I have been busy trying to build a PIC based stepper driver for my CNC machine. That is still in the works, however, I have in the mean time found a simpler solution. EMC can direct drive the coils - well, almost. One still needs to build the power circuit. Which I have completed 1 of 3 (X,Y and Z). This one, and the next, use heavy duty transistors (D1392) from a 9-pin dot matrix printer. It has been tested with big (30oz torque) 5V 1A steppers.