Single axis A3977 stepper motor driver board for CNC ... output 2-phase bipolar stepper motor drive;2, standard parallel port interface, support for MACH2, MACH3,KCAM4 series software;3, ... supply isolation, the full protection of your computer parallel port and equipment;4, supports 4 working modes:hybrid decay ... 1 / 2,1 / 4,1 / 8;6, 12-36V single power supply switching power supply chips to use as a ...