Image Map Image Map
Results 1 to 10 of 10

Thread: Old 800k HFS Mac formatted floppy corrupted?

  1. #1
    Join Date
    Aug 2016
    Location
    Toronto, Canada
    Posts
    26

    Default Old 800k HFS Mac formatted floppy corrupted?

    So I have a colleague at work asking if I could extract files from a floppy.
    I'm having trouble reading from the floppy and before returning it to him
    with 'so sorry I did the best I could' I thought I would ask here. What applications
    are the best to use to attempt to extract from a floppy?

    The floppy is DSDD. I own a Powerbook 165 and a Powerbook 5300c.
    The 5300c crashes when I attempt to read from the floppy (running MacOS v. 8.1).
    The PB165 is better. First Aid can actually name the volume "Bens Disk" but cannot verify
    the contents. I tried Copy II Mac v. 7.2 and did a Bit copy (which fails after I place the
    Duplicate floppy in the drive, it fails at Track 01 B, fails meaning the system becomes
    unresponsive). I tried 'Sector copy no format' option and it completes but with errors.
    Bad sectors, some are unverifiable. But it at least completes a transfer. However, the
    duplicate floppy is also unreadable. I've tried Disk Duplicator and DiskCopy. There's also
    an application I tried (I forget it's name) which allows me to take an image of a floppy.
    Unfortunately, it won't accept the floppy. It prompts me to either eject or format (initialize)
    the disk.

    Any suggestions?

    Thanks,
    Dennis

  2. #2
    Join Date
    Jan 2013
    Location
    Marietta, GA
    Posts
    2,072

    Default

    From my own experiences, real Macintosh hardware is quite poor at dealing with damaged disks.

    What I would do is use a Kryoflux to archive the disk as a preservation stream. That will save every last bit of magnetic flux, including damaged areas. You can go back and analyze the stream file later without putting more wear on the original disk. There are several tools that can then decode the stream in to an image file that can be mounted in an emulator. In some cases these tools can read data that a real floppy controller will not. Even if there are unreadable bits in the file system, you may still be able to manually view and extract contents from the files.

    And yes, a Kryoflux can read Macintosh 400k/800k disks using a normal PC 1.44mb floppy drive. With a little trickery, a Kryoflux can even write them.

    I suspect the disk is physically damaged. Did you visually inspect the disk? If there is dirt or residue, you can try gently cleaning the surface with a q-tip. Unfortunately, once a 3.5" disk is damaged or becomes dirty there is not much else that can be done to repair it. Of course, don't forget to clean your drives with a cleaning disk.

  3. #3
    Join Date
    Aug 2016
    Location
    Toronto, Canada
    Posts
    26

    Default

    Quote Originally Posted by SomeGuy View Post
    From my own experiences, real Macintosh hardware is quite poor at dealing with damaged disks.

    What I would do is use a Kryoflux to archive the disk as a preservation stream. That will save every last bit of magnetic flux, including damaged areas. You can go back and analyze the stream file later without putting more wear on the original disk. There are several tools that can then decode the stream in to an image file that can be mounted in an emulator. In some cases these tools can read data that a real floppy controller will not. Even if there are unreadable bits in the file system, you may still be able to manually view and extract contents from the files.

    And yes, a Kryoflux can read Macintosh 400k/800k disks using a normal PC 1.44mb floppy drive. With a little trickery, a Kryoflux can even write them.

    I suspect the disk is physically damaged. Did you visually inspect the disk? If there is dirt or residue, you can try gently cleaning the surface with a q-tip. Unfortunately, once a 3.5" disk is damaged or becomes dirty there is not much else that can be done to repair it. Of course, don't forget to clean your drives with a cleaning disk.
    Initially when I received the floppy I noticed there were hole-punch remnants (both paper and some black material) in the centre "hub" of the cookie (not sure if I'm using the correct terminology). I removed the two offending pieces and tried reading it. Initially I used a USB floppy drive connected to my modern Macbook Pro (at work). That failed. So I decided to take it home and try with older equipment. When I play with the centre of the floppy it feels like there is some friction. So I'm not sure there isn't any obstructions or material within the floppy jacket. But in terms of residue I can't spot any. It doesn't feel dirty.

    But the Kryoflux product sounds awesome. I want one now. Thanks for the suggestion.

    But ... the Kryoflux product is a floppy controller (a very sophisticated one). So if the floppy drive itself isn't very good, then the result may be spotty? So your suggestion is to ensure the floppy drive has a clean head before attempting a read again? Is that all? I've never done any maintenance on a floppy drive before. Can you suggest a website where I can learn more about maintenance?

    Thanks again for your help. This is more work than I expected (to help a colleague). But I have to admit that it's very interesting.

  4. #4
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    25,232
    Blog Entries
    20

    Default

    Can we assume that you've cleaned the floppy drive heads?

  5. #5
    Join Date
    Aug 2016
    Location
    Toronto, Canada
    Posts
    26

    Default

    Quote Originally Posted by Chuck(G) View Post
    Can we assume that you've cleaned the floppy drive heads?
    I got my two Apple laptops just last week. But no, I haven't cleaned the floppy drive heads.
    I'll look for a cleaning kit and write back after I clean the heads.

  6. #6
    Join Date
    Jan 2013
    Location
    Marietta, GA
    Posts
    2,072

    Default

    Quote Originally Posted by Den2016 View Post
    But ... the Kryoflux product is a floppy controller (a very sophisticated one). So if the floppy drive itself isn't very good, then the result may be spotty? So your suggestion is to ensure the floppy drive has a clean head before attempting a read again? Is that all? I've never done any maintenance on a floppy drive before. Can you suggest a website where I can learn more about maintenance?
    Correct. Even the best controller can't work around a faulty floppy drive. With standard PC style 3.5" floppy drives, all you can really do is keep them clean and use a cleaning disk. I would keep at least two or three 3.5" drives of different brands around, so if one starts to act wonky you can try another to quickly rule out drive specific problems. Plus there are many small variables involved, so sometimes one drive may have better luck than another reading a marginally bad disk.

  7. #7
    Join Date
    Aug 2016
    Location
    Toronto, Canada
    Posts
    26

    Default

    Thanks for the replies, SomeGuy, Chuck(G).

    So I opened the window to the floppy and used a finger on the centre hub to "push" the disk around and found that there is a part of the disk with a crease on it. A half centimetre crease (or dent) that extends further along the cookie. Does the physical damage mean that it's kaput?

  8. #8
    Join Date
    Jan 2013
    Location
    Marietta, GA
    Posts
    2,072

    Default

    In general, yes. Any kind of visible crease, dent, or scratch on a 3.5" disk almost always means that some part of the disk will be unrecoverable. And there is no way to physically fix that.

    That said, you can still *try*, but I would not hold out much hope.

    I'd still try a damp q-tip and gently wipe off the surface, just in case what looks like dent or scratch is actually just some odd residue. (I don't recommend Isopropyl alcohol, especially on scratches as that tends to remove more of the oxide surface).

    I probably wouldn't bother trying it again in any regular computer drive. As I mentioned before a Kryoflux would be able to read any bits that have not been destroyed, but from what you describe, my assumption would be you would only get bits and pieces.

  9. #9

    Default

    There's a program called DiskDup that can make a disk image of a floppy with bad sectors. You can tell it to ignore bad sectors and to copy anyway. After the disk image is made, you can then mount it and see what files are salvageable.

    Incidentally, it's a great program to have on hand for early floppy disks with copy protection that mimic bad sectors.

  10. #10
    Join Date
    Aug 2016
    Location
    Toronto, Canada
    Posts
    26

    Default

    Thanks SomeGuy. I'll clean the drive first, then go over the floppy with the q-tip as you suggest and then attempt a copy (DiskDup as olePigeon suggests).
    I found someone local whom still has a 3.5" floppy cleaning kits. So I'll try that first.

    Thnaks

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •