CD data recovery?

[Henry Spencer]

On Mon, 20 Sep 2004, John Macdonald wrote:
> there's no way that a rejoined disk could handle the stress
> of the current rotational speeds.  (I recall hearing that
> they were approaching the limit of the structural strength of
> the glass disks, and would not be increasing much beyond the
> current speeds.)

The current disks (which are plastic, not glass) in fact cannot take being
spun at (say) 50x normal rotation rate, even though the label on the drive
does say "50X".  There's some specsmanship there, based on the fact that
you can get the data rate up to 50x nominal at much lower rotational rate
if you're working near the outer edge of the disk.  A 50X drive delivers
50x the data rate only in the most favorable part of the disk.

People have experimentally tried spinning CDs at the rate that would be
needed to deliver drive-specified rates near the inner edge.  It's best to
have a blast shield around the disk when you do, because it will
disintegrate. 

                                                          Henry Spencer
                                                       henry-lqW1N6Cllo0sV2N9l4h3zg at public.gmane.org

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