It is economy and convenience to control stepping-motors using a computer plus adigital I /O card. This paper introduces 1mw to build a controlling system for stepping-motors using a computer and a digital I/O card 1 Model: PCL-731. The focus is placed on the controlling of the time interval of the two pulses which are send to stepping-motor drivers and the calculation f the output - number for bits on the I/O card. An application has been carried out for an easy educational manipulator.