通过PC机内8253定时器设置时间常数，使其每隔10MS产生一次中断，并通过定时中断 ，接管中断服务程序，由汇编语言实现主程序，中断服务程序的编写。-PC-8253 timer to set the time constant, so that every 10MS generate an interrupt and timer interrupt and take over the interrupt service routine, assembly language main progra