Hi Doug

Am in the middle of this myself but have NOT gone down to the level of energising each coil as per example.

I opted for a dedicated controller board to run the motors so the controller box could be ran using popular software for CNC such as Kcam and Mach2 etc via the parallel port, but also so people could use the processor board for controlling the motor circuit direct.

By using this method, all your Pic has to do, is supply 2 pins to control each motor.
One for direction High/Low and the other for Pulses using PWM from the Pic or simple toggle high and low with a pauseus in between each step.

On the CNC machine I have built, the motors along with the thread on the shaft work out at 533 pulses per 1 MM in eight step mode and decrease as you step up.

If interested, please check out http://www.cncdudez.com and under the development link you will see the protocol I have gone with to control the motors via USB or Serial using a 18F4550 chip.

The commands shown at the moment are for Jog mode, but am working on taking raw G-code and feeding it straight into the Pic, which is going well.

The huge difference between using a Pic to control the pulses and using a PC Parallel port is incredible. There is too much going on in windows that disturbs the pulses and the motors run so noisey.
Using a Pic lets you hit incredible speeds and hardly any noise of the motors.

Regards

Sean.