.接管INT 9 终端服务程序替换为发声程序.

2.退出并驻留内存,等待触发中断.

3.当有中断产生（如按键盘）,进入新的中断服务程序Music.

4.检查按键是否是ALT+F6,or ALT+F7,如果不是就直接调用原本的INT9 中断服务程序处理.

如果是ALT+F6,就调用speaker发出声音,最后调用原本的INT9 中断服务程序处理.

如果是ALT+F7,就调用draw清屏,然后画图[黄色小矩形],调用原本的INT9 中断服务程序处理.-. Take over the INT 9 replace voice terminal services application program 2. Exit and the presence of memory, waiting for interrupt 3. When the interrupt occurs (eg, keyboard), the new interrupt service routine Music. 4. Checking whether a key is ALT+ F6, or ALT+ F7, if not directly call the original interrupt service routine processing INT9 If the ALT+ F6, you call the speaker sound, and finally call the original interrupt service routine processing INT9 If the ALT+ F7 , calls the draw on the screen is cleared, and then drawing [yellow rectangle], calling the original INT9 interrupt service procedures.