The controller is the device that takes signals from the computer and sends them to the stepper motors to create movement of the particular machine axis.

My controller board fresh out of the package.

It's hard to see in the photo but the small package in front has several resistors for adjusting max motor current and idle current.  The board is made so that they require no soldering.

12-4-05
Progress is slow but, after no less than five trips to the hardware store, I did manage to get the drive contoller and components mounted inside an old computer case.

I had a heat sink and fan from an old Pentium CPU and decided to use it on the rectifier.  If you look above the transformer you can see the cooling fan.  The power cable is tied up to keep it out of the way for now.

I am waiting for parts before I wire up the motors.  The motors from Automation Direct came with connectors already attached.  You can buy their extension cables with the mating connector for $9.00 each, which seems a little pricey to me.  So I planned on cutting them off and wiring straight in or coming up with a more common connector. The other night I saw a Molex part number on one of them.  After a brief Internet search I was able to order the mating parts for about $3.00 total plus shipping.  I ordered some roller micro switches while I was there to help balance out the shipping cost.

I need to dig through the scrap pile at work and see if I can come up with a female DB25 connector to wire to a parallel dongle so I can have a nice clean looking connection on the outside of the case.