程序功能为8155两个8位并口工作于输出方式，6位并口用于读取键盘状态，单片机间隔0.5s读取键通过8155的6位并口读取外接键盘状态，分析按键个数，两个数码管显示按键个数，先是格式为：‘000、111、222、333、444、555、666’-The program features 8155 two 8-bit parallel output, six parallel port is used to read the keyboard state, microcontroller interval 0.5s read key 8155 6-bit parallel read an external keyboard, the analysis of the number of keys, two digital display the number of keys, the first format: ' 000, 111,222,333,444,555,666 '