实验12 编写0号中断的处理程序
本帖最后由 trump 于 2014-7-3 10:31 编辑编写0号中断的处理程序，使得在除法溢出发生时，在屏幕中间显示字符串"divide error!"，然后返回到DOS。
assume cs:codesg
codesg segment
start:
mov ax,cs
mov ds,ax
mov si,offset do_start
mov ax,0
mov es,ax
mov di,200h
mov cx,offset do_end - offset do_start
cld
rep movsb
mov ax,0
mov ds,ax
mov ds:,200h
mov ds:,0
mov ax,4c00h
int 21h
do_start:
jmp main
db 'divide error!',0
main:
mov ax,0
mov ds,ax
mov si,202h
mov ax,0b800h
mov es,ax
mov di,160*12+36*2
s_start:
mov cl,ds:
mov ch,0
jcxz s_end
mov es:,cl
inc si
add di,2
jmp s_start
s_end:
iret
do_end:
nop
codesg ends
end start
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