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From: reo@tikal.UUCP (R.E. Overby)
Newsgroups: net.audio
Subject: Re: error correction in cd's
Message-ID: <163@tikal.UUCP>
Date: Mon, 10-Jun-85 20:57:53 EDT
Article-I.D.: tikal.163
Posted: Mon Jun 10 20:57:53 1985
Date-Received: Wed, 12-Jun-85 07:59:22 EDT
References: <679@charm.UUCP> <371@moncol.UUCP>
Organization: Teltone Corp., Kirkland, WA
Lines: 25

> >>Have you ever put your favourite CD up to a light source?  Choose one
> >>that doesn't have an opaque label.  There are definitely defects there
> >>that are more than 1 bit!  Thank goodness for error correction.
> >
> >You need a lesson in optics.  What you see is not what the laser sees.
> >It has a one-micron depth of focus set below the level of what you're
> >seeing.  You don't.
> 
> I don't see what that has to do with anything.  When I hold a CD up to
> the light and see a large pinhole (a pretty common defect), it seems
> to me that there are no bits at *any* depth.

I agree with Ben. There were several recent articles on the regarding
the need to _PROTECT_ the aluminized back since the manufacturers left
the reflective coating essentially unprotected. What a clever way to
insure that CDs do _NOT_ "last forever"  8-(   (Denotes displeasure)

There is a very effective error correction scheme, but I don't have the
number of bits/sample available here at home. Any one remember out
there?
---
Robert E. Overby, Teltone Corp.
10801 120th. Ave. NE, Kirkland, WA 98033
Phone 206-827-9626	FAX (Group II) 206-827-6050     TWX 910-449-2862
.....uw-beaver!tikal!reo