40 track 5.25-in FDD [was: RE: HP drives]

Holley, Michael michael_holley at mentor.com
Wed Dec 29 22:23:33 CST 2010

Shugart's trademark registration for Minifloppy states the first use in
commerce was on August 27, 1976. That was when the first production
drives were shipped to Wang Laboratories for use in their PCS II desktop
computer. Deliveries of the PCS II systems were to begin in June 1977.
Shugart had shown a prototype of the Minifloppy to select customers in
April 1976 and at a trade show in May 1976. 

Wangco announced the Model 82 Micro-Floppy in late 1976 stating that
evaluation units were to be available in January 1977. (This press
release was in the February 1977 of IEEE Computer. This magazine was
always a month or so behind other trade magazines in announcements.)
Shugart had a design patent on the front panel and door latch (Des
249,343) so Wangco had to have different front panel. 

Shugart later licensed the double sided heads from Tandon and gave a
licensed Tandon to use the Shugart front panel on their TM-100 drive
that was released in November 1978. The TM-100 drive was use on the
original IBM PC (5150).

Michael Holley

-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] On Behalf Of Tom Gardner
Sent: Wednesday, December 29, 2010 10:53 AM
To: cctalk at classiccmp.org
Subject: RE: 40 track 5.25-in FDD [was: RE: HP drives]

> Date: Tue, 28 Dec 2010 11:48:10 -0800
> From: "Holley, Michael" <michael_holley at mentor.com>
> Subject: RE: HP drives
> To: "General Discussion: On-Topic and Off-Topic Posts"
>     <cctalk at classiccmp.org>
> Message-ID:
<1775CC70CD47484EA68ACCD903F02CB302387DD7 at na3-mail.mgc.mentorg.com>
> Content-Type: text/plain;   charset="us-ascii"
> The original Shugart SA400 minifloppy (August 1976) only allowed 35
> tracks. In early 1977 Wangco announced the Model 82 Micro Floppy that
> allowed 40 tracks with new media.
> Here is a photo of both disks.
> Michael Holley


FWIW, I've been told the reason the SA400 could not go beyond 35 tracks
that it used the same slider as the 8-inch product that could run into
spindle.  The SA400L was a redesign that allowed the carriage to go
in.  If anyone cares, I can get details from some ex-Shugart Associates


Can anyone confirm that Wangco was the FIRST to go to 40 tracks?  FWIW
told by Shugart Alumni that it was Tandon.



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