Yes, the xmod and the mini-z both work on the same principle. Both have an H-bridge configuration of FET transistors to drive your motor in both directions at multiple speeds. Both use PWM to turn the transistors on and off. If you knew which 4 signal lines went to the FET's on a z, you could put the same circuit in it(from an xmod) and it would work exactly the same. This goes for
www.atomicmods.com V1 power management board, as well as the whoa nelly and nuero's turbo boards.