I could probably spare a few disks, but postage from Canada is outrageous; let me know if no one else comes up with any.
m On Tue, Apr 30, 2024 at 4:07 PM Mike Katz via cctalk <cctalk@classiccmp.org> 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 > >
