S7-300控制变频器的源程序,启动、停止及多级调速等，绝对少见值得收藏！-S7-300 converter control of the source, start, stop and Multi-Speed, absolutely rare copies!

利用微机8086实现直流电机的键盘输入控制电动机转速和方向(The keyboard input of the direct current motor is controlled by microcomputer 8086 to control the speed and direction of the motor)