A motor, moving at a known speed, is stopped in a controlled manner by a speed control servomechanism which compares the actual speed-versus-distance deceleration profile to an optimum or desired speed-versus-distance deceleration profile, and variably controls the reverse energization, or plugging, of the motor in a manner devised to achieve the desired profile. When the speed servo has reduced motor speed to a low level, and preferably zero, a stop-lock control servomechanism is enabled to position and maintain the motor at a preselected stop-lock position. The stop-lock servo implements a motor-control algorithm which, for a given position error, provides a higher magnitude motor energization when the motor is moving away from the stop-lock position than when the motor is moving back toward the stop-lock position. This control algorithm provides increased servo gain when the motor is moving away from the stop-lock position.