A versatile dual axis programmable stepping motor controller for a personal computer: a specific application and tutorial for implementing a computer-controlled light microscope.

A simple programmable stepping motor circuit for controlling two independent stepping motors has been designed. The circuit is compatible with the IBM personal computer and needs only slight modification to work with virtually any other microcomputer. The motors can either be programmed by the host personal computer for remote operation, controlled directly by a joystick interface provided in the circuit, or a combination of the two procedures. Independent microprocessors control each stepping motor and can be easily programmed by the host computer via Input/Output ports designed into the circuit. A basic understanding of the circuit demonstrates some commonly used techniques for controlling microcomputer electronics through computer programming. The circuit will likely have many uses, although the implementation of a computerized microscope is explicitly described. The circuit is currently used in a neuroanatomical and neurochemical computer charting system at the University of Iowa.