Mastercam backups and gcode backups

[Dead Money]

Whats a good way to save and control backups of Mastercam and gcode files?

 

The boss wants to make the Mastercam files read only so when you open it, make a change and want to save it you have to do a save as and roll an "internal rev". This way if you want to go back a couple process revs you can easily. He would like to do the same with the gcode.