Osborne also replaced the electronics on the drive with their own board. My
O1 had Siemens FDD 100-5 drives.
I have the cable pinout and disk controller schematics in my copy of the
Osborne 1 Technical manual, if anyone wants a copy.
Question: the tech manual says that with the double density option
installed, the O1 could read/write IBM 40 track 8 (512 byte) sectors, Xerox
820 40 track, 18 (128 byte) sectors, and DEC 1820 DD 40 track 9 (512 byte)
sectors. Can anybody verify this (Fred?)?
-----Original Message-----
From: Don Maslin [mailto:donm@cts.com]
Sent: Thursday, March 28, 2002 3:48 PM
To: classiccmp(a)classiccmp.org
Subject: RE: 5.25" floppy model numbers
On Thu, 28 Mar 2002, Erik S. Klein wrote:
  Before you scrap them?
 I'm looking for some old 5.25" drives to bring back a couple of Osborne 1s
 to dual drive status. 
Be advised that the Osborne drives are not directly interchangeable with
`normal' 5.25" drives.  The ribbon cable to the card edge carries drive
power as well as signals and is wired differently.  You will need to
conjure an adapter to use normal ones.
                                                 - don
  Does anyone know of a good source for old floppy
drives?  Or better yet, a
 source for getting them repaired?
 Erik S. Klein 
<snip>