5.0594 CDROMs -- Prices; Longevity (2/44)

Elaine Brennan & Allen Renear (EDITORS@BROWNVM.BITNET)
Wed, 15 Jan 1992 20:09:57 EST

Humanist Discussion Group, Vol. 5, No. 0594. Wednesday, 15 Jan 1992.

(1) Date: Tue, 14 Jan 92 09:11:43 EST (27 lines)
From: Mark Ritchie <AVFILM2@watdcs.UWaterloo.ca>
Subject: CD-ROM longevity

(2) Date: 14 Jan 92 21:31:38 EST (17 lines)
Subject: 5.0590 CDROM Prices & Scholars (1/19)

(1) --------------------------------------------------------------------
Date: Tue, 14 Jan 92 09:11:43 EST
From: Mark Ritchie <AVFILM2@watdcs.UWaterloo.ca>
Subject: CD-ROM longevity

CD's (Both Audio and ROM) have been failing due to several reasons.
A few years ago the main problem was during the manufacturing process
when the adhesive reacted hydroscopically with changes in the humidity
in the pressing plant. This rarely still occurs. The main problem
now is degradation of the polymers from which it is made. This, again,
is related primarily to humidity, this time of the storage area. The
testing that has been done in the UK and France by the archival
community indicates that you should be able to expect a CD to last
about 25 years when stored in a cool 10 C and dry 30% RH environment.
Stored in a regular office with changing cycles of RH and temperature
expect a shorter lifespan. Generally you should consider CDs as
ephemeral materials. One good piece of news was that the French tests
indicated that you could play a CD for 2000+ years with out the laser
effecting the disk. Now all you need is the ability to preserve a player
and disk for the next couple of millenia.

W. Mark Ritchie | Tel: (519) 888-4070
Media Librarian | Fax: (519) 888-6197
Audio-Visual Centre |
University of Waterloo | Net: avfilm2@watdcs.Uwaterloo.ca

(2) --------------------------------------------------------------26----
Date: 14 Jan 92 21:31:38 EST
Subject: 5.0590 CDROM Prices & Scholars (1/19)

The solution to the CD price problem is not always to reduce the price to fit
the pocketbook of the individual user (though that *might* be a strategy for
the MLA bibliography: could they sell 10,000 copies to individuals at $400?),
but to push our libraries and institutions to work the technology, and then
press the distributors of the CD's to allow, for making the database available
on a network from a work station. Inter alia, this would allow the database to
be mounted once in a setting facilitating high-speed access. As it happens,
the CETEDOC CD is well-indexed and works very fast, but using standard
software on the PHI disk of classical Latin authors for a search can run to 2
hours on a fast, but ordinary, desktop machine; even on the purpose-built
Ibycus, a colleague tells me that a full search of a not-ubiquitous word on
the TLG disk runs 45 minutes. Better to have a dedicated machine running the
search; and better then to make one CD serve the needs of a larger group.