Re: World-wide 8-bit computer sales (all-time)?

[mjmahon@aol.com (Michael J. Mahon)]

vairxpert wrote:

>On Mon, 30 Jun 2003 07:28:56 +0000 (UTC), pausch@saaf.se (Paul
>Schlyter) wrote:

<snip>

>>No thanks... :-( ....but here you provide an explanation why these
>>integrated CRT terminals didn't pose a problem to magnetic storage:
>>back then, degaussing coils were rare.
>
>It's not just the degausing coil, a b&w CRT will easily scramble data
>on a cassette or floppy.  The degausing coil was aimed at the ADAM
>warning lablel post about color TV's.

Regardless of the original context, if you do the experiment you
will find that the yoke fields of a monochrome monitor/TV will _not_
affect the data stored on a cassette or floppy in any reasonable
period of time (say, a month).

The field strengths are just not sufficient to overcome the coercivity
of the media.

Now, if you are talking about the leakage fields being strong enough
to interfere with a relatively unshielded read head, I would agree; but
that is just interference, not permanent data loss.

(BTW, the shielding required is low flux density shielding for the
yoke leakage fields (co-netic alloy or permalloy foil), while the proper
shield material for the stronger fields generated by the degaussing
coil is netic alloy or (thicker) soft iron.)

-michael

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