry, we've gone over the whole disk, with insufficient luck.  Lets give
+;   the space back to the free list and tell the caller how much he could have
+;   had.  We have to make sure we remove the "special mark" we put on the last
+;   cluster we were able to allocate, so it doesn't become orphaned.
+;
+;       (CX) = clusters remaining to be allocated
+;       (TOS) = last cluster of file (before call to ALLOCATE)
+;       (TOS+1) = # of clusters wanted to allocate
+
+
+        POP     BX              ; (BX) = last cluster of file
+        MOV     DX,0FFFFH
+        invoke  RELBLKS         ; give back any clusters just alloced
+        POP     AX              ; No. of clusters requested
+                                ; Don't "retc". We are setting Carry anyway,
+                                ;   Alloc failed, so proceed with return CX
+                                ;   setup.
+        SUB     AX,CX           ; AX=No. of clusters allocated
+        invoke  RESTFATBYT      ; Don't "retc". We are setting Carry anyway,
+                                ;   Alloc failed.
+;       fmt     <>,<>,<"$p: disk full in allocate\n">
+        MOV     [DISK_FULL],1   ;MS. indicating disk full
+        STC
+        return
+
+EndProc ALLOCATE
+
+; SEE ALLOCATE CAVEAT
+;       Carry set if error (currently user FAILed to I 24)
+
+        procedure   RESTFATBYT,NEAR
+        DOSAssume   CS,<DS>,"RestFATByt"
+        ASSUME  ES:NOTHING
+
+        PUSH    BX
+        PUSH    DX
+        PUSH    DI
+        XOR     BX,BX
+        MOV     DX,[FATBYT]
+        invoke  PACK
+        POP     DI
+        POP     DX
+        POP     BX
+        return
+EndProc RESTFATBYT
+
+Break   <RELEASE -- DEASSIGN DISK SPACE>
+
+; Inputs:
+;       BX = Cluster in file
+;       ES:BP = Base of drive parameters
+; Function:
+;       Frees cluster chain starting with [BX]
+;       Carry set if error (currently user FAILed to I 24)
+; AX,BX,DX,DI all destroyed. Other registers unchanged.
+
+        procedure   RELEASE,NEAR
+        DOSAssume   CS,<DS>,"Release"
+        ASSUME  ES:NOTHING
+
+        XOR     DX,DX
+entry   RELBLKS
+        DOSAssume   CS,<DS>,"RelBlks"
+        Assert      ISDPB,<ES,BP>,"RelBlks"
+
+;   Enter here with DX=0FFFFH to put an end-of-file mark in the first cluster
+;   and free the rest in the chain.
+
+        invoke  UNPACK
+        retc
+        retz
+        MOV     AX,DI
+        PUSH    DX
+        invoke  PACK
+        POP     DX
+        retc
+        OR      DX,DX
+        JNZ     NO_DEALLOC              ; Was putting EOF mark
+        CMP     ES:[BP.dpb_free_cnt],-1 ; Free count valid?
+        JZ      NO_DEALLOC              ; No
+        INC     ES:[BP.dpb_free_cnt]    ; Increase free count by 1
+NO_DEALLOC:
+        MOV     BX,AX
+        dec     ax              ; check for "1"
+        retz                    ; is last cluster of incomplete chain
+        Invoke  IsEOF
+        JB      RELEASE         ; Carry clear if JMP not taken
+ret12:  return
+EndProc RELEASE
+
+Break   <GETEOF -- Find the end of a file>
+
+; Inputs:
+;       ES:BP Points to DPB
+;       BX = Cluster in a file
+;       DS = CS
+; Outputs:
+;       BX = Last cluster in the file
+;       Carry set if error (currently user FAILed to I 24)
+; DI destroyed. No other registers affected.
+
+        procedure   GETEOF,NEAR
+        DOSAssume   CS,<DS>,"GetEOF"
+        ASSUME  ES:NOTHING
+
+        Assert      ISDPB,<ES,BP>,"GetEof"
+        invoke  UNPACK
+        retc
+        PUSH    BX
+        MOV     BX,DI
+        Invoke  IsEOF
+        POP     BX
+        JAE     RET12           ; Carry clear if jmp
+        MOV     BX,DI
+        JMP     GETEOF
+EndProc GETEOF
+
+Break   <FS_TRUNC_EOF - truncate EOF for Fastseek>
+
+; Inputs:
+;       ES:BP Points to DPB
+;       BX = Cluster in a file
+; Functions: if BX=EOF then truncate it from Fastseek Cache
+; Outputs:
+;       carry set: not EOF
+;       carry clear: EOF and do truncate
+
+        procedure   FS_TRUNC_EOF,NEAR
+        ASSUME  ES:NOTHING,DS:NOTHING
+
+        MOV     BX,DI                             ; get beginning physical#     ;AN000;
+        invoke  IsEOF                             ; is EOF                      ;AN000;
+        JB      noteof2                           ; no                          ;AN000;
+        PUSH    [FSeek_logclus]                   ;                             ;AN000;
+        PUSH    [FSeek_logsave]                   ; logclus=logsave             ;AN000;
+        POP     [FSeek_logclus]                   ; delete EOF                  ;AN000;
+        invoke  FastSeek_Truncate                 ;                             ;AN000;
+        POP     [FSeek_logclus]                   ; redo the look up            ;AN000;
+        CLC                                                                     ;AN000;
+noteof2:                                                                        ;AN000;
+        return                                                                  ;AN000;
+EndProc FS_TRUNC_EOF                                                            ;AN000;
+
+CODE    ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/SEARCH.ASM b/v4.0/src/DOS/SEARCH.ASM
new file mode 100644
index 0000000..1f23942
--- /dev/null
+++ b/v4.0/src/DOS/SEARCH.ASM
@@ -0,0 +1,346 @@
+;       SCCSID = @(#)search.asm 1.1 85/04/10
+TITLE   SEARCH - Directory scan system calls
+NAME    SEARCH
+
+;
+;
+; Directory search system calls.  These will be passed direct text of the
+; pathname from the user.  They will need to be passed through the macro
+; expander prior to being sent through the low-level stuff.  I/O specs are
+; defined in DISPATCH.  The system calls are:
+;
+;
+;   $Dir_Search_First     written
+;   $Dir_Search_Next      written
+;   $Find_First           written
+;   $Find_Next            written
+;   PackName              written
+;
+;   Modification history:
+;
+;       Created: ARR 4 April 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGroup,CS:DOSGroup
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+INCLUDE fastopen.inc
+INCLUDE fastxxxx.inc
+.cref
+.list
+
+        i_need  SEARCHBUF,53
+        i_need  SATTRIB,BYTE
+        I_Need  OpenBuf,128
+        I_need  DMAAdd,DWORD
+        I_need  THISFCB,DWORD
+        I_need  CurDrv,BYTE
+        I_need  EXTFCB,BYTE
+        I_need  Fastopenflg,BYTE
+        I_need  DOS34_FLAG,WORD
+
+; Inputs:
+;       DS:DX Points to unopenned FCB
+; Function:
+;       Directory is searched for first matching entry and the directory
+;       entry is loaded at the disk transfer address
+; Returns:
+;       AL = -1 if no entries matched, otherwise 0
+
+        procedure $DIR_SEARCH_FIRST,NEAR
+ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+        MOV     WORD PTR [THISFCB],DX
+        MOV     WORD PTR [THISFCB+2],DS
+        MOV     SI,DX
+        CMP     BYTE PTR [SI],0FFH
+        JNZ     NORMFCB4
+        ADD     SI,7                    ; Point to drive select byte
+NORMFCB4:
+        SaveReg <[SI]>                  ; Save original drive byte for later
+        Context ES                      ; get es to address DOSGroup
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        invoke  TransFCB                ; convert the FCB, set SATTRIB EXTFCB
+        JNC     SearchIt                ; no error, go and look
+        RestoreReg <BX>                 ; Clean stack
+;
+; Error code is in AX
+;
+        transfer FCB_Ret_Err            ; error
+
+SearchIt:
+        Context DS                      ; get ready for search
+        SaveReg <<WORD PTR [DMAAdd]>, <WORD PTR [DMAAdd+2]>>
+        MOV     WORD PTR [DMAAdd],OFFSET DOSGroup:SEARCHBUF
+        MOV     WORD PTR [DMAAdd+2],DS
+        invoke  GET_FAST_SEARCH         ; search
+        RestoreReg <<WORD PTR [DMAAdd+2]>, <WORD PTR [DMAAdd]>>
+        JNC     SearchSet               ; no error, transfer info
+        RestoreReg <BX>                 ; Clean stack
+;
+; Error code is in AX
+;
+        transfer FCB_Ret_Err
+
+;
+; The search was successful (or the search-next).  We store the information
+; into the user's FCB for continuation.
+;
+SearchSet:
+        MOV     SI,OFFSET DOSGroup:SEARCHBUF
+        LES     DI,[THISFCB]            ; point to the FCB
+        TEST    [EXTFCB],0FFH           ;
+        JZ      NORMFCB1
+        ADD     DI,7                    ; Point past the extension
+NORMFCB1:
+        RestoreReg <BX>                 ; Get original drive byte
+        OR      BL,BL
+        JNZ     SearchDrv
+        MOV     BL,[CurDrv]
+        INC     BL
+SearchDrv:
+        LODSB                           ; Get correct search contin drive byte
+        XCHG    AL,BL                   ; Search byte to BL, user byte to AL
+        INC     DI
+;       STOSB                           ; Store the correct "user" drive byte
+                                        ;  at the start of the search info
+        MOV     CX,20/2
+        REP     MOVSW                   ; Rest of search cont info, SI -> entry
+        XCHG    AL,BL                   ; User drive byte back to BL, search
+                                        ;   byte to AL
+        STOSB                           ; Search contin drive byte at end of
+                                        ;   contin info
+        LES     DI,[DMAAdd]
+        TEST    [EXTFCB],0FFH
+        JZ      NORMFCB2
+        MOV     AL,0FFH
+        STOSB
+        INC     AL
+        MOV     CX,5
+        REP     STOSB
+        MOV     AL,[SATTRIB]
+        STOSB
+NORMFCB2:
+        MOV     AL,BL                   ; User Drive byte
+        STOSB
+ IF  DBCS                                                                       ;AN000;
+        MOVSW                           ; 2/13/KK                               ;AN000;
+        CMP     BYTE PTR ES:[DI-2],5    ; 2/13/KK                               ;AN000;
+        JNZ     NOTKTRAN                ; 2/13/KK                               ;AN000;
+        MOV     BYTE PTR ES:[DI-2],0E5H ; 2/13/KK                               ;AN000;
+NOTKTRAN:                               ; 2/13/KK                               ;AN000;
+        MOV     CX,15                   ; 2/13/KK                               ;AN000;
+ ELSE                                                                           ;AN000;
+        MOV     CX,16                   ; 32 / 2 words of dir entry             ;AN000;
+ ENDIF                                                                          ;AN000;
+        REP     MOVSW
+        transfer FCB_Ret_OK
+
+EndProc $DIR_SEARCH_FIRST
+
+; Inputs:
+;       DS:DX points to unopenned FCB returned by $DIR_SEARCH_FIRST
+; Function:
+;       Directory is searched for the next matching entry and the directory
+;       entry is loaded at the disk transfer address
+; Returns:
+;       AL = -1 if no entries matched, otherwise 0
+
+        procedure $DIR_SEARCH_NEXT,NEAR
+ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+        MOV     WORD PTR [THISFCB],DX
+        MOV     WORD PTR [THISFCB+2],DS
+        MOV     [SATTRIB],0
+        MOV     [EXTFCB],0
+        Context ES
+        MOV     DI,OFFSET DOSGroup:SEARCHBUF
+        MOV     SI,DX
+        CMP     BYTE PTR [SI],0FFH
+        JNZ     NORMFCB6
+        ADD     SI,6
+        LODSB
+        MOV     [SATTRIB],AL
+        DEC     [EXTFCB]
+NORMFCB6:
+        LODSB                           ; Get original user drive byte
+        SaveReg <AX>                    ; Put it on stack
+        MOV     AL,[SI+20]              ; Get correct search contin drive byte
+        STOSB                           ; Put in correct place
+        MOV     CX,20/2
+        REP     MOVSW                   ; Transfer in rest of search contin info
+        Context DS
+        SaveReg <<WORD PTR [DMAAdd]>, <WORD PTR [DMAAdd+2]>>
+        MOV     WORD PTR [DMAAdd],OFFSET DOSGroup:SEARCHBUF
+        MOV     WORD PTR [DMAAdd+2],DS
+        invoke  DOS_SEARCH_NEXT         ; Find it
+        RestoreReg <<WORD PTR [DMAAdd+2]>, <WORD PTR [DMAAdd]>>
+        JC      SearchNoMore
+        JMP     SearchSet               ; Ok set return
+
+SearchNoMore:
+        LES     DI,[THISFCB]
+        TEST    [EXTFCB],0FFH
+        JZ      NORMFCB8
+        ADD     DI,7                    ; Point past the extension
+NORMFCB8:
+        RestoreReg <BX>                 ; Get original drive byte
+        MOV     ES:[DI],BL              ; Store the correct "user" drive byte
+                                        ;  at the right spot
+;
+; error code is in AX
+;
+        transfer FCB_Ret_Err
+
+EndProc $DIR_SEARCH_NEXT
+
+;   Assembler usage:
+;           MOV AH, FindFirst
+;           LDS DX, name
+;           MOV CX, attr
+;           INT 21h
+;       ; DMA address has datablock
+;
+;   Error Returns:
+;           AX = error_path_not_found
+;              = error_no_more_files
+
+        procedure $FIND_FIRST,NEAR
+ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+        MOV     SI,DX                   ; get name in appropriate place
+        MOV     [SATTRIB],CL            ; Search attribute to correct loc
+        MOV     DI,OFFSET DOSGroup:OpenBuf  ; appropriate buffer
+        invoke  TransPathSet            ; convert the path
+        JNC     Find_it                 ; no error, go and look
+FindError:
+        error   error_path_not_found    ; error and map into one.
+Find_it:
+        Context DS
+        SaveReg <<WORD PTR [DMAAdd]>, <WORD PTR [DMAAdd+2]>>
+        MOV     WORD PTR [DMAAdd],OFFSET DOSGroup:SEARCHBUF
+        MOV     WORD PTR [DMAAdd+2],DS
+        invoke  GET_FAST_SEARCH         ; search
+        RestoreReg <<WORD PTR [DMAAdd+2]>, <WORD PTR [DMAAdd]>>
+        JNC     FindSet                 ; no error, transfer info
+        transfer Sys_Ret_Err
+
+FindSet:
+        MOV     SI,OFFSET DOSGroup:SEARCHBUF
+        LES     DI,[DMAAdd]
+        MOV     CX,21
+        REP     MOVSB
+        PUSH    SI                      ; Save pointer to start of entry
+        MOV     AL,[SI.dir_attr]
+        STOSB
+        ADD     SI,dir_time
+        MOVSW                           ; dir_time
+        MOVSW                           ; dir_date
+        INC     SI
+        INC     SI                      ; Skip dir_first
+        MOVSW                           ; dir_size (2 words)
+        MOVSW
+        POP     SI                      ; Point back to dir_name
+ IF  DBCS                                                                       ;AN000;
+        PUSH    DI                      ; XXXX save dest name 2/13/KK           ;AN000;
+        CALL    PackName                                                        ;AN000;
+        POP     DI                      ; XXXX Recover dest name 2/13/KK        ;AN000;
+        CMP     BYTE PTR ES:[DI],05H    ; XXXX Need fix?         2/13/KK        ;AN000;
+        JNZ     FNXXX                   ; XXXX No                2/13/KK        ;AN000;
+        MOV     BYTE PTR ES:[DI],0E5H   ; XXXX Yes, Fix          2/13/KK        ;AN000;
+FNXXX:                                  ; 2/13/KK                               ;AN000;
+ ELSE                                                                           ;AN000;
+        CALL    PackName
+ ENDIF
+        transfer    Sys_Ret_OK          ; bye with no errors
+EndProc $FIND_FIRST
+
+        procedure $FIND_NEXT,NEAR
+ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+
+;   Assembler usage:
+;       ; dma points at area returned by find_first
+;           MOV AH, findnext
+;           INT 21h
+;       ; next entry is at dma
+;
+;   Error Returns:
+;           AX = error_no_more_files
+
+        Context ES
+        MOV     DI,OFFSET DOSGroup:SEARCHBUF
+        LDS     SI,[DMAAdd]
+        MOV     CX,21
+        REP     MOVSB                   ; Put the search continuation info
+                                        ;  in the right place
+        Context DS                      ; get ready for search
+        SaveReg <<WORD PTR [DMAAdd]>, <WORD PTR [DMAAdd+2]>>
+        MOV     WORD PTR [DMAAdd],OFFSET DOSGroup:SEARCHBUF
+        MOV     WORD PTR [DMAAdd+2],DS
+        invoke  DOS_SEARCH_NEXT         ; Find it
+        RestoreReg <<WORD PTR [DMAAdd+2]>, <WORD PTR [DMAAdd]>>
+        JNC     FindSet                 ; No error, set info
+        transfer Sys_Ret_Err
+
+EndProc $FIND_NEXT
+
+Break   <PackName - convert file names from FCB to ASCIZ>
+;
+;   PackName - transfer a file name from DS:SI to ES:DI and convert it to
+;       the ASCIZ format.
+;
+;   Input:      DS:SI points to an 11 character FCB or dir entry name
+;               ES:DI points to a destination area (13 bytes)
+;   Output:     Above pointers advanced
+;   Registers modified: SI,DI,CX,AL
+        Procedure PackName,NEAR
+        ASSUME  CS:DOSGroup,DS:NOTHING,ES:NOTHING,SS:DOSGroup
+        MOV     CX,8                    ; Pack the name
+        REP     MOVSB                   ; Move all of it
+main_kill_tail:
+        CMP     BYTE PTR ES:[DI-1]," "
+        JNZ     find_check_dot
+        DEC     DI                      ; Back up over trailing space
+        INC     CX
+        CMP     CX,8
+        JB      main_kill_tail
+find_check_dot:
+        CMP     WORD PTR [SI],(" " SHL 8) OR " "
+        JNZ     got_ext                 ; Some chars in extension
+        CMP     BYTE PTR [SI+2]," "
+        JZ      find_done               ; No extension
+got_ext:
+        MOV     AL,"."
+        STOSB
+        MOV     CX,3
+        REP     MOVSB
+ext_kill_tail:
+        CMP     BYTE PTR ES:[DI-1]," "
+        JNZ     find_done
+        DEC     DI                      ; Back up over trailing space
+        JMP     ext_kill_tail
+find_done:
+        XOR     AX,AX
+        STOSB                           ; NUL terminate
+        return
+EndProc PackName
+
+        procedure   GET_FAST_SEARCH,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING
+
+        OR      [DOS34_FLAG],SEARCH_FASTOPEN  ;FO.trigger fastopen              ;AN000;
+        invoke  DOS_SEARCH_FIRST
+        return
+
+EndProc GET_FAST_SEARCH
+CODE ENDS
+END
diff --git a/v4.0/src/DOS/SEGCHECK.ASM b/v4.0/src/DOS/SEGCHECK.ASM
new file mode 100644
index 0000000..992eac2
--- /dev/null
+++ b/v4.0/src/DOS/SEGCHECK.ASM
@@ -0,0 +1,288 @@
+;       SCCSID = @(#)segcheck.asm       1.2 85/07/24
+TITLE   SegCheck - internal consistency check
+NAME    SegCheck
+
+.xlist
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+
+ShareF  = FALSE
+
+IF NOT SHAREF
+include dosseg.asm
+ENDIF
+.list
+
+AsmVars <NET, DEBUG>
+
+DEBUG   = FALSE
+
+IF NOT SHAREF
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+ASSUME  CS:DOSGroup
+ELSE
+SHARE   SEGMENT BYTE PUBLIC  'SHARE'
+ASSUME  CS:SHARE
+ENDIF
+
+DEBUG   = FALSE
+
+BREAK   <SegCheck - validate segments in MSDOS>
+
+Off Macro   reg,var
+IF SHAREF
+        mov     reg,offset var
+else
+        mov     reg,offset DOSGroup:var
+endif
+endm
+
+zfmt    MACRO   fmts,args
+local   a,b
+        PUSHF
+        PUSH    AX
+        PUSH    BP
+        MOV     BP,SP
+If (not sharef) and (not redirector)
+Table   segment
+a       db      fmts,0
+Table   ends
+        MOV     AX,OFFSET DOSGROUP:a
+else
+        jmp     short b
+a       db      fmts,0
+if sharef
+b:      mov     ax,offset share:a
+else
+b:      mov     ax,offset netwrk:a
+endif
+endif
+        PUSH    AX
+cargs = 2
+IRP item,<args>
+IFIDN   <AX>,<item>
+        MOV     AX,[BP+2]
+ELSE
+        MOV     AX,item
+ENDIF
+        PUSH    AX
+cargs = cargs + 2
+ENDM
+        invoke  PFMT
+        ADD     SP,Cargs
+        POP     BP
+        POP     AX
+        POPF
+ENDM
+
+segFrame    Struc
+segbp       DW  ?
+segip       DW  ?
+segmes      dw  ?
+segtemp     DW  ?
+segFrame    ENDS
+;
+;   SegCheck - assure that segments are correctly set up
+;
+;   Inputs:     top of stack points to:
+;               2-byte jump
+;               byte flags 04h is ES 02h is DS 01 is CS/SS
+;               offset asciz message
+;
+;   Outputs:    message to screen (via INT 29h)
+;   Nothing modified (flags too)
+
+Procedure   SegCheck,NEAR
+        ASSUME  DS:NOTHING,ES:NOTHING,SS:NOTHING
+        SaveReg <BP>
+        MOV     BP,SP                   ; set up addressing
+        PUSHF
+        SaveReg <AX,BX,CX,DX>
+        MOV     AL,BYTE PTR [BP].segtemp; get flags
+        MOV     CX,SS
+        TEST    AL,1                    ; shall we use CS or SS?
+        JZ      SegUseSS                ; use SS
+        MOV     CX,CS                   ; use CS instead
+SegUseSS:
+        TEST    AL,2                    ; do we check DS?
+        JZ      SegTestES               ; no, go check ES
+        MOV     DX,DS
+        CMP     CX,DX
+        JZ      SegTestES               ; DS is valid, go check ES
+        MOV     AX,[BP].segmes
+        zfmt    <"Assumed DS invalid $s\n">,<AX>
+SegTestES:
+        TEST    AL,4                    ; do we check ES?
+        JZ      SegTestDone             ; no, all done
+        MOV     DX,ES
+        CMP     CX,DX
+        JZ      SegTestDone             ; ES is valid, all done
+        MOV     AX,[BP].segmes
+        zfmt    <"Assumed ES invalid $s\n">,<AX>
+SegTestDone:
+        RestoreReg  <DX,CX,BX,AX>
+        POPF
+        RestoreReg  <BP>
+        ret     4                       ; release message, temp
+EndProc SegCheck
+
+
+IF NOT SHAREF
+I_need  DPBHead,DWORD
+I_need  BuffHead,DWORD
+I_need  sftFCB,DWORD
+I_need  AuxStack,BYTE
+I_need  IOStack,BYTE
+I_need  renbuf,byte
+I_need  CurrentPDB,WORD
+I_need  User_In_AX,WORD
+
+extrn   ECritDisk:NEAR
+
+CritNOP label   byte
+        RET
+
+AstFrame    STRUC
+Astbp       dw  ?
+Astip       dw  ?
+Astmes      dw  ?
+Astarg      dd  ?
+AstFrame    ENDS
+
+Public SGCHK001S,SGCHK001E
+SGCHK001S label byte
+DPBMes  DB  "DPB assertion failed: ",0
+BUFMes  DB  "BUF assertion failed: ",0
+SFTMes  DB  "SFT assertion failed: ",0
+BlankSp DB  " ",0
+Colon   DB  ":",0
+
+Msg     DW  ?
+
+SGCHK001E label byte
+
+Table   segment
+    Extrn SectPDB:WORD, SectRef:WORD
+Table   ends
+
+;   DPBCheck - validate a supposed DPB pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   DPBCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:DPBMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+        LES     DI,DPBHead
+        LDS     SI,[BP].Astarg
+DPBLoop:CMP     DI,-1
+        JZ      DPBNotFound
+        invoke  PointComp
+        JZ      DPBRet
+        LES     DI,ES:[DI.dpb_next_dpb]
+        JMP     DPBLoop
+DPBNotFound:
+        MOV     AX,[BP].Astmes
+        zfmt    <"$s$x:$x $s\n">,<msg,ds,si,AX>
+        CLI
+a:      JMP     a                       ; slam the door.
+DPBRet: RestoreReg  <DI,ES,SI,DS,BX,AX> ;   Done:
+        POPF
+        RestoreReg  <BP>
+        RET     6
+EndProc DPBCheck
+
+;   SFTCheck - validate a supposed SFT pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   SFTCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:SFTMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+        LDS     SI,[BP].Astarg
+        XOR     BX,BX                   ;   i = 0;
+SFTLoop:
+        SaveReg <BX>
+        invoke  SFFromSFN               ;   while ((d=SF(i)) != NULL)
+        RestoreReg  <BX>
+        JC      Sft1
+        invoke  PointComp
+        JZ      DPBRet                  ;               goto Done;
+SFTNext:INC     BX                      ;           else
+        JMP     SFTLoop                 ;               i++;
+SFT1:   LES     DI,sftFCB
+        MOV     BX,ES:[DI.sfCount]
+        LEA     DI,[DI.sfTable]
+SFT2:
+        invoke  PointComp
+DPBRETJ:JZ      DPBRet
+        ADD     DI,SIZE sf_entry
+        DEC     BX
+        JNZ     SFT2
+;
+; The SFT is not in the allocated tables.  See if it is one of the static
+; areas.
+;
+        Context ES
+        MOV     DI,OFFSET DOSGROUP:AUXSTACK - SIZE SF_ENTRY
+        Invoke  PointComp
+        JZ      DPBRet
+        MOV     DI,OFFSET DOSGROUP:RenBuf
+        Invoke  PointComp
+        JZ      DPBRetj
+DPBNotFoundJ:
+        JMP     DPBNotFound
+EndProc SFTCheck
+
+;   BUFCheck - validate a supposed BUF pointer
+;   Inputs:     Pushed arguments
+;   Outputs:    Message to screen
+;   Registers modified: none
+
+Procedure   BUFCheck,NEAR
+        MOV     Msg,OFFSET DOSGroup:BUFMes
+        SaveReg <BP>
+        MOV     BP,SP
+        PUSHF
+        SaveReg <AX,BX,DS,SI,ES,DI>
+;
+; CheckDisk - make sure that we are in the disk critical section...
+;
+        MOV     AL,BYTE PTR ECritDisk
+        CMP     AL,CritNOP
+        JZ      CheckDone
+        MOV     AX,CurrentPDB
+        CMP     SectPDB + 2 * critDisk,AX
+        MOV     AX,[BP].astmes
+        JZ      CheckRef
+        zfmt    <"$p: $x $s critDisk owned by $x\n">,<User_In_AX,AX,SectPDB+2*critDisk>
+CheckRef:
+        CMP     SectRef + 2 * critDisk,0
+        JNZ     CheckDone
+        zfmt    <"$p: $x $s critDisk ref count is 0\n">,<User_In_AX,AX>
+CheckDone:
+
+        LDS     SI,[BP].Astarg
+        LES     DI,BUFFHead
+BUFLoop:CMP     DI,-1
+        JZ      DPBNotFoundJ
+        invoke  PointComp
+        JNZ     BufNext
+        JMP     DPBRet
+BufNext:
+        LES     DI,ES:[DI.buf_link]
+        JMP     BUFLoop
+EndProc BUFCheck
+
+CODE    ENDS
+ELSE
+SHARE   ENDS
+ENDIF
+END
diff --git a/v4.0/src/DOS/SHARE.ASM b/v4.0/src/DOS/SHARE.ASM
new file mode 100644
index 0000000..ded4cd7
--- /dev/null
+++ b/v4.0/src/DOS/SHARE.ASM
@@ -0,0 +1,151 @@
+;       SCCSID = @(#)share.asm  1.1 85/04/10
+TITLE   SHARING ROUTINES - Routines for file Sharing
+NAME    SHARE
+
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xlist
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+AsmVars <IBM, Installed>
+
+Installed = True
+
+        i_need  THISDPB,DWORD
+        i_need  EXTERR,WORD
+        i_need  ReadOp,BYTE
+        i_need  ThisSFT,DWORD
+        i_need  ALLOWED,BYTE
+        I_need  RetryCount,WORD
+        i_need  JShare,DWORD
+
+; Inputs:
+;       [THISSFT] Points to filled in local file/device SFT for new
+;               instance of file sf_mode ALWAYS has mode (even on FCB SFTs)
+;       [WFP_START] has full path of name
+;       [USER_ID] Set
+;       [PROC_ID] Set
+; Function:
+;       Check for sharing violations on local file/device access
+; Outputs:
+;    Carry clear
+;       Sharing approved
+;    Carry set
+;       A sharing violation detected
+;           AX is error code
+; USES    ALL but DS
+
+        procedure   SHARE_CHECK,NEAR
+        DOSAssume   CS,<DS>,"Share_Check"
+        ASSUME  ES:NOTHING
+
+if installed
+        call    JShare + 1 * 4
+else
+        Call    MFT_Enter
+endif
+        return
+
+EndProc SHARE_CHECK
+
+; Inputs:
+;       [THISDPB] Set
+;       AX has error code
+; Function:
+;       Handle Sharing errors
+; Outputs:
+;       Carry set if user says FAIL, causes error_sharing_violation
+;       Carry clear if user wants a retry
+;
+; DS, ES, DI preserved, others destroyed
+
+        procedure   SHARE_VIOLATION,NEAR
+        DOSAssume   CS,<DS>,"Share_Violation"
+        ASSUME  ES:NOTHING
+
+        PUSH    DS
+        PUSH    ES
+        PUSH    DI
+        MOV     [READOP],0                      ; All share errors are reading
+        MOV     [ALLOWED],allowed_FAIL + allowed_RETRY
+        LES     BP,[THISDPB]
+        MOV     DI,1                            ; Fake some registers
+        MOV     CX,DI
+        MOV     DX,ES:[BP.dpb_dir_sector]
+        invoke  HARDERR
+        POP     DI
+        POP     ES
+        POP     DS
+        CMP     AL,1
+        retz                    ; 1 = retry, carry clear
+        STC
+        return
+
+EndProc SHARE_VIOLATION
+
+;   ShareEnd - terminate sharing info on a particular SFT/UID/PID.  This does
+;       NOT perform a close, it merely asserts that the sharing information
+;       for the SFT/UID/PID may be safely released.
+;
+;   Inputs:     ES:DI points to an SFT
+;   Outputs:    None
+;   Registers modified: all except DS,ES,DI
+
+        procedure   ShareEnd,Near
+        DOSAssume   CS,<DS>,"ShareEnd"
+        ASSUME  ES:NOTHING
+
+if installed
+        Call    JShare + 2 * 4
+else
+        Call    MFTClose
+endif
+        return
+
+EndProc ShareEnd
+
+break <ShareEnter - attempt to enter a node into the sharing set>
+
+;
+;   ShareEnter - perform a retried entry of a nodde into the sharing set.  If
+;   the max number of retries is exceeded, we notify the user via int 24.
+;
+;   Inputs:     ThisSFT points to the SFT
+;               WFP_Start points to the WFP
+;   Outputs:    Carry clear => successful entry
+;               Carry set => failed system call
+;   Registers modified: all
+
+Procedure   ShareEnter,NEAR
+        DOSAssume   CS,<DS>,"ShareEnter"
+        assume  es:nothing
+
+        SaveReg <CX>
+retry:
+        mov     cx,RetryCount
+attempt:
+        les     di,ThisSFT              ; grab sft
+        XOR     AX,AX
+        MOV     ES:[DI.sf_MFT],AX       ; indicate free SFT
+        SaveReg <CX>
+        call    Share_Check             ; attempt to enter into the sharing set
+        RestoreReg  <CX>
+        jnc     done                    ; success, let the user see this
+        invoke  Idle                    ; wait a while
+        loop    attempt                 ; go back for another attempt
+        call    Share_violation         ; signal the problem to the user
+        jnc     retry                   ; user said to retry, go do it
+done:
+        RestoreReg  <CX>
+        return
+EndProc ShareEnter
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/SHRPRINT.ASM b/v4.0/src/DOS/SHRPRINT.ASM
new file mode 100644
index 0000000..6854eca
--- /dev/null
+++ b/v4.0/src/DOS/SHRPRINT.ASM
@@ -0,0 +1,35 @@
+;       SCCSID = @(#)shrprint.asm       1.1 85/04/10
+TITLE   SHRPRINT - PRINTF at SHARE level
+NAME    SHRPRINT
+;
+;
+;   Modification history:
+;
+;       Created: MZ 16 June 1984
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+Share   SEGMENT PARA PUBLIC 'SHARE'
+        ASSUME  SS:DOSGROUP,CS:SHARE
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+.sall
+
+        I_Need  Proc_ID,WORD
+        I_Need  User_ID,WORD
+
+BREAK   <debugging output>
+
+include print.asm
+
+SHARE   ENDS
+END
diff --git a/v4.0/src/DOS/SRVCALL.ASM b/v4.0/src/DOS/SRVCALL.ASM
new file mode 100644
index 0000000..26064c8
--- /dev/null
+++ b/v4.0/src/DOS/SRVCALL.ASM
@@ -0,0 +1,306 @@
+;       SCCSID = @(#)srvcall.asm        1.4 85/08/02
+TITLE SRVCALL - Server DOS call
+NAME  SRVCALL
+;
+; Server DOS call functions
+;
+;
+;   $ServerCall
+;
+;   Modification history:
+;
+;       Created: ARR 08 August 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+AsmVars <Installed>
+
+include dpl.asm
+
+Installed = TRUE
+
+        i_need  USER_ID,WORD
+        i_need  PROC_ID,WORD
+        i_need  SaveBX,WORD
+        i_need  SaveDS,WORD
+        i_need  SWAP_START,BYTE
+        i_need  SWAP_ALWAYS,BYTE
+        i_need  SWAP_END,BYTE
+        I_Need  ThisSFT,DWORD
+        I_need  fSharing,BYTE
+        i_need  OpenBuf,128
+        I_Need  ExtErr,WORD
+        I_Need  ExtErr_Action,BYTE
+        I_Need  ExtErrPt,DWORD
+        I_Need  EXTERR_LOCUS,BYTE       ; Extended Error Locus
+        i_need  JShare,DWORD
+        i_need  SWAP_AREA_TABLE,BYTE
+        i_need  SWAP_ALWAYS_AREA,DWORD
+        i_need  SWAP_ALWAYS_AREA_LEN,WORD
+        i_need  SWAP_AREA_LEN,WORD
+
+BREAK <ServerCall -- Server DOS call>
+
+TABLE   SEGMENT
+Public SRVC001S,SRVC001E
+SRVC001S label byte
+
+ServerTab       DW      DOSGroup:Server_Disp
+SERVERLEAVE     DW      DOSGROUP:ServerReturn
+SERVER_DISP     DB      (SERVER_DISP_END-SERVER_DISP-1)/2
+                DW      OFFSET DOSGROUP:SRV_CALL        ; 0
+                DW      OFFSET DOSGROUP:COMMIT_ALL      ; 1
+                DW      OFFSET DOSGROUP:CLOSE_NAME      ; 2
+                DW      OFFSET DOSGROUP:CLOSE_UID       ; 3
+                DW      OFFSET DOSGROUP:CLOSE_UID_PID   ; 4
+                DW      OFFSET DOSGROUP:GET_LIST        ; 5
+                DW      OFFSET DOSGROUP:GET_DOS_DATA    ; 6
+                DW      OFFSET DOSGROUP:SPOOL_OPER      ; 7
+                DW      OFFSET DOSGROUP:SPOOL_OPER      ; 8
+                DW      OFFSET DOSGROUP:SPOOL_OPER      ; 9
+                DW      OFFSET DOSGroup:$setExtendedError   ; 10
+SERVER_DISP_END LABEL   BYTE
+
+SRVC001E label byte
+
+TABLE   ENDS
+
+; Inputs:
+;       DS:DX -> DPL  (except calls 7,8,9)
+; Function:
+;       AL=0    Server DOS call
+;       AL=1    Commit All files
+;       AL=2    Close file by name (SHARING LOADED ONLY) DS:DX in DPL -> name
+;       AL=3    Close all files for DPL_UID
+;       AL=4    Close all files for DPL_UID/PID_PID
+;       AL=5    Get open file list entry
+;                   IN: BX File Index
+;                       CX User Index
+;                   OUT:ES:DI -> Name
+;                       BX = UID
+;                   CX = # locked blocks held by this UID
+;       AL=6    Get DOS data area
+;                   OUT: DS:SI -> Start
+;                       CX size in bytes of swap if indos
+;                       DX size in bytes of swap always
+;       AL=7    Get truncate flag
+;       AL=8    Set truncate flag
+;       AL=9    Close all spool files
+;       AL=10   SetExtendedError
+;       AL=11   DOS4.00 Get DOS data area
+;                   DS:SI -> swap table
+
+        procedure   $ServerCall,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+        CMP     AL,7
+        JB      SET_STUFF
+        CMP     AL,9
+        JBE     NO_SET_ID               ; No DPL on calls 7,8,9
+        CMP     AL,11                              ;IFS.                        ;AN000;
+        JNZ     SET_STUFF                          ;IFS.                        ;AN000;
+        MOV     DI,OFFSET DOSGROUP:SWAP_AREA_TABLE ;IFS.                        ;AN000;
+        PUSH    SS                                 ;IFS.                        ;AN000;
+        POP     ES                                 ;IFS.                        ;AN000;
+        invoke  GET_USER_STACK                     ;IFS.                        ;AN000;
+        MOV     [SI.user_DS],ES                    ;IFS.   ds:si -> swap tab    ;AN000;
+        MOV     [SI.user_SI],DI                    ;IFS.                        ;AN000;
+        transfer SYS_RET_OK                        ;IFS.                        ;AN000;
+SET_STUFF:
+        MOV     SI,DX                   ; Point to DPL with DS:SI
+        MOV     BX,[SI.DPL_UID]
+        MOV     [USER_ID],BX            ; Set UID
+        MOV     BX,[SI.DPL_PID]
+        MOV     [PROC_ID],BX            ; Set process ID
+NO_SET_ID:
+        PUSH    SERVERLEAVE             ; push return address
+        PUSH    ServerTab               ; push table address
+        PUSH    AX
+        Invoke  TableDispatch
+        MOV     EXTERR_LOCUS,errLoc_Unk ; Extended Error Locus
+        error   error_invalid_function
+ServerReturn:
+        return
+
+; Commit - iterate through the open file list and make sure that the
+; directory entries are correctly updated.
+
+COMMIT_ALL:
+ASSUME  DS:NOTHING,ES:NOTHING
+        XOR     BX,BX                   ;   for (i=0; ThisSFT=getSFT(i); i++)
+        Context DS
+        EnterCrit   critSFT             ; Gonna scan SFT cache, lock it down
+CommitLoop:
+        SaveReg <BX>
+        Invoke  SFFromSFN
+        JC      CommitDone
+        CMP     ES:[DI].sf_Ref_Count,0  ;       if (ThisSFT->refcount != 0)
+        JZ      CommitNext
+        CMP     ES:[DI].sf_Ref_Count,sf_busy  ; BUSY SFTs have god knows what
+        JZ      CommitNext                    ;   in them.
+;       TEST    ES:[DI].sf_flags,sf_isnet
+        invoke  Test_IFS_Remote         ;IFS.                                   ;AN000;
+        JNZ     CommitNext              ;  Skip Network SFTs so the SERVER
+                                        ;       doesn't deadlock
+        MOV     WORD PTR ThisSFT,DI
+        MOV     WORD PTR ThisSFT+2,ES
+        Invoke  DOS_Commit              ;           DOSCommit ();
+CommitNext:
+        RestoreReg  <BX>
+        INC     BX
+        JMP     CommitLoop
+CommitDone:
+        LeaveCrit   critSFT
+        RestoreReg  <BX>
+        transfer    Sys_Ret_OK
+
+CLOSE_NAME:
+ASSUME  DS:NOTHING,ES:NOTHING
+
+if installed
+        Call    JShare + 5 * 4
+else
+        Call    MFTcloN
+endif
+CheckReturns:
+        JC      func_err
+        transfer SYS_RET_OK
+func_err:
+        transfer SYS_RET_ERR
+
+CLOSE_UID:
+ASSUME  DS:NOTHING,ES:NOTHING
+
+if installed
+        Call    JShare + 3 * 4
+else
+        Call    MFTclU
+endif
+        JMP     CheckReturns
+
+CLOSE_UID_PID:
+ASSUME  DS:NOTHING,ES:NOTHING
+
+if installed
+        Call    JShare + 4 * 4
+else
+        Call    MFTCloseP
+endif
+        JMP     CheckReturns
+
+GET_LIST:
+ASSUME  DS:NOTHING,ES:NOTHING
+if installed
+        Call    JShare + 9 * 4
+else
+        Call    MFT_get
+endif
+        JC      func_err
+        invoke  get_user_stack
+        MOV     [SI.user_BX],BX
+        MOV     [SI.user_DI],DI
+        MOV     [SI.user_ES],ES
+SetCXOK:
+        MOV     [SI.user_CX],CX
+        transfer    SYS_RET_OK
+
+SRV_CALL:
+ASSUME  DS:NOTHING,ES:NOTHING
+        POP     AX                      ; get rid of call to $srvcall
+        SaveReg <DS,SI>
+        invoke  GET_USER_STACK
+        RestoreReg  <DI,ES>
+;
+; DS:SI point to stack
+; ES:DI point to DPL
+;
+        invoke  XCHGP
+;
+; DS:SI point to DPL
+; ES:DI point to stack
+;
+; We now copy the registers from DPL to save stack
+;
+        SaveReg <SI>
+        MOV     CX,6
+        REP     MOVSW                   ; Put in AX,BX,CX,DX,SI,DI
+        INC     DI
+        INC     DI                      ; Skip user_BP
+        MOVSW                           ; DS
+        MOVSW                           ; ES
+        RestoreReg  <SI>                ; DS:SI -> DPL
+        MOV     AX,[SI.DPL_AX]
+        MOV     BX,[SI.DPL_BX]
+        MOV     CX,[SI.DPL_CX]
+        MOV     DX,[SI.DPL_DX]
+        MOV     DI,[SI.DPL_DI]
+        MOV     ES,[SI.DPL_ES]
+        PUSH    [SI.DPL_SI]
+        MOV     DS,[SI.DPL_DS]
+        POP     SI
+        MOV     [SaveDS],DS
+        MOV     [SaveBX],BX
+        MOV     fSharing,-1             ; set no redirect flag
+        transfer REDISP
+
+GET_DOS_DATA:
+ASSUME  DS:NOTHING,ES:NOTHING
+        LES     DI,[SWAP_ALWAYS_AREA]        ;IFS. get beginning addr of swap ;AC000;
+        MOV     DX,[SWAP_ALWAYS_AREA_LEN]    ;IFS. get swap always area len   ;AC000;
+        AND     DX,7FFFH                     ;IFS. clear high bit             ;AC000;
+        MOV     CX,[SWAP_AREA_LEN]           ;IFS. get swap len               ;AC000;
+        invoke  GET_USER_STACK
+        MOV     [SI.user_DS],ES              ;  set user regs
+        MOV     [SI.user_SI],DI              ;
+        MOV     [SI.user_DX],DX              ;
+        JMP     SetCXOK                      ;                                ;AN000;
+
+SPOOL_OPER:
+ASSUME  DS:NOTHING,ES:NOTHING
+        CallInstall NETSpoolOper,multNet,37,AX,BX
+        JC      func_err2
+        transfer SYS_RET_OK
+func_err2:
+        transfer SYS_RET_ERR
+
+Break   <$SetExtendedError - set extended error for later retrieval>
+
+;
+; $SetExtendedError takes extended error information and loads it up for the
+; next extended error call.  This is used by interrupt-level proccessors to
+; mask their actions.
+;
+;   Inputs: DS:SI points to DPL which contains all registers
+;   Outputs: none
+;
+
+$SetExtendedError:
+        ASSUME  DS:NOTHING,ES:NOTHING
+        MOV     AX,[SI].dpl_AX
+        MOV     [EXTERR],AX
+        MOV     AX,[SI].dpL_di
+        MOV     WORD PTR ExtErrPt,AX
+        MOV     AX,[SI].dpL_ES
+        MOV     WORD PTR ExtErrPt+2,AX
+        MOV     AX,[SI].dpL_BX
+        MOV     WORD PTR [EXTERR_ACTION],AX
+        MOV     AX,[SI].dpL_CX
+        MOV     [EXTERR_LOCUS],AH
+        return
+EndProc $ServerCall
+
+CODE    ENDS
+    END
diff --git a/v4.0/src/DOS/STDASW.ASM b/v4.0/src/DOS/STDASW.ASM
new file mode 100644
index 0000000..d9fa382
--- /dev/null
+++ b/v4.0/src/DOS/STDASW.ASM
@@ -0,0 +1,29 @@
+;       SCCSID = @(#)stdasw.asm 1.1 85/04/10
+TRUE    EQU     0FFFFH
+FALSE   EQU     NOT TRUE
+
+; Use the switches below to produce the standard Microsoft version or the IBM
+; version of the operating system
+MSVER   EQU     TRUE
+IBM     EQU     FALSE
+WANG    EQU     FALSE
+ALTVECT EQU     TRUE
+
+; Set this switch to cause DOS to move itself to the end of memory
+HIGHMEM EQU     FALSE
+
+        IF      IBM
+ESCCH   EQU     0                       ; character to begin escape seq.
+TOGLPRN EQU     TRUE                    ;One key toggles printer echo
+ZEROEXT EQU     TRUE
+        ELSE
+        IF      WANG                    ;Are we assembling for WANG?
+ESCCH   EQU     1FH                     ;Yes. Use 1FH for escape character
+        ELSE
+ESCCH   EQU     1BH
+        ENDIF
+CANCEL  EQU     "X"-"@"                 ;Cancel with Ctrl-X
+TOGLPRN EQU     FALSE                   ;Separate keys for printer echo on
+                                        ;and off
+ZEROEXT EQU     TRUE
+        ENDIF
diff --git a/v4.0/src/DOS/STDCODE.ASM b/v4.0/src/DOS/STDCODE.ASM
new file mode 100644
index 0000000..0332898
--- /dev/null
+++ b/v4.0/src/DOS/STDCODE.ASM
@@ -0,0 +1,17 @@
+;       SCCSID = @(#)stdcode.asm        1.1 85/04/10
+TITLE   MS-DOS MISC DOS ROUTINES - Int 25 and 26 handlers and other
+NAME    STDCODE
+
+;
+; System call dispatch code
+;
+
+.xlist
+.xcref
+include stdsw.asm
+.cref
+.list
+
+include ms_code.asm
+        END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/STDCPMIO.ASM b/v4.0/src/DOS/STDCPMIO.ASM
new file mode 100644
index 0000000..44bbb57
--- /dev/null
+++ b/v4.0/src/DOS/STDCPMIO.ASM
@@ -0,0 +1,16 @@
+;       SCCSID = @(#)stdcpmio.asm       1.1 85/04/10
+;
+; Standard device IO for MSDOS (first 12 function calls)
+;
+
+.xlist
+.xcref
+include stdsw.asm
+include dosseg.asm
+.cref
+.list
+
+TITLE   STDCPMIO - device IO for MSDOS
+NAME    STDCPMIO
+
+include cpmio.asm
diff --git a/v4.0/src/DOS/STDCTRLC.ASM b/v4.0/src/DOS/STDCTRLC.ASM
new file mode 100644
index 0000000..90af372
--- /dev/null
+++ b/v4.0/src/DOS/STDCTRLC.ASM
@@ -0,0 +1,15 @@
+;       SCCSID = @(#)stdctrlc.asm       1.1 85/04/10
+;
+; ^C and error handler for MSDOS
+;
+
+.xlist
+.xcref
+include stdsw.asm
+.cref
+.list
+
+TITLE   Control C detection, Hard error and EXIT routines
+NAME    STDCTRLC
+
+include ctrlc.asm
diff --git a/v4.0/src/DOS/STDDATA.ASM b/v4.0/src/DOS/STDDATA.ASM
new file mode 100644
index 0000000..ddbb1bc
--- /dev/null
+++ b/v4.0/src/DOS/STDDATA.ASM
@@ -0,0 +1,33 @@
+;       SCCSID = @(#)stddata.asm        1.1 85/04/10
+;
+; DATA Segment for MS-DOS
+;
+
+.xlist
+.xcref
+include stdsw.asm
+include dosseg.asm
+debug = FALSE                           ; No dossym (too big)
+INCLUDE DOSMAC.INC
+INCLUDE SF.INC
+INCLUDE DIRENT.INC
+INCLUDE CURDIR.INC
+INCLUDE DPB.INC
+INCLUDE BUFFER.INC
+INCLUDE ARENA.INC
+INCLUDE VECTOR.INC
+INCLUDE DEVSYM.INC
+INCLUDE PDB.INC
+INCLUDE FIND.INC
+INCLUDE MI.INC
+.cref
+.list
+
+TITLE   STDDATA - DATA segment for MS-DOS
+NAME    STDDATA
+
+installed = TRUE
+
+include msdata.asm
+include msinit.asm
+        END
diff --git a/v4.0/src/DOS/STDDISP.ASM b/v4.0/src/DOS/STDDISP.ASM
new file mode 100644
index 0000000..9010b98
--- /dev/null
+++ b/v4.0/src/DOS/STDDISP.ASM
@@ -0,0 +1,16 @@
+;       SCCSID = @(#)stddisp.asm        1.1 85/04/10
+TITLE   MS-DOS DOS DISPATCHER - System call dispatch code
+NAME    DISP
+
+;
+; System call dispatch code
+;
+
+.xlist
+.xcref
+include stdsw.asm
+.cref
+.list
+
+include disp.asm
+        END
diff --git a/v4.0/src/DOS/STDDOSME.ASM b/v4.0/src/DOS/STDDOSME.ASM
new file mode 100644
index 0000000..c1d5a53
--- /dev/null
+++ b/v4.0/src/DOS/STDDOSME.ASM
@@ -0,0 +1,20 @@
+;       SCCSID = @(#)stddosmes.as       1.2 85/10/07
+;       SCCSID = @(#)stddosmes.as       1.2 85/10/07
+;
+; Standard device IO for MSDOS (first 12 function calls)
+;
+
+.xlist
+.xcref
+include stdsw.asm
+include dosseg.asm
+.cref
+.list
+
+debug=0
+
+TITLE   STDDOSMES - DOS OEM dependancies
+NAME    STDDOSMES
+
+include dosmes.asm
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/STDIOCTL.ASM b/v4.0/src/DOS/STDIOCTL.ASM
new file mode 100644
index 0000000..9444530
--- /dev/null
+++ b/v4.0/src/DOS/STDIOCTL.ASM
@@ -0,0 +1,5 @@
+;       SCCSID = @(#)STDIOCTL.INC       1.1 85/04/10
+IBM     EQU     0          ;FALSE
+
+INCLUDE IOCTL.INC
+       SCCSID = @(#)STDIOCTL.INC       1.1 85/04/10
diff --git a/v4.0/src/DOS/STDPROC.ASM b/v4.0/src/DOS/STDPROC.ASM
new file mode 100644
index 0000000..c83fe2b
--- /dev/null
+++ b/v4.0/src/DOS/STDPROC.ASM
@@ -0,0 +1,15 @@
+;       SCCSID = @(#)stdproc.asm        1.1 85/04/10
+;
+; Pseudo EXEC system call for MSDOS
+;
+
+.xlist
+.xcref
+include stdsw.asm
+.cref
+.list
+
+TITLE   STDPROC - process maintenance for MSDOS
+NAME    STDPROC
+
+include proc.asm
diff --git a/v4.0/src/DOS/STDSW.ASM b/v4.0/src/DOS/STDSW.ASM
new file mode 100644
index 0000000..c9fc581
--- /dev/null
+++ b/v4.0/src/DOS/STDSW.ASM
@@ -0,0 +1,32 @@
+;       SCCSID = @(#)stdsw.asm  1.1 85/04/10
+TRUE    EQU     0FFFFH
+FALSE   EQU     0
+
+; Use the switches below to produce the standard Microsoft version or the IBM
+; version of the operating system
+MSVER   EQU     TRUE
+IBM     EQU     FALSE
+WANG    EQU     FALSE
+ALTVECT EQU     FALSE
+Rainbow EQU     FALSE
+
+
+; Set this switch to cause DOS to move itself to the end of memory
+HIGHMEM EQU     FALSE
+
+        IF      IBM
+ESCCH   EQU     0                       ; character to begin escape seq.
+CANCEL  EQU     27                      ;Cancel with ESCAPE
+TOGLPRN EQU     TRUE                    ;One key toggles printer echo
+ZEROEXT EQU     TRUE
+        ELSE
+        IF      WANG                    ;Are we assembling for WANG?
+ESCCH   EQU     1FH                     ;Yes. Use 1FH for escape character
+        ELSE
+ESCCH   EQU     1BH
+        ENDIF
+CANCEL  EQU     "X"-"@"                 ;Cancel with Ctrl-X
+TOGLPRN EQU     FALSE                   ;Separate keys for printer echo on
+                                        ;and off
+ZEROEXT EQU     TRUE
+        ENDIF
diff --git a/v4.0/src/DOS/STDTABLE.ASM b/v4.0/src/DOS/STDTABLE.ASM
new file mode 100644
index 0000000..a06b3e6
--- /dev/null
+++ b/v4.0/src/DOS/STDTABLE.ASM
@@ -0,0 +1,16 @@
+;       SCCSID = @(#)stdtable.asm       1.1 85/04/10
+;
+; Table Segment for MS-DOS DOS
+;
+
+.xlist
+.xcref
+include stdsw.asm
+.cref
+.list
+
+TITLE   STDTABLE - Table segment for MS-DOS
+NAME    STDTABLE
+
+include mstable.asm
+        END
diff --git a/v4.0/src/DOS/STRIN.ASM b/v4.0/src/DOS/STRIN.ASM
new file mode 100644
index 0000000..ac4b963
--- /dev/null
+++ b/v4.0/src/DOS/STRIN.ASM
@@ -0,0 +1,403 @@
+;       SCCSID = @(#)strin.asm  1.2 85/04/18
+Break
+
+; Inputs:
+;       DS:DX Point to an input buffer
+; Function:
+;       Fill buffer from console input until CR
+; Returns:
+;       None
+
+        procedure   $STD_CON_STRING_INPUT,NEAR   ;System call 10
+ASSUME  DS:NOTHING,ES:NOTHING
+
+        MOV     AX,SS
+        MOV     ES,AX
+        MOV     SI,DX
+        XOR     CH,CH
+        LODSW
+;
+; AL is the buffer length
+; AH is the template length
+;
+        OR      AL,AL
+        retz                    ;Buffer is 0 length!!?
+        MOV     BL,AH           ;Init template counter
+        MOV     BH,CH           ;Init template counter
+ ;
+ ; BL is the number of bytes in the template
+ ;
+        CMP     AL,BL
+        JBE     NOEDIT          ;If length of buffer inconsistent with contents
+        CMP     BYTE PTR [BX+SI],c_CR
+        JZ      EDITON          ;If CR correctly placed EDIT is OK
+;
+; The number of chars in the template is >= the number of chars in buffer or
+; there is no CR at the end of the template.  This is an inconsistant state
+; of affairs.  Pretend that the template was empty:
+;
+NOEDIT:
+        MOV     BL,CH           ;Reset buffer
+EDITON:
+        MOV     DL,AL
+        DEC     DX              ;DL is # of bytes we can put in the buffer
+;
+; Top level.  We begin to read a line in.
+;
+NEWLIN:
+        MOV     AL,[CARPOS]
+        MOV     [STARTPOS],AL   ;Remember position in raw buffer
+        PUSH    SI
+        MOV     DI,OFFSET DOSGROUP:INBUF        ;Build the new line here
+        MOV     [INSMODE],CH    ;Insert mode off
+        MOV     BH,CH           ;No chars from template yet
+        MOV     DH,CH           ;No chars to new line yet
+        invoke  $STD_CON_INPUT_NO_ECHO          ;Get first char
+        CMP     AL,c_LF         ;Linefeed
+        JNZ     GOTCH           ;Filter out LF so < works
+;
+; This is the main loop of reading in a character and processing it.
+;
+;   BH is the index of the next byte in the template
+;   BL is the length of the template
+;   DH is the number of bytes in the buffer
+;   DL is the length of the buffer
+;
+entry   GETCH
+        invoke  $STD_CON_INPUT_NO_ECHO
+GOTCH:
+;
+; Brain-damaged TP ignored ^F in case his BIOS did not flush the
+; input queue.
+;
+        CMP     AL,"F"-"@"
+        JZ      GETCH
+;
+; If the leading char is the function-key lead byte
+;
+        CMP     AL,[ESCCHAR]
+        JZ      ESCape          ;change reserved keyword DBM 5-7-87
+;
+; Rubout and ^H are both destructive backspaces.
+;
+        CMP     AL,c_DEL
+        JZ      BACKSPJ
+        CMP     AL,c_BS
+        JZ      BACKSPJ
+;
+; ^W deletes backward once and then backs up until a letter is before the
+; cursor
+;
+        CMP     AL,"W" - "@"
+; The removal of the comment characters before the jump statement will
+; cause ^W to backup a word.
+;***    JZ      WordDel
+        NOP
+        NOP
+        CMP     AL,"U" - "@"
+; The removal of the comment characters before the jump statement will
+; cause ^U to clear a line.
+;***    JZ      LineDel
+        NOP
+        NOP
+
+;
+; CR terminates the line.
+;
+        CMP     AL,c_CR
+        JZ      ENDLIN
+;
+; LF goes to a new line and keeps on reading.
+;
+        CMP     AL,c_LF
+        JZ      PHYCRLF
+;
+; ^X (or ESC) deletes the line and starts over
+;
+        CMP     AL,[CANCHAR]
+        JZ      KILNEW
+;
+; Otherwise, we save the input character.
+;
+SAVCH:
+        CMP     DH,DL
+        JAE     BUFFUL                  ; buffer is full.
+        STOSB
+        INC     DH                      ; increment count in buffer.
+        invoke  BUFOUT                  ;Print control chars nicely
+        CMP     BYTE PTR [INSMODE],0
+        JNZ     GETCH                   ; insertmode => don't advance template
+        CMP     BH,BL
+        JAE     GETCH                   ; no more characters in template
+        INC     SI                      ; Skip to next char in template
+        INC     BH                      ; remember position in template
+        JMP     SHORT GETCH
+
+BACKSPJ: JMP    SHORT BACKSP
+
+BUFFUL:
+        MOV     AL,7                    ; Bell to signal full buffer
+        invoke  OUTT
+        JMP     SHORT GETCH
+
+ESCape:                         ;change reserved keyword DBM 5-7-87
+        transfer    OEMFunctionKey      ; let the OEM's handle the key dispatch
+
+ENDLIN:
+        STOSB                           ; Put the CR in the buffer
+        invoke  OUTT                    ; Echo it
+        POP     DI                      ; Get start of user buffer
+        MOV     [DI-1],DH               ; Tell user how many bytes
+        INC     DH                      ; DH is length including CR
+COPYNEW:
+        SaveReg <DS,ES>
+        RestoreReg <DS,ES>              ; XCHG ES,DS
+        MOV     SI,OFFSET DOSGROUP:INBUF
+        MOV     CL,DH                   ; set up count
+        REP     MOVSB                   ; Copy final line to user buffer
+        return
+;
+; Output a CRLF to the user screen and do NOT store it into the buffer
+;
+PHYCRLF:
+        invoke  CRLF
+        JMP     GETCH
+
+;
+; Delete the previous line
+;
+LineDel:
+        OR      DH,DH
+        JZ      GetCh
+        Call    BackSpace
+        JMP     LineDel
+
+;
+; delete the previous word.
+;
+WordDel:
+WordLoop:
+        Call    BackSpace               ; backspace the one spot
+        OR      DH,DH
+        JZ      GetChJ
+        MOV     AL,ES:[DI-1]
+        cmp     al,'0'
+        jb      GetChj
+        cmp     al,'9'
+        jbe     WordLoop
+        OR      AL,20h
+        CMP     AL,'a'
+        JB      GetChJ
+        CMP     AL,'z'
+        JBE     WordLoop
+GetChJ:
+        JMP     GetCh
+;
+; The user wants to throw away what he's typed in and wants to start over.  We
+; print the backslash and then go to the next line and tab to the correct spot
+; to begin the buffered input.
+;
+        entry   KILNEW
+        MOV     AL,"\"
+        invoke  OUTT            ;Print the CANCEL indicator
+        POP     SI              ;Remember start of edit buffer
+PUTNEW:
+        invoke  CRLF            ;Go to next line on screen
+        MOV     AL,[STARTPOS]
+        invoke  TAB             ;Tab over
+        JMP     NEWLIN          ;Start over again
+
+
+;
+; Destructively back up one character position
+;
+entry   BackSp
+        Call    BackSpace
+        JMP     GetCh
+
+BackSpace:
+        OR      DH,DH
+        JZ      OLDBAK          ;No chars in line, do nothing to line
+        CALL    BACKUP          ;Do the backup
+        MOV     AL,ES:[DI]      ;Get the deleted char
+        CMP     AL," "
+        JAE     OLDBAK          ;Was a normal char
+        CMP     AL,c_HT
+        JZ      BAKTAB          ;Was a tab, fix up users display
+;; 9/27/86 fix for ctrl-U backspace
+        CMP     AL,"U"-"@"      ; ctrl-U is a section symbol not ^U
+        JZ      OLDBAK
+        CMP     AL,"T"-"@"      ; ctrl-T is a paragraphs symbol not ^T
+        JZ      OLDBAK
+;; 9/27/86 fix for ctrl-U backspace
+        CALL    BACKMES         ;Was a control char, zap the '^'
+OLDBAK:
+        CMP     BYTE PTR [INSMODE],0
+        retnz                   ;In insert mode, done
+        OR      BH,BH
+        retz                    ;Not advanced in template, stay where we are
+        DEC     BH              ;Go back in template
+        DEC     SI
+        return
+
+BAKTAB:
+        PUSH    DI
+        DEC     DI              ;Back up one char
+        STD                     ;Go backward
+        MOV     CL,DH           ;Number of chars currently in line
+        MOV     AL," "
+        PUSH    BX
+        MOV     BL,7            ;Max
+        JCXZ    FIGTAB          ;At start, do nothing
+FNDPOS:
+        SCASB                   ;Look back
+        JNA     CHKCNT
+        CMP     BYTE PTR ES:[DI+1],9
+        JZ      HAVTAB          ;Found a tab
+        DEC     BL              ;Back one char if non tab control char
+CHKCNT:
+        LOOP    FNDPOS
+FIGTAB:
+        SUB     BL,[STARTPOS]
+HAVTAB:
+        SUB     BL,DH
+        ADD     CL,BL
+        AND     CL,7            ;CX has correct number to erase
+        CLD                     ;Back to normal
+        POP     BX
+        POP     DI
+        JZ      OLDBAK          ;Nothing to erase
+TABBAK:
+        invoke  BACKMES
+        LOOP    TABBAK          ;Erase correct number of chars
+        JMP     SHORT OLDBAK
+
+BACKUP:
+        DEC     DH              ;Back up in line
+        DEC     DI
+BACKMES:
+        MOV     AL,c_BS         ;Backspace
+        invoke  OUTT
+        MOV     AL," "          ;Erase
+        invoke  OUTT
+        MOV     AL,c_BS         ;Backspace
+        JMP     OUTT            ;Done
+
+;User really wants an ESC character in his line
+        entry   TwoEsc
+        MOV     AL,[ESCCHAR]
+        JMP     SAVCH
+
+;Copy the rest of the template
+        entry   COPYLIN
+        MOV     CL,BL           ;Total size of template
+        SUB     CL,BH           ;Minus position in template, is number to move
+        JMP     SHORT COPYEACH
+
+        entry   CopyStr
+        invoke  FINDOLD         ;Find the char
+        JMP     SHORT COPYEACH  ;Copy up to it
+
+;Copy one char from template to line
+        entry   COPYONE
+        MOV     CL,1
+;Copy CX chars from template to line
+COPYEACH:
+        MOV     BYTE PTR [INSMODE],0    ;All copies turn off insert mode
+        CMP     DH,DL
+        JZ      GETCH2                  ;At end of line, can't do anything
+        CMP     BH,BL
+        JZ      GETCH2                  ;At end of template, can't do anything
+        LODSB
+        STOSB
+        invoke  BUFOUT
+        INC     BH                      ;Ahead in template
+        INC     DH                      ;Ahead in line
+        LOOP    COPYEACH
+GETCH2:
+        JMP     GETCH
+
+;Skip one char in template
+        entry   SKIPONE
+        CMP     BH,BL
+        JZ      GETCH2                  ;At end of template
+        INC     BH                      ;Ahead in template
+        INC     SI
+        JMP     GETCH
+
+        entry   SKIPSTR
+        invoke  FINDOLD                 ;Find out how far to go
+        ADD     SI,CX                   ;Go there
+        ADD     BH,CL
+        JMP     GETCH
+
+;Get the next user char, and look ahead in template for a match
+;CX indicates how many chars to skip to get there on output
+;NOTE: WARNING: If the operation cannot be done, the return
+;       address is popped off and a jump to GETCH is taken.
+;       Make sure nothing extra on stack when this routine
+;       is called!!! (no PUSHes before calling it).
+FINDOLD:
+        invoke  $STD_CON_INPUT_NO_ECHO
+        CMP     AL,[ESCCHAR]            ; did he type a function key?
+        JNZ     FindSetup               ; no, set up for scan
+        invoke  $STD_CON_INPUT_NO_ECHO  ; eat next char
+        JMP     NotFnd                  ; go try again
+FindSetup:
+        MOV     CL,BL
+        SUB     CL,BH           ;CX is number of chars to end of template
+        JZ      NOTFND          ;At end of template
+        DEC     CX              ;Cannot point past end, limit search
+        JZ      NOTFND          ;If only one char in template, forget it
+        PUSH    ES
+        PUSH    DS
+        POP     ES
+        PUSH    DI
+        MOV     DI,SI           ;Template to ES:DI
+        INC     DI
+        REPNE   SCASB           ;Look
+        POP     DI
+        POP     ES
+        JNZ     NOTFND          ;Didn't find the char
+        NOT     CL              ;Turn how far to go into how far we went
+        ADD     CL,BL           ;Add size of template
+        SUB     CL,BH           ;Subtract current pos, result distance to skip
+        return
+
+NOTFND:
+        POP     BP              ;Chuck return address
+        JMP     GETCH
+
+entry   REEDIT
+        MOV     AL,"@"          ;Output re-edit character
+        invoke  OUTT
+        POP     DI
+        PUSH    DI
+        PUSH    ES
+        PUSH    DS
+        invoke  COPYNEW         ;Copy current line into template
+        POP     DS
+        POP     ES
+        POP     SI
+        MOV     BL,DH           ;Size of line is new size template
+        JMP     PUTNEW          ;Start over again
+
+        entry   EXITINS
+        entry   ENTERINS
+        NOT     BYTE PTR [INSMODE]
+        JMP     GETCH
+
+;Put a real live ^Z in the buffer (embedded)
+        entry   CTRLZ
+        MOV     AL,"Z"-"@"
+        JMP     SAVCH
+
+;Output a CRLF
+        entry   CRLF
+        MOV     AL,c_CR
+        invoke  OUTT
+        MOV     AL,c_LF
+        JMP     OUTT
+
+EndProc $STD_CON_STRING_INPUT
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/TIME.ASM b/v4.0/src/DOS/TIME.ASM
new file mode 100644
index 0000000..0d3895c
--- /dev/null
+++ b/v4.0/src/DOS/TIME.ASM
@@ -0,0 +1,380 @@
+;       SCCSID = @(#)time.asm   1.1 85/04/10
+TITLE   TIME - time and date functions
+NAME    TIME
+;
+; System Calls and low level routines for DATE and TIME
+;
+;   $GET_DATE
+;   $SET_DATE
+;   $GET_TIME
+;   $SET_TIME
+;   DATE16
+;   READTIME
+;   DSLIDE
+;   SETYEAR
+;   DODATE
+;   DSUM
+;
+;   Modification history:
+;
+;       Created: ARR 30 March 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE        SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+
+
+    i_need  DAY,BYTE
+    i_need  MONTH,BYTE
+    i_need  YEAR,WORD
+    i_need  WEEKDAY,BYTE
+    i_need  TIMEBUF,6
+    i_need  BCLOCK,DWORD
+    i_need  DAYCNT,WORD
+    i_need  YRTAB,8
+    i_need  MONTAB,12
+    i_need  DATE_FLAG,WORD
+
+    FOURYEARS = 3*365 + 366
+
+SUBTTL DATE AND TIME - SYSTEM CALLS 42,43,44,45
+PAGE
+        procedure   $GET_DATE,NEAR
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Return current date
+; Returns:
+;       Date in CX:DX
+
+        Context DS
+        CALL    READTIME                ;Check for rollover to next day
+        MOV     AX,[YEAR]
+;
+; WARNING!!!! DAY and MONTH must be adjacently allocated!
+;
+        MOV     BX,WORD PTR [DAY]       ; fetch both day and month
+        invoke  get_user_stack          ;Get pointer to user registers
+ASSUME  DS:NOTHING
+        MOV     [SI.user_DX],BX         ;DH=month, DL=day
+        ADD     AX,1980                 ;Put bias back
+        MOV     [SI.user_CX],AX         ;CX=year
+        MOV     AL,BYTE PTR [WEEKDAY]
+        return
+EndProc $GET_DATE
+
+        procedure   $SET_DATE,NEAR      ;System call 43
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       CX:DX valid date
+; Function:
+;       Set current date
+; Returns:
+;       AL = -1 date bad, = 0 OK
+
+        MOV     AL,-1                   ;Be ready to flag error
+        SUB     CX,1980                 ;Fix bias in year
+        retc                            ;Error if not big enough
+        CMP     CX,119                  ;Year must be less than 2100
+        JA      RET24
+        OR      DH,DH
+        retz
+        OR      DL,DL
+        retz                            ;Error if either month or day is 0
+        CMP     DH,12                   ;Check against max. month
+        JA      RET24
+        Context DS
+        invoke  DODATE
+RET24:  return
+EndProc $SET_DATE
+
+        procedure   $GET_TIME,NEAR      ;System call 44
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       None
+; Function:
+;       Get current time
+; Returns:
+;       Time in CX:DX
+
+        Context DS
+        CALL    READTIME
+        invoke  get_user_stack          ;Get pointer to user registers
+        MOV     [SI.user_DX],DX
+        MOV     [SI.user_CX],CX
+        XOR     AL,AL
+RET26:  return
+EndProc $GET_TIME
+
+        procedure   $SET_TIME,NEAR      ;System call 45
+ASSUME  DS:NOTHING,ES:NOTHING
+
+; Inputs:
+;       CX:DX = Time
+; Function:
+;       Set time
+; Returns:
+;       AL = -1 time bad, = 0 OK
+
+        MOV     AL,-1                   ;Flag in case of error
+        CMP     CH,24                   ;Check hours
+        JAE     RET26
+        CMP     CL,60                   ;Check minutes
+        JAE     RET26
+        CMP     DH,60                   ;Check seconds
+        JAE     RET26
+        CMP     DL,100                  ;Check 1/100's
+        JAE     RET26
+        PUSH    CX
+        PUSH    DX
+        Context DS
+        MOV     BX,OFFSET DOSGROUP:TIMEBUF
+        MOV     CX,6
+        XOR     DX,DX
+        MOV     AX,DX
+        PUSH    BX
+        invoke  SETREAD
+        DOSAssume   CS,<ES>,"TIME/SetRead"
+        PUSH    DS
+        LDS     SI,[BCLOCK]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2              ;Get correct day count
+        POP     DS
+        DOSAssume   CS,<DS>,"TIME/DevIOCall2"
+        POP     BX
+        invoke  SETWRITE
+        POP     WORD PTR [TIMEBUF+4]
+        POP     WORD PTR [TIMEBUF+2]
+        LDS     SI,[BCLOCK]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2              ;Set the time
+        XOR     AL,AL
+        return
+EndProc $SET_TIME
+
+SUBTTL DATE16, READTIME, DODATE -- GUTS OF TIME AND DATE
+PAGE
+
+;
+; Date16 returns the current date in AX, current time in DX
+;   AX - YYYYYYYMMMMDDDDD  years months days
+;   DX - HHHHHMMMMMMSSSSS  hours minutes seconds/2
+;
+; DS = DOSGROUP on output
+
+procedure   DATE16,NEAR
+        Context DS
+        ASSUME  ES:NOTHING
+        PUSH    CX
+        PUSH    ES
+        CALL    READTIME
+        POP     ES
+        SHL     CL,1                    ;Minutes to left part of byte
+        SHL     CL,1
+        SHL     CX,1                    ;Push hours and minutes to left end
+        SHL     CX,1
+        SHL     CX,1
+        SHR     DH,1                    ;Count every two seconds
+        OR      CL,DH                   ;Combine seconds with hours and minutes
+        MOV     DX,CX
+;
+; WARNING!  MONTH and YEAR must be adjacently allocated
+;
+        MOV     AX,WORD PTR [MONTH]     ;Fetch month and year
+        MOV     CL,4
+        SHL     AL,CL                   ;Push month to left to make room for day
+        SHL     AX,1
+        POP     CX
+        OR      AL,[DAY]
+        return
+EndProc DATE16
+
+;Gets time in CX:DX. Figures new date if it has changed.
+;Uses AX, CX, DX.
+
+        procedure   READTIME,NEAR
+        DOSAssume   CS,<DS>,"ReadTime"
+        ASSUME  ES:NOTHING
+
+        MOV     [DATE_FLAG],0           ; reset date flag for CPMIO
+        PUSH    SI
+        PUSH    BX
+        MOV     BX,OFFSET DOSGROUP:TIMEBUF
+        MOV     CX,6
+        XOR     DX,DX
+        MOV     AX,DX
+        invoke  SETREAD
+        PUSH    DS
+        LDS     SI,[BCLOCK]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2              ;Get correct date and time
+        POP     DS
+        DOSAssume   CS,<DS>,"ReadTime/DevIOCall2"
+        POP     BX
+        POP     SI
+        MOV     AX,WORD PTR [TIMEBUF]
+        MOV     CX,WORD PTR [TIMEBUF+2]
+        MOV     DX,WORD PTR [TIMEBUF+4]
+        CMP     AX,[DAYCNT]             ;See if day count is the same
+        retz
+        CMP     AX,FOURYEARS*30         ;Number of days in 120 years
+        JAE     RET22                   ;Ignore if too large
+        MOV     [DAYCNT],AX
+        PUSH    SI
+        PUSH    CX
+        PUSH    DX                      ;Save time
+        XOR     DX,DX
+        MOV     CX,FOURYEARS            ;Number of days in 4 years
+        DIV     CX                      ;Compute number of 4-year units
+        SHL     AX,1
+        SHL     AX,1
+        SHL     AX,1                    ;Multiply by 8 (no. of half-years)
+        MOV     CX,AX                   ;<240 implies AH=0
+        MOV     SI,OFFSET DOSGROUP:YRTAB;Table of days in each year
+        CALL    DSLIDE                  ;Find out which of four years we're in
+        SHR     CX,1                    ;Convert half-years to whole years
+        JNC     SK                      ;Extra half-year?
+        ADD     DX,200
+SK:
+        CALL    SETYEAR
+        MOV     CL,1                    ;At least at first month in year
+        MOV     SI,OFFSET DOSGROUP:MONTAB   ;Table of days in each month
+        CALL    DSLIDE                  ;Find out which month we're in
+        MOV     [MONTH],CL
+        INC     DX                      ;Remainder is day of month (start with one)
+        MOV     [DAY],DL
+        CALL    WKDAY                   ;Set day of week
+        POP     DX
+        POP     CX
+        POP     SI
+RET22:  return
+EndProc READTIME
+
+        procedure   DSLIDE,NEAR
+        MOV     AH,0
+DSLIDE1:
+        LODSB                           ;Get count of days
+        CMP     DX,AX                   ;See if it will fit
+        retc                            ;If not, done
+        SUB     DX,AX
+        INC     CX                      ;Count one more month/year
+        JMP     SHORT DSLIDE1
+EndProc DSLIDE
+
+        procedure   SETYEAR,NEAR
+;Set year with value in CX. Adjust length of February for this year.
+        MOV     BYTE PTR [YEAR],CL
+
+CHKYR:
+        TEST    CL,3                    ;Check for leap year
+        MOV     AL,28
+        JNZ     SAVFEB                  ;28 days if no leap year
+        INC     AL                      ;Add leap day
+SAVFEB:
+        MOV     [MONTAB+1],AL           ;Store for February
+RET23:  return
+EndProc SETYEAR
+
+        procedure   DODATE,NEAR
+        DOSAssume   CS,<DS>,"DoDate"
+        ASSUME  ES:NOTHING
+        CALL    CHKYR                   ;Set Feb. up for new year
+        MOV     AL,DH
+        MOV     BX,OFFSET DOSGROUP:MONTAB-1
+        XLAT                            ;Look up days in month
+        CMP     AL,DL
+        MOV     AL,-1                   ;Restore error flag, just in case
+        retc                            ;Error if too many days
+        CALL    SETYEAR
+;
+; WARNING!  DAY and MONTH must be adjacently allocated
+;
+        MOV     WORD PTR [DAY],DX       ;Set both day and month
+        SHR     CX,1
+        SHR     CX,1
+        MOV     AX,FOURYEARS
+        MOV     BX,DX
+        MUL     CX
+        MOV     CL,BYTE PTR [YEAR]
+        AND     CL,3
+        MOV     SI,OFFSET DOSGROUP:YRTAB
+        MOV     DX,AX
+        SHL     CX,1                    ;Two entries per year, so double count
+        CALL    DSUM                    ;Add up the days in each year
+        MOV     CL,BH                   ;Month of year
+        MOV     SI,OFFSET DOSGROUP:MONTAB
+        DEC     CX                      ;Account for months starting with one
+        CALL    DSUM                    ;Add up days in each month
+        MOV     CL,BL                   ;Day of month
+        DEC     CX                      ;Account for days starting with one
+        ADD     DX,CX                   ;Add in to day total
+        XCHG    AX,DX                   ;Get day count in AX
+        MOV     [DAYCNT],AX
+        PUSH    SI
+        PUSH    BX
+        PUSH    AX
+        MOV     BX,OFFSET DOSGROUP:TIMEBUF
+        MOV     CX,6
+        XOR     DX,DX
+        MOV     AX,DX
+        PUSH    BX
+        invoke  SETREAD
+        DOSAssume   CS,<ES>,"DoDate/SetRead"
+        PUSH    DS
+        LDS     SI,[BCLOCK]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2              ;Get correct date and time
+        POP     DS
+        POP     BX
+        DOSAssume   CS,<DS>,"DoDate/DevIOCall2"
+        invoke  SETWRITE
+        POP     WORD PTR [TIMEBUF]
+        PUSH    DS
+        LDS     SI,[BCLOCK]
+ASSUME  DS:NOTHING
+        invoke  DEVIOCALL2              ;Set the date
+        POP     DS
+        DOSAssume   CS,<DS>,"DoDate/DevIOCall2(second)"
+        POP     BX
+        POP     SI
+WKDAY:
+        MOV     AX,[DAYCNT]
+        XOR     DX,DX
+        MOV     CX,7
+        INC     AX
+        INC     AX                      ;First day was Tuesday
+        DIV     CX                      ;Compute day of week
+        MOV     [WEEKDAY],DL
+        XOR     AL,AL                   ;Flag OK
+Ret25:  return
+EndProc DODATE
+
+        procedure   DSUM,NEAR
+        MOV     AH,0
+        JCXZ    RET25
+DSUM1:
+        LODSB
+        ADD     DX,AX
+        LOOP    DSUM1
+        return
+EndProc DSUM
+
+CODE         ENDS
+    END
+
\ No newline at end of file
diff --git a/v4.0/src/DOS/UTIL.ASM b/v4.0/src/DOS/UTIL.ASM
new file mode 100644
index 0000000..3c9c516
--- /dev/null
+++ b/v4.0/src/DOS/UTIL.ASM
@@ -0,0 +1,232 @@
+;       SCCSID = @(#)util.asm   1.1 85/04/10
+TITLE   UTIL - Handle utilities
+NAME    UTIL
+;
+; Handle related utilities for MSDOS 2.X.
+;
+;   pJFNFromHandle  written
+;   SFFromHandle    written
+;   SFFromSFN       written
+;   JFNFree         written
+;   SFNFree         written
+;
+;   Modification history:
+;
+;       Created: MZ 1 April 1983
+;
+
+.xlist
+;
+; get the appropriate segment definitions
+;
+include dosseg.asm
+
+CODE    SEGMENT BYTE PUBLIC  'CODE'
+        ASSUME  SS:DOSGROUP,CS:DOSGROUP
+
+.xcref
+INCLUDE DOSSYM.INC
+INCLUDE DEVSYM.INC
+.cref
+.list
+.sall
+
+        I_need  CurrentPDB,WORD         ; current process data block location
+        I_need  SFT_Addr,DWORD          ; pointer to beginning of table
+        I_Need  PROC_ID,WORD            ; current process ID
+        I_Need  USER_ID,WORD            ; current user ID
+if debug
+        I_need  BugLev,WORD
+        I_need  BugTyp,WORD
+include bugtyp.asm
+endif
+
+BREAK   <pJFNFromHandle - return pointer to JFN table entry>
+
+;
+;   pJFNFromHandle - Given a handle, return the pointer to the JFN location
+;       in the user's data space
+;   Inputs:     BX - Handle
+;   Outputs:    Carry Set
+;                   AX has error code
+;               Carry reset
+;                   ES:DI point to the handle spot
+;   Registers modified:
+;               If no error, ES:DI, else AX,ES
+; NOTE:
+;   This routine is called from $CREATE_PROCESS_DATA_BLOCK which is called
+;       at DOSINIT time with SS NOT DOSGROUP
+procedure   pJFNFromHandle,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        MOV     ES,[CurrentPDB]         ; get user process data block
+        CMP     BX,ES:[PDB_JFN_Length]  ; is handle greater than allocated
+        JB      JFNAdd                  ; no, get offset
+        fmt     TypAccess,LevSFN,<"$p: Illegal JFN %x\n">,<BX>
+        MOV     AL,error_invalid_handle ; appropriate error
+ReturnCarry:
+        STC                             ; signal error
+        return                          ; go back
+JFNAdd: LES     DI,ES:[PDB_JFN_Pointer] ; get pointer to beginning of table
+        ADD     DI,BX                   ; add in offset
+ReturnNoCarry:
+        CLC                             ; no holes
+        return                          ; bye!
+EndProc pJFNFromHandle
+
+BREAK <SFFromHandle - return pointer (or error) to SF entry from handle>
+
+;
+; SFFromHandle - Given a handle, get JFN and then index into SF table
+;
+;   Input:      BX has handle
+;   Output:     Carry Set
+;                   AX has error code
+;               Carry Reset
+;                   ES:DI has pointer to SF entry
+;   Registers modified: If error, AX,ES, else ES:DI
+; NOTE:
+;   This routine is called from $CREATE_PROCESS_DATA_BLOCK which is called
+;       at DOSINIT time with SS NOT DOSGROUP
+procedure   SFFromHandle,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        CALL    pJFNFromHandle          ; get jfn pointer
+        retc                            ; return if error
+        CMP     BYTE PTR ES:[DI],-1     ; unused handle
+        JNZ     GetSF                   ; nope, suck out SF
+        fmt     TypAccess,LevSFN,<"$p: Illegal SFN $x:$x\n">,<ES,DI>
+        MOV     AL,error_invalid_handle ; appropriate error
+        jump    ReturnCarry             ; signal it
+GetSF:
+        SaveReg <BX>                    ; save handle
+        MOV     BL,BYTE PTR ES:[DI]     ; get SFN
+        XOR     BH,BH                   ; ignore upper half
+        CALL    SFFromSFN               ; get real sf spot
+        RestoreReg  <BX>                ; restore
+        return                          ; say goodbye
+EndProc SFFromHandle
+
+BREAK <SFFromSFN - index into SF table for SFN>
+
+;
+; SFFromSFN - index into SF tables for SFN.
+;
+;   Input:      BX has SF index
+;   Output:     ES:DI points to SF entry
+;   Registers modified: ES:DI, BX only
+; NOTE:
+;   This routine is called from SFFromHandle which is called
+;       at DOSINIT time with SS NOT DOSGROUP
+procedure   SFFromSFN,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:NOTHING
+        LES     DI,[SFT_Addr]           ; get pointer to beginning of table
+ScanLoop:
+        CMP     BX,ES:[DI].SFCount      ; is handle in this table?
+        JB      GetOffset               ; yes, go grab it
+        SUB     BX,ES:[DI].SFCount
+        LES     DI,ES:[DI].SFLink       ; get next table segment
+        CMP     DI,-1                   ; end of tables?
+        JNZ     ScanLoop                ; no, try again
+        STC                             ; error...
+        JMP     SHORT Restore           ; go restore
+GetOffset:
+        SaveReg <AX>                    ; save AX
+        MOV     AX,SIZE SF_Entry        ; put it in a nice place
+        MUL     BL                      ; times size
+        ADD     DI,AX                   ; offset by size
+        RestoreReg  <AX>                ; get world back
+        ADD     DI,SFTable              ; offset into structure
+        CLC                             ; no holes
+Restore:
+        return                          ; bye!
+EndProc SFFromSFN
+
+BREAK <JFNFree - return a jfn pointer if one is free>
+
+;
+; JFNFree - scan through the JFN table and return a pointer to a free slot
+;
+;   Input:  None.
+;   Output: Carry Set
+;               AX has error code, BX,ES,DI garbage
+;           Carry Reset
+;               BX has new handle, ES:DI is pointer to JFN slot
+;   Registers modified: As above only.
+procedure   JFNFree,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        XOR     BX,BX                   ; try starting low
+JFNScan:
+        CALL    pJFNFromHandle          ; get the appropriate handle
+        JC      JFNNone                 ; no more handles
+        CMP     BYTE PTR ES:[DI],-1     ; free?
+        JZ      JFNFound                ; yes, carry is clear
+        INC     BX                      ; no, next handle
+        JMP     JFNScan                 ; and try again
+JFNNone:
+        MOV     AL,error_too_many_open_files
+JFNFound:
+        return                          ; bye
+EndProc JFNFree
+
+BREAK <SFNFree - find a free SFN>
+
+;
+;   SFNFree - scan through the sf table looking for free entries
+;   Inputs:     none
+;   Outputs:    Carry Set - AX has error code, BX destroyed
+;               Carry Clear - BX has SFN
+;                   ES:DI - pointer to SFT
+;                   SFT_ref_count is set to 1
+;   Registers modified: none
+
+Procedure SFNFree,NEAR
+        ASSUME  CS:DOSGROUP,DS:NOTHING,ES:NOTHING,SS:DOSGROUP
+        XOR     BX,BX                   ; start at beginning
+SFNFreeLoop:
+        SaveReg <BX>                    ; Next call zaps BX
+        CALL    SFFromSFN               ; get the potential handle
+        RestoreReg  <BX>
+        JNC     SFNCheck                ; no carry, check to see if its free
+        MOV     AL,error_too_many_open_files    ; appropriate error
+        JMP     SFNDone
+SFNCheck:
+        CMP     ES:[DI.sf_Ref_Count],0  ; free?
+IF NOT DEBUG
+        JZ      SFNGot                  ; yep, got return him
+ELSE
+        JNZ     NoGot
+        JMP     SFNGot
+NoGot:
+ENDIF
+        CMP     ES:[DI.sf_ref_count],sf_busy
+        JNZ     SFNNext                 ; not marked busy...
+        fmt     TypAccess,LevSFN,<"$p: SFT $x:$x($x)is busy, owner $x:$x\n">,<ES,DI,BX,ES:[DI].sf_UID,ES:[DI].sf_pid>
+        SaveReg <BX>
+        MOV     BX,User_ID
+        CMP     ES:[DI.sf_UID],BX
+        JNZ     SFNNextP
+        MOV     BX,Proc_ID
+        CMP     ES:[DI.sf_PID],BX
+        JZ      SFNGotP
+SFNNextP:
+        fmt     TypAccess,LevSFN,<"$p: SFT unusable\n">
+        RestoreReg  <BX>
+SFNNext:
+        INC     BX                      ; no, try next sf number
+        JMP     SFNFreeLoop             ; and go until it fails
+SFNGot:
+        SaveReg <BX>
+SFNGotP:
+        CLC                             ; no error
+        fmt     TypAccess,LevSFN,<"$p: SFT $x:$x($x) marked busy\n">,<ES,DI,BX>
+        MOV     ES:[DI.sf_ref_count],sf_busy    ; make sure that this is allocated
+        MOV     BX,User_ID
+        MOV     ES:[DI.sf_UID],BX
+        MOV     BX,Proc_ID
+        MOV     ES:[DI.sf_PID],BX
+        RestoreReg  <BX>
+SFNDone:
+        return                          ; bye
+EndProc SFNFree
+
+CODE    ENDS
+END