说明：  【微机原理课程设计】【计算机钢琴】【用键盘模拟琴键，一共二十一个音符，经过本人测试，担保确定能用，尽管下好了】
(Computer Principles of curriculum design [] [] [computer piano keys with the keyboard simulation, a total of 21 notes, after my test, can be secured to determine, although under good])