单片机实验，键盘电子乐器（proteus仿真）要求：利用并行接口8255作为键盘接口，设计一个具有2个八度音阶的键盘乐器，音阶键不少于16个，采用扫描方式管理键盘，音域范围自行定义。-SCM experiment, keyboard electronic musical instruments (proteus simulation) requirements: use of a keyboard interface, parallel interface 8255 to design a two octave keyboard, key scale of not less than 16, by scanning management of the keyboard, the scope of self-defined range .