Date: Mon, 15 Sep 1997 16:52:09 +0930 From: Greg Lehey <grog@lemis.com> To: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de> Cc: hackers@FreeBSD.ORG Subject: Re: Do *you* have problems with floppies? Message-ID: <19970915165209.18022@lemis.com> In-Reply-To: <19970915082959.QR50985@uriah.heep.sax.de>; from J Wunsch on Mon, Sep 15, 1997 at 08:29:59AM %2B0200 References: <19970914142654.GG28248@uriah.heep.sax.de> <199709142144.OAA22143@usr09.primenet.com> <19970915082959.QR50985@uriah.heep.sax.de>
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On Mon, Sep 15, 1997 at 08:29:59AM +0200, J Wunsch wrote: > As Terry Lambert wrote: > >> Actually... 0x42 READ TRACK does not check the sector number stored in >> the ID field. This could be a curse as well as a blessing; I don't >> know how it could deal with interleaved data. > > You apparently don't know much about this command at all. :-) Trust > me, i've been using it once (in CP/M), it's only useful as a debugging > tool, nothing else. I'm not too sure we're talking about the same command. It's been a while, but my recollection of READ TRACK was that it did just that: it started at the index pulse and returned everything that it could sync on until it got another index pulse, including gaps, flags, headers and all. I once used it for reading a floppy which had been written on a strange disk controller. All the gaps were filled with 1 bits instead of 0s (I can't remember exactly, it's been 18 years, but I seem to recall that the 1793 needed at least 6 bytes of 0 bits before a flag in order to be able to recognize it). It worked surprisingly well. Greg
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