On Feb 6, 7:12 am, Warren Ernst  wrote:
> On Feb 5, 12:25 pm, "Michael J. Mahon"  wrote:
>
>
>
> > Warren Ernst wrote:
> > > All,
>
> > > I'm starting to come to the conclusion that High Density SuperDrives
> > > (connected to a SuperDrive Controller, of course) do not reliably
> > > format 800KB Double Density 3.5" disks. I wonder if
anyone can confirm
> > > or deny this in their personal experience.
>
> > > Here's my evidence.I have the following hardware:
>
> > > A ROM3 GS with a SuperDrive Controller, two SuperDrives, and one
> > > "regular" Apple 3.5" Drive.
>
> > > An enhanced Apple //e with a Liron card and two UniDisk
3.5" drives.
>
> > > A Windows PC with a known-good 3.5" drive. I have a
formatting tool
> > > that manually verifies every block to weed out bad disks.
>
> > > A few jillion old HD and DD 3.5" disks.
>
> > > I can format the same HD 3.5" disks under Windows or
ProDOS (Copy II
> > > +) and then run a Disk Verify tool and they all come up with no
> > > errors. I can format it MSDOS and then verify it good, then reformat
> > > it ProDOS and verify it good with every SuperDrive I have. HD disks
> > > that fail verification on one machine fail it on another machine.
>
> > > Similarly, I can format 800KB DD disks, and verify them, with the
> > > Apple 3.5" Drive on the GS and on both UniDisk
3.5" drives, and then
> > > reverse the disks with the machines and verify them again. Disks that
> > > fail verification on one drive will fail it on another drive.
>
> > > Finally, if I take a verified-good 800KB DD 3.5" disk
and attempt to
> > > format it in a SuperDrive (as an 800KB disk, of course), the format
> > > invariably fails with a block error. This happens with both my
> > > SuperDrives. I can then reformat the "bad" disk
with the Apple 3.5"
> > > drive and test it, and it verifies fine.
>
> > > The SuperDrives can *READ FROM* the 800KB disks without any problems.
> > > They will do a Disk Verify operation on 800KB disks without problems
> > > either. They seem to write files to the disks just fine too. They just
> > > can't seem to format them properly.
>
> > > Does this jive with anyone else's experience?
>
> > ISTR that there was a format failure mode that occurred when a
> > Superdisk controller was used to format a PC-formatted disk in a
> > Superdrive without first doing a "read"...
>
> > I'm not sure that applies to your case, but here's the reference:
>
> >http://groups.google.com/group/comp.sys.apple2/msg/945863e9f1acb86c
>
> > -michael
>
> > NadaPong: Network game demo for Apple II computers!
> > Home page:  http://members.aol.com/MJMahon/
>
> > "The wastebasket is our most important design
> > tool--and it's seriously underused."
>
> Ah yes, I remember that bug. I don't think it applies here though,
> since I can format an 800KB ProDOS disk in a regular Apple 3.5" drive
> first, verify it there, and THEN let the SuperDrive try to format it
> and I get the error.

I don't recall seeing this problem, but I'll attempt to replicate it
on my setup and let you know.

Matt
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