flowers@CS.UCLA.EDU (12/01/87)
Recently people suggested unformatting a floppy by using a magnet. I
needed to do so, so used a donut magnet about 1 inch in diameter
(don't know the strength), and the floppys were readible just fine
afterwards. While I'm gratified to know that they aren't THAT
vulnerable, I'm wondering just how strong of a magnet is needed for
this task. (This time I ended up formatting them on a PC to get the
needed effect).
thanks,
Margot Flowers Flowers@CS.UCLA.EDU ...!{ucbvax|ihnp4}!ucla-cs!flowersdeano@hope.UUCP (Dean Benz) (12/02/87)
In article <9554@shemp.UCLA.EDU> flowers@CS.UCLA.EDU () writes: >Recently people suggested unformatting a floppy by using a magnet. I >needed to do so, so used a donut magnet about 1 inch in diameter >(don't know the strength), and the floppys were readible just fine >afterwards. While I'm gratified to know that they aren't THAT >vulnerable, I'm wondering just how strong of a magnet is needed for >this task. (This time I ended up formatting them on a PC to get the >needed effect). I personally have 2 four inch diameter x 1 inch thich Speaker magnets that I use to "unformat disks". It does seem to take quite a bit of effort to convince the mac the disk is completely unreadable. I tried using a cassete deck demagnetizer a few times but was unable to make the disk completely unreadable. The big magnets do quite a nice job and are readily available? (Know anyone who has recently blown a home or car speaker, ask them for the dead one and pry the magnet off the back.) Good Luck. Dean Benz UUCP: {ucbvax!ucdavis,sdcsvax,ucivax,ucla-cs}!ucrmath!hope!deano ARPA: ucrmath!hope!deano@sdcsvax.ucsd.edu or ucrmath!hope!deano@ics.uci.edu USNail: Dean Benz, 1110 Blaine St. Apt. 108 Riverside Ca 92507. Phone: (714) 686-6131 (U.C. Riverside: Home of, Ah, Well, Gimme a sec.)
jack@cs.hw.ac.uk (Jack Campin) (12/04/87)
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This may be an FOAF story (urban folklore) but I have heard that the mag-lev
train at Birmingham Airport lets enough field into the passenger compartment
to wipe floppies.
Then again, I have also heard that story about ordinary underground railways
and it certainly isn't true of them.
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