Date   : Thu, 23 May 1991 04:22:56 GMT
From   : comp.vuw.ac.nz!actrix!ewen@uunet.uu.net (Ewen McNeill)
Subject: Osborne 1, Questions Answered

A great big thank you to all the people who replied to my request for
help with the Osborne 1 that I have been given.

The verdict is that an IBM drive can be put into the machine, if one
tries hard enough.  One has to handle the power supply connections,
which are a separate connector on the IBM drives, but on the underside
of the Osborne drives.  The IBM drives have an earth on the underside of
the connector.  Do *NOT* try connecting it up just to find out if it
would work.  Something will melt down.

The verdict on the serial port and modem port appear to be that they are
the same control lines inside the machine.  The RS232 port apparently is
only TTL levels, so some line driver/receivr chips would be needed.
Speed choices are 300 and 1200, although there is apparently a link
inside which can make this 600 or 2400 (from IMP overlay).

The good news about my Osborne is that the B drive appears to be sort of
working.  It works once I have formatted a disk in it.  I think the main
reason that this works is that it causes the drive to step, and thus
realign onto the disk.  The BIOS in my Amstrad does this automatically
when it has problems (steps out a track, and back, and also seeks to
first/last track and back -- solves some problems).

This semi-strongly suggests an alignment problem to me, so I might have
a look around and see what I can fiddle with... :-)

Anyway, thank you very much to everyone who offered help.

-- 
Ewen McNeill, ewen@actrix.gen.nz