Mike,
You can get new and guaranteed recycled 720K diskettes at floppydisk.com.
As you probably already know the drive in the 9114A is known to have
issues with lubricants becoming gummy and the mechanism not operating
properly, one particularly nasty effect is it may result in the upper
head not retracting when the diskette is ejected and then gets damaged
or pulled off when the diskette is removed from the drive.
Paul.
On 2024-04-30 5:06 p.m., Mike Katz via cctalk wrote:
Thank you for trying to help. My situation is unusual at best and I'm
apologize for the extra bandwidth my question is causing.
I am formatting the floppies in an HP-9114A battery operated floppy
drive connected to an HP-41 calculator over the HP_IL serial interface.
The HP9114A drive uses a modified Sony 3.5" floppy drive running at
600 RPM instead of the normal 300 RPM. This is an extremely unusual
configuration that is different from any PC/MAC/Commodore/Amiga
situation.
I have been working with floppies since 1980. I have written floppy
low level formatters (WD1771 & WD1791 controllers). I currently use a
greaseweasel connected to a pair of 8" drives to create and copy
floppies for the RX02 on my PDP-8. I fully understand about density
and number of tracks, sectors per track, tracks per inch, fm/mfm/gcr
encoding, etc.
I'm sure if I tried enough 1.44MB floppies I would find a few that
might work on the HP9114A drive. However, that was not my question.
I am looking for a dozen or two Double Sided, Double Density 720K
(formatted capacity) disks to use with this drive.
I appreciate all of the suggestions and help but let's keep the
bandwidth down and take any floppy compatibility discussions off of
the group.
Than you again everyone for offering to help,
Mike
On 4/30/2024 2:41 PM, Wayne S wrote:
What errors are you seeing?
Sent from my iPhone
On Apr 30, 2024, at 12:29, Mike Katz via cctalk
<cctalk@classiccmp.org> wrote:
I have tried bulk erasing 1.44 MB disks and they still won't format
in the HP9114A battery operated HP-IL Floppy Disk drive.
On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote:
On 30/04/2024 18:08, Anders Nelson via cctalk wrote:
Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?
I think it's entirely possible. I'd definitely format them in a
720kb drive though to be extra safe. Though original 720KB disks
written/formatted in 1.44MB drives seem perfectly cromulent from
my experience.
However don't quote me on it, The only double density drives i have
are super early Sony ones built in 1982 and they get pampered with
NOS 720kb media (with the sliders sellotaped open because no auto
opening shutters on my drives!)
Josh Rice
