Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!asuvax!mcdphx!teroach.UUCP!stan
From: stan@teroach.UUCP (Stan Fisher)
Newsgroups: comp.sys.amiga
Subject: Re: Is this odd?
Message-ID: <12167@mcdphx.phx.mcd.mot.com>
Date: 15 Dec 89 22:05:27 GMT
References: <3309@hub.UUCP> <1487@uwm.edu>
Sender: listen@mcdphx.phx.mcd.mot.com
Reply-To: stan@teroach.UUCP (Stan Fisher)
Organization: Motorola Microcomputer Division, Tempe, Az.
Lines: 30

In article <1487@uwm.edu> mamba@csd4.csd.uwm.edu (Paul A Deisinger) writes:
>In article <3309@hub.UUCP> dougp@voodoo.ucsb.edu writes:
>>-Message-Text-Follows-
>>In article <814@jc3b21.UUCP>, fgd3@jc3b21.UUCP (Fabbian G. Dufoe) writes...
>>>     A trick that I've used successfully with disks that wouldn't format
>>>clean is to pass them over a bulk tape eraser.  That seems to erase more
*stuff deleted*
>
>Wouldn't this have the sideaffect of magnetizing the metal hub and shutter
>on the disk?  This would be *very* bad I would think.
*stuff deleted*
>--
>  Paul Deisinger                     "Me wa kuchi hodo ni mono o ii"
>  Joe Pantuso                        "Bushi wa kuwanedo takayooji"
>  mamba@csd4.csd.uwm.edu<-- easy to reach and read every day.
> joe@lakesys.lakesys.com<-- only get's read every week or two.

Nope.  Degausers (demagnetizers) are AC electromagnets not DC.  It takes a
DC electromagnet to generate a field that magnetizes.  If used properly, an
AC electromagnet by having its poles swap at 60HZ scrambles the polarity of
any ferrous (sp?) materials thereby demagnetizing or eraseing the disk. By
saying "if used properly" I refer to the method of slowly pulling the
degauser away from the tape/disk until the object is out of the field to
ensure the object doesn't get magnetized to some more uniform polarity if the
field were abruplty withdrawn.   This may not be the most technically
accurate description, but I think it's adequate?

  Stan Fisher -  stan@teroach.phx.mcd.mot.com -  asuvax!mcdphx!teroach!stan
  Motorola Microcomputer Division, Tempe, Arizona   -  Voice (602) 438-3228
  Call our User Group BBS "M.E.C.C.A." running Atredes 1.1 @ (602) 893-0804