说明：   利用51单片机计算双字节的定时器数据 at89c2051就可以用 生成查表用的数据 数据经串口送到电脑，用串口接收软件接收 白菜奉献
(calculated using the double byte data at89c2051 timer can be generated on the use of look-up table the data to the computer via serial port, and serial port software to receive contributions received cabbage)