Jazz Thanks so much for the kind offer! Can you link to something that explains what an external motion controller does differently than my current parallel port to break-out-board setup? Looking at the smooth stepper site it basically looks like a USB to parallel port but I assume it must be more than that because such a thing is very cheap and small. Would I still use my break-out-board?

If it means anything I get a 'Time In Int.' on Mach3 sitting at about 4 when idle and jumping between 4 and 11 when running. Does that occasional jump mean something bad?

https://youtu.be/0hVQXoq_eqI

DeagonFly, the laptop is dedicated to CNC and runs WinXP. I chose it because it has a built in parallel port which I assumed would be better than a USB or PCMCIA adaptor.