This driver may be used for a 3 Axis CNC Machine. Based on the PIC16F870, for 3x Unipolar(5, 6 or 8 wire) Stepper Motors. It provides Full Stepping for good torque, with ability to toggle auto-shutdown of motor coils, which allows the motors and current regulation device to run cooler and require a lower output power supply. Most simple CNC drivers will leave the last coil stepped turned On, wasting current and producing heat. Connects via parallel port, with Opto-Isolators for PC protection.

Source: ChromationSystems