基于80C51单片机的九九乘法口诀显示器，每次单击按键，数码管随机显示九九乘法表里的一条内容。通过Proteus结合Keil环境，用C语言编写-Each time you click the button, based the 80C51 microcontroller Jiujiushengfa formulas display, a digital tube random display multiplication table. Through the the Proteus combin