From 2d04cacc5322951f187bb17e017c12920ac8ebe2 Mon Sep 17 00:00:00 2001
From: Mark Zbikowski
Date: Thu, 25 Apr 2024 21:24:10 +0100
Subject: MZ is back!

---
 v4.0/src/MAPPER/SCROLLUP.ASM | 103 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 v4.0/src/MAPPER/SCROLLUP.ASM

(limited to 'v4.0/src/MAPPER/SCROLLUP.ASM')

diff --git a/v4.0/src/MAPPER/SCROLLUP.ASM b/v4.0/src/MAPPER/SCROLLUP.ASM
new file mode 100644
index 0000000..cb92e8c
--- /dev/null
+++ b/v4.0/src/MAPPER/SCROLLUP.ASM
@@ -0,0 +1,103 @@
+;
+page 60,132
+;
+title CP/DOS VioScrollUp mapper
+;
+vioxxx  segment byte public 'vio'
+        assume  cs:vioxxx,ds:nothing,es:nothing,ss:nothing
+;
+; ************************************************************************* *
+; *
+; *      MODULE: VioScrollUp
+; *
+; *      FILE NAME: scrollup.asm
+; *
+; *      CALLING SEQUENCE:
+; *
+; *
+; *             push    word    toprow
+; *             push    word    leftcol
+; *             push    word    botrow
+; *             push    word    rightcol
+; *             push    word    lines
+; *             push@   dword   cell
+; *             push    word    vio handle
+; *             call    vioscrollup
+; *
+; *      MODULES CALLED:  BIOS Int 10h
+; *
+; *
+; *
+; *************************************************************************
+
+        public vioscrollup
+        .sall
+        .xlist
+        include macros.inc
+        .list
+
+error_bvs_parameter equ 0002h
+
+str     struc
+old_bp   dw      ?
+return   dd      ?
+handle   dw      ?        ; vio handle
+cell     dd      ?        ; cell to be written
+lines    dw      ?        ; number of blank lines
+rightcol dw      ?        ; right column
+botrow   dw      ?        ; bottom row
+leftcol  dw      ?        ; left column
+toprow   dw      ?        ; top row
+str     ends
+
+vioscrollup proc   far
+        Enter   VioScrollUp             ; save registers
+
+        mov     bx,[bp].lines           ; get number of blank lines
+        cmp     bl,25                   ; check for validity
+        jg      error                   ; jump if invalid
+
+        mov     al,bl
+        jmp     ar02
+
+ar01:   mov     al,00h
+ar02:   mov     ah,06h                  ; set scroll up function code
+
+        mov     bx,[bp].rightcol        ; get right col number
+        cmp     bl,80                   ; check the validity
+        jg      error                   ; branch if error
+        mov     dl,bl                   ; right column number in DL
+
+        mov     bx,[bp].botrow          ; get bottom row
+        cmp     bl,25                   ; check for validity
+        jg      error                   ; branch if error
+        mov     dh,bl                   ; bottom row in DH
+
+        mov     bx,[bp].leftcol         ; get left column number
+        mov     cl,bl                   ; left column in CL
+
+        mov     bx,[bp].toprow          ; get top row number
+        mov     ch,bl                   ; top row in CH
+
+        lds     si,[bp].cell            ; Set up cell in BX
+        mov     bx,ds:[si]              ;                    *****************
+;       cmp     bl,15                   ; check validity     ** assume good **
+;       jg      error                   ; branch if error    ** attribute!  **
+                                        ;                    *****************
+        mov     bh,bl                   ; filler attribute in BH
+        pushal                          ; Save registers in case int 10h
+                                        ;   messes them up
+        int     10h                     ; scrollup the display
+
+        popal
+        sub     ax,ax                   ; set no error code
+        jmp     exit                    ; return
+
+error:  mov     ax,error_bvs_parameter  ; set error code
+
+exit:   Mexit                           ; pop registers
+        ret     size str - 6            ; return
+
+vioscrollup endp
+vioxxx  ends
+        end
-- 
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