a method for controlling the speed of a motor for a tape drive in a mailing machine includes providing an optical sensor for signaling the appearance of slots in a slotted wheel connected to the motor shaft . the time intervals between slots are used to make a prediction in respect of expected future time intervals and the motor speed is adjusted in accordance with the predicted value to obtain the desired value . for best results , the data is received at the microprocessor using the &# 34 ; capture &# 34 ; mode of operation in order to avoid excessive errors due to a &# 34 ; busy &# 34 ; processor . the invention enables the small motor of a tape drive to avoid over and undershoot even when operating under highly variable load conditions .