下面这段代码显示满屏的A后就不能动了,原因肯定在iret身上,不知道程序最后CS:IP指向哪了
assume cs:code
code segment
start:
mov ax,cs
mov ds,ax
mov si,offset int9
mov ax,0
mov es,ax
mov di,204h
mov cx,offset int9end-offset int9
cld
rep movsb
push es:[9*4]
pop es:[200h]
push es:[9*4+2]
pop es:[202h]
cli
mov word ptr es:[9*4],204h
mov word ptr es:[9*4+2],0
sti
mov ax,4c00h
int 21h
;---------------------------------------
int9:
push ax
push es
push bx
push cx
in al,60h
cmp al,9eh
jne int9close
mov ax,0b800h
mov es,ax
mov di,0
mov cx,2000
s:
mov byte ptr es:[di],'a'
add di,2
loop s
pop cx
pop bx
pop es
pop ax
iret
int9close:
pushf
call dword ptr cs:[200h]
pop cx
pop bx
pop es
pop ax
iret
int9end:nop
code ends
end start |
