PC口接8个拨动开关K1-K8，PB口接8个LED。初始由开关K1-K8设定8位不同的值，当执行程序后LED按K1-K8初始设定的值点亮，并向右流动（8255A工作在0方式），同时在数码管上显示“8255---A”。-PC port access 8 toggle switches K1-K8, PB port access 8 LED. The initial setting by the switch K1-K8 eight different values, when executing the program LED K1-K8 initially set by the value of lights and the right mobile (8255A operates at 0 mode), while the digital display. "　8255--- A " .