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Digital Storage To Survive a 25-Year Dirt Nap?
AlHunt writes "I've been tasked with finding a way to bury digitally stored photographs in a small underground time capsule to be opened in 25 years. It looks like we'll be using a steel vessel, welded closed. I've thought of CDs, DVDs, a hard drive, or a thumb drive — but they all have drawbacks, not the least of which is outdated technology 25 years from now. Maybe I'll put a CD and a CD-ROM drive in the capsule and hope that the IDE interface is still around in 25 years? Ideas and feedback will be appreciated."
AC power should still be around.
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You can't guarantee that the data will be intact when they open the capsule. Nor can you guarantee that the gear you send will survive.
Seems to me that your best bet is three separate distribution mechanism.
1. CDs AND DVDs (two copies of everything), a small portable DVD player with multiple interfaces - component/composite/s-video out
2. NAS device with at least two disks (two copies of everything) and multiple interfaces - eSATA/SCSI/USB2/FireWire/ethernet(dhcp)/etc.
3. Digital picture frame and a handful of memory modules (two copies of everything)
Ensure that whatever device you send goes complete with power adapter and user manual. In at least two languages.
All there is to do when you're done, is cross your fingers and hope that video displays still operate in two dimensions :)
Of all the interfaces that will still be around 25 years from now USB has the best chance. I am not so sure about wether or not the flash memory will hold up. But with the BILLIONS of usb devices out there nowadays I find it hard to believe the format will be gone 25 years from now.
If you use paper, SD card, USB memory stick, hard drive, or whatnot it would have to survive being welded into the box, as well as opening the box.
If I have nothing to hide, don't search me
It would be entirely possible to make a paper copy of binary data that could easily be read in with the correct software. Of course, the paper you would want to use would be acid-free.
One could simply encode the binary as forward slashes and backward slashes. Or as x's and o's.
But those would be really wasteful.
I've often thought that what would make a really good software contest would be to develop a format to back data up to a paper copy on a laser printer using the best compression possible but with enough error correction and detection to be able to read just about any paper put in that comes out in reasonable shape.
For example, one might use individual pixels on the paper. Or you might want to group several together and treat as a bit. Or use an innovative coding scheme that doesn't just map individual bits to spots on the paper.
I think that a scheme that spreads the information out over the entire paper might be interesting. In other words, the individual bits of a byte and any bits dealing with the error detection and correction would be located remotely from each other.
In such a contest, testing would be easy. Write images of several datasets to paper and then scan the images in after different stages of intentional damage to the paper. For example, you might read two data files back from the pristine paper without doing anything. Another two data sets might come from paper that has been crumpled up into a ball and then flattened. Two more might be from paper that has been moistened. Two more from paper with a tear across the middle. And, finally, make copies of two data sets on an everyday copier and then scan them in and decode.
Rank the results by the numbers of errors, possibly with factors to take in levels of difficulty based on the amount of damage to the paper, and select a winner.
...for the vessel.
And yes, photographic paper and black-and-white images would last the longest.
Many consumer grade photo printers actually produce pictures with significantly shorter lifespans than their digitally stored copies. There was a great comparison a few months back of 6 different printers/papers/inks that varied greatly in their performance at only 6 months.
Now, if you really want to get long term with it, write the binary value of the image out on paper, or even punched in steal. 10101010101 etc... sure, it'll take a whole lot of time, money, and metal, but you could be sure that all that data is going to be around for a lot longer than 20 years ;)
Although, if you're going that route, Microfiche would probably work just as well, along with being cheaper and a lot more compact. It would still leave the person who recovers it the tedious task of recreating the file digitally, but it would last, and you know some undergrad would write get a grant to figure it out and write a thesis on it.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
Bit of a weird one I know, but if you want guaranteed data retrieval (barring internet annihilation), why not make a deal with a hosting company to keep a website of yours live for 25 years, and write the URL of it in stone with a date, to be placed underground and dug up in the future?
2 EeePCs loaded with images in at least JPEG, PNG and TIFF formats, OS of choice and a couple of graphic programs that can convert your images into various formats.
Separate backups on SD cards.
A set of USB to cables.
Also... if it is going to sit in the ground for 25 years, I'd remove the batteries and pack them separately.
Don't forget to pack the chargers.
Mit der Dummheit kämpfen Götter selbst vergebens
http://science.slashdot.org/article.pl?sid=08/08/25/0312229
Take black and white photographs of them and print on acid free fiber based paper. Then it will last for 100+ years.
what format was around 25 years ago, that is still available today?
now- what was around 50 years ago- that is still available today?
now-- for the hell of it, what's been around since 1844--- and still available today?
every day http://en.wikipedia.org/wiki/Special:Random
just stick it on a stack of cd's. And evacuate the vessel. Welding it shut might *not* be such a good idea because you will not be able to check if the heat affected your datastore after the welding.
The reason for a stack of cd's is that in a vacuum they should last a long long time and a whole bunch of them will allow you to do error recovery.
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Electrolytic capacitors are used in the power supply filtering of essentially all circuitry currently in use. These components will be present in a number of places on the circuit boards of both disk drives and memory sticks.
The insulating layer between the plates in electrolytic capacitors is formed by electricity-driven chemical action. It gradually degrades over a period of several years. If the capacitor is operated occasionally the operating voltage across it will rebuild the insulating layer. But if it's left unused for too long the layer will degrade to the point that, when power is finally applied, the capacitor will short and (because most of them are hooked across a power supply) fail catastrophically. Like by blowing open and jetting chemical fumes, while shorting out the supply and damaging other components in the current path.
Mechanical moving parts may lose lubrication and spot-weld with time. This also makes storing entire drives problematic.
Recordible CDs usually record on a die layer that will degrade with time.
Some types of flash memory store data as stored charges, which will leak away with time.
So IMHO degradation of the medium itself is likely to be a killer problem. Much more than readability with future devices. (After only 25 years there should still be some working players available for currently widely-deployed standards, even if no new ones are being manufactured. Once you've go the bits read you can transfer them to new media.)
Things I'd consider:
- Integrated circuit memory devices using a technology like fusible link or a crystalline/amorphous transition. (Replace any electrolytic capacitors with ceramic types - which will greatly increase the size of the assembly.)
- CD masters involving actual removal of material - a material inert enough that it will not corrode away with time.
- If you want to store drives for removable media (and convert the caps), check with the manufacturers about what the bearings are like and talk with a mechanical engineer with applicable experience (like mil-spec or space-rated). I'd avoid sealed hard drives, especially those that don't lift the heads off the platters when parked.
Also: Use a coding scheme that has industrial-grade error correction. B-)
One downside to your task is that, with only a 25-year storage time, you'll probably still be alive to be blamed for failures when they open it. B-)
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Really, 25 years isn't all *that* long. 9 pin serial has been around longer than that, and USB and SD are much more broadly adopted than it ever was.
The ASUS EEE PC would probably fit the bill with a SD card as the storage media as well as a copy of the date on the EEE PC internal drive.
I would store it without the battery though as that will likely explode in that time frame.
Toss in A DVD drive and DVD copy for good measure.
DVDs and SD are both fairly popular formats and have already gone through iterations that have maintained backward compatibility.
EA David Gardner -"... but the consumers have proven that actually what they want is fun."
Printing would be a space issue as well as the varying qualities of print sources, commercial or otherwise. It seems odd that nobody mentioned microfilm though, the libraries and newspapers have been using it for far more than 25 years and would surely be able to retrieve from it in the future. In fact retrieval will probably be even easier with advances in scanning technology. It saves space and could easily be saved in a smaller and more optimum storage container within the capsule to prevent decay.
What about backing up on paper? With a good printer you can store up to 3 megabytes per page
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Considering filling the container with an inert gas like nitrogen in order to reduce any wear and tear caused by corrosion. Just make sure that whatever inert gas you pick, unless it is helium or neon, is really inert with respect to the contents of your time capsule.
Would storing the laptop in some type of inert gas (nitrogen) help? Hell, should the whole capsule be pumped full of nitrogen to reduce corrosion effects?
"I could read a 5 1/4 floppy disk today,"
Maybe. 1 out of 5-10 probably after 25 years.
Now try that with a 25 year-old 3-1/2" floppy. Not sure i would bet on 1 out of 10. The newer the format the shorter the lifespan it seems as densities increase :(
I had a failure rate of about 5% on 5-1/4" but at least twice that on 3-1/2" disks trying to transfer my old DOS stuff :(
Like someone else said, maybe several formats and/or many copies. 1 of 10 DVDs might survive.
Almost, think lithography onto a stable substrate
http://www.rosettaproject.org/about-us/disk/concept
Needs a microscope to read
everything needs to be sealed well, however. double or triple on some water-tight somethingsomething to be safe,
Or maybe submerging it into mineral oil. Does anyone know if electronics can withstand 25 years submerged into oil ?
Everything will also need to be redundant :
- burned DVD-R/CD-R media may rot. Harddrive may refuse to spin because of chemical aging of the mechanical part, flash memory could fail, etc...
- as much spares as possible. 25 years from now, spare parts will probably be hard to find.
- a couple of SATA and USB drives/readers. Whatever the are the connection 25 years in the future, USB is currently so popular that in the future, we're bound to see adapters, just the we we currently see Serial-2-USB adapter even if serial connector have been phased out for quite some time.
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Come to think of it, printouts of data compressed and printed out as 2D barcode may be the most durable technology.
- extensive experience shows that, under proper conditions, paper can be made survive for even longer than 25 years.
- reading and decoding a 2D barcode doesn't require any technology specific to the current generation of hardware.
- as long as the data is stored in a redundant manner and that it use open and well documented standard with source code available. It would still be accessible by computer 25 years later, even if it requires some programming and/or re-implementation of a long lost standard.
(as a bonus, include documentation of formats printed in clear on paper too)
- choose simpler standards. chance are none of the current open source library processing it will be available in 25 years. the kids will probably have to re-code a reader / decompressor using whatever will be the popular high-level language du jour ( Ruberlython#++ or something similar ). may make a fun science project for them.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
USB 3.0 was just finalized, backwards pin compatible. We'll be seeing the USB interface for quite awhile.
Good-bye
The old black and white Silver halide prints last for a very long time. I've got a 11X14 family print of my GG-grandmother and her children that is exquisite in it's clarity and quality. It was taken in 1893. Color prints from the 1950s haven't fared nearly so well. The dyes fade.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
> and I know for a fact that CDRs deteriorate after about 10 years.
Some archival media is rated for 100 years. But forget that, just make a gold master and send it out to be commercially duplicated. It isn't THAT exensive, so have a small run of 100 copies made. Sell 90 of them in a fundraiser to recoup the expense of duplication and stick the other ten into a small stainless steel airtight container with an inert gas. Wrap that in some quality insulation to protect it againt the heat when the main capsule gets welded shut. I have heard lots of 25 year old audio compact discs and they sound just fine. But if there is enough bit rot to make recovering data dodgy, well you have nine more still shrinkwrapped copies to try reading any bad blocks from.
The only remaining question is whether equipment to read a Compact Disc will still be available in twenty five years. And the answer is almost certainly. It probably won't be nearly as popular as it is today but the LP is ten years in the grave and you can still buy a new turntable at Sears.
A pressed DVD might be even better because the recorded media is safely between two layers of substrate instead of only protected by the screenprinted label on the top. On the other hand we have enough history with the CD to know beyond any doubt that they survive in readable condition for the required time, even under typical consumer storage conditions.
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Nither.
Audio tape and a player coupled with instructions on how to read it.
If you encode the file as a very basic encoding and then put it simple on an audio form computers 300 years from now will be able to read and then decode the images easily.
Building a SATA interface in 25 years will be harder than 1 hour of coding based on clear instructions in the box and reading in an audio signal.
Do not look at laser with remaining good eye.
25 years isn't such a problem but say you wanted to store the box for 250 years, then you really might have some issues...
The thing that scares me about digital storage these days is that redundancy is much lower as we cram more and more into tinier and tinier spaces. We offset the increased probability of errors with coding but IMHO that is a non-trivial operation from an archaeological perspective.
If you have only a small amount of data to store, is it possible to somehow print it in small, but recoverable dot patterns on long-life paper with long-life inks? I can't see scanner/camera technology disappearing anytime soon...
I recently read some tapes of software I wrote for my TRS-80 Pocket PC. I made those tapes back in 1983 and stored them carelessly in a box in the basement.
They all read perfectly fine. I'd trust magnetic tape going 50 years easy if stored right and put on high quality tape. Mine were crap quality tape.
Do not look at laser with remaining good eye.
Seems like a lot of trouble for just 25 years. It isn't that long. I've still got access to my 25 year old data. In fact, my 22 year old Kaypro 1 still works (and I have an emulator). I have an old Sony Vaio laptop that originally came with Windows 95. I've replaced a lot of parts on it, including the CMOS battery - but that has lasted over half the time period. I think our tech is pretty tough - at least for a modest timeframe like 25 years.
These systems, however, have not been sealed in a box - to a greater or lesser extent they are actively maintained.
What about this as a method - it's a bit "outside the box" (ha ha): Encrypt the digital data, store it redundantly on many systems across the internet or wherever you want - make it your email sig! Put a hard-copy of the key and passphrase in the time capsule.
Data is perfectly preserved! I don't know if our current cryptography is capable of keeping it secure for 25 years - but you never know.
Yes, yes it would. You see photographers actually care about their prints lasting (or at least they have since Wilhelm started doing permanence testing on color materials and discovered they all sucked at the time). A pigment inkjet print on acid-free paper or a good B&W silver halide print will probably outlast most digital media you can easily come up with. And the print is it's own reader. That said in 2012 we will still be able to find hardware to read 3.5in floppies from 1987 so it's perfectly reasonable to believe there will still be drives that can read archival gold CD-R and DVD+-R's in 25 years.
If he vacuum sealed it with packages of dessicant where the battery would be (removed because it would never last 25 years), I imagine it might do fairly well. Just make sure it's damn well sealed, or you might wind up with something along the lines of this.
The solutions to those are easy.
1. Remove the CMOS battery before storage.
2. Replace capacitors when digging it out again.
I have 25 year old computers with perfectly good electrolytic capacitors (well, perhaps not perfectly good, but good enough). But I suspect the majority of the caps in a laptop are multilayer ceramic or tantalum.
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I'd just swaddle the contents in a welding blanket, and design the vessel so the "welding shut" took place at a flange edge.
Better yet, just gasket the thing with a good automotive sealer and bolt together using anti-seize on the bolts. That way whoever digs it up doesn't have to cut it open and spew grinder sparks everywhere.
Hint: Build it like a hunk of pipeline. Flanges, bolts, all that stuff are common as dirt (and often buried therein for decades after assembly).
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
I thought of the capacitor/battery issue as well when laptops were mentioned but who says that you have to power it up with the original components in place. Just put a circuit board enclosed in as hermetically sealed ESD bag in the capsule with a BOM, schematics, and parts locater and let them build the computer when they open it up. If you are feeling really generous give them assembly instructions as well. I might even include a little leaded solder for posterities sake.
There are classic guitar amps that were built in the 50s that are still in use today. The tubes, caps, pots, and other components have been replaced over time but the same basic wiring is there.
There will be components that can stand-in for the ones that are obsolete. We are only talking digital here, 5V is 5V you don't "color" a digital signal by changing the material that a component is made from. Now if the data was stored on a metal stamped DVD or CD and sealed up it would probably stand a decent chance. It might be a little labor intensive but so is digging up and opening a big steel capsule that has been welded shut 25 years earlier and they will also get to build an "old-school" computer in the process.
Over 25 years connectors have changed a hell of a lot: The most popular keyboard connector in 1983 was DIN, then PS/2 in the late 80s and early 90s, then USB in the late 90s and early 2000s. It was possible, with an adapter, to use a 1983 keyboard on a PC up until most PCs eschewed with the PS/2 keyboard adapter a few PC generations back.
USB may well survive, but I'm doubtful; even RS-232 didn't last that long.
SATA almost certainly will not survive beyond a decade or so. Disk drive interfaces have tended to last only about 5 years, with another 5 or so of backward compatibility. Someone will start shouting "IDE IDE" I'm sure, or maybe "SCSI" from some old hats. But the IDE drive connector standard is just 14 years old and the last round of computers I bought a bit more than a year ago had no IDE connectors at all. Trying to connect an IBM AT drive to a modern PC will be an experience ... I was unable to connect drives from the early to mid 90s within 10 years.
I will be surprised if peripherals even use electrical interconnects 25 years from now. Think optical, baby.
I don't have any good ideas related to long-term digital storage. I have experience with this going back more than 20 years now and the experience is mostly bad. I do have 25 year old floppies that still work, but they need 15+ year old PCs to read them.
The good news, I suppose, is that those old PCs do still work. (I have a Kaypro II that I boot up occasionally.) If I really wanted to do this I would put a whole laptop full of data with a non-flash drive system in a baggie, fill the baggie with an inert gas, seal it up real good, then seal that in the box. If it all works 25 years from now you're good to go; if it doesn't maybe you can still talk to the drive. Maybe.
jim frost
jimf@frostbytes.com