Re: Stepper drive problem

They offer an opto isolator input option. Their internal logic runs
on 12VDC. If you get the opto option you can interface directly with
the parallel port. Your other option is to build up a small circuit
with NPN transistors. (one for each signal) The emitters are
grounded. The base connects to the PC parallel port through a 10K
series resistor and the collector then connects to the input on the
card.