Date: Wed, 9 May 2001 22:04:34 -0700 (PDT) From: "Brian W. Buchanan" <brian@CSUA.Berkeley.EDU> To: hackers@freebsd.org Subject: fd driver hacking to recover data Message-ID: <Pine.BSF.4.21.0105092153220.3063-100000@thought.adamantsys.com>
next in thread | raw e-mail | index | archive | help
Any fdc driver gurus in the house? I have a bunch of old floppy disks with some text files I'd like to recover. Many of them have errors and are unreadable past a certain point in the disk. Others I can't read from at all. The ones I can't read, period, are all 1.44MB-size floppies. I've tried dd'ing from /dev/fd0c, /dev/fd0.1440, etc., but exits with "Input/Output Error" before copying anything. The kernel prints: fd0c: hard error reading fsbn 0 of 0-31 (ST0 40<abnrml> ST1 1<no_am> ST2 0 cyl 0 hd 0 sec 1) I've been more successful reading 720K floppies from /dev/fd0.720, but many of them have errors that stop dd in its tracks, yielding another Input/Output error. The kernel prints: fd0c: hard error reading fsbn 1503 of 1488-1503 (ST0 44<abnrml,top_head> ST1 20<bad_crc> ST2 20<bad_crc> cyl 41 hd 1 sec 10) Since the files on the disks are just text, all I want to do is to be able to extract as many of the bits on the disk as possible, even if some of the bits are wrong, and then run strings over it and sort out the content. I've looked at the floppy driver source and it seems to be incredibly low-level, i.e. it turns the drive motor on and off, even. Can someone familiar with the driver give me some pointers as to what I'd have to modify to let it 1) read those 1.44MB disks, and 2) tolerate data errors? Thanks, Brian -- Brian Buchanan brian@CSUA.Berkeley.EDU -------------------------------------------------------------------------- FreeBSD - The Power to Serve! http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.21.0105092153220.3063-100000>