Thoughts on PC Based Control Retrofit....pictures of the specimen

Ok, I made a deal. I need encouragement here. Dan Jon? Anyone?
Its a Bridgeport Series I. Machine is complete. Looks like hard
chrome ways in nice shape. Stepper motor drive, limit switches are
there. I heard the head run sounded good.

Now, here is the question. I want to keep the conversion low buck.
spend the money where it makes sense and as I get it. Little at a
time. I want to go PC based. What will I need to do the conversion?

Anyone done one of these?

Thanks for the advice, glad to have found this group! :-)
http://members.home.net/escarcega/bptcnc/CNC.html

Marty