RE: [AV Media Matters] several new questions about digitalarchiving methods

[Charles Repka <Charles.P.Repka@abc.com>]

>Brian Levy here again, still trying to navigate the unknown
>digital waters,
>hoping to bring the precious vessels of a dying culture to
>future shores
>securely.
>
>So what's the scoop on CD-R 'pro'?  Does anyone on this list
>use them?  Are
>they truly more long-term durable, archival than say regular
>Kodak Gold
>Ultima's?

The problem here is finding truly independent test data.  All the
manufacturers will claim their products will last 100 years or more
but just remember, everything you read is put out by the Sales dept.
not the engineering Dept.

>And while we're at it, I've been meaning to ask a few more questions:
>
>1.  Is it ok to store archival CD-R's in a Case Logic "CD
>wallet" or would this compromise durability?  I have been using jewel cases
>with all paper removed to avoid degradation caused by slow release of acid gases from
>decomposing liner notes and the like.  I would like to use CD wallets due
>to their space-saving features and easy access, but not if they in any way
>scratch the backs of these already fragile media, or expose them to more
>atmospheric gases than would jewel cases.

I have been using the plastic sleeves with Tyvec liners.  Tyvec is a
long term, durable woven plastic cloth and should last a long time.
I would hesitate to store a disc in a plastic sleeve without a liner
for fear the disc may eventually stick to the plastic.  I am not
aware of any king of harmful out gassing from Tyvec.  The plastic
sleeve is another matter.

>2.  Are computer-grade Kodak Gold's and Mitsui's etc. more archival than
>their 'consumer audio' (used in stand-alone burners like the Harmon Kardon
>CDR-2 we're currently using)?

See above

>I am wanting to get us a HHB CDR-800 as
>soon as possible, and thus switch to always using computer-grade
>CDR's.  For now we do most of our CDR multiple copy backup's using a
>Plextor computer CD-R burner.

There is no difference in the manufacture or quality of Audio only CD-R's
and "computer grade" CD-R's the only difference is a code placed at the
inner diameter of the disc that allows the disc to be used in audio only
CD-R burners.  You should be aware that the HHB CD-R 800 uses what is
essentially a consumer mechanism made by Pioneer with some professional
level electronic added.  I have client sending me master discs made on HHB
burners and I have lots of problems with them.  Some of the problems
include:  a pop at the very beginning of the disc.  This is caused by a
burst of digital noise that is generated when the laser is first turned on.
The noise burst is ignored by audio players but is read as data in a
computer CD-ROM player so a copy made on a typical computer setup will have
an audible pop.  This causes problems with some replicators. I have to check
these master discs by loading the first track into my DAW and then expanding
the opening few seconds on my editing screen.  If the glitch is there, I
edit it out and then make a and image copy for dubbing.  As part of an ill
conceived anti piracy scheme, the burns the machine serial number into the
first 6 minutes of the disc using the unused "user bits" that are available
in the CD format.  This causes problems with some players and some
replicators and drives some CD testers nuts.  The 800 is a 1X burner only.
The newer formulations are really optimized for higher burning speeds.  Your
should really make some test burns using the brands of you plan to use and
get them tested for error rates.  The 800 is basically a "track at once"
burner which means you can burn s few tracks, remove the disc, put it back
later and burn a few more tracks and then finalize the disc.  This means
that "bridge data" has to be added at the transition between the 2 sessions
that the bridge data can cause problems during playback or replication.

>3.  Apart from keeping CD-R's out of excessive heat, light, humidity, are
>there other storage conditions to consider?  Was the mention of argon gas
>(in a posting today by a list member) serious?

I'm the one who mentioned argon gas and it was intended as a joke,
but that is what you would have to do for really long term storage.

>We are planning to keep one copy of all our CD-R's in an underground
>salt mine storage facility near  Hutchinson, KS as a backup against
>all our copies kept in archives in  Oklahoma City and at the Caddo
>tribe's own archive facility.  I'd be interested in others'
>perspectives on storage conditions, locations, etc.

I'm not sure that a salt air environment is a good place for CD-R's
but I have no data.

>4.  So what was the verdict for predicted longevity of the Kodak g/s CD-R
>now being sold as a replacement for the Kodak g/g which we and others were
>using?  Only 2-4 years?  25 years?

Your guess is as good as mine.  And that's about all you can do,
make and educated guess.

>5.  How often would you migrate your CD-R's to newer CD-R's and/or to
>DVD-R's or newer technology likely to emerge within the next
>five years or so?

The problem is not so much with the media but rather in finding a
machine to play back the damn things 50 or so years from now.  I
assume you still have your Edison cylinder machine in your parlor.

Charles Repka