What can I use to create a step & direction file?

[Sojourner]

I have a controller based on an Atmega chip. It is very similar to the Phigdgets controller at

Phidgets Inc. - Unique and Easy to Use USB Interfaces.

Like the Phidget connects via USB instead of parallel port and takes ascii text instructions. Unlike the Phidgets it takes only one simple instruction set. The instructions are basically step and direction, except you can tell it to take multiple steps per instruction. M1R1000 = Motor 1 move Right 1000 steps.

I would like to use this controller with a standard PC CNC program. It shouldn't be rocket science to turn standard step/direction instructions into something this machine can read, but I need a file with step/direct instructions to start with. Does anyone either know of a standard PC programs that will write a step/direct file, or of a stand-alone program which does the same thing from either G-coode or a vector image? Open source preferred, but not required.

TIA

[doorknob]

I don't know how easy or difficult it might be to jump into the source code and intercept the step and direction controls for output to a file (or whether they might already support such functionality), but in the following thread, two gcode-to-stepper solutions were suggested that might be worth investigating (EMC2 and RepRap arduino gcode interpreter):

G code to Stepper interpreter