8255的汇编程序，各种工作方式尽有，是初学者学习的好帮手，也是利用8255扩展IO的普遍方法，只用改下地址直接拿去用就行-8255 compilation of procedures, a variety of working methods have to do is a good helper for beginners to learn, but also the use of 8255 to expand the universal method of IO only change t