an assembly program that shows how to use keypad 4 by 4 by using the parallel port the program display each entered key on dos screen

4输入，4输出，clos网络所用，有利于连接处理器和处理器，处理器和存储器传输数据。-4 inputs, 4 outputs, clos network use is conducive to connecting the processor and processor, processor and memory to transfer data.