Oddball floppies for trade - 8", HS (outer edge), weird cutout

Chuck Guzis cclist at sydex.com
Sun Oct 18 13:51:56 CDT 2015

On 10/18/2015 10:50 AM, Eric Smith wrote:
> Did the disks for the original IBM 23FD "Minnow" floppy disk also
> have the sector/index hole near the edge, like the Memorex 650/651?
> The Minnow was used as a read-only device for loading microcode, and
> the disks were only factory written. I haven't seen an actual Minnow
> disk, but since Memorex was one of the companies making
> plug-compatible equipment, I wouldn't be surprised if they designed
> the 650/651 medium to be mechanically interchangeable with the 23FD
> disks.
> The Memorex 650/651 supported read/write use, and had more than
> twice the formatted capacity of the 23FD, so the on-disk format
> clearly didn't match the 23FD.

To the best of my recollection, the Minnow used disks with 8 sector 
holes.  I don't recall the modulation scheme, but FM would be reasonable.


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