Re: cbmlink with 3032/3040 pair

From: Spiro Trikaliotis <ml-cbmhackers_at_trikaliotis.net>
Date: Mon, 5 Mar 2018 22:19:53 +0100
Message-ID: <20180305211953.dfjotrthvulgndn5@hermes.local.trikaliotis.net>
Hello,

* On Mon, Mar 05, 2018 at 10:07:08PM +0100 Francesco Messineo wrote:

> > I would have to check exactly what the differences are but there are
> > other people who I bet have them in their heads ;-) while I vaguely
> > recall that the DOS 2.6 in 1541 is not the same as DOS 2.x in other
> > drives. This means there may be nuance differences, and if you write
> > a D64 (from a 1541 disk?) to another drive using DOS 2.x things like
> > you describe may show. Once you re-VALIDATE, the drive updates the
> > metadata to what it expects, rather than what 1541 would expect.

What is the "format byte" of the IEEE drive? The 3rd byte (0x02) of
sector 18/0 contains it. On a 1541 disk, it is 0x41 ("A").

You can also see it in the directory listing of a disk: If the disk was
formatted with the ID 98, then you have the ending "98 2A" on the title
of a 1541 disk.

Is the format byte identical between the formatted disk and the image?
IIRC, the 1541 refuses to write on a disk if the byte is not correct,
but my memory may be wrong. I am not sure if it refuses to write to 18/0
only, or to any block, though, or if my memory is completely wrong. ;)


> I would expect that cbmlink just writes sectors, starting from 1,0 and
> ending to 35,16. I don't think it even knows about directory, BAM and
> so on. On a 1541, even disk id (the two characters you give at format
> time) gets changed from the .d64 image.

Only the *visible* cosmetical disk ID (that is seen in a dir listing) is
changed.  The on-disk ID in the header of each sector, that is the
important one, remains unchanged.

Regards,
Spiro.

-- 
Spiro R. Trikaliotis
http://www.trikaliotis.net/

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Received on 2018-03-05 23:05:34

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