Re: Unrecognized 800k disk

[David A Lyons <dlyons@apple.com>]

In article <1993Sep2.171122.17406@news.weeg.uiowa.edu> Steven Nelson,
snelson@news.weeg.uiowa.edu writes:
> Problem:  One of my 3.5 800k disks reads/writes/verifies just fine on
my IIe
> with superdrive controller and superdrive and Unidisk3.5 drives. 
Likewise,
> it works fine in the 3.5drives on the GS when in P8, but GS/OS doesn't
> recognize the disk and puts up the eject/initialize box.  I'm pretty
sure
> it used to work on the GS under ss6.0.  Clue: I also think this disk was
> originally formatted as a HFS disk, then was made into a prodos disk
using
> the erase function rather than the initialize function in the 'Disk'
options
> under ss6.0.  What does GS/OS use to reject a disk that P8 doesn't?
> 
> I haven't tried, but I imagine I could copy the disk under P8 to a fresh
> disk and everything would be fine.  Incidently, the disk has 1 folder in
> the main dir, and 12 files in the folder, using about 49% of the blocks.

I don't have an explanation, just some information.

If the message says it "doesn't recognize" the disk, then no FST thought
the disk was the right format.  If it says "can't read" the disk, it got
an I/O error (drive alignment problems across different systems, or
whatever), so you have to watch the messages carefully (you get
Eject/Initialize in both cases).

The ProDOS FST under GS/OS -does- care about some thing that ProDOS 8
doesn't.  The one I know off the top of my head is backwards links on
directories; P8 doesn't care if they are wrong.

However, nothing in ProDOS disk recognition should have changed from
System 6.0 to 6.0.1.

Dave Lyons, dlyons@apple.com
Mr Tangent

My opinions are my own, not Apple's.