通过对8255并行口的控制，使J15开关的状态与发光二级管J88的状态对应。

运行程序，改变拨动开关设置好数据后，按动STBA输入请求，LED9闪现，数据输出至八位发光二极管，观察发光管的状态是否与输入对应。

-8255 parallel port control, status and the status of the corresponding light-emitting diode J88 J15 switch.

Run the program, change the toggle switch to set up the data, press the STBA input request LED9 flash, and data output to eight light-emitting diodes to observe the status LED corresponding to the input.