It's taken me almost 4 hours, but I've attached my EEEBox XP PC, monitor and PSU to my build assembly. No end of axis sensors wired or fitted yet, that can be another day. I have some reasonably heavy MDF attached, and it seems to be moving freely on the M6 and M8 threads. The Y axis still needs to be connected, it's the only floating one. X and Z are fixed motors, and have fixed wiring looms. Z is not yet used.
I have the stepper axis calculations back running on alternate interrupts, as I think excessively high frequency resetting of the PWM was preventing cycle completions from occuring.
It occurred to me today that I could run a "lawn mowing" operation with a router bit and some X & Y stepper excercises, and clean myself a perfectly flat platform if required.