Tell us what CAD/CAM system you need a post processor for. If the machine is working that's your shortest path and free. I was successful in downloading Mastercam X post and modifying it to work on my DM2800. I then evaluated DNC packages, found one for free (NCLink) that I configured to work with the control to run programs longer than 900 lines. Since it's a school and according to your profile in Minnesota I might be able to make a visit and help you out.
If you want technical help on a control upgrade you should post this in the "Dyna Mechtronics" forum. There are several examples of control retrofits using a PC, breakout board, and axis drives. This might take students several semesters and could be considered by the instructor for a long term project. I've decided for my own purposes to keep the machine running until something big goes wrong with the control. It's got some quirks but has some nice features as well.