First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

[Tom Gardner]

Well it all depends upon what u mean by "first"

The Sony drive and cartridge were not compatible in many ways with what
became the physical, magnetic and electrical interface standards for the
3.5-inch drive and cartridge.  The standards came out of the "Microfloppy
Industry Committee" (Google it with quotes) organized by Shugart Corp.
Either Shugart or Tandon was the first to ship drives compatible to the
standard.  Tandon probably did the first such cartridge.

The original Sony drive and cartridge died out and Sony didn't come out with
a compatible set until well after Shugart and Tandon.  The early adopters of
the Sony design like HP then changed to the industry standard design.

Tom

-----Original Message-----
From: Fred Cisin [mailto:cisin at xenosoft.com] 
Sent: Wednesday, August 22, 2018 1:25 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Prototype IBM DemiDiskette drive

>> I just picked up a Model 350 on eBay, just because I'd never seen a 
>> Shugart sub 5" drive.
>> https://www.ebay.com/itm/Vintage-Sankyo-Shugart-Venture-Model-350-
>> Computer-Disk-Drive-/253708808435

On Wed, 22 Aug 2018, Ali via cctalk wrote:
> Interesting. I wonder if IBM was looking at those drives for use. The
seller (or more accurately the seller's father) used to work for IBM
Industrial services in Boca Raton.

Well, the SA300 (single sided version) were not the first 3.5" drives, but
they may have been the first 300 RPM ones with an SA400 interface. 
(The Sony 600RPM drives would require more changes)

The SA300 could be dropped into a 5150 (with only issues of mounting
brackets (Erector set) and power connector) and were supported by some OEM
versions of MS-DOS 2.11.  IBM public support of 3.5" began with PC-DOS 3.20.