Mfarber@udel-relay@sri-unix.UUCP (08/26/83)
This program clears the screen from DOS. It will do it from any graphics
/alpha mode.
In the graphics modes, the DOS 2.00 CLS will fill the screen with bars;
this doesn't.
-Manny
; This program clears the screen from DOS. To clear the screen,
; it defines a window the size of the whole screen and then
; scrolls that window to clear its contents.
; EXE2BIN
clear segment
assume cs:clear
mov ah,15 ; get current video state data
int 10h
mov bl,bh ; save video page
xor cx,cx ; set upper-left-corner
mov dl,ah ; set lower-left-corner
dec dl ; (adjust)
mov dh,24
mov bh,7 ; normal attr
cmp al,4 ; graphics screen?
jb c1 ; no
cmp al,7
je c1 ; no
mov bh,cl ; yes-use attr 0
c1: mov al,cl ; scroll length 0-clear window
mov ah,6 ; scroll page to clear the screen
int 10h
mov ah,2 ; reposition cursor
mov bh,bl ; (restore video page)
mov dx,cx ; upper-left-corner (CX=0 from scroll)
int 10h
int 20h ; return to DOS
clear ends
end
after it is linked, don't forget to use EXE2BIN CLEAR.EXE CLEAR.COM
to convert it to a COM file