A version of thia drive was used in the HP9114 drive unit (and I suspect in other HP peripherals). You can find 'my' schematics for the 9114B on http://www.hpmuseum.net/ and yes, I did include diagrams for the drive itself. Most of the special parts other than the digial ASIC are used on the Apple 800K dirve I think. That might be a useful source of spares. I have no idea what the different versions are. The one in the 9114B rotates at 600rpm (not the 300rpm of normal PC drives) and has the power supplies coming in on the odd-numbered pins of the 34 pin connector (no separate power connecotr). That can certainly be changed by soldered jumpers on the PCB (and there are pads for a normal 4 pin power connector). There also seems to be the capability to add a motorised eject mechanism. -tony