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From: deano@hope.UUCP (Dean Benz)
Newsgroups: comp.sys.mac
Subject: Re: how strong of a magnet?
Message-ID: <73@ucrmath.UUCP>
Date: Tue, 1-Dec-87 20:32:56 EST
Article-I.D.: ucrmath.73
Posted: Tue Dec  1 20:32:56 1987
Date-Received: Sat, 5-Dec-87 11:17:21 EST
References: <9554@shemp.UCLA.EDU>
Sender: news@ucrmath.UUCP
Reply-To: deano@hope.UUCP (Dean Benz)
Organization: University of California, Riverside
Lines: 24

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



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USNail: Dean Benz, 1110 Blaine St. Apt. 108 Riverside Ca 92507.
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