This is one project I have on the back-burner as well.
But I would go a different route. Each axis does the same processing, so I would use one board (PIC) per axis. In theory it would be more efficient and would not need 100 pin PICs. Same with the limits switches, I'd put that on a separate board.
I just find it easier to work in a modular fashion. It must be the mainframe programmer in me (COBOL).
OH DARN! I just checked Mach's site for fun:
http://www.machsupport.com/32-bit version of Windows 2000, Windows XP, Windows Vista, or Windows 7 Operating System (64-bit will not work)
WOW! Gecko sure has grown since I last saw them!
http://www.geckodrive.com/
(Mach and Gecko drives were my first idea for a home CNC system)
Robert
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