p272.asm

王爽汇编语言的课件

assume cs:code

stack segment
 db 128 dup (0)
stack ends

code segment
start:	mov ax,stack
	mov ss,ax
	mov sp,128

	push cs
	pop ds

	mov ax,0
	mov es,ax

	mov si,offset int9			;设置ds:si指向源地址
	mov di,204h				;设置es:di指向目的地址
	mov cx,offset int9end - offset int9	;设置cx为传输长度
	cld					;设置传输方向为正
	rep movsb	

	push es:[9*4]
	pop es:[200h]
	push es:[9*4+2]
	pop es:[202h]

	cli
	mov word ptr es:[9*4],204h
        mov word ptr es:[9*4+2],0
	sti
	
	mov ax,4c00h
	int 21h


 int9:	push ax
	push bx
	push cx
	push es
        
	in al,60h

	pushf        
        call dword ptr cs:[200h] 	;当此中断例程执行时(CS)=0

	cmp al,3bh			;F1的扫描码为3bh
	jne int9ret

	mov ax,0b800h
	mov es,ax
	mov bx,1
	mov cx,2000
    s:	inc byte ptr es:[bx]
	add bx,2
	loop s

int9ret:pop es
	pop cx
	pop bx
	pop ax
	iret

int9end:nop

code ends
end start