数码管显示 1） 8个键盘（实现中音1~7和高音1共8个音），8位LED数码管可以记忆并显示最近8个按下的音，用喇叭送出按下的音。要求必须使用8255/8155扩展实现键盘和显示部分。

2） 长时间（如2s）按下某一键（可自己定义），可播放某一歌曲。

-Digital display 1) 8 keyboard (the realization of tenor 1 to 7 and a total of eight high tone), 8-bit LED digital tube can remember and display the most recent eight audio press, press out with the audio speakers. 8255/8155 require the expansion of the use of keyboard and display part of the achievement. 2) a long time (for example, 2s) by pressing a button (which can be their own definition), can play a song.