Wash your mouth out with soap... steppers... lol. Well, just kidding.
I am looking for your documentation, and this is the closest I can find so far:
See page 17.
It appears that your drive is specifically position control ( not 100% sure), and this is what we want. If that is the case, we need to get a CN1 connector (this could take further research, phone calls, and an order from digikey), and the step/direction signals from your parallel port will get fed there.
Puls and Sign = Step and direction. Dont forget the 0V wires, this thing needs a ground signal too.
Page 34-35 briefly covers the dividing ratio. This is now known as electronic gear, and will be necessary to run this from mach. To set my drives (newer yaskawa drives), I set it to where 10000 pulses = 1 inch. Not quite clear how this is set on yours, but the feature is there.
Keep those servos, and give them a shot.