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Sometimes a floppy disk (or other magnetic media like it) won’t read or write properly. Specifically, a format won’t work an gives various errors such as Unable to write track 0 or opening the disk in a hex-editor returns a read error.

I have always wondered if using a strong magnet (like that from the back of a car speaker) would be able to “re-initialize” the magnetic elements in the disk so that it can work again.

Googling it today only finds some discussion about disks that are corrupted by a magnet needing to be re-formatted, implying that a format can initialize such a disk. However I recall from the old days that floppies had tracks “printed” on them and a magnet could mess that up, preventing them from being used.

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Do you have any floppy disks that could be used as test subjects? :P –  iglvzx Mar 5 '12 at 1:34
    
Expendable ones on hand that already exhibit the problem? Unfortunately not. –  Synetech Mar 5 '12 at 1:53
    
Are you sure it is the floppy and not the reader/writer? Degaussing a floppy removed the magnatism, using a magnet on it would polarise the the particles in one direction. Wouldn't you risk further negative effects to the reader by the readers head then needed degaussing , because you would then effectivly be passing a "magnet" across the heads of the reader? Its not like you have anything to lose :-) But "one way" directional polarisation should not help anything. –  Psycogeek Mar 5 '12 at 7:17
    
Someone didn’t like the question for some reason. :roll: –  Synetech Mar 6 '12 at 2:02

1 Answer 1

Maybe, if the damage is due to magnetic corruption.

But rather than use a magnet, a "bulk eraser" (an electromagnet that emits a strong alternating magnetic field) should be used.

But if the floppy has actual surface damage (e.g. worn out tracks) then erasure won't help. The issue is then a lack of ferrite material to polarize and generate current in the read head.

However I recall from the old days that floppies had tracks “printed” on them and a magnet could mess that up, preventing them from being used.

This "printing" does not ring a bell. The tracks on 8", 5.25" and 3.5" floppies are all written magnetically by polarizing ferrite particles. Unlike hard drives which have "flying heads", the read/write heads on floppy drives actually touches the media during normal operation. Hence the floppy media can physically wear out. The closest to "magnetic printing" I'm aware of was the process Sony developed to duplicate Betamax tapes (i.e. instead of real-time helical scanning, the videotape could be duplicated linearly at high speed).

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> The tracks on 8", 5.25" and 3.5" floppies are all written magnetically by polarizing ferrite particles. That’s what I mean. Can they be wiped? Can they be re-written? –  Synetech Mar 5 '12 at 2:16
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I have erased floppies using a bulk eraser, and then formatted them for reuse. But they were all okay to start. Once a floppy starts generating errors, I prefer to discard them rather than hope there is no data loss later on. –  sawdust Mar 5 '12 at 2:20
    
> I have erased floppies using a bulk eraser, and then formatted them for reuse. So then a floppy can indeed be formatted if it is scrambled with a magnet? If so, then perhaps a disk that is generating errors can be “blasted” with a magnet to get it going. > Once a floppy starts generating errors, I prefer to discard them rather than hope there is no data loss later on. Well yes, obviously long-term storage of important data will need a good disk (floppy or otherwise), but running a magnet over a disk may be useful for getting it to work long enough to install RAID drivers or something. –  Synetech Mar 5 '12 at 3:53
    
You need to use a bulk eraser or degausser to properly demagnetize the ferrite coating. A magnet will not erase a floppy or magnetic tape; the magnet will leave the coating magnetized and digitally corrupted. The floppy drive's erase head may not be sufficient to allow rewriting the tracks (e.g. the area between tracks would not be cleanly erased to ensure a high read signal-to-noise ratio). –  sawdust Mar 5 '12 at 9:22
    
> The floppy drive's erase head may not be sufficient to allow rewriting the tracks (e.g. the area between tracks would not be cleanly erased to ensure a high read signal-to-noise ratio). That’s what I was wondering. So the answer is “not generally”? –  Synetech Mar 5 '12 at 16:44

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