A drawing apparatus is disclosed which has two wheels of equal diameter mounted coaxially on a frame. A writing implement is preferably mounted in a aperture at the midpoint of the line defined by the centers of the wheels. The wheels are driven by a pair of stepping motors which rotate in response to digital pulses. If the wheels are turned at the same rate in the same direction linear movement is accomplished. If the wheels are turned at the same rate in opposite directions, directional motion is accomplished.