I have a question, can I use Mastercam files in Mach3? If not what CAD/CAM program CAN use it's files in Mach3?
Most any CAM program should be able to output g-code that Mach3 can use. You may need to configure a proper post processor, though.
Mach3 2010 Screenset
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)