利用芯片8279控制键盘和LED，对每一次的键盘输入检查其对应的字符并作出相应操作，其结果体现在LED。比如：用户输入连续数字时，按用户输入的顺序依次显示在LED上；当用户输入加法操作时，LED不变化；当用户再输入第二个数时，再次依次体现在LED上；按“等于号”时其运算结果显示在LED上。其操作过程与体验与现在普遍使用的计算器相同。-The use of 8279 to control the keyboard and check the corresponding character LED, keyboard input and a corresponding operation, its results are reflected in the LED. Example: user input consecutive numbers, in order of user input in turn is displayed on the LED　LED does not change when the user input addition operation　When the user re-enter the second number, again in turn is reflected in the LED　press the " equal The number " when the calculation result is displayed on the LED. Operation with the same experience with the now widespread use of calculators.