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From: msp33327@uxa.cso.uiuc.edu (Michael S. Pereckas)
Newsgroups: comp.arch
Subject: Re: CD-ROM documents (was Paperless Office)
Message-ID: <1990Nov30.151523.20697@ux1.cso.uiuc.edu>
Date: 30 Nov 90 15:15:23 GMT
References: <0094070F.B370E000@KING.ENG.UMD.EDU> <1181@dms.UUCP>
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Organization: University of Illinois at Urbana
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In <1181@dms.UUCP> albaugh@dms.UUCP (Mike Albaugh) writes:

>	Which might, of course, revive the raging flame-war from
>sci.electronics about the increase in error rate with time on this
>supposedly "read only" media. I don't mind the occasional drop out
>in ZZ top, and probably wouldn't even see the "interpolation" that
>audio CDs do when they are a little more confident that the errors
>were "small", but I don't really want to deal with "just a few little
>errors" in, say, "as" or "ld". :-)

>BTW: I know about error correcting codes, etc, but the story from
>the audiophiles is that the little "correction light" (_If_ you have
>one) tends to light more and more often with age (of the disk), which
>perhaps explains why newer decks tend not to have them. "Don't lets alarm
>the users, now" :-). And a n-bit correction scheme with n-1 _known_ bad
>bits gets us a bit close to the edge...


Note that CD ROM puts an additional layer of error correcting code on
top of the usual ECC on CDs.  

Does anyone know of any good research on bit decay on CDs?  We keep
hearing about people who have friends with neat CD players who say
that they think that... but who knows how true it is.

And of course, CDs haven't been around all that long yet.

I heard a while ago about CDs made of glass instead of plastic, the
idea being that while it is hoped that CDs will last 20 years, the
glass ones should last 100 years, of so it was claimed.  Does anyone
know what happend to that?  


--


Michael Pereckas               * InterNet: m-pereckas@uiuc.edu *
just another student...          (CI$: 72311,3246)
Jargon Dept.: Decoupled Architecture---sounds like the aftermath of a tornado