I wrote such a program on Win2000. If you feel this is helpful,email me
and I will send it to you.
JAn
>
> I have a program that will rescue your data !
> It runs on DOS-3.2 & FreeBSD-any BUT the rescue component only runs on DOS
> (however at least you can compile & play with it on BSD to get used to it).
>
> I have no idea if the FreeBSD ports DOS emulators allow access to floppy
> hardware or not ? If not, the other options are:
> - to boot with DOS to run my program,
> - or modify the FreeBSD fd driver to pass the buffer on error.
>
> By chance my program was just being discussed on another list, Here's extracts:
> ---------------------
> > Message-Id: <[EMAIL PROTECTED]>
> > To: [EMAIL PROTECTED]
> > Cc: [EMAIL PROTECTED], "Ron Klinkien" <[EMAIL PROTECTED]>
> > Subject: Re: Recovered data with positive head offset field replaceable unit msg
> > Date: Mon, 07 May 2001 23:57:31 +0200
> > From: "Julian Stacey [EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> > Sender: [EMAIL PROTECTED]
> >
> > <stuff deleted>
> >
> > It's possible to recover most text data from bad floppies by repeat
> > scanning, even without varying the offset, even with failing CRCs:
> > I wrote a program that does that in ~87
> > http://bim.bsn.com/~jhs/src/bsd/jhs/bin/public/valid/valid.c & valid.1
> > (The recover part of the program's now larger functionality runs
> > only on DOS though, not on Unix, as DOS passes filled buffers back
> > even when read() returns CRC error, whereas FreeBSD discards the
> > buffer content on error.
> >
> > Julian
> ---------------------
> > Date: Wed, 9 May 2001 09:11:58 +0200 (MET DST)
> > Message-Id: <[EMAIL PROTECTED]>
> > From: [EMAIL PROTECTED] (J Wunsch)
> > Subject: Re: Recovered data with positive head offset field replaceable unit msg
> > To: [EMAIL PROTECTED]
> >
> > Arranging for a `read track' functionality in the FreeBSD floppy
> > driver should be possible. This will return you the entire /bit/
> > contents of the track, no CRC checks &c. Only the first sector ID
> > will be synchronized, the remainder of the track is returned as it
> > appears on the floppy; you need to manually bit-dealign and perhaps
> > bit-reverse the remaining data.
> ---------------------
>
> Hi Joerg,
> Thanks,
> Doing a track was what Greg L suggested to [EMAIL PROTECTED],
> however that sounds like more work, & not optimal maybe ?
> In 1987 with DOS I was lucky, I did a read() on each sector, copied each
> sector with a good CRC to hard disc, & only repeat tried
> bad floppy sectors, doing a statistical average of each bit,
> (if none of the reads gave me a good CRC).
> (I also did multi sectors initially, then dropped to single sectors on error).
> To avoid head (*) wear & increase chance of a good CRC to the max,
> I'd prefer to stick to doing single sector seeks & reads, not tracks.
> (*) Forget media wear: I reccomend anyone who uses my valid.c
> to read odd sectors a few hundred/thousand times off already bad media,
> to discard media after reading :-)
> In an ideal world with lots of free time ;-) Brian Julian or Joerg
> would extend src/sys/isa/fd.c to support
> http://bim.bsn.com/~jhs/src/bsd/jhs/bin/public/valid/valid.c :-)
>
> -
> Julian Stacey Unix Consultant - Munich Germany http://bim.bsn.com/~jhs/
> Ihr Rauchen => mein allergischer Kopfschmerz ! Kau/Schnupftabak probieren !
> Like Linux ? Then also look at FreeBSD with its 5000+ packages !
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> sector, & though I got -1, the sector data was there (even if mangled)
>
> Julian
> -
> Julian Stacey Unix Consultant - Munich Germany http://bim.bsn.com/~jhs/
> Ihr Rauchen => mein allergischer Kopfschmerz ! Kau/Schnupftabak probieren !
> Like Linux ? Then also look at FreeBSD with its 5000+ packages !
>
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