;程序12.2

assume cs:code
code segment
start:	mov ax,cs
	mov ds,ax
	mov si,offset do0		;設(shè)置ds:si指向源地址
	mov ax,0
	mov es,ax
	mov di,200h			;設(shè)置es:di指向目的地址
	mov cx,offset do0end - offset do0;設(shè)置cx為傳輸長(zhǎng)度
	cld				;設(shè)置傳輸方向?yàn)檎?	rep movsb

	;設(shè)置中斷向量表

      	mov ax,4c00h
      	int 21h

  do0:	jmp short do0start
      	db "overflow!"
do0start:
      	mov ax,cs
      	mov ds,ax
      	mov si,202h			;設(shè)置ds:si指向字符串

      	mov ax,0b800h
      	mov es,ax
	mov di,12*160+36*2		;設(shè)置es:di指向顯存空間的中間位置

        mov cx,9			;設(shè)置cx為字符串長(zhǎng)度
    s:	mov al,[si]
      	mov es:[di],al
      	inc si
      	add di,2
      	loop s

      	mov ax,4c00h
      	int 21h
do0end:nop

code ends
end start