It should be G ZERO X1, above you have GoX1. You probably had a zero however as Mach would have come up with an error saying that "Unknown word where unary operation could be"
Ok so you are saying it ran away,that is strange, it should have only moved 1mm or 1 inch depending on how it is set up. Do you know anything about the hardware on your machine suck as the type of motors, tyoe of drives, the pitch of the screws and any reduction between motors and screws? If we know that we can get you set up in Imperial.
Hood