Help on DC speed control on vision max engraver

I recently obtained a Vision Max engraver (the older model) and everything seems to work on it. I do not have the Vision software or dongle to run it with, but am OK with controlling the stepper drivers (4 of them) straight from a printer port and just by-passing their control board. The only problem I have run into is the spindle motor driver. It's a 15 amp speed controller made by an Australian company called "Project Technology". I have had no luck in locating the company nor any information on the controller, model# 97SCA02 Rev 3.

The Vision control box is their Version II.

I would like to control the spindle motor from the PC as well, and I am betting it's a PWM controller. The control input is a small ribbon cable about 10 pins I think.

Does anyone have any info on this controller or perhaps what company bought Project Technology if any?

Edit 2/8/13
The ribbon cable has only 4 connections

1. Current sense (tap of voltage divider connected to Current sense resistors in series with the -V out)
2. PWM drive (through a resistor to base of a small transistor that drives the output transistor)
3. Current sense Connected to -V out (to motor)
4. GND (connected to power supply -V and frame/earth GND)

So I'm thinking pins 1 and 3 will have a voltage that is proportional to the current in the motor. Pin 2 is the PWM input in relation to pin 4 GND. Sound reasonable?