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Memory Card Torture Tests
saikatguha266 writes "BBC is reporting that five types of memory cards were dipped into cola, put through a washing machine, dunked in coffee, trampled by a skateboard, run over by a child's toy car, given to a six-year-old boy to destroy, smashed by a sledgehammer and nailed to a tree. It was still possible to retrieve photos from the xD and Smartmedia cards while the others didn't survive just the last two tests. "
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Although this only really applies to the nailed-to-a-tree test, where the nail goes through will matter. In DIL ICs, most of the area is taken up by connections to the pins. If these cards have the core close to the edge with the connectors, and a nail is put through the center, it could miss the core entirely. And if the nail went through the bridges, a data recovery person could wire a reader the the connectors inside the package.
perl -e 'print $i=pack(c5, (41*2), sqrt(7056), (unpack(c,H)-2), oct(115), 10);'
Most ICs are surprisingly resilient. I remember hearing about somebody testing an atari cartridge to see what it would take to break one. He was trying to see if the arguement for the legality of ROM dumping as a way to backup your games in case they become corrupt really had any merit. IIRC he through it a couple stories onto the sidewalk, rolled over one with his car, hit it with a sledgehammer, dumped soda in it, etc. The case cracked earlier on, but I think the cartridge didn't actually stop working until the actually IC broke after a couple hits with the sledgehammer, although it did continue to work after the circuit board was broken.
The Tunsten has something of a reptutation for destroying memory cards. Check out this list of problems encountered using different cards in different machines.
Note that in the Tungsten T3 only 1 out of 7 tested cards actually survived the ordeal! Of course, this particular test isn't scientific, but it is based on real user feedback really using them for real things, so it's probably worth a read.
And just too late, I found a more specific article:
0 86
http://www.palminfocenter.com/view_story.asp?ID=6
no idea, perhaps the floating gate of the flash cell is affected (shifting bandgap,ect), and a read will accidently write ?
ok, you would need a few tesla, but the point is that if you have moving electrons, you cant just say magnetic field cant do anything...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
And I do mean bad, not just corrupted. I've seen more bad CF than anything else. Part of this is because CF is so popular. But another part is because CF lends itself well physically and as a market thing to making crap cards from crap parts.
There is a big market for low priced CF and a market for good quality CF. Compare this to a less thriving market like MemoryStick. All MemorySticks are essentially the same. The Sony and the Lexar ones are made in the same factory. And since MemoryStick is so small, you can't go buying up lousy old surplus flash chips and try to make a card from them.
I'm not trying to complain about CF either, if you buy decent CF it works great. On the other hand, I can't stand SmartMedia. It is and always was a poor standard. xD replaces it and is a better standard, I just don't think we need another memory format.
It may have been the USB controller that was damaged. The way that these drives were designed was that the connector was attached directly to the circuit board, without anything else holding it in place. Or, perhaps it may have been the flash memory that was faulty, like in your circumstance.
Just use such a card as Knoppix home directory, work on it intensively for a month or two. You'll exceed write cycle limit of the flash memory and it will die without a squeak. That's how I busted my Nokia 5510 flash memory. First sectors are corrupted and unwritable.
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
When you move though a magnetic field, that induces a voltage which could mess up the memory card. That is, don't bring your camera to a MRI machine (Nuclear Magnetic Resonance describes it better but people freaked out about the word "Nuclear"!)
It is not the magnetic field that does the damage. It is always the rate of change of the magnetic field that is the problem (its gradient). This is how power plants make the electrons flow from the wall socket :)
X-ray scanners are quite weak and will do nothing. You get more problems with the background radiation which can be more ionizing to RAM. Things like muons (heavy electrons) can flip a gate or two if lucky. X-ray will do nothing. At least at the levels that people survive.
As to magnetic fields, well, check out the MRI machines. Those have a huge magnetic field and there is the ramp (magnetic field getting changed type of ramp) in the scan area of a quite large amount.
My dad dropped his camera in the lake while fishing. The camera was fubar, the XD memory cards still worked and I retreived the photos off them. I use them even today in my own digital camera, he hasn't got one now!
Jonathanjk.com
So... as you can see, with a strong enough electric field, you may surely be able to move the charge across the barriers (e.g. break-through of the insulation or maybe tunneling of the electrons when you skew the potentials alot).
Now the magnetic thing:
Because the electrons in the floating gate move (they must do that in every case because of quantum uncertainty, but the greater effect here is the temperature movement!), they have a speed and as you may know, moving electric charges in magnetic fields feel the lorentz force... BUT this force does not change the energy of the particles, i.e. they do not get faster when one applies a magnetic field. So, yes, maybe there're weird changes in the bandgap. I don't know. Try it out, would be a nice experiment.
Post a link to a graph here that shows the total number bit errors over magnetic field strength
Static RAM mainly consists of two MOS inverter structures wired together on the chip to form a flip-flop. Static RAM needs a small bit of current (because of inevitable leakage currents) to keep it's state.
At least, that's how I read it some time ago for a seminar in the semiconductor book from the creator of these devices (S.M. Sze).
I had a compact flash survive the washing machine and drier (permanent press cycle)! The Yellowstone photos came out okay in the end, and that flash card still works. The labels got a little rubbed off though.
These are the cards that you use in your camera, non-volatile flash memory cards, not RAM. Your standard RAM card would certainly not survive jack. But then, RAM is normally confined to the inside of your case, which is generally too large to stick in coffee.