使用Proteus程序，P1口做输入口，接八个开关，以74LS273做输出口编写程序读取开关状态，在发光二极管上显示出来。(Using the Proteus program, the P1 port is the input port, and then eight switches are connected. The program reads the switch state with the 74LS273 as the output port and displays it on t