Hello Robert!

  AB> ...I'd like a machine I can fit a disk drive into.

  RE> That isn't a 3/60.   A 3/60 is just a 3/50 with more (and
    > installable) memory, a faster cpu, and usually a colour (8bit)
    > display, and certainly no dimple.  Much better than a 3/50.  But
    > no internal drives...

I understood there was room to mount a 3.5" drive on the logic board
(assuming disabled termination on the board, enabled it on the drive,
and possibly soldering in a 50 pin header).

  RE> Yes.  Watch the TERMPWR pin on 3/60's - it is connected to
    > ground, and will fry anything that attempts to supply TERMPWR
    > unless you break the connection (usually in the connector).

I noticed some question marks there on the pinout I have.  Thanks for
the confirmation.  I'll beware of that (potentially nasty) one.

Regards,
  - Andy.