Optical media shelf life?

[bargora]

I was reading a thread in the Restoration Society forum about the effect of magnetism on cart data and bit-rot in various media, and it got me curious about the lifespan of CD-ROMs. I've read that CDs supposedly begin to degrade after 35 to 100 years (although they should be readable for a longer period). I was wondering if anybody knows what the mechanism of degradation is, as I am assuming that this includes even properly stored CD media.

[YoshiM]

I'm guessing exposure to the air. Many types of plastic get somewhat brittle over the years and perhaps that change in flexibility causes the CD to not be read properly. There could also be an issue where the ink changes slightly due to age. That's about the best guess I can give.

[Cheese]

It's my belief that optical media has a shelf life longer then the medias viability. If that makes any sense. Much like cd's are getting replaced by DVD's, DVD's getting replaced by 57gig blue light dvd's, replaced by data cards, by isoliner optical chips, by biogenic gelpacks, by etc., etc., etc.

[bargora]

I agree, Cheese. I mean, it's already happened to cartridge media, no? In (what will probably be astonishingly little) time, only we oddball collectors will care about archaic media like CD-ROM.

[stargate]

so what happens to cartridge media and how do we protect our carts???

[bargora]

Oh, SG, go check out the thread in the Restoration forum. In short, carts are good for the loooong haul.

[Bratwurst]

Most of that talk revolves around CD-R lifespans- I wouldn't lose much sleep over the professionally pressed CD-ROMs, as that's a sheet of foil encased in plastic. Sure, it'll warp eventually, but nothing lasts forever. I found the webpage that quoted that, btw, Bargora.

This it? (http://www.mmcreations.com/elecpub/cdrec.htm#special)

If so, they're definately talking about CD-R's there, they're misusing the term 'CD-ROM' in this instance.

[wberdan]

as the error correction gets better and better in cd drives, this may not be a concern for an even longer period then 35-100 years.
personally, i wouldnt worry about it.
however, if you own laserdiscs... they arnt manufactured the same way, and their data may not be around in 30 years.


willie

[Anonymous]

mmm biogenic gel packs....ahghhg </drool>

http://www.kindstranger.com/images/homer.jpg

[CrazyImpmon]

Forget CRC, if you use PAR, you could make a backup set of parity files that could be used to reconstruct damaged file or replace missing segment. And PAR files are generally small so it could easily fill in the CD-R with your main files.

The one thing that can ruin CD-R in a blink is a scratch on the label side as there's only an extremely thin sheet protecting data layer. Get those CD label kit and slap label on the label side for added protection against accidental scratch. Plus you can make your backup set look better than those with felt marker scribbled on it. ;)

[bargora]

Most of that talk revolves around CD-R lifespans- I wouldn't lose much sleep over the professionally pressed CD-ROMs, as that's a sheet of foil encased in plastic. Sure, it'll warp eventually, but nothing lasts forever. I found the webpage that quoted that, btw, Bargora.

This it? (http://www.mmcreations.com/elecpub/cdrec.htm#special)

If so, they're definately talking about CD-R's there, they're misusing the term 'CD-ROM' in this instance.
Yes, Sir Sausage. That is one of the sites I was looking at. I was not sure whether they were offering to simply take your data and go to town with a CD burner (CD-R) or if they were actually going to make a professional-quality CD-ROM. You say the former, not the latter. Bastards.


Forget CRC, if you use PAR, you could make a backup set of parity files that could be used to reconstruct damaged file or replace missing segment. And PAR files are generally small so it could easily fill in the CD-R with your main files.
While I understood the second paragraph of your post, CI, I feel like Homer Simpson when I read this part.

[Bratwurst]

What tipped me off on the site was the mention that you, the consumer, could even make your own CD-ROMs, all you needed was a computar properly equipped with a burner drive!!!!1

[Sylentwulf]

If you take reaonsable care of your CD's, they'll out-last you, why on earth would you need to know more than this?

[Bratwurst]

Crap, after reading the site some more there is no mention of a burner drive. Though some of the information on it is a little dated.. zip disks = $20?

Still, they're offering to 'print labels' onto the disk as a service, wonder if that's paper based or actually printed on the surface. I wouldn't take information from a small time Texas company as too reliable anyways!

SHUT UP

REMEMBER THE ALAMAOO

[bargora]

If you take reaonsable care of your CD's, they'll out-last you, why on earth would you need to know more than this?
Counting Up this as curious me.

Besides, I wasn't sure whether they actually WOULD outlast me. I don't wanna be in The Home quaking with fury because Klonoa won't boot.

[CrazyImpmon]

Crap, after reading the site some more there is no mention of a burner drive. Though some of the information on it is a little dated.. zip disks = $20?

100MB ZIP disk = too small for most anything
250MB ZIP disk = no longer supported, hard to find, very slow when reading 100MB disk
750MB ZIP disk = expensive vs CD-R and burner.

Add to that ZIP drives had high failure rate (particularly Click of Death, which destroys both the disk and the drive), prone to more dangers than CD-R (ie magnet) and the host computer needs a ZIP drive to read a disk.

With CD-R, virtually all computers made in the last 10 years can read the CD-R using plain vanilla CD-ROM.