CompuPro floppy controller differences - test-drb@ccmp.vtda.org

18 Sep 2006

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Subject: RE: CompuPro floppy controller differences
   From: Fred Cisin <cisin at xenosoft.com>
   Date: Mon, 18 Sep 2006 17:51:43 -0700 (PDT)
     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>

On Mon, 18 Sep 2006, Chuck Guzis wrote:
  You've forgotten the original DOS 1.x 160K SS
and 320K DS.  I wonder if the
 conservative 8-sector approach on the part of IBM/Microsoft was the
 miserable track record of the original (IIRC, Shugart) drives.  The one While there
might be regional variations, I NEVER saw IBM use a
Shugart in the 5150.  For the first year or so, it seems like they were
all Tandon TM100-1, and later IBM contracted to have drives made with IBM
front panels by CDC? and others. 
Likely because every working SA400 (400L) I have has been repaired or
lightly used, lousy track record for reliability.

...
 But not Shugart.  OTOH, TRS80 and Apple][ both used
Shugart mechanisms
(SA400 for TRS80, SA390?? for Apple(with Apple's own board on them))
Most of the early Shugart SA400s were 35 track, instead of 40. 
By 1980 the SA400 was always the SA400L 40 track version.  One issue of 
the time was shortages of TTL ICs and disk drive getting scarce due 
to demand.

Allison