The Type:FILL is just something my slicer puts in. There are no actual commands issued in that line. The ";" tells the printer to ignore what come after in that line. At least that is how I learned it. I could be wrong.

The M600 command causes the machine to move to the home position and retract the filament, then pause while you load new filament and push the button. I had thought it was supposed to lock the x and y axis motors but I can still move them. It is tricky and I wish there was a way to have it work better. What is a M604 command?