🚀 go-pugleaf

In article <129...@sun.Eng.Sun.COM> landman@sun.UUCP (Howard A. Landman x61391) writes:
>In article <18...@odin.SGI.COM> ci...@bananaPC.sgi.com (Dave Ciemiewicz) writes:
[...}
>
>O.K., now I was getting mad.  A year or so back I blew out the woofer on an
>Advent speaker.  For some reason I had the corpse of the woofer on a shelf.
>The magnet on the woofer was capable of lifting MANY pounds of metal.  Prying
>a nail off this magnet requires BOTH HANDS.  I lugged the woofer into the
>living room (didn't want it in the same ROOM as my precious backup disks!)
>and rubbed the DISK all over the MAGNET.
>
>You guessed it.  Put the disk back in the drive.  All the data was still there.
>
>I gave up and reformatted the disk.
>
>MORAL: It takes a lot more than a medium-size magnet to trash most of today's
>floppy disks.  (On the other hand, don't press your luck, and don't blame it
>on me if you do and it doesn't work out.)

About ten years ago there was a lot of anxiety about the possibility of
technicians wiping out data by carrying magnetized screwdrivers near discs
and tapes.  The National Bureau of Standards did a study, and found
exactly the same thing you found (only they did it quantitatively.  I
can't remember all the details, but holding one of those really strong
horseshoe magnets to the surface of a tape on a reel caused no loss of
data.  There was some attenuation, but no real loss.  They were able to
cause some loss near the front of the tape (first fourteen feet I think,
but don't quote me) by some other dirty, and improbable, trick.  The
conclusion was the same as yours, you've really got to whack it before it
breaks.

Side issue: In Tom Clancy's latest techno-thriller, "Clear and Present
Danger", one of the villains uses a refrigerator magnet to destroy the
incriminating contents of a floppy.  The FBI calls in a long haired
consultant (why are all his computer "consultants" long haired?) to
attempt a reconstruction.  It's partially successful because the spook
didn't use the magnet correctly.  Now Clancy is usually pretty careful,
but this time he blew it.