实验12——编写0号中断的处理程序

assume cs:code
code segment
data segment

data ends

start:
	mov ax,cs ;让DS代表code段的短地址
	mov ds,ax ;以从code段复制中断处理程序
	mov si,offset do0 ;(si) = 传送原始位置的起始偏移地址
	
	mov ax,0
	mov es,ax 
	mov di,200h  ;设置es:di指向目的地址
	mov cx,offset do0end-offset do0 ;设置cx为传输长度
	
	cld  ; DF 标志位置零, 设置传输方向为正
	rep movsb ;cx个字节的内容从ds:si复制到es:di  
	
	;设置中断向量表
	mov ax,0
	mov es,ax ;[es] = 0
	mov word ptr es:[0*4],200h ;设置0号中断的偏移地址为200h
	mov word ptr es:[0*4+2],0 ;设置0号中断的短地址为0
	
	;测试新的0号中断
	mov ax,data
	mov ds,ax
	mov ax,50h
	mov cl,0
	div cl
	
	
	mov ax,4c00h
	int 21h
	
	
	mov ax,4c00h
	
do0:
	jmp short do0start
	db 'devide error!'
do0start:	
	mov ax,0
	mov ds,ax
	mov si,202h  ;设置ds:si 指向字符串
	 
	mov ax,0b00h
	mov es,ax
	mov di,12*160+36*2
	
	mov cx,13
s:	mov al,[si]
	mov es:[di],al
	inc si
	add si,2
	loop s
	
	mov ax,4c00h
	int 21h

do0end:
		nop

code ends
end start