I looked at a used mill today. It has a Fanuc 0M controller. All of the main features of the controller seemed to work we ran a small program that was already on the controller. Did some manual jogging etc.

I was not able to transfer a program to the Fanuc from PC when I looked at the machine. My main question is how large of a GCode file can the Fanuc 0M controller take before I have to drip feed the gcode to the machine?

Also what type of support is there for this controller. What do I do when the controller starts to act up or I have problems with it. Can you repair the controller or how difficult is it to retrofit with easy stepper and mach. Would I have to gut all of the electronics and replace all of the servo drives?