说明：  电子钟程序全部用汇编语言编写，利用8255A外接6个LED，作为时分秒的显示，利用四个按键修改时间，非常适合初学单片机的学生或人员参考
(Used up all of the electronic clock assembly language program to prepare, using 8255A external 6 LED, as when the display minutes and seconds, using the four keys modified, very suitable for beginner students or single-chip reference)