The rt-stepper software is used to drive the dongle over the USB bus. This software is open source similar to the EMC2 open source project at www.linuxcnc.org. Both projects are separate PC applications that interpret gcode and drive CNC controllers. Instead of re-inventing another gcode interpreter the rt-stepper software is based on the EMC2 software from www.linuxcnc.org. By re-purposing the EMC2 software the rt-stepper software provides - 4-axis support, complete gcode interpreter, trajectory planner, GUI front-end and Backploting.