Alright, it's a long shot, but anyone know what I'd have to do to get the analog board in the classic to just drive the electron gun all the time? I've got the PWM brightness signal on 5v, and the video out signal on 5v, I assume all I need now is a sync signal.
What exactly does the sync signal help the monitor sync on? I'm a bit sketchy on how this part of the analog board actually works, so any more info would be good.
My goal is to get the gun driven all the time so I can connect one of the deflection coils up to a little amp and have a nice little dead-Mac-come-visualisation-box thing. It's working nicely when there's a motherboard connected, but it seems like a waste of a logic board to just leave it in, besides, it only drives every second pixel most of the time on the "insert a disk" screen, which makes my waveforms dotty. So far I've disconnected the horizontal drive circuit and rotated the yoke so the vertical deflection coil is now the horizontal one, under the theory that vertical deflection runs at a lower frequency. It remains to be seen if this is correct, or indeed useful 
-Michael
Well, it's working quite nicely with the motherboard in place. I'll grab a photo later. Perhaps this would make a useful tutorial for Applefritter?