I've got a Fanuc 3T on a Victor flat bed with 2 turrets. I have been programming the front turret with X+ and the rear turret with X-. My post on my cad/cam doesn't support this. I have written a macro in my editing software to handle this. I would like to use the G68 mirror code for the rear turret so that i can program both turrets using X+. I understand that G68 was an option. The machine is 25 years old. How can I switch this on?