From owner-freebsd-hackers Wed May 9 22: 4: 3 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from thought.adamantsys.com (w120.z064002057.sjc-ca.dsl.cnc.net [64.2.57.120]) by hub.freebsd.org (Postfix) with ESMTP id 79C4337B422 for ; Wed, 9 May 2001 22:03:58 -0700 (PDT) (envelope-from brian@CSUA.Berkeley.EDU) Received: from localhost (localhost [127.0.0.1]) by thought.adamantsys.com (8.11.2/8.11.2) with ESMTP id f4A54Ys03574 for ; Wed, 9 May 2001 22:04:35 -0700 (PDT) (envelope-from brian@CSUA.Berkeley.EDU) Date: Wed, 9 May 2001 22:04:34 -0700 (PDT) From: "Brian W. Buchanan" X-Sender: brian@thought.adamantsys.com To: hackers@freebsd.org Subject: fd driver hacking to recover data Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG 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 ST1 1 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 ST1 20 ST2 20 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