8" Floppies

[Eric Smith]

William Donzelli wrote:
> I could use some extra 23FD media, and REALLY use a drive that can write a 23FD.
>   
I imagine that one could contrive to wire the head connector of a 23FD 
to a write amplifier of one's own devising, and use a 23FD to write.  
Not trivial, but perhaps not too terribly difficult.  Since there's no 
erase head, it would be necessary to bulk-erase the disk first.

Are the technical specs for 23FD in any surviving IBM maintenance 
documents?  It might be helpful to know the track 0 radius, track pitch, 
media coercivity, etc.

Beyond the obvious difference in the location of the index/sector hole, 
is here much other difference in the jacket of 23FD disks as compared to 
the later (standard) 8" disks?

Back before I had any blank Twiggy disks for a Lisa, I took 5.25" 
high-density ("1.2MB") disks and hacked up the jackets to make crude but 
usable Twiggy disks.  Could you make 23FD media that way?

Eric