Prototype IBM DemiDiskette drive

[Fred Cisin]

>> 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.