I wrote a cnc plotter program that took hpgl files and output steps out of the parallel port. I was building plotter / cnc machines at the time and there wasn't much code avilable.
A great resource is Luberth Dijkman in the netherlands. I think there is still a copy of my code there in the archives written in of all things..Pascal.
Here is a link to that page.
http://cstep.luberth.com/
A couple of other names are Ian Harries and Tomi Engdahl.
I think both were Brits. If you google either of those names and "tandon disk drive" you should get some intresting info on a "free" source for stepper controller boards and motors.
The old full height 5 1/4 disk drives for IBM were made by Tandon. Each has a TTL level control (you can control it with the parallel port of your computer) that Engdahl has mapped for you. The stepper motors are kind of weak but are great for building an experimental cnc / plotter / engraver.
A student of mine build one three or four years ago using tandon control boards, information from the above sites, and a bunch of MDF.
http://www.smallmetals.com/educoopwi...r.MikesPlotter
Building plotters and CNC machines was an educational experience, I would suggest starting with a NC etch-a-sketch run from the paralel port using tandon driver boards and tandon steppers. If you make it print out the first logo and bring it to a competition....
Good luck,