Abstract: A speed and position controller for a DC motor, having SCR power circuits, has a digital computing device directly connected to the SCR firing circuits for controlling the SCR firing angle. A command signal in the form of a number is applied to the computing device from a tape reader or other command signal generator. An encoder, operatively connected to the shaft of the motor, furnishes a feedback pulse frequency indicative of motor speed to a counter. The computing device periodically samples the number in the counter for speed and position computations. The computed firing angles are compared with maximum firing angles loaded into the computing device to prevent excessive currents which could cause arcing or demagnetization.