Ok, slight problem with using the machine hold function of the PMDX: I only have one parallel port and it signals on port 2 pin 10. As I'm a glutton for punishment I was going try using LinuxCNC at first; if I was going the SmoothStepper route this wouldn't be an issue, sigh. I assume the only way I'm going to be able to use the machine hold function is fit a second parallel port so can anyone recommend a brand of card that works well?

I'm obviously not understanding something because I don't really see how the "K" input (assuming it's in machine hold mode) is different to the e-stop input on the BOB. Both inputs disable the step and direction signals and tell the computer the machine has stopped. The computer can tell the two situations apart because they come in on different pins but the machine is stopped either way so surely there's nothing the computer can do. Given that I currently only have one parallel port would an option be to put a machine hold switch in the limits circuit?