matt Sohn wrote:
> >There is no answer to your question except the one that you determine. >For
> archiving, the question is: How well is the disc written.
> The Question (assuming the disc is well written) is "How long will the disc
> remain readable (or recoverable).
> >I find with current, quality media I can achieve that goal at 12x regularly
> >and 8x frequently. If I must write at lower speed, I'm essentially out of
> >luck since the last media I have which recorded well at that speed >passed
> their shelf life and were tossed due to excessive errors.
> so reasonably fast speeds are better than slower ones? This is essentially
> what I was wondering. The faster and smaller things get, the more nervous I
> am. I use a Masterlink for 24-bit preservation copies, and it gives me no
> choice for the burning speed (4X). It also gives me very reliable copies.
> >Note, too, that "certification" is of little value. Ultimately, it means
> >that the manufacturer will replace a disc which you can demonstrate >failed
> >because of write speed when you wrote within its limit. To the extent that
> >replacing the blank - your data are not covered - is meaningful, the
> >warranty is of value.
> What if the disc shatters in my burner and ruins it? Would the CD
> manufacturer be liable for damages, or would the burner manufacturer replace
> it under warranty only if I was using "certified" media for the fast speed I
> was burning at (if at all)?
> >a few recoverable errors are quite acceptable for ordinary
> >use and may even be acceptable for your archiving,
> I guess the key word is "recoverable". I can accept "recoverable" errors,
> but my question is "how long will they be recoverable?". Here I am basically
> concerned with how soon I will have to migrate the collection. This question
> applies to any medium I choose to archive in, be it CDR, DVD-R, Hard Disc or
> wax cylinder. We're all searching for the perfect long-term storage medium.
> We seem to be pretty close to the "perfect" part, but the "long-term" part
> seems questionable. I am drawn to the idea of storing data on firwire hard
> drives, but the idea of putting all that data in one spot is scary. If the
> drive goes bad, I lose 200 Gigabytes, not just 700 mB. The CDR method seems
> to be the accepted choice, as long as the format remains viable, but I was
> somewhat shocked to see how quickly vinyl disappeared from the general
> marketplace and became a "niche" market. The fact that single-well
> standalone CD players are getting difficult to find doesn't fill me with
> confidence.
> The problem we seem to be facing is that the technology we are using to
> archive our materials is becoming more and more "delicate" and complicated
> to replicate once it has become obsolete. If wax cylinders became the medium
> of choice again, it would be relatively simple to tool up a factory to
> produce players. With the miniaturization of components to the chip level,
> none of us worker bees have the ability to "get under the hood" of the tools
> they are working with. If your tool breaks, you replace it. And if the
> people that make it go out of business, you're out of luck. We are all
> banking on our technological developments as a society to continue and
> develop. With the state of the world these days, I don't take that as a sure
> bet. If our civilization crumbles, can we replicate the technology to
> recover the information we have stored?
> As archivists, we are primarily concerned with preserving audio material and
> artifacts for future generations, yes? What is the best way to do that?

No one knows precisely how long a high quality disc that is properly
handled and stored will last, but 50-100 years is not unreasonable. You
can then visit the Smithsonian Museum and use their drive to confirm

High speed drives are not better than lower speed drives. Writers tend
to record best at their top speed since vibration damping is usually
optimized for that usage. Writing at less than the top speed may give
good results or may result in a disaster.

Disc cracking and shattering at high speeds is a serious issue. Of
course the disc manufacturer will point to a bad drive, and the drive
supplier will claim that the disc is defective. In truth, the user
should be held responsible for unreasonable high speed expectations.

"Recoverable" errors normally relate to E22, E32, or burst errors. A
draft longevity standard recommends re-recording if these occur so that
a high quality disc can be obtained before the disc with errors becomes
unreadable. When that will occur is not predictable.

All archival methods have risks of degradation and obsolescence.
Archivists must confirm and monitor quality, and port the data to newer
storage technologies as appropriate. There is no "magic bullet."

For details please visit

Media Sciences, Inc.