掌握 IO 译码方法和 8086 的存储器扩展方法，以 74LS244 作为开关输入口，以 74LS273 为输出口控制 LED 灯显示。(Master the IO decoding method and 8086 memory expansion method, use 74LS244 as the switch input, and use 74LS273 as the output port to control the LED light display.)