PURPOSE:To select accelerating and decelerating loci freely by driving a motor with a pulse train obtained by serially reading out a bit pattern stored in a memory and establishing the bit pattern arbitrarily. CONSTITUTION:A pulse train is similar to a driving-clock pulse train which can obtain desired operational loci at the time of acceleration and deceleration of a motor. Said pulse train is stored in a memory 2, and the memorized data are scanned by an address counter 3 in sychronization with the clock pulse CP1. The read- out pulses are given to a driving circuit 1 through an OR gate G1 and an inhibiting gate G2. Every time the driving pulse is given, the motor is driven in the direction of a direction-instruction signal at every very-small-unit amount of variation. Since the operational loci of the acceleration and deceleration of the motor can be freely selected, the variation can be accomplished very easily, and the setting is made by a digital memory; reliability and stability can be enhanced.