assume cs:code
code segment
start:
;将Do0程序代码复制至0:200处
mov ax,cs
mov ds,ax
mov si,offset do0
mov ax,0
mov es,ax
mov di,200h
mov cx,offset do0end-offset do0
cld
rep movsb
;设置0号中断向量表指向0:200h
mov word ptr es:[0*4],200h
mov word ptr es:[0*4+2],0h
mov ax,4c00h
int 21h
do0:
jmp short do0start
db "Divide error!"
do0start:
push ax ;保存现场
push ds
push si
push di
push cx
mov ax,cs
mov ds,ax
mov si,202h
mov ax,0b800h ;设置显存开始位置
mov es,ax
mov di,12*160+34*2 ;设置显示位置
mov cx,13 ;复制字符串
s:
mov al,ds:[si]
mov es:[di],al
mov byte ptr es:[di+1],07h
inc si
add di,2
loop s
pop cx ;恢复现场
pop di
pop si
pop ds
pop ax
mov ax,4c00h ;正常应使用iret回到中断结束程序处,实验要求返回DOS,所以调用int 21h
int 21h
do0end:nop
code ends
end start