ARCHIVAL CDs - 300 YEARS LIFE!

RichA wrote:

Antoine Dese wrote:

TheDave© wrote:


Using pure gold reflective layers, phthalocyanine dye, and
triple-layer protection, they say the useful life of a CD is 300
years, and the DVDs 80 - 100 years.

Of course, they know, because they've had some actually last that
long...

;-)

And of course, in the year 2306, there will be CD drives to read these
discs!


We dispense with technology now to make things cheaper, faster, etc.
But, all they need to read a CD is a laser.


and a sensor, and a control program to interpret the results.

Tried reading any 5-1/4 floppy disks recently?

"ColinD" wrote in message
...
Well, the CD versus negative storage longevity arguments are now put to
rest. Kodak have announced their new Gold Preservation CDs and DVDs.

Using pure gold reflective layers, phthalocyanine dye, and triple-layer
protection, they say the useful life of a CD is 300 years, and the DVDs
80 - 100 years.



Many, if not most people, are under the misconception that CD-Rs are good
archival media. They are not.

CDs were never designed to store data for long time horizons. And
rewritable CDs are not as permanent as manufactured CDs. The National
Archives has been running experiments with glass-coated CD-Rs, and the jury
is still out on whether they represent an improvement.

We have not yet developed a reliable digital medium for long-term archival
use. So we just must do the best we can with what we have. And that means
trying to store them under optimal conditions, not just buying the best
quality CDs we can get.

We can try to create multiple copies and store them in geographically
diverse locations, but even then the element of risk remains.

The Department of Defense, along with other Government agencies, continues
to store essential data on microfilm, in addition to any digital techniques.
Properly stored, today's microfilm has a lifespan in excess of 5 centuries.
No one knows how well CDs will stand up just yet.

None of my comments are meant to discourage archiving images and data; they
are simply meant to underscore that the techniques that are currently
available to us are by no means foolproof.

"no_name" wrote in message
...
RichA wrote:

Antoine Dese wrote:

TheDave© wrote:


Using pure gold reflective layers, phthalocyanine dye, and
triple-layer protection, they say the useful life of a CD is 300
years, and the DVDs 80 - 100 years.

Of course, they know, because they've had some actually last that
long...

;-)

And of course, in the year 2306, there will be CD drives to read these
discs!


We dispense with technology now to make things cheaper, faster, etc.
But, all they need to read a CD is a laser.


and a sensor, and a control program to interpret the results.

Tried reading any 5-1/4 floppy disks recently?

I noticed the laser disc put in a time capsule and dug up recently they had
trouble reading that. It was a data one not a commercial video player type.
MInd you thats a technology that didn't really take off. Considering Dvd
players will play cds. dual layers will play single and the new HD and blue
ray are backwards compatible it won't be such an issue.

"jeremy" wrote in message
news:IrmFg.36$0J6.26@trnddc02...
"ColinD" wrote in message
...
Well, the CD versus negative storage longevity arguments are now put to
rest. Kodak have announced their new Gold Preservation CDs and DVDs.

Using pure gold reflective layers, phthalocyanine dye, and triple-layer
protection, they say the useful life of a CD is 300 years, and the DVDs
80 - 100 years.



Many, if not most people, are under the misconception that CD-Rs are good
archival media. They are not.

CDs were never designed to store data for long time horizons. And
rewritable CDs are not as permanent as manufactured CDs. The National
Archives has been running experiments with glass-coated CD-Rs, and the
jury is still out on whether they represent an improvement.

We have not yet developed a reliable digital medium for long-term archival
use. So we just must do the best we can with what we have. And that
means trying to store them under optimal conditions, not just buying the
best quality CDs we can get.

We can try to create multiple copies and store them in geographically
diverse locations, but even then the element of risk remains.

The Department of Defense, along with other Government agencies, continues
to store essential data on microfilm, in addition to any digital
techniques. Properly stored, today's microfilm has a lifespan in excess of
5 centuries. No one knows how well CDs will stand up just yet.

None of my comments are meant to discourage archiving images and data;
they are simply meant to underscore that the techniques that are currently
available to us are by no means foolproof.

speed and ease of reproduction are the advantages. plus new formats are
typically backwards compatible. i had a 3..5 5.25 combo drive. My 3.5
discs of any importance are now on HD and cd. I recently converted my 25cd
back to 6 dvds. I have external and internal Hdrives too.

However scanning my slide collection on my dimage 2800dpi film scanner took
months. i had no intention of buying a new film scanner and going again at
5400. or again at 9000. If i ever look for a slide i look it up on which
cd first. The cds are organised and numbered exactly as the actual slides.
So once i've flicked through my 1000 slides and found what i wanted i look
up the directory and file name and go straight to the appropriate box. No
lightboxes, holding up to light or hours loading a projector.

If you've ever spent 3 months searching for contracts in a loft and spent a
fraction of the time going through files on a canoscan document archiver you
will really appreciate digital storage.

plus my stored scans went from cd to dvd within a week. From my small 40gb
dvd to 120gb drive in 30 mins. from 120gb to external 160gb drive was even
easier.

Try restoring old micofisch that has got wet warm and mouldy.

"ian" wrote in message
. uk...

I noticed the laser disc put in a time capsule and dug up recently they
had trouble reading that. It was a data one not a commercial video player
type. MInd you thats a technology that didn't really take off.
Considering Dvd players will play cds. dual layers will play single and
the new HD and blue ray are backwards compatible it won't be such an
issue.
I admire your optimism but let's hope you're right.

It's interesting that the original Domesday book (dating from 1085) is still
easily legible by an unassisted human but the slightly more recent one
(1980s) that was compiled on BBC computers and used laser discs takes a bit
more technology to read. Luckily both are now accessible using modern
computers - see:
http://www.nationalarchives.gov.uk/d...e/domesday.asp and
http://news.bbc.co.uk/1/hi/technology/2534391.stm.

We have not yet developed a reliable digital medium for long-term
archival

Paper tape rules! I knew I shouldn't have chucked that ASR-11. Lets
see: 11 bytes/second and 8MP * 3 colors = 4.15 years to store a picture.

I haven't seen it but high density 'bar code' on microfilm may work:
at 240 bits/mm 15 * 15 bytes/mm^2 * 24 x 36 = ~800KB/frame. 8Mpix =
10 frames.

HRMPH: might as well do a 3-color seperation on TechPan and do it in
3 frames at far better quality than 8MPix & 24 bit.

Film rules! Archive your digital pictures to B&W film! Probably
have to use TMX100 though.

Film recorders are going for peanuts. A service bureau
for archiving?


use. So we just must do the best we can with what we have. And that
means trying to store them under optimal conditions, not just buying the
best quality CDs we can get.

We can try to create multiple copies and store them in geographically
diverse locations, but even then the element of risk remains.

The Department of Defense, along with other Government agencies,
continues to store essential data on microfilm, in addition to any
digital techniques. Properly stored, today's microfilm has a lifespan in
excess of 5 centuries. No one knows how well CDs will stand up just yet.

None of my comments are meant to discourage archiving images and data;
they are simply meant to underscore that the techniques that are
currently available to us are by no means foolproof.

speed and ease of reproduction are the advantages. plus new formats are
typically backwards compatible. i had a 3..5 5.25 combo drive. My 3.5
discs of any importance are now on HD and cd. I recently converted my
25cd back to 6 dvds. I have external and internal Hdrives too.

However scanning my slide collection on my dimage 2800dpi film scanner
took months. i had no intention of buying a new film scanner and going
again at 5400. or again at 9000. If i ever look for a slide i look it up
on which cd first. The cds are organised and numbered exactly as the
actual slides. So once i've flicked through my 1000 slides and found what
i wanted i look up the directory and file name and go straight to the
appropriate box. No lightboxes, holding up to light or hours loading a
projector.

If you've ever spent 3 months searching for contracts in a loft and spent
a fraction of the time going through files on a canoscan document archiver
you will really appreciate digital storage.

plus my stored scans went from cd to dvd within a week. From my small
40gb dvd to 120gb drive in 30 mins. from 120gb to external 160gb drive
was even easier.

Try restoring old micofisch that has got wet warm and mouldy.

ian wrote:

"no_name" wrote in message
...

RichA wrote:


Antoine Dese wrote:


TheDave© wrote:



Using pure gold reflective layers, phthalocyanine dye, and
triple-layer protection, they say the useful life of a CD is 300
years, and the DVDs 80 - 100 years.

Of course, they know, because they've had some actually last that
long...

;-)

And of course, in the year 2306, there will be CD drives to read these
discs!


We dispense with technology now to make things cheaper, faster, etc.
But, all they need to read a CD is a laser.


and a sensor, and a control program to interpret the results.

Tried reading any 5-1/4 floppy disks recently?


I noticed the laser disc put in a time capsule and dug up recently they had
trouble reading that. It was a data one not a commercial video player type.
MInd you thats a technology that didn't really take off. Considering Dvd
players will play cds. dual layers will play single and the new HD and blue
ray are backwards compatible it won't be such an issue.



Maybe. OTOH, I think yer extrapolatin' from 3 years to 300 on kinda'
thin evidence.

Me, I just hope they'll still be readable 30 years from now.

At that, I just hope I'm around to worry about readin' 'em 30 years from
now!


--

These are my views. If you've got a problem with it, you can blame it on
me, but this is what I think. I am not the official spokes-person for
any Government, Commercial or Educational institution.

John

Nicholas O. Lindan wrote:

We have not yet developed a reliable digital medium for long-term
archival


Paper tape rules! I knew I shouldn't have chucked that ASR-11. Lets
see: 11 bytes/second and 8MP * 3 colors = 4.15 years to store a picture.


Hmmm ???

You could UUencode it and print out the files. A good scanner with OCR
should then be able to reconstruct UUencoded file and assuming the
program to decode a UUencoded file still existed ...

And for really long term storage, take the UUencoded printouts and have
them recorded on microfilm or microfiche. Perhaps include the source
code for the UUdecode program as well.


--

These are my views. If you've got a problem with it, you can blame it on
me, but this is what I think. I am not the official spokes-person for
any Government, Commercial or Educational institution.

John

According to no_name :
Nicholas O. Lindan wrote:

We have not yet developed a reliable digital medium for long-term
archival


Paper tape rules! I knew I shouldn't have chucked that ASR-11. Lets
see: 11 bytes/second and 8MP * 3 colors = 4.15 years to store a picture.


Hmmm ???

You could UUencode it and print out the files. A good scanner with OCR
should then be able to reconstruct UUencoded file and assuming the
program to decode a UUencoded file still existed ...

And for really long term storage, take the UUencoded printouts and have
them recorded on microfilm or microfiche. Perhaps include the source
code for the UUdecode program as well.

Not just the source code, but also a *clear* description of the
algorithm involved, because we can't bet that 'C' will still be the
language available on many systems.

For that matter -- uuencode/uudecode are dependent on the
encoding of the ASCII characterset, so the description should also
include a table translating the codes for the various characters in the
ASCII characterset.

Given the move towards an encoding scheme which will handle all
the world's characters, 10-bit bytes, or perhaps 16 or even 32 bit bytes
may become common in the future.

And -- even with the current uuencoding scheme, that one 8MB
image postulated above would take approximately 6500 pages at 80
characters per line and 60 lines per page. So -- you would want direct
COM (Computer Output on Microfiche/Microfilm) not to go through the
dead-trees format.

I forget how many pages can be on a single microfiche, but I
think that we are talking about several microfiche instead of just one
per image.

How about just saving the *image* on film? Or is that too
"retro"? :-)

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

ColinD wrote:
Well, the CD versus negative storage longevity arguments are now put to
rest. Kodak have announced their new Gold Preservation CDs and DVDs.


They weren't first. Just loudest.

Cheers,
Alan

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