Weird 8-inch floppy disk

[Tom Gardner]

They might actually be the Memorex 650 media.  The 650 media had 8 sector (9
holes) while the 651 media had 32 sectors (33 holes)
See
http://www.textfiles.com/bitsavers/pdf/memorex/disc/2944.010_650floppyOEM.pd
f, Fig 3 
Or
http://www.textfiles.com/bitsavers/pdf/memorex/disc/2644.002-01_651Maint_Nov
74.pdf , Fig. 1-5

Or they might be for one of the other early FDD vendors such as Century Data
or Potter, but they really look like the Memorex FDs

With the shipment of IBMs 33FD the indes/sector hole moved to the center as
did the rest of the industry, starting with the Shugart 900 series.

Memorex had enough volume in the early FDDs that third parties such as
Verbatim made compatible media.

Tom

-----Original Message-----
From: Josh Dersch [mailto:derschjo at gmail.com] 
Sent: Monday, December 01, 2014 10:04 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Weird 8-inch floppy disk

On 12/1/2014 9:53 PM, David Griffith wrote:
>
> I found a ten-pack of 8-inch floppy disks that have me confused. 
> They're from STAM@, a name I've never heard of before.  It's clear 
> that they're hard-sectored, but the index and sector holes are along 
> the outer edge. There's also a notch cut into the corner. Both of 
> these appear to be done in an attempt to restrict users to a single 
> vendor of floppies.
>
> Here are some pics:
> http://661.org/images/weird-floppy-front.jpg
> http://661.org/images/weird-floppy-back.jpg

Those look suspiciously like floppies for the Memorex 650/651 -- the first
commercially available read/write floppy drive (1972).  I just picked up a
651 myself (mostly because it looks cool, I can only hope to someday have a
machine to use it with...)  If you're willing to spare one of those disks
(so I have a matching set) let me know... :).

- Josh