I found a plug-in to run Mach3 on a PC with a Galil motion control board that I got for free. I found all the documentation that I needed on the Galil website, and the project of turning an older scoring machine into a CNC router looks promising.
I removed the computer and the controller from the machine. However, this system uses 3 phase motors (which is rather surprising given the small dimension of the servo motors, about 5x5x6"). I would like to know if it would be possible to hook up this controller box at VHS to verify that I have established communication with the motors and that I can actually control the position from Mach3.