1 files changed, 68 insertions, 0 deletions

diff --git a/v4.0/src/MAPPER/LSEEK.ASM b/v4.0/src/MAPPER/LSEEK.ASM
new file mode 100644
index 0000000..450f8c7
--- /dev/null
+++ b/v4.0/src/MAPPER/LSEEK.ASM
@@ -0,0 +1,68 @@
+;
+page 80,132
+;0
+title CP/DOS DosChgFilePtr mapper           * * *
+;
+dosxxx  segment byte public 'dos'
+        assume  cs:dosxxx,ds:nothing,es:nothing,ss:nothing
+
+;**********************************************************************
+;*
+;*   MODULE:   doschgfileptr
+;*
+;*   FILE NAME: dos007.asm
+;*
+;*   CALLING SEQUENCE:
+;*
+;*       push      word    file handle
+;*       push      dword   distance
+;*       push      word    move type
+;*       push@     dword   new pointer
+;*       call      doschgfileptr
+;*
+;*   MODULES CALLED:  PC-DOS Int 21h, ah=42h, move file pointer
+;*
+;*********************************************************************
+
+            public   doschgfileptr
+            .sall
+            .xlist
+            include  macros.inc
+            .list
+
+str         struc
+old_bp      dw       ?
+return      dd       ?
+newptr      dd       ?       ; new file pointer
+movtyp      dw       ?       ; move type
+dstnce      dd       ?       ; distance to be moved
+handle      dw       ?       ; file handle
+str         ends
+
+doschgfileptr  proc  far
+            Enter    doschgfileptr       ; push registers
+
+            push     es
+            les      dx,[bp].dstnce
+            mov      cx,es               ; set distance
+            pop      es
+            mov      ax,[bp].movtyp      ; get move type
+            mov      bx,[bp].handle      ; get handle
+
+            mov      ah,42h
+            int      21h                 ; move file pointer
+            jc       exit                ; return if error
+
+            lds      si,[bp].newptr        ; set pointer
+            mov      word ptr [si],ax      ; save the new pointer
+            mov      word ptr [si]+2,dx    ;
+            sub      ax,ax                 ; set godd return code
+
+exit:       mexit                      ;pop registers
+            ret      size str - 6      ;return
+
+doschgfileptr endp
+
+dosxxx      ends
+
+            end