汇编语言 实验13 第一题

assume cs:codesg

codesg segment
start:
	   ;安装中断处理程序内容
	   mov ax,0
	   mov es,ax
	   mov di,200h
	   mov ax,cs
	   mov ds,ax
	   mov si,offset show
	   mov cx,offset show_end- offset show
       cld
	   rep movsb
       ;设置中断向量表
	   mov ax,0
	   mov es,ax
	   mov es:[01F0h],0200h
	   mov word ptr es:[01F4h],0
	   mov ax,4c00h
	   int 21h
	   ;中断处理程序
show:  
       mov al,160
       mul dh
       add dl,dl
       mov dh,0
       add ax,dx
       mov di,ax
       mov ax,0B800h
       mov es,ax
copy:  mov al,ds:[si]
       cmp al,0
       je show_back
       mov es:[di],al
       inc si
       inc di
       mov es:[di],cl
       inc di
       jmp short copy
show_back: iret
show_end: nop
codesg ends
end start