🚀 go-pugleaf

This evening, I noticed some strange symptoms that lead me to believe
that System 6.0 doesn't get along with at least one model of Micah hard
disk.  The disk in question is the model AT100 internal hard disk for
the Mac II.

Symptoms:

1) Disk First Aid 1.4 (which comes with the System Software 6.0 update)
   refuses to scan the disk;  it reports "This is not an HFS disk".

2) Disk First Aid 1.3 (from the System Software 5.0 package) scans the
   disk and finds no errors at all.

3) Attempting to erase the AT100 disk while running under System 6.0
   results in the appearance of a floppy-disk-style "Do you really want
   to erase this disk?" dialog box;  the disk's icon is displayed
   correctly, but the box is equipped with "one-sided" and "two-sided"
   buttons.

4) Actually erasing the disk causes the disk to become unmounted, with
   no error message... the icon simply disappears from the Finder
   desktop.

5) Attempting to mount the drive by rebooting causes a crash (ID=02)
   when the Finder desktop appears.

6) Reformatting the drive doesn't help... System 6.0 insists on trying
   to initialize it as if it were a floppy disk, with ID=02 crashes
   resulting.

The only way out, as far as I can tell, is to reboot under System 4.2,
reformat the drive, and then reboot and initialize the drive under 4.2.
Once I had done this I was able to restore my backup set (including
System 6.0) and continue without problems.

I've sent a complete description of the problem off to one of Micah's
people via email, and will call them next week.

NOTE: Users of Rodime 100-meg internal drives might encounter similar
problems... I believe that the Micah driver/formatter is based on the
Rodime version.  If Disk First Aid 1.4 reports that the disk isn't HFS,
then _don't_ try to erase and restore it under System 6.0!

HYPOTHESIS: Based on these symptoms, and on the symptoms that some users
of CMS drives have been reporting, I'm beginning to suspect that the Mac
is now looking at some fields in the driver information, or in the disk
partition tables, that it had not previously been examining... and that
some vendors' drivers or formatters haven't been filling these fields in
correctly.  Just a guess...
-- 
Dave Platt                                             VOICE: (415) 493-8805
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