Dave,
No, I got these boards from a company called Keling Technology, although I have seen them for sale elsewhere. They are not optoisolated, but use the 74HC245 tri state buffer to isolate inputs and outputs to and from the PC parallel port. I just looked up the Bob Campbell unit you mentioned, and it appears to be nearly the same thing. In the end, it just gets the encoder channels A and B to Mach3. I'm hoping that the software will use these inputs to make sure that the motors indeed stepped to the location they were supposed to.
Any suggestions on how to set that up would be appreciated.
Thanks,
Rick