bobmon@iuvax.UUCP (Bob, Mon) (02/11/88)
I need some help with a couple of trashed floppy disks. The problem is as follows: A friend has two disks which had contained text files, were written to on a particular PC, and now report "General Format Error" when trying to read their directories. I believe that the PC had a fairly badly misaligned disk drive (I'm too embarrassed to say how I think it got misaligned), and that it tried to write to the directories of these disks (as well as to some of the data tracks) and thereby made 'em unreadable. At any rate, most of the data is still there. Norton Utilities v3 had some problems due to wanting to immediately read the (unreadable) directory; but I faked it out with an okay disk and then did sector-by-sector reads on the bad one. By using Sidekick to grab each displayed sector as it came up, I was able to reconstruct the most important document...eventually. It's worth noting that a group of unreadable sectors would appear every once in a while, in a quasi-periodic fashion (maybe truly periodic -- I didn't think to keep track soon enough). Umm, I should also mention that I couldn't recover anything by treating it as an erased file. Norton searches the directory for erased file entries, and the directory is totally unreadable. A diskcopy of the trashed disk claimed to be completely unused, with no file entries (erased or otherwise) in its directory. So, nothing to unerase. Now, there _has_ to be a better way. Maybe I can fake out the unerase with a different disk, then "recover" it sector by sector. Is there anything better that I'm overlooking? What about a program that just reads each sector, writes what it gets to a different file (on a different drive, of course), and ignores any errors (such as in the directory?) Diskcopy isn't quite doing this, as it is trying to make an exact copy of the disk and I just want to put all its contents in a file or files somewhere else. Any ideas?? Thanks for any help, Bob Montante bobmon@iuvax,cs.indiana.edu, whatever my signature may say. -- You TOO Can Defeat The 4-Line .signature Limit And Be Obnoxious To Your Friends And Neighbors!!!!! ...---... Charles Cabbage on the Difference Engine running SE grade 10W40 at UKnoWhere Babble@diffEQ bob,mon@iuvax.cs.indiana.edu Chucky on Ada The Slide Rules!"Spaceship Earth! There IS no substitute!"
murillo@sigi.Colorado.EDU (Rodrigo Murillo) (02/12/88)
In article <6109@iuvax.UUCP> bobmon@iuvax.UUCP (Bob, Mon) writes: >I need some help with a couple of trashed floppy disks. The problem is as >follows: [Summary: The FAT and/or directory of this disk is bad, but there is data still out on the disk.] > A diskcopy of the trashed disk >claimed to be completely unused, with no file entries (erased or otherwise) >in its directory. So, nothing to unerase. Any errors during the diskcopy? The following solution assumes that DOS could not correctly diskcopy the FAT, but did copy the data from the rest of the disk anyway. > Now, there _has_ to be a better way. Maybe I can fake out the unerase >with a different disk, then "recover" it sector by sector. Is there anything >better that I'm overlooking? What about a program that just reads each sector, >writes what it gets to a different file (on a different drive, of course), >and ignores any errors (such as in the directory?) Diskcopy isn't quite doing >this, as it is trying to make an exact copy of the disk and I just want to >put all its contents in a file or files somewhere else. Any ideas?? I have faked out Norton before in a similar situation before. As you suggest Norton needs an erased file out there before it can start unerasing. My work around is to create a 0 byte file elsewhere, and then copy it to your thrased disk, then delete it. If you get this far, you can select this file to unerase and start writing sectors from anywhere to it. Make sure to use a 0 byte file so that no data is overwritten during the copy. This will only work with NU, not QU. Good luck. If you get a program that just writes sectors, let me know. -- ----------- Rodrigo Murillo, UC - Boulder (303)761-0410 ----------- murillo@boulder.Colorado.EDU -or- ..{hao|nbires}!boulder!murillo (Machines have less problems. I'd like to be a machine. -- Andy Worhol)