Im planning to attach 5th & 6th Stepper Motors for assigning B & C Axis to slave but Pin 2-9 in printer port is already used for my 4 axis stepper motors. What other Pin number in printer port should I assign my 5th & 6th stepper motors to Slave B & C Axis using Mach3? I dont use BOB as all my setup is connected directly to printer port pins.