17 Jan
1999
17 Jan
'99
1:59 p.m.
Presumably you can counter the effects of gravity by rotating the capsule
every 'n' units of time.
As for semiconductor degredation, that can be mititgated by lower
temperatures. Also when I worked at Intel we measured dopant migration
which was not measurable when power was not applied. There were concerns
that during operation the temperatures and electric fields generated would
cause things to migrate and the chip to eventually fail. Analysis of 5 year
old chips that had not been powered up showed no measurable change.
Given that I don't believe the semiconductors will have a problem. However
the EEPROMs and FLASHes can very well have a problem. The BIOS on most
mother boards is flashed in and it requires that the system boot to flash a
new bios in. Perhaps a tool to flash the bios in circuit would need to be
supplied as well.
I like the mylar paper tape idea. Although I cannot imagine how much tape I
would need to hold a 128K byte flash image. Wait a minute, let me get some
tape here .... 10 bytes/in so 13,107" or 1092' or roughly 11 100' rolls.
That is a lot of tape and that is only the BIOS!
I agree with Sam we may be relying on 22nd century technology to recover
the bits from the mag tape.
And while Tony's comments about restoring a PDP-8 or 11 are good ones, I
suspect that in the 22nd century they would be able to fabricate one fairly
easily. The goal is to create a snapshot of "current" computing as it is at
the turn of the century. And it may be an exercise in futility to expect it
to work, but my goal was to make a credible best effort to address those
things (like batteries) that would be known to make it _not_ work.
--Chuck
17 Jan
17 Jan
2:42 p.m.
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4:41 p.m.
On Mon, 18 Jan 1999, Tony Duell wrote:
Consider that the Dead Sea scrolls lasted 2000+ years. They were stored
inside clay containers in a cave in a dry climate. By actually trying to
we could probably create a self-contained perpetual preservation
chamber that could probably achieve at least that.
So why bother with punched tape? Can't one get a much higher density with
optical-mark encoded paper documents?
Sure the reader will have to be more complex but unless we manage to
annihilate ourselves in the next 100 years we should have the technology
to put together an optical mark reader.
Paper will last longer than anything we've been discussing so far (save
for Mylar) but is much, much easier, and cheaper, to implement.
Sellam Alternate e-mail: dastar(a)siconic.com
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I like the
mylar paper tape idea. Although I cannot imagine how much tape I
would need to hold a 128K byte flash image. Wait a minute, let me get some
tape here .... 10 bytes/in so 13,107" or 1092' or roughly 11 100' rolls.
That is a lot of tape and that is only the BIOS!
The big reels of paper tape are 1000 feet, I think. One reel is about
100K of data. I've punched 80K files onto a single reel of tape, for example. 
4:49 p.m.
On Sun, 17 Jan 1999, Sam Ismail wrote:
Paper will last longer than anything we've been
discussing so far (save
Where did you get that idea? Paper will disolve in just about any
solvent, including water, and is subject to tearing. Again, if we're
talking about preservation in controlled environments, a CD-ROM kicks
paper's butt.
What makes some of today's technology fragile is simply the density, or
equivalenty, the lack of redundancy in a given area. A plain old EPROM
should be fine for 100 years if you include 100 copies of the information
within it.
-- Doug
4:52 p.m.
It bears mentioning that the dead sea scrolls were written on sheep hide.
On Sun, 17 Jan 1999, Sam Ismail wrote:
--
Jim Strickland
jim(a)DIESPAMMERSCUMcalico.litterbox.com
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Paper will last longer than anything we've
been discussing so far (save
Where did you get that idea? Paper will disolve in just about any
solvent, including water, and is subject to tearing. Again, if we're
talking about preservation in controlled environments, a CD-ROM kicks
paper's butt.
What makes some of today's technology fragile is simply the density, or
equivalenty, the lack of redundancy in a given area. A plain old EPROM
should be fine for 100 years if you include 100 copies of the information
within it.
-- Doug
5:33 p.m.
On Sun, 17 Jan 1999, Jim Strickland wrote:
It bears mentioning that the dead sea scrolls were
written on sheep hide.
Doh!
Sellam Alternate e-mail: dastar(a)siconic.com
------------------------------------------------------------------------------
Always being hassled by the man.
Coming in 1999: Vintage Computer Festival 3.0
See http://www.vintage.org/vcf for details!
[Last web site update: 01/15/99]
4:57 p.m.
On Sun, 17 Jan 1999, Doug wrote:
What are you talking about? The whole aversion to using CD's was the fact
that they have a theoretical shelf life of only 50-100 years. Like I
said, the Dead Sea scrolls lasted more than two millenia without much
thought going into how to preserve them. And here you are talking about
going thru the trouble of filling a chamber with inert gasses to promote
preservation. Unless your line of thinking is to fill the chamber with
water just to give paper a challenge.
Paper has passed the test of time. You can go into antique book shops and
find volumes hundreds of years old that are still very readable and very
intact.
CDs, on the other hand, have only been with us a couple decades.
Paper will
last longer than anything we've been discussing so far (save
Where did you get that idea? Paper will disolve in just about any
solvent, including water, and is subject to tearing. Again, if we're
talking about preservation in controlled environments, a CD-ROM kicks
paper's butt. What makes some of today's technology fragile is
simply the density, or
equivalenty, the lack of redundancy in a given area. A plain old EPROM
should be fine for 100 years if you include 100 copies of the information
within it.
100 copies on what? 100 other EPROMs? On CD? Or encoded on paper?
Sellam Alternate e-mail: dastar(a)siconic.com
------------------------------------------------------------------------------
Always being hassled by the man.
Coming in 1999: Vintage Computer Festival 3.0
See http://www.vintage.org/vcf for details!
[Last web site update: 01/15/99]
5:04 p.m.
On Sun, 17 Jan 1999, Sam Ismail wrote:
What are you talking about? The whole aversion to
using CD's was the fact
that they have a theoretical shelf life of only 50-100 years. Like I
said, the Dead Sea scrolls lasted more than two millenia without much
thought going into how to preserve them. And here you are talking about
going thru the trouble of filling a chamber with inert gasses to promote
preservation. Unless your line of thinking is to fill the chamber with
water just to give paper a challenge.
I really think you're mixing two concepts here. Do you think a "shelf
life of 50 years" means that the thing disintegrates completely in 50
years, or do you think it means that under "normal" conditions you can
expect some data loss in 50 years?
100 copies on what? 100 other EPROMs? On CD? Or
encoded on paper?
In the same device! Don't pack the data so densly that a one-bit error
makes the whole thing worthless. Expect that one bit in N will have an
error over time, and increase the redundant info by at least a factor of
N.
-- Doug
5:10 p.m.
A plain old EPROM
should be fine for 100 years if you include 100 copies of the information
within it.
I find this proposition very doubtful at best, although I don't have any
solid figures for EPROM data retention. You seem to be suggesting a
linear relationship between elapsed time and the number of bits that remain
good. The actual curve is an inverse exponential (if memory serves).
5:19 p.m.
On 18 Jan 1999, Eric Smith wrote:
I find this proposition very doubtful at best,
although I don't have any
solid figures for EPROM data retention. You seem to be suggesting a
linear relationship between elapsed time and the number of bits that remain
good. The actual curve is an inverse exponential (if memory serves).
Wow! That would imply some sort of self-catalyzed reaction, and I'd be
very interested in hearing how that works!
-- Doug
6:01 p.m.
Wow! That would imply some sort of self-catalyzed
reaction, and I'd be
very interested in hearing how that works!
It works because an EPROM is a bunch of tiny little capacitors (storing
electrons on the floating gates), and the charge gradually leaks off of them.
Just like bits in a DRAM, but much more slowly.
6:08 p.m.
On 18 Jan 1999, Eric Smith wrote:
It works because an EPROM is a bunch of tiny little
capacitors (storing
electrons on the floating gates), and the charge gradually leaks off of them.
Just like bits in a DRAM, but much more slowly.
I can believe that, but that means the graph is sigmoidal rather than
exponential. What about a mask-programmed PROM, then?
-- Doug
18 Jan
18 Jan
10:50 a.m.
Doug wrote:
On Sun, 17 Jan 1999, Sam Ismail wrote:
CD-ROM _may_ last longer than paper, but CD-ROM isn't human-readable.
There were comments that the Dead Sea scrools were on parchment rather
than paper. True. There are Egyptian papyri that are older than the
Dead Sea scrolls (some retaining quite a bit of color).
And yes, there's the chiselled stone media. If somebody can get me a
good source for affordable media, I'll start work on a printer (I
think the headstone folks have some items that could be built into a
prototype).
--
Ward Griffiths <mailto:gram@cnct.com> <http://www.cnct.com/home/gram/>
WARNING: The Attorney General has determined that Alcohol, Tobacco,
and Firearms can be hazardous to your health -- and get away with it.
Paper will last longer than anything we've
been discussing so far (save
Where did you get that idea? Paper will disolve in just about any
solvent, including water, and is subject to tearing. Again, if we're
talking about preservation in controlled environments, a CD-ROM kicks
paper's butt.
What makes some of today's technology fragile is simply the density, or
equivalenty, the lack of redundancy in a given area. A plain old EPROM
should be fine for 100 years if you include 100 copies of the information
within it. 
20 Jan
20 Jan
3:31 a.m.
> What makes some of today's technology fragile
is simply the density, or
> equivalenty, the lack of redundancy in a given area.
Take a look at the specification for how CDs are formatted. You may be
suprised to find out that a good chunck (more than just a few percent) is
dedicated to error correction! That is why you do not hear all of the
scratches in poorly handled CDs.
William Donzelli
william(a)ans.net
9321
days inactive
9324
days old
13 comments
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