Osborne-1 SD format

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Sat Feb 19 16:58:55 2005

On Sat, 19 Feb 2005, Dave Dunfield wrote:
> Can anyone tell me what is going on? Can anyone confirm the actual
> diskette format of an Osborne-1 single-density diskette?

I don't remember ALL of the specs (reserved tracks, etc.) of them, but the
Osborne single-density was 10 sectors with 256 bytes per sector, single
sided. Except for being 40 track (v 35), it has a similar physical format
to the TRS80.

IIRC, the Osborne Double density was 5 sectors with 1024 bytes per sector.

> Why do they "appear" to read at FM 1024 byte sectors (with correct
> 1-5 sector numbers/ordering)?

I'm not familiar with the quirks of Teledisk. Could you be looking at a
double density Osborne disk? (and seeing MFM) Or is Teledisk giving
"random" results when it doen't have an answer?

There were a few, but VERY few, non-standard alternate formats on the O1,
made by people with special uses. (such as P-system)

Good luck,
Grumpy Ol' Fred     		cisin_at_xenosoft.com
Received on Sat Feb 19 2005 - 16:58:55 GMT

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