Re: life of storage media ...

James W Cerny (mailto:jim.cerny@UNH.EDU)
Mon, 22 Aug 1994 12:25:23 -0400

Message-Id: <mailto:199408221658.LAA11497@library.wustl.edu>
Date:         Mon, 22 Aug 1994 12:25:23 -0400
From: James W Cerny <mailto:jim.cerny@UNH.EDU>
Subject:      Re: life of storage media ...
To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>

As someone noted, there are definite problems of lifespan and
reliability for magnetic storage media.  It appears that other
media such as CD-ROM and magneto-optical disks should be better.
I have not tracked down any information on magneto-optical
storage, but the following Q/A is taken from the CD-ROM
frequently-asked-questions (FAQ) file for the USENET Newsgroup
alt.cdrom:

"41. What is the shelf-life of a CD-ROM?

If a CD-ROM is not manufactured properly, the lifetime can be very short, perhaps only a few years. This can happen if the edge of the disc is not properly sealed, and oxygen reaches the metal surface.

If the disc is manufactured properly, it will last a very long time. Most CD-ROMs should last for more than a human lifetime.

Philips has proposed new standards for testing CD-ROMs that are expected to result in discs that will enjoy a life span of more than a thousand years. For more information see Fox, Barry "CD Makers Perform in Unison to Stop the Rot" New Scientist 134(1815) (April 4, 1992):19.

The laser used in a CD-ROM drive is very low power, and does not harm the disc in any way. Reading the disc will not shorten the lifetime."

I wonder what the lifespan of Kodak CD-ROMs are relative to other CD-ROMs (ignoring other issues of resolution)? I also recall seeing information that was less optimistic about the lifespan of CD-ROMs, but can't relocate it.

Jim Cerny, Computing and Information Services, Univ.N.H. mailto:jim.cerny@unh.edu