There's a 7805 5V controller onboard. It can take 8-35V as an input (actually whatever voltage the steppers need) and output 5V for the UCN chips Depending on the software you use, you can use NC or that as the switch being pressed and it will stop. You can spare some parallel port pins by wiring all three limit switches in series. The limit switches are no to be used on purpose like the home switches so you can live with that. If the machine hits a limit, you can visually check which axis it was. Now, that's hard. Google each and every marking, serial number or brandname you see on them and try to find a datasheet. Nikolas