#: 17011 S1/General Interest
    09-Nov-92  22:07:38
Sb: #16926-#Hard drive
Fm: Pete Lyall 76703,4230
To: PHIL SCHERER 71211,2545 (X)

Phil -

Hmmm... it sounds as if the device descriptor bytes are set improperly.

Most HD formatting routines simply issue a FORMAT TRACK 0 to the device driver.
This in turn causes the driver to issue a formatting command to the hard disk
controller, which handles the physical formatting.

When the formatting is 'done', the hard disk driver causes all sectors on all
platters to be read back to effect a physical verify. This part IS controlled
by the computer, and is where you seem to be getting into trouble.

Since os9 uses 256 byte sectors (not usually the 512 byte sectors used by DOS),
there's typically more overhead per sector, and you can only get 32 256 byte
sectors per track on a traditional MFM disk.

Use the DMODE utility to verify that your hard disk descriptor is setup for 640
cyls (or maybe 639), 4 heads, and 32 sectors per track, both on track 0 and the
regular tracks.

Pete Lyall

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