Path: utzoo!utgpu!water!watmath!clyde!bellcore!decvax!tektronix!tekcrl!tekgvs!keithe
From: keithe@tekgvs.TEK.COM (Keith Ericson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Norton Speed Disk Bug and Fix?
Keywords: Speed Disk Bug
Message-ID: <3120@tekgvs.TEK.COM>
Date: 16 Feb 88 00:54:46 GMT
References: <327@ttrdf.UUCP> <2023@bsu-cs.UUCP> <990@neoucom.UUCP> <20291@amdcad.AMD.COM> <1673@mipos3.intel.com>
Reply-To: keithe@tekgvs.UUCP (Keith Ericson)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 16

In article <1673@mipos3.intel.com> dbraun@cadev4.UUCP (Doug Braun ~) writes:
>

[deleted discussion and "schematic" diagram]

>The point is that to forward bias the diodes, there must be a dc
>current running through the heads at all times. This would produce
>some magnetic field.  This field, possibly in conjunction with the
>earth's (rotating at 3600 rpm relative to the platters) could
>eventually start erasing the disks.

I'll bet dollars to donuts that the current goes thru the head such
that the magnetic field from each "half-head" portion (see previous
article for schematic) cancels out the other. 

keith