bit late to the thread. interesting about mach3 and the system timer enabling real time control. I wondered how that worked since desktop OS'es are not supposed to be real time. is this an issue with Linux CNC (emc2)? in fact I thought it made sense that an external controller did the well controlling since that was the only thing it had to do. I was wondering if you had any experience with the Smoothie project. it runs on a low cost ARM board and contains its own g-code interpreter.