编写0号中断的处理程序

 实验12 编写0号中断的处理程序

    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:code

code segment

start:
mov ax,cs
mov ds,ax
mov si,offset do

mov ax,0
mov es,ax
mov di,200h

mov cx,offset doend-offset do     ;存放中断处理程序 
cld
rep movsb

mov word ptr es:[0],200h
mov word ptr es:[2],0            ;设置中断向量表

mov dx,0ffffh
mov bx,1                          ;测试一下
div bx

mov ax,4c00h
int 21h


do:jmp short dostart
db 'divide error!'
dostart:
mov ax,0
mov ds,ax
mov si,202h

mov ax,0b800h
mov es,ax
mov di,160*10+80

mov cx,13
s:
mov al,ds:[si]
mov ah,2
mov es:[di],ax
inc si
inc di
inc di
loop s

mov ax,4c00h
int 21h

doend:nop

code ends

end start