Category : Assembly Language Source Code
Archive   : ASM-SUBR.ZIP
Filename : CLSOFF

;-------------------------routine begins--------------------------+
; ROUTINE FOR CLEAR GRAPHICS SCREEN
;
; FUNCTION: This routine clears the color graphics screen.
; INPUT: None
; OUTPUT: Just to the screen.
; REGISTERS USED: No registers are modified.
; SEGMENTS REFERENCED: Upom entry ES: must point to the screen RAM
; at B8000h.
; ROUTINES CALLED: None
; SPECIAL NOTES: None
;
cls proc far
push cx ; save registers
push ax
;
; set up the registers
mov cx,2000h ; word count of whole screen
mov ax,0FFh ; zero pattern for screen
mov di,ax ; get starting address
cld ; go in forward direction
;
; clear screen with a single string operation
rep stosw ; this clears screen
;
pop ax ; restore registers
pop cx
ret ; return
cls endp
;-------------------------routine ends---------------------------+