Re: Need help on hooking step driver to paralle port
You absolutely, positively, beyond ANY shadow of a doubt do NOT (NOT NOT NOT) need anything between the parallel port and the stepper driver boards. You maybe /should/ have a buffer, or a break out board, but that is NOT required.
I've built multiple devices like this with an old parallel cable. Just cut the printer end off and ohm out the wires. As long as you are using a standard PC desktop with a standard parallel port, it will work just fine.
A buffer can help to increase speed or get the correct voltage levels if you are using a parallel port on some laptops.
Opto-isolation can help protect your PC from getting fried if the drivers short out. I don't trust it, and always use old PC's that can get fried without costing me anything.
A break out board just makes it easier for people who don't know how to ohm out a cable. I recommend you learn. It isn't hard.
James hosts the single best wiki page about steppers for CNC hobbyists on the net:
http://www.piclist.com/techref/io/steppers.htm Disagree? Tell him what's missing! ,o)