german physicist on cd-r longevity

[I'm Painting Again]

http://news.yahoo.com/s/pcworld/2006011 ... NlYwM5NjQ-

[joel hamilton]

Everyone I know that does archiving for a living, including a good pal that is the chair of the archival committee at AES, says that redundancy is the best possible solution for archiving, along with multiple format backups.

Nothing more, nothing less. If you can put something on DAT that you want to keep around for 20 years, do that . Put in on a CD and a DVD as well. Put it on whatever you want, just make a few copies. Update as new formats emerge.

Nobody is going to all of a sudden go, "oh, crap! nobody uses PCM anymore! I guess all the recorded history up till now is useles!"

We just make new copies of data/audio as these things emerge.

Like putting old DAT's onto DVD, for instance. or old 1/4" tapes on CDR and a hard drive..

[stinkpot]

Does anyone know about the long term viability of flash memory? Obviously the USB interface may not be around forever, but I do like the idea of no moving parts or light sensitive chemicals.

Thoughts?

[I'm Painting Again]

true..getting it on every format available is definitely the best safeguard for your media..its just crazy that our media is so fragile..we put so much work into it..I can understand how it would be important for someone to preserve that work..

Navajo sandpainters make those sand paintings as temporary structures..they think its the act of creating thats the important part..its so different from our western preservation fetish..I don't have much of a point its just the article got me thinking about that stuff..

[I'm Painting Again]

heres another POV..thesres a conversation about this elsewhere :

his article is pure ( almost ) bravo sierra . I have some of the first cdrs
burned at NRP in 1992 when they got their first Sonic Solutions workstation .
They are Sony and TDK brand , recorded on a Sony CD-900 E recorder . They
play perfectly now 14 years later .

The important point is that the cheap cdrs sold at discount stores
are made in Taiwan or India in factories that have very low quality
contol standards . Some of those manufacturers don't reject any
of their production unless it comes out of the machine waffled or
a shape other than round . CDRs have become so inexpensive
that it makes no sense to use anything less than a premium disc
for professional purposes . Personally , I recommend Taiyo Yuden
CDRs , and so does most of the professional CD mastering fraternity .
I have been using TYs exclusively in my work since spring 1997 and have
yet to have a single bad one !

Happy New Year !

John Eberle

[Professor]

Yeah, I gotta say that while it had nothing to do with seeing that article yesterday, I pulled up a recital disc I recorded back in 1998 onto a TDK disc (TDKs are made in the US) and it played just fine.
Certainly it wouldn't hurt to have the disc also archived on DAT (if it were that critical of a project) but then DAT is among the most fragile media types we've ever used and their interactions with the mechanics inside the machines is none-too-great either
Not sure about flash memory aside from the dangers of magnetic fields, which of course will also screw up DAT though not CDR. Too confusing.

-Jeremy

[Mark Alan Miller]

Redundancy, quality media, and multiple formats. Helps me sleep at night.

[lsn110]

I used some old work CD-Rs (ie stuff not worth keeping) to scare away birds from the blueberries last summer. Certainly no way to store them, but many had lost their silver by the end of the summer.

I didn't expect that.

[joel hamilton]

I have CDR's from 1994 that play fine.

[;ivlunsdystf]

Technical question: When I dub a CDR to another CDR using a CD player with optical or coax digital output into a standalone CD burner, am I also passing along all the degradation of the master CDR or is it corrected by the circuits that pass it along? The standalone-burned CDRs sure seem to work better and last longer than the computer-burned discs.

Philosophical rambling: Our best hope is to listen and listen so that we can keep some good stuff available in our heads for later enjoyment via music-running-through-the-head. If there is a heaven and a hell, do we get to keep our memories of Big Star records for eternal enjoyment after we enter the pearly (or burning) gates?

[evan]

I thought it was weird that he recommended using data tape to back things up. I'd think storing digital information on an analog medium would be the worst of the two worlds -- not only do you have mechanical wear and risk of failures, but a higher susceptibility to data corruption (if you lose few bits through mechanical or electrical error, you may lose the entire file, since the data isn't necessarily stored sequentially). I could be wrong about it though, since I don't know the technical details of data tape storage intimately.

[Mark Alan Miller]

Technical question: When I dub a CDR to another CDR using a CD player with optical or coax digital output into a standalone CD burner, am I also passing along all the degradation of the master CDR or is it corrected by the circuits that pass it along? The standalone-burned CDRs sure seem to work better and last longer than the computer-burned discs.

Red Book Audio data has no inherent error-correction. It's when the playback device encounters errors that it tries to correct them, with interpolation and other tricks. In those cases, the errors are copied to the target disc.
File data (even audio as files, or any file for that matter) has parity bits and other methods of making sure that bit-perfect data can be retained. It takes extra space to do this, but without it, you wouldn't likely be able to open anything that even had a bit or two of data loss. In those cases, CD-Rs that are copied will be (upon verification of a successful burn) perfect.

On that latter note, that explains why a CDR can hold 80 minutes of muisc (Red Book PCM data is approx. 10MB per stereo minute) or the rough equivalent of 800 MB of music, while the same disc can only hold about 730 MB of data-data. The 70 MB difference apparently is used for error-checking data like parity bits and whatnot. Or so I've been told.

[I'm Painting Again]

I don't know but cd-rs and hard drives definitely do fail pretty often..and sometime mysteriously..that much I've experienced..I guess its a variety of factors that lead to degradation and we should be cautious in any case..

[penelec]

I have CDR's from 1994 that play fine.

I have vinyl from 1948 that plays fine.

I have cassettes from 1979 that play fine.

I have CD-Rs from 1998 that won't play.

I'm not a betting man, but my money is simplicity over complexity.

Roger Hodge wrote:

"[W]hat the landscape of West Texas suggests is that the ranchers ... are a good deal more likely to vanish without a trace than the Indians, whose art, exposed to the elements for thousands of years, still bears witness to their lifeways. The metal implements used by ranchers to make horseshoes and axes and elaborate irrigation systems have rusted and are crumbling into dust, together with concrete water troughs and cedar picket stock pens some of these artifacts may survive to be puzzled over by future generations. (Harper's, Feb. 2006)

Efficacy of production is totally separate from duration. Things meant to move off shelves are more likely to deteriorate off your shelf, too. Things made with simpler tools are easier to revive later. It's gonna be easier for Smithsonianists in 2200 to build a stylus than a circa 2006 cd reader.

[@?,*???&?]

Technical question: When I dub a CDR to another CDR using a CD player with optical or coax digital output into a standalone CD burner, am I also passing along all the degradation of the master CDR or is it corrected by the circuits that pass it along? The standalone-burned CDRs sure seem to work better and last longer than the computer-burned discs.

Philosophical rambling: Our best hope is to listen and listen so that we can keep some good stuff available in our heads for later enjoyment via music-running-through-the-head. If there is a heaven and a hell, do we get to keep our memories of Big Star records for eternal enjoyment after we enter the pearly (or burning) gates?

You can configure the destination disc to use the master recorder as the clock reference. If you've done that, and the burn is be done in real time, then yes, that would be a better quality burned copy than the CPU burned disc. A CDR burned in a computer is typically burned at multi speed which can introduce errors. 4x is usually as fast as I'll go for audio, but most new Toast software allows you to burn 'Master' quality audio discs. 'Master' is their word and what the software does is spread the information out over the surface of the disc more liberally so it's not all crammed together. Theory being, it writes with a higher integrity. One last thing to consider is laser scatter and perhaps treating the disc to be copied first before playing it, but others would argue that point on this board. My ear tells me it's better, but those are my ears, not yours.