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From: csbrod@immd4.informatik.uni-erlangen.de (Claus Brod)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: 1024-byte floppy sectors?
Message-ID: <1991Jun17.160958.22766@informatik.uni-erlangen.de>
Date: 17 Jun 91 16:09:58 GMT
References: <3251@krafla.rhi.hi.is> <3792@malung.cs.tu-berlin.de>
Organization: CSD., University of Erlangen, Germany
Lines: 24

rkrueger@opal.cs.tu-berlin.de (Robert 'red sea' Krueger) writes:

>The problem is as follows: 
>A sector-size of 512 bytes is *hardcoded* in (older) TOS versions !
>TOS can recognize other sector-sizes than 512, and reports them right
>in the BPB, but internally, the floppy routines, which access the DMA
>controller, expect 512 byte per sector.

In fact, the problem is even more complicated than this: The TOS 1.0
floprd and flopwr functions could handle 1024 sector sizes! This,
however, was a side effect of the FDC command used, not a deliberate
design. Due to problems with the old solution, this undocumented features
has been removed.

It's not too hard, however, to write a 1024-bytes-per-sector floppy driver.
Actually, I've seen one some time ago; it had been sent to me for
testing purposes.

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Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, Germany		 	(Piet Hein)
csbrod@medusa.informatik.uni-erlangen.de
Claus_Brod@wue.maus.de
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