Craig, thank you for the reply. I had apparently been under the misconception that step and direction were two separate signals. As I managed to successfully make a cable and connect Mach3 to one of the drives, the drive went the opposite direction than what was being called out. I assume (scary thought, assuming) that pins 23 and 25 are reversed in my cable (now to find my pin extractor).
I can probably get ahold of the drive software, but I'm not sure what, other than parameters, I would need to alter, if at all. I can access parameters from the display, and the drives have been working fine with regard to the most common settings.
As for the choice between Mach3 and Mach4, the good people at Mach Support were not sure they would, so Mach3 was purely for beta testing.
The original software that came with the machine, WinCNC, has it's own internal controller card (which is where the 5v comes from). And yes, the limits are wired directly in to the card.
So, all of that being said, my task list moves to the next 2 items;
1) Should I leave the servos as they are with respect to open collector, or should I move to differential mode? That may be a question for the servo guys, and maybe the correct answer is to leave well enough alone.
2) I need to find spindle motors, within my small budget, that will drive between 400-1000 rpm, and have a minimum of 20 inch pounds of torque at those speeds. The speeds will most likely be set it and forget it in most cases, and the need for the range (400-1000) is mostly because I'm not sure what will work best. The existing spindle (just a 90v dc gearmotor) spins at 360, and I'm sure the other axis' could handle ramping up. The existing spindle motor is going to be replaced by two spindles (already have two vertical axis', but one is empty), and will need to spin at the same speed. The vertical axis' will drive the spindles, equipped with form taps, down and up in to existing holes. X and Y will only move when Z and W are up, out of the part.
Once I have the new drives nailed down, I can begin looking for a controller card, BoB, etc. to move in to the Mach4 software.
I thank you again for your assistance Craig, and hope to hear from you and others with suggestions on my project.