中断例程及其安装程序:
assume cs:code
code segment
start:mov ax,cs
mov ds,ax
mov si,offset showstr
mov ax,0
mov es,ax
mov di,200h
mov cx,offset showstrend-offset showstr
cld
rep movsb
mov word ptr ES:[7ch*4],200h
mov word ptr ES:[7ch*4+2],0
mov ax,4c00h
int 21h
showstr:push es
push si
push di
push ax
mov ax,0b800h
mov es,ax
mov ax,0a0h
mul dh
mov di,ax
mov ax,2
mul dl
add di,ax
mov ah,cl
showstr_r:cmp byte ptr [si],0
je showstr_ok
mov al,[si]
mov ES:[di],ax
inc si
add di,2
jmp short showstr_r
showstr_ok:pop ax
pop di
pop si
pop es
iret
showstrend:nop
code ends
end start