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The Myth Of The 100-Year CD-Rom

Toshito writes "Are we putting too much faith in the ubiquitous "recordable CD", or CD-R? A lot of manufacturer claims 100 years of shelf life for a CD-R. But in real life, it can be much less. Expect failure after only 5 years... Personnaly I just discovered 6 audio cassettes with the voice of my late grandfather, talking about old times. These tapes are copies of reel to reel recorded in 1971, and they are still in excellent shape. I was thinking about digitizing everything, do a little noise reduction, and burning this on CD's, for my childrens and great grand-childrens enjoyment, but it seems that old analog tech from the '70 is more reliable than digital. The full story at Rense. Other links about the subject: Practical PC, Mscience, and an excellent reasearch by the Library of Congress (warning! PDF): Study of CD longevity, html version (google):Study html."

94 of 671 comments (clear)

  1. Nonsense! by Kris+Thalamus · · Score: 5, Interesting

    I was thinking about digitizing everything, do a little noise reduction, and burning this on CD's, for my childrens and great grand-childrens enjoyment, but it seems that old analog tech from the '70 is more reliable than digital.

    Record it to your HDD in an non-lossy format and store copies of it on various friends' and family members' computers. Back up frequently and your recordings won't suffer from the kind of decay and generation loss that analog tape does.

    1. Re:Nonsense! by cuzality · · Score: 5, Informative

      Well, the recordings *will* go through decay, but that's what the constant backing-up process is about. Your basic point is right on the money, though.

      The only way to keep bits in any kind of order and in good condition over a long period of time with the kind of technology available to the average consumer is to keep making multiple fresh copies before each individual storage media begins to suffer loss of data.

    2. Re:Nonsense! by Neon+Spiral+Injector · · Score: 5, Funny

      What happens when the amount time it takes to transfer all the data from one medium to another is longer than the life time of the media on which it currently resides?

    3. Re:Nonsense! by Anonymous Coward · · Score: 5, Insightful

      Whether CDs last a long time or not is really missing the point. The benefit of going digital is that the data can be backed up.

      If you're oriented on the media you're forever on the upgrade path. Should you move the collection to DVDs? But wait, blue light DVDs are right around the corner. It will never end.

      120Gbyte hard disks are getting cheap. This trend will continue. What you store something on will literally become unimportant. The only important thing that will remain is still: how well is it backed up?

    4. Re:Nonsense! by Fweeky · · Score: 5, Informative

      You're better off storing audio as FLAC or so; the format's open, lossless, streamable, error checking, robust, and has a proper metadata standard. Use the space it saves to make a bunch of PAR2's, and you're laughing.

      Support for this stuff's not going to disappear overnight; you can keep specifications and reference implementations about if need be.

    5. Re:Nonsense! by Anonymous Coward · · Score: 5, Insightful

      What happens when the amount time it takes to transfer all the data from one medium to another is longer than the life time of the media on which it currently resides?

      Then obviously you couldn't have copied all the data to the "current" medium in the first place.

    6. Re:Nonsense! by penguinstorm · · Score: 5, Interesting

      This is, of course, the very thing the comment points out can be a problem.

      Who's really going to remember this schedule? /. maybe; my mother - not.

      This is my beef with digital photography: I found a negative for a photo that was taken sometime between 1891 & 1934 - prints were beautiful. This negative was not stored properly at all. No special effort to preserve.

      With digital photography & CD-R disks I'm not so sure that we're not just creating a set of transient memories which will disappear into the ephemera in 10 years time.

      --
      Skot Nelson music is my saviour / i was maimed by rock and roll
    7. Re:Nonsense! by Captain+Splendid · · Score: 3, Insightful
      But wait, blue light DVDs are right around the corner. It will never end.

      Well, yes, but every so often, a format comes along that works, is cheap, and enjoys widespread use and support. CDs were the last one. Eventually, the multiplicity of DVD options will coalesce around one of them. After that, we can bitch about the next gen of data storage here on Slashdot.

      --
      Linux, you magnificent bastard, I read the fucking manual!
    8. Re:Nonsense! by SEWilco · · Score: 5, Funny
      He needs a quantum storage device.
      They store all possible data at the same time, and when you need a file it somehow produces the right file.

      However, he probably doesn't have enough cats.

    9. Re:Nonsense! by SEWilco · · Score: 4, Interesting
      What happens when the amount time it takes to transfer all the data from one medium to another is longer than the life time of the media on which it currently resides?

      Then obviously you couldn't have copied all the data to the "current" medium in the first place.

      • He might still be writing the current backup.
      • He might have such a huge amount of old data that the remaining life time is the problem.
        • Reports are that NASA has huge amounts of data on magnetic tape which is fading, and copying to new media will take longer than the remaining life time of the magnetic data. Obviously they need to start shipping out tape drives and tapes to volunteers who will have their computers copy tapes in their spare time, and let them see if they can find anything odd in the data at the same time; a Distributed Search for Earth Intelligence.
        • For years old films have been degrading faster than they have been copied to more stable media. Part of the problem is money, part is the time required for the delicate task.
    10. Re:Nonsense! by squidfood · · Score: 4, Insightful
      I found a negative for a photo that was taken sometime between 1891 & 1934 - prints were beautiful. This negative was not stored properly at all. No special effort to preserve.

      Not quite. The difference is robustness.

      The negative may have had a small crease, or off-color spot or three (i.e. "bit" decay), or even be torn in half, but the basic information was intact.

      The problem is that for many electronic storage formats, copy fidelity is strong but robustness (tolerance to a few corrupt bits, eg. in the FAT, or a plain an simple crack) is low.

      So what's a robust way of storing gigabytes, so that the corruption of a few makes a few "off-color" pixels but doesn't destroy the image overall? Give me a format that I can still read most of it, with no crucial weak spots (eg FATs) even if a few words are smudged or faded. That's why papyrus works.

    11. Re:Nonsense! by BoomerSooner · · Score: 3, Insightful

      Par, it works.

      Link

    12. Re:Nonsense! by Phisbut · · Score: 5, Funny
      How about this. Take your file, serialize it so it's a huge list of 1's and 0's, then pick up a cardboard card, divide it in the number of bits you have in your file, then punch a hole in the sections you need 1's and leave it untouched in the sections you need 0's.

      Paper can last for thousands of years... this could be a good solution for long-term storage... right?

      --
      After 3 days without programming, life becomes meaningless
      - The Tao of Programming
    13. Re:Nonsense! by Detritus · · Score: 3, Insightful
      Then obviously you couldn't have copied all the data to the "current" medium in the first place.

      Not true. The data could have been collected and recorded on the current media by multiple field sites, which may no longer exist, may have upgraded their recording equipment, or be too busy with current data collection projects to dupe media. You can easily end up with many thousands of tapes in a warehouse and insufficient equipment and time to copy them to new media before they rot. That's assuming you can get the funding for the work in the first place.

      --
      Mea navis aericumbens anguillis abundat
    14. Re:Nonsense! by Safety+Cap · · Score: 5, Interesting
      In effect, you have to keep running just in order to stay in the same place. (I believe there's a reference here to the Alice books of Lewis Carroll)
      That is a condition known as "The Red Queen's Race":
      Alice never could quite make out, in thinking it over afterwards, how it was that they began: all she remembers is, that they were running hand in hand, and the Queen went so fast that it was all she could do to keep up with her: and still the Queen kept crying "Faster!" but Alice felt she could not go faster, though she had no breath to say so. The most curious part of the thing was, that the trees and the other things round them never changed their places at all: however fast they went, they never seemed to pass anything. "I wonder if all the things move along with us?" thought poor puzzled Alice. And the Queen seemed to guess her thoughts, for she cried, "Faster! Don't try to talk!"

      Not that Alice had any idea of doing that. She felt as if she would never be able to talk again, she was getting so out of breath: and still the Queen cried, "Faster! Faster!" and dragged her along. "Are we nearly there?" Alice managed to pant out at last.

      "Nearly there!" the Queen repeated. "Why, we passed it ten minutes ago! Faster!" And they ran on for a time in silence, with the wind whistling in Alice's ears, and almost blowing her hair off her head, she fancied.

      "Now! Now!" cried the Queen. "Faster! Faster!" And they went so fast that at last they seemed to skim through the air, hardly touching the ground with their feet, till suddenly, just as Alice was getting quite exhausted, they stopped, and she found herself sitting on the ground, breathless and giddy. The Queen propped her against a tree, and said kindly, "You may rest a little now."

      Alice looked round her in great surprise. "Why, I do believe we've been under this tree all the time! Everything's just as it was!"

      "Of course it is," said the Queen: "what would you have it?"

      "Well, in our country," said Alice, still panting a little, "you'd generally get to somewhere else -- if you ran very fast for a long time, as we've been doing."

      "A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!"

      -- Carrol, Lewis. Through the Looking-Glass and What Alice Found There. Peter Pauper Press edition, Mount Vernon, New York 1940. 45-47.
      --
      Yeah, right.
    15. Re:Nonsense! by ericspinder · · Score: 4, Funny

      Better than that...
      Encode your data into the DNA of Cockroaches!

      --
      The grass is only greener, if you don't take care of your own lawn.
    16. Re:Nonsense! by iabervon · · Score: 3, Insightful

      Unfortunately, paper doesn't last as well with holes in it, and it tends to develop holes as it degrades. If, on the other hand, you print out 2D bar codes, you could probably get it to last thousands of years. You might want to be sure to include documentation of the file format in a couple of languages, though.

      "Hey, if you make 8-dot chunks of the dots on these pages, there is a 256-element field such that every 255 chunks, when considered as a polynomial and evaluated at a particular set of elements, gives zero for all of them, on every page." "Eh, it's probably just an incredible coincidence."

    17. Re:Nonsense! by BorgCopyeditor · · Score: 3, Insightful
      There is and probably will never be any such situation where it takes so long to write to a media that you cannot fill it before it dies.

      The human brain?

      --
      Shop as usual. And avoid panic buying.
  2. CD Rot by Liselle · · Score: 5, Interesting

    The story about the Rot of Death seems to come up every once and a while. My fun strategies for longevity:

    - If you can rub the top of a CD and have your finger come back silver, that's a bad sign. I avoid cheap CD-Rs. Sorry, CompUSA.
    - I burn at 2x, always, unless I am burning something that I don't care about. Someone showed me the difference in color, I was convinced.
    - Sticker on top = CD death.
    - Take care of your media. Had a friend who left a CD on the windowsill and forgot about it. Many months later, you could see right through it. Nice corrosion.

    I find it weird that anyone can stick a 100 year lifespan on a product that hasn't been around that long. I know that they have processes that supposedly accelerate the process and give you a rough estimate, but I am skeptical. Maybe they really are that durable, and people are just careless/cheapskates. You know what they say about malice and idiocy.

    --
    Auto-reply to ACs: "Truly, you have a dizzying intellect."
    1. Re:CD Rot by Liselle · · Score: 4, Informative

      It's the glue. It can corrode the top layer. I've seen some stories about it, still a few floating around, seems to depend largely on which one you use. The problem may be mitigated by this point, now that they know, but I still don't trust labels over cases/sleeves. You have to get that label on really well, air bubbles being your enemy. :D

      --
      Auto-reply to ACs: "Truly, you have a dizzying intellect."
    2. Re:CD Rot by TedCheshireAcad · · Score: 4, Funny

      Ripping the reflective surface off CDRs is a good way to impress kids with shiny things. The only problem is, they then want to do it.

      While counselor at a computer camp, once I showed a kid how to rip the reflective face off a CDR with some duct tape, and he spread that information to all the kids. Little did they know that the dye underneath is toxic, and like 7 or 8 kids were puking up their lunch later on. I told the boss I had no idea what happened. :-\

    3. Re:CD Rot by Wavicle · · Score: 4, Informative

      This is all true. You may not know the vast difference in materials used for CD's.

      If the CD feels sticky around the edges, it may (may) mean a low quality glue was used. It provides a potential path for fungus to migrate into your CD.

      Gold reflecting layers (very rare to find anymore) are the absolute best. Gold generally doesn't react with the stuff in the atmosphere.

      High quality archival stabilized dye layers are also hard to find anymore. Phthalocyanine was the absolute best last I looked (a few years ago) with an estimated stable lifetime of 200 years.

      A CD that you want to hold data for 100 years should have a quality glue job, gold reflective layer and Pthalocyanine dye. I know of only two brands that have ever been made to this quality. One was Kodak Gold (some marketing suffix here), but it went out of production several years ago. The other is Mitsui Gold, which cost about $1 each in 100 packs.

      And no matter how nice the CD manufacture is, it will not last unless properly stored. The three tenets of archival storage are: Cool, Dry and Dark. Don't leave your CD-R's on the shores of a tropical beach.

      --
      Education is a better safeguard of liberty than a standing army.
      Edward Everett (1794 - 1865)
    4. Re:CD Rot by bgalehouse · · Score: 5, Informative
      As of a few months ago you could certainly still get gold reflecting layers with Phthalocyanine dye, though you have to pay for it. I ordered 100 Mitsui gold's (now apparently called MAM-A) from dsgi for digital photo archival.


      I have to burn them at less than max speed, apparently the more stable dye requires more laser power. Otherwise no surprises so far. (knock on wood)

    5. Re:CD Rot by BlackHawk-666 · · Score: 4, Insightful

      Burning at slow speeds is still a good way to ensure more players can read a CD. This technique does work, and I used it again just last night. I burnt an SVCD of a *cough* movie I found umm, somewhere in a cupboard, at the rated speed of my medium which was 10x (rewritable). The DVD player rejected it, unable to read the data. I burnt it again from the same .bin file at 4x and the DVD player read it perfectly. It may not matter when you read it back on the same drive you burnt it on, but it sure can matter when you want to hear it in your car or watch it on your DVD player.

      --
      All those moments will be lost in time, like tears in rain.
    6. Re:CD Rot by swv3752 · · Score: 3, Insightful

      Burning at slower than optimal speeds will result in more low level errors. Burning at lower speeds may produce a slightly greater phase change (or darker burn spots). However with more low level errors that disc will wear out faster. The type of dye used is usually a better indicator of lifespan. The dark blue dye lasts best. The lighter colored silver-green that is used by most cdrs is crap.

      Informal testing shows that the silver-green dye lasts about 6 months in a hostile environment (namely the visor in my car- and I live in FL). The dark blue has lasted upwards of 6 years.

      --
      Just a Tuna in the Sea of Life
    7. Re:CD Rot by Yewbert · · Score: 3, Interesting
      I've been a consistent audio CD-R hobbyist/trader since 1997, have burned upwards of 5000 discs, and the ONLY CD-Rs I've ever had go bad on me were ones with labels stuck on 'em - and MOST of the ones I've acquired with labels HAVE gone bad. A long time ago, I thought labels would protect the more delicate top coating of a CD-R - and over the SHORT term, for discs that are handled regularly/carelessly, maybe it's so - but over the long-term, I observed this speculation to be quite wrong. Buy a brand with a good top-coating already on it (Verbatim, Mitsui), and you're far better off.

      I've successfully used BlindRead/BlindWrite (www.blindread.com) to perform raw reads of otherwise unreadable discs - and I'm talking CD-Rs that can't be ripped in a CD-ROM, played in a stereo CD player or *anything*. BlindRead instructs the reading device to ignore the error-correction encoding, which may only confuse matters when the disc is mechanically damaged/degraded. Once read in (as an "image") and burned to a second (usually RW, to conserve resources) disc, I could frequently recover the content in sufficiently flawless (for audio, at least) condition for material for which I had no other source. A few discs were just lost completely. (Taught me to NEVER erase or record over the master DAT.)

      A note on manufacturers: It's getting more difficult all the time to find blanks sourced from reputable manufacturers. a) most "brand name" blanks [Fuji, H-P, Imation, etc.] are actuallly manufactured by other companies [Ritek, CMC Magnetics, Taiyo Yuden, etc.]; b) the "name brand" companies change their sources to minimize cost at whim and with no notice to the consumer; c) there's usually little outward indication of the actual manufacturer to tell you, when looking at spindles of blanks on a store shelf, who made them, in order to decide which to buy.

      Up till sometime last year, Fuji and H-P sold re-branded Taiyo Yuden blanks. T-Y blanks have tested (in BLER tests similar to the Library of Congress studies cited in the story) as competitive with the best quality brands, FAR better than Ritek-manufactured discs and those of other mfrs. (Sorry, I don't have a ready reference for that data at hand,...) But recently, both Fuji and H-P have gone to another source - the only outward evidence of which on their packaging is a "Made in Taiwan" where there used to be a "Made in Japan" legend, and the spindles look a little different; SOMETIMES the label side of the disc is different, but not always.

      In order to determine the actual manufacturer of a blank, you need to use (on the Windows side) a utility program such as CDR-ID or Feurio (www.feurio.de), the latter of which displays the manufacturer in a pre-burn dialog box.

      As a side note, other brands whose blanks tested at the top of the curve, were those manufactured "in-house" - Verbatim, Mitsui and Kodak all make/made their own blanks, and they tended to have better quality control. Of course, they also tended to be more expensive, and Kodak has since stopped making their own blanks.

      Another thing I've noticed recently about "off-brand" CD-RW blanks (and I'd guess it's the same for CD-Rs, but I've never bought any CD-Rs branded by these low-budget outfits), is that it appears that ValuDisc (ValueDisc? Valu-Disc?) and possibly KHypermedia blanks are REJECTS from other re-branders. I snagged a spindle of Valu-Disc CD-RWs on a free-after-rebate deal at OfficeMax a couple weeks ago. On close inspection, the top coating appears to be a thick blue dye/paint layer, made from many, many skewed layers of logo-print, all in the same color, and augmented with a few solid layers, apparently in order to disguise a logo that had originally been applied to the surface of the disc. Anybody know anything about this? Are they selling blanks that were labelled for one reseller, rejected "en batch" by that seller's QC, and then painted over to cover the original branding? I've not written data to any of them yet, and so don't know how they perform,...

  3. Using RIAA math by Anonymous Coward · · Score: 5, Funny

    The 100 year CD-ROM becomes a 27 million year CD-ROM, and they plan to have their copyrights extended that far.

  4. Solution! by Morgahastu · · Score: 5, Funny

    Store them on a series of floppy diskettes. They have proven to be VERY reliable. ;)

    1. Re:Solution! by bhtooefr · · Score: 4, Informative

      Actually, 5.25" double-density disks have been shown to theoretically last 90 years, and many of these disks have lasted 20+ years IN PRACTICE (I have some 25 year old Apple II disks that STILL work without errors to this day).

  5. Doooom(esday)! by llamaguy · · Score: 5, Interesting

    Factor that in with the project the BBC did in the mid-1980s (A digital Domesday book, designed to be a snapshot of life at that particular moment of time) that was unreadable withing 20 years because of the fast pace of technology and no way will CDs last 100 years.

    --
    HAH! I just wasted a second of your life making you read this, but I wasted a minute of mine thinking it up. DAMN.
    1. Re:Doooom(esday)! by EpsCylonB · · Score: 4, Interesting

      Wasn't that because the format they recorded it on was quite obscure and they couldn't find a player to read back the data ?. That is related to this I guess but the first hurdle is to ensure the integrity of the data in the first place.

  6. date, reburn, rinse, repeat by wren337 · · Score: 5, Interesting


    Blank CDs in bulk are cheap. For archival stuff I make a new copy every 5 years. I have a bunch of scanned photos I don't want to lose, so I re-copied them all onto new CDs.

    You aren't supposed to write on the CDs either but I've not had any trouble with that, probably because I'm not trying to keep them very long.

    1. Re:date, reburn, rinse, repeat by Late · · Score: 3, Insightful

      I'd like to add that with the current progress of storage technology there is really no need to copy CDs to other CDs every five years. Instead you'll probably want to copy CDs to DVDs to HD-DVDs to whatever in order to save physical storage space more often than every five years. Thus refreshing will happen automatically as long as you do not lose the media.

      Losing and then finding media is of course the real problem as lost digital recordings do not get refreshed and may be destroyed.

  7. Eternal archiving. by Guano_Jim · · Score: 5, Funny

    Rename the MP3s of your grandfather's voice to coors_twins_baby_oil.mpg and put it on Kazaa.

    Repeat every year with the current cover girls of Maxim, Stuff, or whatever men's mag suits your fancy.

    Guarantee you'll never be at a loss for a copy of dear old granddad.

    1. Re:Eternal archiving. by lacrymology.com · · Score: 3, Funny

      Yeah but if I d/l that recording of his grandfather's voice, then his family will sue me for copyright infringement!

      -m

      --

      #
      # Modus Ponens
      #
    2. Re:Eternal archiving. by BarryJacobsen · · Score: 4, Funny

      Daddy, what's great-grampa doing with those ladies?

      Oh, sorry son. Wrong file. Don't tell your mother.

  8. 100-year shelf life, but 3 year usage life?? by 192939495969798999 · · Score: 4, Informative

    I know lots of people that have "worn out" cd's. The first time I heard that, I thought they were kidding, but no... even if you take super great care of say, an audio cd, it will eventually wear out. It's especially bad if you keep it in the original plastic jewel case, and take it out each time -- my friend's rare Pearl Jam CD's are nearly scratched beyond playability, but he was able to extract the digital information before it got lost. What makes CD's better than tapes is that the 0's and 1's will always "be the same" logically, unfortunately the physical media wears out quickly with use. I prefer to think of CD's as a temporary storage mechanism for a permanent idea, like a sketch on newsprint. Once the newsprint disintegrates, you'd better hope you made something good with the idea... it doesn't mean the idea is gone, but the medium isn't like stone.

    --
    stuff |
    1. Re:100-year shelf life, but 3 year usage life?? by mahdi13 · · Score: 4, Insightful

      I still have perfectly working music CDs from the late 80s.
      I have data CDs from the early 90s that are fine also
      I just dug up some CD-Rs I burned from 1998 and they were fine also.

      I think CDs can last a long time, but just like everything else...you need to take care of them. If it's something you use all the time, make backups and use those.
      It's not time that kills CDs...it's scratches and wear.

      --
      "Some things have to be believed to be seen." - Ralph Hodgson
  9. Re:Or.... by crow · · Score: 4, Insightful

    But be sure to use blanks from different manufacturers. Otherwise your failures won't be independent, so the odds of all your copies going bad at roughly the same time (i.e., before you notice the first one has failed) is high.

  10. Old formats require old machines by thoth · · Score: 5, Insightful

    The danger in "old" storage formats is lack of machines to read them. Those tapes may be in good shape, and so might the data on an 8" floppy I have, but the 8" floppy is effectively lost to me because I don't have easy access to a drive that can read it anymore! The paper tape programs I "printed" out from a VAX PDP-11 are probably good (if I hadn't lost them years ago) but I can't get to a tape reader, etc.

    You almost have to make dozens of copies of data on a modern cheap format, and keep moving it forward.

  11. First of all... by unperson · · Score: 5, Insightful

    How do you know there is no loss with analog?

    Analog quality loss is acceptable, because it results in static. Digital loss isn't acceptable, because (at least practically) it is a binary property...the CD works or it doesn't. Scratch the hell out of a record, and at least you still have something.

    We could build acceptable redundancy into digital backups, its just that most people think of it as wasteful. You know what though?... I have everything worthy of backup "backed up" in at least 3 places, one of which is always CD stored somewhere out of reach. Digital is better. Once you convert to digital, you can have zero quality loss with near 100% efficiency, you just have to want it that bad.

    1. Re:First of all... by Neon+Spiral+Injector · · Score: 4, Informative

      Have you ever head of Reed-Solomon? There is redundancy built into CDs.

    2. Re:First of all... by unperson · · Score: 3, Interesting

      But I think the problem is that CD media doesn't have what most people consider "acceptable redundancy"

      When a CD ages, and the surface scratches, and the ink degrades, the data doesn't fade to yellow and get wrinkled like a newspaper, or it doesn't sound like its being pumped over a telephone like a record would, it is just gone. At least with analog data (especially newspaper) there isn't this working/not working parity...we can see the degradation and recopy the data before its too late.

      Of course we try to get around this by adding error detection/correction schemes, but I think the original post is about how (apparently) these aren't adequate.

  12. Analog Audio is not a fair comparison by dankney · · Score: 5, Informative

    It's not exactly a fair comparison between CD-R and analog tape for audio. The audio tape isn't "more reliable." It just degrades differently.

    As the tape ages, the quality of the audio signal degrades dramatically, but because it is an analogue signal, it can still be deciphered by or ears.

    With digital medium, the audio never gets worse. As the media degrades, it just reaches a point where it isn't able to be deciphered as audio data.

    If you want to compare the mediums (magnetic tape vs. CR-R), data is probably a better place to do so. You can easily measure the amount of readable/unreadable data in bytes and make a fair, quantifiable comparison.

  13. Storage Conditions by EpsCylonB · · Score: 4, Insightful

    In the wrong conditions, such as sunlight, humidity and upper surface damage, your CD-R will slowly turn into a coaster. "CD-Rs should never be left lying in sunlight as there's an element of light sensitivity, certainly in the poor quality media," says Stevenson. "I wouldn't rely on CD-Rs for long-term storage unless you're prepared to deal with them as recommended."

    Surely storing cd's correctly is the key, if the dye on a cdr fades after being kept in a jewel case at a room temperature fr 2 years then that is obviously very bad (and there could be some lawsuits in the future).

  14. Redundancy by KalvinB · · Score: 3, Informative

    Keep original copies on the Harddrive, Cassette, ect and then make copies as needed.

    Tape isn't going to last forever. At least when it's digital you can easily transfer to new media without loss of quality.

    If it's really important you just need to make sure you keep ahead of obsolecence. Transfer the stuff to the new standard before the old standard completely goes away. There's always a transition period.

    Ben

  15. 5 Years is accurate by nurb432 · · Score: 3, Informative

    I have found most of my cdr's that are that age or older are starting to fail.

    Rather dissapointing the first time it happened.

    seems to be from several big brand names, so it must be a limitation of the Dye, not just a bad batch.

    But then again, it was designed to be written too ( i.e. physcially changed ) so how can one expect it to last forever?

    --
    ---- Booth was a patriot ----
  16. You're citing Rense.com as an authority? by Anonymous Coward · · Score: 5, Informative

    The first link is to rense.com, a website that promulgates the theory that the US government is experimenting on us with "chem trails" emitted by otherwise innocuous-looking aircraft flying overhead. The webmaster at that site obviously has a very low threshold for rubbish, and no critical thinking ability!

    1. Re:You're citing Rense.com as an authority? by WormholeFiend · · Score: 4, Funny

      Chemtrails, CIA mindcontrol, UFOs, Bigfoot, and now CDRs...

      Do I have to wrap my por^H^H data archives in tinfoil now as well?

  17. Another 6 months, another CD longevity article by Pedrito · · Score: 4, Interesting

    What's the deal? This same article with a slightly different look shows up every 6 months, it seems.

    Besides the fact that CDs DON'T have a 100 year shelf life, we've also discussed the CD eating fungus several times here, which for people in hot and humid environments (particularly, it seems, Mexico, Central, and South America) can reduce a CDs lifespan to months or a couple of years.

    And then you have the fact that rewriteables have an even shorter lifespan.

    One thing that's rarely mentioned is the fact that most CDs are defectively manufactured. I say this because the metalic layer between the plastic is supposed to be sealed. But the fact that the aforementioned CD eating fungus enters through the two layers of plastic says to me that CDs are generally defective in that they fail to properly seal this layer.

    I personally lost about 25% of my CD collection to this fungus over a 2 year period in Mexico, so I speak with some experience. These CDs were not abused. Most were in plastic cases, some were in sleeved carriers.

  18. Why 100 years ? by da_reboot · · Score: 5, Interesting

    I don't get this obsession with hoping to keep media for 100 years. Technically punch cards are forever. Do you still use them ? No, because their storage capacity is ridiculous by today's standard. In five years you will store your data probably on your solid-state 200 g key-chain.... move with the times..

  19. FUD by polyp2000 · · Score: 3, Interesting

    All this about CD's not lasting very long is just FUD by the RIAA. In the next few years or so they will want to bring out a new type of media so that everybody has to restock their cd collection with the new media format.

    Bottom line, buy cheap media then you will suffer the consequences. Buy decent media; buy a reputable brand and you can expect reasonable lifespan.

    Hey, and wasnt this a dupe? albeit one with a twist ?

    nick ...

    --
    Electronic Music Made Using Linux http://soundcloud.com/polyp
  20. Long term audio storage by shawkin · · Score: 4, Informative

    The BBC Library still uses vinyl records for long term audio storage. For some items they cut a lacquer master, plate the metal stampers on the lacquer and leave the metal stampers attached to the lacquer.

    They believe that this will preserve the audio for about 300 years and they say that vinyl is the only storage medium with a real and predictable life span.

  21. Archive the raw samples! by Just+Some+Guy · · Score: 5, Informative
    I've said this before, but it bears repeating: do not filter or otherwise "enhance" the audio files before you store them. Instead, save them losslessly, hisses, pops, and all.

    Audio processing technology will get better. Don't ruin your grandkids' heirloom recordings by using today's technology to permanently alter them.

    Make working copies and filter those as much as you want, but keep those masters pristine! Maybe somewhere in the background you can hear your grandma yelling at dear ol' grandpa to put that thing away and paint the house, and a clumsy run with an agressive low-pass filter will throw that data away forever. You have something really valuable; please take care of it for the future.

    --
    Dewey, what part of this looks like authorities should be involved?
  22. CD tips for longetivity by jd · · Score: 4, Funny
    • Avoid exposure to UV radiation. Keep locked in a lead casket when not in use.
    • To prevent chemical reactions from affecting the disk, keep chilled at -90' or so. Liquid notrogen is a useful cooling system.
    • Prevent scratches by always using ultra-smooth surfaces and clean-room environments.
    • To stop acids and other chemicals from the body attacking the CD, use those space-suits from the Intel commercials.


    Now, you can enjoy your CDs for a long time...

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  23. Oblig 'Me Too' Post by da3dAlus · · Score: 4, Informative

    I'm sure what I'll say has already been said, but I can certainly attest to the shorter-than-advertised longevity of CDR media. I recently had to pull some long lost files off of CD's I burned back in the college days, probably 5 years ago or so. These consisted of several types of media, both cheap and expensive, green and blue dye, sticker and no sticker. Basically the dye color has little effect, and stickers really do call for the early death of the media. But most of all, I think it was the early CD burning software or the actual CD-Rec drive that I used. Some earlier CD's, that I know I burned at work (using the latest software at the time) were near flawless. But a batch burned later, on a friend's computer using some lesser known software, was completely corrupt (TOC and CRC errors abound). I now make sure I get decent CDR's like TDK's (not the cheap CompUSA stuff), don't use stickers, always keep them in a multi-CD case, and run a bit-for-bit check on the archive after burning with Nero. I have yet to have a problem since I started this practice at least 2 years ago...although time will certainly tell.

    --

    Sometimes I doubt your commitment to Sparkle Motion.
  24. Periodically check CDRs by bigberk · · Score: 3, Informative

    I now write myself a little note on my CDRs to indicate how much of the surface causes read errors. Nero's "CD Speed" tool is very useful for this, as it has a ScanDisc tool incorporated within it.

    When too much of my CD's surface has read errors, I make a new copy of the CDR. So far I've only had to do this for 3 of my discs over the past 6 years or so.

  25. Burning at 2x... by ajutla · · Score: 5, Informative

    Although it seems like burning at a slower speed means that your data lasts longer, for some newer CDs burning at 2x might actually cause your data to be less secure. Most CDs sold nowadays are optimized for faster burns, say at 48x. The "fast" media doesn't handle slow burn speeds quite as well as older media optimized for 2x would.

    1. Re:Burning at 2x... by pair-a-noyd · · Score: 3, Informative

      I'll say this,
      I burn a lot of discs at max speed and they frequently won't run on OLDER pc's.

      So when I KNOW I have to burn one for an old pc I burn it at 4x or 6x (with k3b) and it always works.

  26. use gmail? by Frederic54 · · Score: 3, Funny

    convert everything to mp3, and send them to your gmail account, they will be kept here forever in multiple redundant copies

    --
    "Science will win because it works." - Stephen Hawking
  27. CD RW are better ??? by iMaple · · Score: 3, Interesting

    The article says Not all optical media is vulnerable. The rewritable variants (RW) use metallic materials that change the phase of the light, rather than light-sensitive dyes. Commercial magneto-optical and ultra-density optical systems are different too. Do they mean to say that CD RW's are resistant to aging compared to CD-Rs ??

    I always thought that CD-R s are more reliable than the RW's and genrally back up my data to CDRs ( and of course CDRW are more expensive)

  28. Re:my first audio cds are dying by tuffy · · Score: 4, Informative
    Some of my first cds purchased in 86 (Are You Experienced and Electric Ladyland) are clearly losing sound quality.

    Pressed CDs shouldn't be as vulnerable to bit rot as burned CD-Rs. But I can't understand how the discs would lose quality. One either gets a valid frame of redbook audio or not. I can understand that some of the frames might go bad (even to the point where the built-in error correction can't help) and lead to audio defects, but I don't see how the whole disc would sound different than before.

    --

    Ita erat quando hic adveni.

  29. punchcards are better by WormholeFiend · · Score: 4, Funny

    that's why I bought the Unreal Tournament 2004 Special Punchcard Edition.

    http://img53.photobucket.com/albums/v162/Cordata /U T04-PunchCard.gif

    As long as I keep them in a dark and dry place, it's going to last forever!

  30. Re:Or.... by No.+24601 · · Score: 4, Funny
    But be sure to use blanks from different manufacturers. Otherwise your failures won't be independent, so the odds of all your copies going bad at roughly the same time (i.e., before you notice the first one has failed) is high.

    So i guess someone was paying attention in Stats class ;)

  31. That does it by AtariAmarok · · Score: 4, Funny

    That does it. I'm converting all my mp3 collection to 8-track tapes. Does anyone know of a good 8-track tape recorder that mounts in a typical tower 5.25" drive bay to make this easy?

    --
    Don't blame Durga. I voted for Centauri.
  32. Re:As Linus Said by Anonymous Coward · · Score: 5, Funny

    "Real men don't use backups, they post their stuff on a public ftp server and let the rest of the world make copies." - Linus Torvalds

  33. Redundant hard drives is my solution too by phildog · · Score: 3, Insightful

    I think you are doing the right thing. Who has time to dick around backing up to CDs, tapes, etc? To me, any backup solution that spans multiple tapes, etc is severely broken.

    I have a big honkin hard drive 120gig with all my stuff at home. I have a 2nd big honkin 120gig that has USB2. I take the USB2 drive to work once a month and leave it there. Bingo--off-site backup solution. (Yes, encrypted file system so co-workers can't browse my comprehensive porn collection.)

    The stuff that changes more often (like photos) that I couldn't really bear to lose I rsync to my linux box over the net.

    Everything fails, redundancy is the way to go. And it has to be easy.

    --
    slashsearch.org - slashdot search. powered by google.
  34. NIST Study by JoshuaDFranklin · · Score: 4, Informative
    1. Re:NIST Study by CyberLord+Seven · · Score: 5, Informative

      Sharpies should be OK as they are alchohol based. Beware of any "oil" based permanent markers as they will degrade the surface plastic.

      --
      We have always been at war with Eurasia!
    2. Re:NIST Study by mphase · · Score: 3, Informative

      Exactly WRONG! Alchohol based markers can in fact break down the layers whereas oil based ones cannot. I can't believe you could get it so completely ass backwards and be modded informative.

  35. Re:Free Biz Idea by Quill_28 · · Score: 3, Insightful

    I wouldn't even allow 100 per month, maybe 10 times a month. Or even completely offline altogether.

    Better get some great insurance, I wouldn't want someone to have their 1850's relatives diary destroyed and then find out that I also lost their only digital copy!

  36. Re:my first audio cds are dying by the+arbiter · · Score: 3, Informative

    Actually, most of the CDs from that era sound horrible...digital mastering has come a long way since then, as has playback equipment. A disc from 2001 is going to sound much better than one from the late 80's.

    --
    Boycott everything - they're all trying to fuck you one way or another
  37. Writing speed by cdrguru · · Score: 5, Informative
    If you get a $20K+ testing system and a large number of CD-R samples, write them at various speeds and check the results, you will find that writing at a speed other than the "optimal" for the recorder results in a measurable degradation in the quality of the recording. This sort of testing has been done at Media Sciences (www.mscience.com

    This means that if you have a 2X recorder, writing at 2X is *much* better than 1X. If you have a 32X recorder, writing at 32X will produce measurably better discs than writing at 4X, 2X or 1X. This has been true since around 1998 or so. It is quite true that you could get better results with some early 4X recorders when writing at 1X than 4X. However, none of those devices are current any longer.

    The "writing slower is better" story is a myth. Please don't spread it further. And yes, if you want more information about disc testing Media Sciences is a company that is dedicated to disc quality and testing. I do not work for them.

    1. Re:Writing speed by unorthod0x · · Score: 4, Interesting

      I don't claim to know much about this at all, but I know as a complete fact that the slower I burn Audio CDs on my 24x the less they'll skip when they're in my car. This has been true for me at least one hundred times over, and I drive the same route pretty much every day (same bumps).. How does this experience fit in to the above?

    2. Re:Writing speed by bashamer · · Score: 3, Interesting


      It would be interesting to see if the difference between readin and writing speeds causes the problem. Since if you write at the same speed as you read both processes will see the same wobles in the disk. These wobles are caused since CD's are never quite round, and uniform desity.


      This would mean that for a normal CD player you want to write at 1x, and for a Car cd player, or a portable CD player you would want to write at what ever speed they sample (more than 1x since they have skip protection). If you check the site they meantion that you should write at more than 1x but less than 12x.


      So the question is at what speed they wrote and read the CD-R's, not just the writing speed. I checked the site but I didn't find any data on that.

    3. Re:Writing speed by DroopyStonx · · Score: 4, Informative

      Honestly, I think it depends on the burner. I have no solid proof to back this up, but I have had experiences with it.

      It is a popular misconception that burned PS2 games will not work if burned over 1x. The reason this APPEARS to be true is because a lot of DVD burners suck ass, even the big brand name ones. Burn anything over 1x, and the PS2 can't read the data.

      Is it the PS2's fault? No. Reason being... I've witnessed DVD-Rs burned on 2.4-4x using a friend's DVD burner that will NOT play at all, but I take a DVD burned with MY DVD burner at 4x, it works perfectly! Same brand of disc and everything.

      Based on that, I think it's safe to say that it all depends on what you burn it with.

      --
      We have secretly replaced these Slashdot mods' sense of humor with a rusty nail. Let's see if they notice!!
  38. CD-Rs can last longer by Cecil · · Score: 4, Informative

    ... if you know what you're doing. First of all, there are specialty CD-Rs intended for archival purposes. These will inherently last longer than normal CDs for numerous reasons, assuming the manufacturers are not full of crap. To find these CD-Rs, check a photography store, as photographers tend to have a need for both archival and mass storage thanks to digital cameras. You will likely find some there.

    Second, the biggest mistake most people make in CD archival is to write on the CDs with magic marker -- DO NOT DO THIS. The ink will, given several years, leach through the extremely thin plastic on the labelled side of the CD and pollute the optical layer, resulting in a ruined CD. Adhesive stickers, I'm told, are not much better. There are special CD-labelling markers out there, I don't know if they work well as I haven't tried them, but I doubt they're worse than a magic marker. I have found that writing very lightly with a soft, dark graphite pencil works well. If you're very paranoid, you might consider not labelling the CD at all and just be meticulous in returing it to its (properly labelled) case when you're done.

    Additionally, store the CDs properly. Somewhere reasonable. Not in direct sunlight. Safely stowed in their jewel cases.

    Of course, even doing all this, no one can tell you that your CDs will still work in 100 years. It hasn't even been 100 years since we invented the damn things, how do we know how long they will last? Still, these are steps that should allow your CDs to last for at least as long as a magnetic tape, and with perfect accuracy, as opposed to the slow degradation of audio tapes.

    What we really need is something similar to the S.M.A.R.T. technology in harddrives nowadays, to alert you that "Listen, I'm getting close to reaching the limit of my error-correction techniques here. This media probably isn't going to last a whole lot longer. You may want to do something about that." Currently, there's really no way to tell until it's too late.

    1. Re:CD-Rs can last longer by hankwang · · Score: 4, Interesting
      I have found that writing very lightly with a soft, dark graphite pencil works well.

      I wouldn't be so keen on having particles of electrically conducting graphite being spun off the disc inside the drive... But you're right that it probably won't damage the disc.

      If you're very paranoid, you might consider not labelling the CD at all

      Or write in the data-less area around the center of the disc.

  39. People are cheap by Rex+Code · · Score: 4, Informative

    Really, what do you expect when most people pick up spindles that all some from the crappy Ritek or Princo plants in Taiwan because they can get them for $9 a spindle? I've had those go blank on my shelf too, and now I know better.

    Want a long lasting CD-R? Search the spindles to find the ones that are made in Japan. Sometimes these will be on the same shelf with the Taiwan ones, wearing the same packaging, and for the same price (if you're lucky). Usually these are made by Taiyo-Yuden, a high-quality CD-R manufacturer (and one of the co-developers of CD-R technology). Look for a frosted hub for positive ID.

    For archival quality, you'll need to spend a couple of bucks a disc on media that has a gold reflective layer. The standard here has always been Mitsui (now branded as MAM-A). Even their silver discs are a cut above in quality.

    Oh, while I'm here. In 1996 I scribbled all over a burned CD-R with various colored Sharpies, then last year cleaned it all off with carb cleaner. It hadn't migrated into the disc at all, and cleaned off without a trace. The data was fine. Anyway, I mention this because I hear people claim Sharpies kill CD-Rs all the time, and think it's nonsense. These people probably bought the cheap-o discs and are looking for something other than their own cheapness to blame it on. Oh, BTW, the scribble disc was a Sony, made by Taiyo-Yuden.

  40. Risk of data loss for nth generation copies? by zerosignal · · Score: 3, Interesting

    Many people seem to suggest reburning data every few years. But each time you do this, are you not risking corrupting a small number of files? I know OSs and hardware have error correction, but when you're dealing with gigabytes of data isn't there a risk that eventually an error will go through uncaught?

  41. best bet... by Byteme · · Score: 4, Interesting
    ...is to cut your own vinyl and then play it on a laser turntable. Isn't vinyl the preference for the Library of Congress?

  42. Re:CD-RW slow rot by doc+modulo · · Score: 3, Interesting

    CD-RW disks will last longer than CD-R because of the way it stores it's bits.

    CD-R uses a dye that changes color under influence of light. CD-RW uses a phase change material that changes it's properties because of heat. The phase change material won't change color but changes the way light passes through it. Differences in the duration of the laser hitting it will change a bit from one phase to another.

    CD-RW disc information is much safer because of these differences. The only problem with CD-RW is that you can accidentally overwrite files you wanted to keep.

    --
    - -- Truth addict for life.
  43. Andy McFadden's CD-R FAQ says... by antdude · · Score: 5, Informative
    From Subject: [7-5] How long do CD-Rs and CD-RWs last?
    (2004/02/17) in CD-Recordable FAQ:

    CD-RWs are expected to last about 25 years under ideal conditions (i.e. you write it once and then leave it alone). Repeated rewrites will ccelerate
    this. In general, CD-RW media isn't recommended for long-term backups or archives of valuable data.

    The rest of this section applies to CD-R.

    The manufacturers claim 75 years (cyanine dye, used in "green" discs), 100 years (phthalocyanine dye, used in "gold" discs), or even 200 years
    ("advanced" phthalocyanine dye, used in "platinum" discs) once the disc has been written. The shelf life of an unrecorded disc has been estimated at
    between 5 and 10 years. There is no standard agreed-upon way to test discs for lifetime viability. Accelerated aging tests have been done, but they may not provide a meaningful analogue to real-world aging.

    Exposing the disc to excessive heat, humidity, or to direct sunlight will greatly reduce the lifetime. In general, CD-Rs are far less tolerant of environmental conditions than pressed CDs, and should be treated with greater care. The easiest way to make a CD-R unusable is to scratch the
    top surface. Find a CD-R you don't want anymore, and try to scratch the top (label side) with your fingernail, a ballpoint pen, a paper clip, and
    anything else you have handy. The results may surprise you.

    Keep them in a cool, dark, dry place, and they will probably live longer than you do (emphasis on "probably"). Some newsgroup reports have complained of discs becoming unreadable in as little as three years, but without knowing how the discs were handled and stored such anecdotes are
    useless. Try to keep a little perspective on the situation: a disc that degrades very little over 100 years is useless if it can't be read in your
    CD-ROM drive today.

    One user reported that very inexpensive CD-Rs deteriorated in a mere six weeks, despite careful storage. Some discs are better than others.

    An interesting article by Fred Langa (of http://www.langa.com/) on http://www.informationweek.com/story/showArticle.j html?articleID=15800263&pgno=1
    describes how to detect bad discs, and discusses whether putting an adhesive label on the disc causes them to fail more quickly.

    By some estimates, pressed CD-ROMs may only last for 10 to 25 years, because the aluminum reflective layer starts to corrode after a while.

    One user was told by Blaupunkt that CD-R discs shouldn't be left in car CD players, because if it gets too hot in the car the CD-R will emit a gas that can blind the laser optics. However, CD-Rs are constructed much the same way and with mostly the same materials as pressed CDs, and the temperatures required to cause such an emission from the materials that are exposed would
    melt much of the car's interior. The dye layer is sealed into the disc, and should not present any danger to drive optics even if overheated.
    Even so, leaving a CD-R in a hot car isn't good for the disc, and will probably shorten its useful life.

    See also http://www.cd-info.com/CDIC/Technology/CD-R/Media/ Longevity.html,
    especially http://www.cd-info.com/CDIC/Industry/news/media-ch ronology.html about some inaccurate reporting in the news media.

    See "Do gold CD-R discs have better longevity than green discs?" on http://www.mscience.com/faq53.html.

    --
    Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
  44. Reel to Reel WILL FAIL by SatanicPuppy · · Score: 4, Interesting

    The number of things that can go wrong with old magnetic media is so long I won't even go there. If nothign else, the magnetic tape will get old and brittle. It also stretches slightly when you play it, which could leave granddad sounding like James Earl Jones in a few years. Certain types of mildew love it. AAAAAA! Make a copy! Make a copy!

    Add to that the cost of replacing r2r tech, and you've got a scary situation. I agree with the parent. CD may not be the answer, but digital sure as hell is. I'd be super paranoid having anything I cared about stuck on old tape.

    --
    ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
  45. The Sharpie rumor again by Rex+Code · · Score: 3, Interesting

    Second, the biggest mistake most people make in CD archival is to write on the CDs with magic marker -- DO NOT DO THIS. The ink will, given several years, leach through the extremely thin plastic on the labelled side of the CD and pollute the optical layer, resulting in a ruined CD.

    Got some studies supporting that? I did my own little study after highly doubting this rumor. Here's how I think the rumor got started:

    1. Buy cheapest Taiwanese media
    2. Write on it with a Sharpie
    3. Down the road, blame the Sharpie for media failure

    My (unscientific, but the only data point I'm aware of) test:

    In 1996, I wrote all over a Japanese Taiyo-Yuden made, unbranded Sony CD-R. In 2003, I tested the data, which was fine. I then cleaned the Sharpie ink off the disc with carburator cleaner (harsh treatment, for sure). It wiped off in seconds with no trace whatsoever, so in 7 years the ink did not migrate into the disc at all. After this, the data was still good.

    Conclusion: Buy good media and quit worrying about writing on the discs. They'll take it fine, and if they die, it wasn't the pen that killed them.

  46. MAM-A "gold" metallized layer is aluminum not gold by bani · · Score: 4, Informative

    AFAICT, reading all the available literature from Mitsui on their gold MAM-A discs, the reflective metallized layer _is not actually gold_. It's aluminum.

    Mitsui is claiming their _special dye_ is what makes their MAM-A discs last so long, and the dye is what gives their discs their gold color. Not the metallized layer.

    And really when you think about it, it doesnt matter how long-lived the reflective layer is, if your dye deteriorates. Since you're recording your data onto the dye layer -- not the reflective layer.

  47. 100 years? Can be done! by Anonymous Coward · · Score: 3, Informative

    How long a medium lasts is related to how well its cared for. I've seen cassettes that have lasted 30 years, but I've also seen 2 Inch multitrack tape (eg Ampex 499, around $300 for a 15-minute reel) become totally unusable after 10 years.

    Edison cyliders have lasted 100 years (with proper care), shellac 78's and magnetophon recordings have lasted 70 years (with proper care), reel-to-reel recordings have lasted 40 years (with proper care), and I suspect that CDs will last a long time - with proper care. Commercial CDs are nowhere near as resiliant as the inital marketing told us (who ever doubts marketing?), burned CDs substantially less so.

    So, for those who STILL haven't a clue on CD care, here it is again:

    1) Choose a CD that sandwiches that data layer between two polycarbonate sheets, rather than ones that have the data layer printed on (I'm looking at you, TDK). Make sure the rim of the disk is sealed with varnish (you can tell by looking closely);

    2) Keep away from light (of any kind). I know geeks don't get out much, but leaving anything in the sun is bad, and the polycarb in CDs is NOT UV stable, nor is the chemistry in the data layer (if it was that chemically stable, you wouldn't be able to burn it, would you? Think about it...);

    3) Store them somewhere not subject to large temerature variations (an old fire safe is good for this. I've said this before in other posts, but people got the wrong idea: a fire safe will not protect CDs from fire! It is simply a large, heavy, thermally stable box. Sure, you could use a cupboard in your basement, but most basements are not very dry, which brings up the next point);

    4) Keep 'em away from moisture & humidity. Don't throw out all those old silica gel packs, they're ideal. Tupperware is a good investment for archiving;

    5) Labels? Hmm, lets see, take a piece of paper covered with volatile solvents, and place it against your data layer. Anyone with half a brain could see that it was never a good idea (I've never labeled CDs with anything other than Xylene-free markers - not neat, but who cares what the CD looks like, I want my data intact). Labels, improperly positioned can cause imbalances in a CD which can make it unreadable, and gloss labels can cause CDs to become stuck in slot-load drives (iMac owner speaking from experience here, but it applies to car stereos too);

    6) Never, EVER, use CD-RW for permanent backups. They are less stable than CD-R, naturally. Use some logic, folks: if CD-RW were more stable that CD-R, it would be easier to erase a CD-R than a CD-RW, wouldn't it? Its more complicated in reality, but that sums it up in a nutshell (and I've already exceeded the attention span of most /.'ers)

    The down side of any digital medium is that in order to recover the data, you have to read ALL the 1's and 0's (or at least a good percentage of them, given reasonable error correction). Analog storage at least has the advantage that even a degraded signal is recoverable and intelligable, at least for speech applications. So while a cassette might be readable for much longer, it will start having problems like print-through, particle shedding and substrate stretch from day 1.

    No medium will last long if it isn't well cared for. Its as simple as that, but unfortunately some people are even more simple.

  48. Re:MAM-A "gold" metallized layer is aluminum not g by bgalehouse · · Score: 5, Informative

    Umm... what literature would that be? There is a white paper which explicitly states that the reflective later is 24k gold.

  49. Re:As Linus Said by SEWilco · · Score: 5, Funny

    Real men write stuff that the rest of the world wants to copy.

  50. Re:Writing speed - audio vs. data by MikeMo · · Score: 4, Interesting

    We burn about 200K CD-R's here per month. We have found, unequivocally, that you can burn data CD-R's at 40x, but the best we can do for audio is 12x. We don't really know why, but we think it has more to do with the error correction capabilities that the data format has. That's the theory, anyway. Of course, we use only the best drives and media.

  51. Re:NO JOKE by red+floyd · · Score: 4, Funny

    No, the cassette was just changing to reflect the current Jackson.

    --
    The only reason we have the rights we have is that people just like us died to gain those rights. -- Cheerio Boy
  52. Re:The 100-year problem... by michael_cain · · Score: 3, Insightful
    The real problem will be that the file formats of today will be replaced in 10 years, and will be a legacy file format only readable with a compatibility layer in 20 years. In 50 years, that CD will be unreadable. Of course, storing it in ISO 9660 format would offer some protection. If nothing can read the CD 50 years from now, you could at least fall back to the standard spec write your own code to read it.

    Not just the format of the file system (your example), but the format of the individual files. Does anyone believe that, outside of a handful of people in museums, anyone will be able to read GIF files in 100 years? Or MPEG-1 compressed video? Or documents stored as Microsoft Word 97 files? I've worked with computers for the past 25 years, and have encountered all of the problems that people have mentioned in this discussion: tapes for which there are no drives available, tapes and disks which degrade to the point that they are unreadable, file systems on disks that are not supported by contemporary OSs, and individual file formats for which no software (or specifications) exist. I also have a box filled with the paper copies of 25 years' worth of writing, and even the oldest are in good shape and WORK. If they were especially valuable, I'd make another paper copy and put it in the safe deposit box at the bank.

    Audio and video are more difficult, since there's nothing as good as paper for them.

  53. The embarassing part... by gillbates · · Score: 4, Funny

    Is that I can still read data from Iomega Zip disks that are 6 years old, yet can't read CD's I burned 6 months ago. For some reason, the perils of magnetic media and Zip drives never came true for me.

    What really irks me is that CD-R was sold to the public as a way of _permanently_ archiving data. Once written, it was supposed to be permanent. The non-magnetic, non-rewritable nature of the media was supposed to prevent accidental overwrites and erasures from magnetic fields.

    Top Ten reasons to love CD-R/CD-RW:

    1. No Pesky Aborts or Retries: CD-R is the only media in which a failed write ruins the media. Retrying a failed write is so 80's. I never liked that "Abort, Retry, Ignore" stuff anyway....
    2. No Multitasking: I don't like to surf the internet or do other things when a CD is being burned. I'd rather shut down all applications, turn off my screensaver*, and watch the progress meter and wait.
    3. Home Improvement with the PC: I like having a CD coaster place setting for every chair at the dining room table. I could never ruin enough floppies for a full table's worth.
    4. Software is Never Obsolete: You never have to worry about restoring obsolete software during a system restore - by the time the software is obsolete, your CD-R backup has long been unreadable.
    5. No Pithy Operations: I hate updating single files. When I want to update an archive, I want to reburn the whole disk! (CD-R, some CD-RW here...)
    6. Snazzy Disk-Cache Progress Meter: I like disk caches. In fact, I'm not comfortable with a file transfer until I see the "flushing cache to disk" progress meter.
    7. Laid Back Attitude: I'm never in a hurry. Whether I'm just starting work or on my way out the door, I want a file transfer to take at least one minute. I would never want to save what I'm working on and immediately run out the door. (Office space, anyone?)
    8. Security: With CD-R/CD-RW, your files are always safe from editing at a public or shared computer. Even should you come across a machine with a CD-RW drive installed, the read-write latency of a CD-RW will make editing the files practically impossible. And you can forget running an application from your removable media.
    9. No Obsolete Computers: With UDF, all your friends and colleagues will have to upgrade to the latest Microsoft Operating system in order to read your disks.
    10. Prosecutorial Immunity: Should your illegal mp3 CD-R collection get seized by the police, it will be unreadable by the time it gets to trial.

    * - yes, these are the recommendations that came with a 2004 Toshiba laptop regarding making CD's.

    --
    The society for a thought-free internet welcomes you.
  54. Magneto Optic by Ask-A-Nerd · · Score: 4, Interesting

    I was one of the original developers for Magneto Optic for MaxOptics and Pinnacle Micro Systems approx 20 years ago. I still have media recorded back then on truly rewritable optical media that is 100% flawless to this day. And all this is on Plastic Media. I never did understand why magneto optic didn't catch on more. The Glass Media units I'm sure would go to 100+ years and were tested in Europe for the telephone and data companys 20 years ago, and the last I heard they still hadn't seen a single cartridge with glass media go bad.