Walt, you wrote,
>Before we toss optical media, I should note that the media discussed so
>far is not the real archival optical media. That I consider to be the
>true optical disks. The most durable and reliable format available. The
>one that things like banks and so on depend on for their ultimate
>backup. Though they too are being sucked into keeping arrays of hard
>disks spinning.
>
>That is the media I use for my main archive. 3.5" optical disks. I've
>been using them for more than 10 years now. I've yet to have a failure
>of media or drive. I do expect that at some point I will have a problem
>if the current trend to believe that archival optical media means CD-R's
>continue. The real optical format is not mainstream with consumer
>computing in the US. Though much more common in other parts of the world.
So far as I can tell, what you call "real optical" is MO;
magneto-optical. We've been through this before. Because of the
educational function of this list, I implore you to use accurate
technology.
>I do maintain a copy of my stuff on audio CD as well. Seven years and
>counting, and none of those have failed. Audio CD is not a computer tied
>format, so has a greater chance of surviving longer as a format. I am
>very careful how I burn them.
My CDRs in audio and CD-ROM formats are the same age and still good.
I second the motion about being careful; the big problem now is
finding stock optimized for robust quality rather than speed. I just
found 200 older CDRs in Canada, from a dealer who sold them off cheap
because they were old! That'll cover my mastering for a couple of
years.
>And, of course since I record on MD, which is about as good as real
>opticals, I file away the originals of those too.
MD is also a magneto-optical disc. I think one long-term stability
factor might be how small the recorded track is. I note that data MD
discs hold 140MB. I assume audio MDs use the same track pitch. Given
5X audio data compression, that would give the equivalent audio time
of 700MB, which is CD-size. An MD is about a 2.5" MO disc.
I note in dealer listings that 3.5" MOs can be bought with capacities
from 128MB up to 1G. What capacity do you use? Do you think the
smaller capacities have wider (more reliable) tracks? Are the drives
made in different capacities, or is it just the disc?
>...The future will remember this time period as a blank. Little will
>survive out of it in the way of graphics, sound, text etc. Because so
>little thought is given to preserving it for the future. We have the
>actual photographic negatives and prints from the civil war. How much of
>the computer/digital camera photographs will survive that long?
A word to the wise...
-Dan Dugan
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