用8251a实现串行口异步方式双机通信，波特率1200bps，采用查询方式发送，中断方式接收。双方平时处在查询键盘、等待中断接收状态，并显示相关提示-8251a achieved using an asynchronous serial interface mode dual-machine communication, baud rate 1200bps, using queries sent, interrupt reception. Look at the two sides usually the keyboard, waiting for interrupt reception status, and display-related tips