Go to
http://www.hpmuseum.net/ and follow the links
for disks and then
the 9114. On the 'product documentation' page you'll find 'my'
schematics
for the 9114V. That includes the drive itself.
Tony, many thanks - the schematics/circuit diagrams appear to be 100%
relevant to my board. I can now start trying to figure out what I zapped.
It looks like the -50 and -30 suffixes are little more than cosmetic changes
or switch configurations. My FDD is also a half height.
I was thinking about the Z0765A FDC and how to make it compatible with a
300rpm FDD. It seems that all that needs to be done (in theory) is to
reduce all the FDC clocks by half - the 8MHz clock to 4MHz and the Write
Clock to 500KHz. (NEC indicates this in their uPD 765A datasheet). Clearly
not as simple to execute as it sounds, but not beyond the realms of
possibility.
Thanks to everyone else who responded.
Peter