qt.asm

来自「微机原理——接口应用编程源码」· 汇编 代码 · 共 40 行

stack segment
     db 64 dup(?)
stack ends
data segment
     st db 30h,30h,3ah,30h,30h
data segment
code segment
     assume cs:code,ds:data
atart: mov ax,data
       mov ds,ax
       push ds
       mov ax,0000h
       mov ds,ax
       mov ax,offset irq0
       add ax,2000h
       mov si,20h
       mov [si],ax
       mov ax,0000h
       mov si,22h
       mov [si],ax
       pop ds 

       mov al,13h ;8259
       out 20h,al
       mov al,08h
       out 21h,al
       mov al,09h
       out 21h,al
       mov al,0feh
       out 21h,al

       mov al,31h   ;8253
       out 43h,al
       mov al,7fh
       out 40h,al
       mov al,2eh
       out 40h,al
       sti
irq0: