ScanTek 2000 (Benford MicroMill 2000) conversion

I am in the process of converting a ScanTek 2000 Scan Mill (a rebranded Balfor MicroMill 2000 that uses a Sherline CNC unit inside a nice fancy steel case) to parallel port control. You can read what I've done at the following links:

www.summet.com/blog/2016/01/16/how-to-co...rt-1-3-axis-control/

www.summet.com/blog/2016/01/17/how-to-co...ome-switches-e-stop/

www.summet.com/blog/2016/01/21/how-to-co...indle-motor-control/

Two videos here:



The ScanTek uses a Dalfor NextMoveST motion control card that has two parts. The bottom part has the stepper motor drivers and some power electronics, and the top part (connected by a 96 way DIN connector) had all of the logic that drove things.
By removing the top board and connecting a parallel port break out board to the correct pins on the bottom board you can get access to the limit switches, and step/dir pins for the stepper drivers, as well as turn the spindle on (full speed).

I have everything working with the exception of the PWM spindle speed control. If anybody has gotten spindle speed control working with a Dalfor NextMoveST board, please send me pointers or tips.

Thanks,
Jay