DrawBuff.asm

ORG 0h

%define _ScreenSize (80*25)
%define _ScreenSeg 0B800h

%define _BuffSeg  BP+(6+18+2)
%define _BuffAddr BP+(6+18+0)

Start:
    PUSHA
    PUSH ES
    PUSH DS
    MOV BP, SP

    MOV DS, WORD [_BuffSeg]  ;Buffer segment
    MOV SI, WORD [_BuffAddr] ;Buffer Address
                             ;Buffer is DS:SI

    MOV DI, 00h              ;Start drawing at 0
    MOV AX, _ScreenSeg       ;Set screen segment
    MOV ES, AX               ;Screen is ES:DI

    MOV CX, _ScreenSize

    REP MOVSW                ;Write buffer to screen

End:
    POP DS
    POP ES
    POPA
    RETF