As far as I can make out the video isn't interrupt unfriendly (at least I haven't determined that yet, but reading other's work suggests its ok in this respect) as its got a separate GPU acting on the frame buffer independent of the main CPU. But thats my next goal - to see the effect of throwing a few thousand interrupts at it... I'm sure others have done this already and moved onto the cleverer stuff but I think starting at the bottom and working up is a good way to learn... and if it doesnt work, then plan B or whatever...

My goal is to have something I can send a g-code file to over the network, remotely viewed via VNC, and set running... I dont plan to use the RPi for design or CADCAM etc... just a g-code interpreter, putting motion data into a buffer and playing out the buffer in 'real-time' to the hardware while providing some level of visualisation of the cutter location on the screen...