Do a "parallel port" interfacing search via the search engine on this site.
It is pretty easy to get the port to flash a lite or two with some DOS code but controlling a machine is pretty difficult even with only step and direction commands - you need software.
Get the book "Real World Interfacing with your PC" 2nd edition by J.J. Bargarello ISBN 0-7906-1145-7. It will help you even more.
YOu may also want to do a 'cnc retrofit' with "parallel port interface" as a modifier when you do the search on google.
A place called kitsrus or something like that sells diy kits to interface with the parallel ports driving steppers.
By the way, the Mach system advertised on this board already does what you want to do. Thus, you may find it to be difficult to get a whole system FOC (free of charge).
Depending on the motherboard, you can add another parallel port to control the spindle motor.
USE EXTREME CARE WITH O/S. Some new O/S's do not do direct/realtime calls to LPT port. May want to limit your O/S to DOS 6.22, Win 3x or Win 95,98,98se. Newer Win's can be REAL problematic.
Good luck in your search....