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POKEB.ASM
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Assembly Source File
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1986-07-08
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1KB
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58 lines
Comment *
┌────────────────────────────────────────────────────────────────────────────┐
│pokeb │
│Poke a byte into memory │
│ │
│Synopsis │
│ int seg = 0xb800,ofs = 0; │
│ │
│ pokeb(seg,ofs,'A'); (write the letter "A" to the first byte │
│ of screen memory) │
└────────────────────────────────────────────────────────────────────────────┘
*
;=============================================================================
; Data
;=============================================================================
DGROUP group _DATA
_DATA segment word public 'DATA'
assume ds:DGROUP
; Your Data goes here . . .
_DATA ends
;=============================================================================
; Code
;=============================================================================
assume cs:_text
_text segment public byte 'code'
PUBLIC _pokeb
_pokeb proc near
push bp ; save base of stack
mov bp,sp ; establish stack frame
push di ; save MS-C's Register vars
push es
mov ax,[bp].8 ; get value to poke
mov di,[bp].6 ; get offset
push [bp].4 ; segment
pop es
stosb
pop es ; restore data and extra segs
pop di ; Restore MS-C's Register vars
mov sp,bp ; restore stack pointer
pop bp ; and base of stack
ret ; return to caller
_pokeb endp
_text ends
end