Wow! Thank you all so much for your input. I figured that many of you would have seen this in 80's and early 90's music CD's but I'm actually relieved to hear at least a few here have had it happen with CD-based games as well. I've seem close-ups of discs with that pinhole effect and many customers have told me about their CD's suddenly stop working but I have never had a disc "go bad" like this for me.
As for EPROMs, I do consider that a form of bit rot but as stated above, it's true that EPROM manufacturers never guaranteed they'd last longer than 10 years and yes, simply re-writing over them will refresh the data within.
And I'd completely forgotten about laserdiscs. Not sure if I'll be able to squeeze that into a 20-second bit rot blurb but thanks for the reminder!
Well, it was way, way, way more evident in LaserDiscs because they didn't make many compared to CDs, so when they manufactured them badly, it affected a lot of discs.
Bought a sealed copy of Windows 98 Second Edition last year and the disc has a dark spot on the data side, it installs and works correctly so I imagine it must be language packs and other useless optional crap on the far edge of the disc.
I've had a few discs like that, it seems the top coat seal isn't that good and the reflective layer is oxidising. If it gets bad enough it won't be readable. I've seen this happen on water damaged discs too.
Now I have to check the laserdiscs I have, I don't have a player but I've picked up a few discs somewhat recently. I'm hoping they're all right.
From what I understand the problem with the early laserdiscs was that the glue used (laserdiscs are actually two discs that are glued together) ate into the discs. Which is why virtually all of the discovision (which were the first ones made) suffer from various degrees of laser rot.
When I come home from a long day in Hell, there's nothing I'd rather reach for than a fire-brewed bottle of Styx Beer. Made from the filthiest waters from our own River Styx. Styx Beer is a third more toxic than any other regular beer. The worst beer - the filthiest beer - the deadliest beer. It's Styx Beer!
I have some VCS games that are Brazilian pirate carts. I carefully peeled back the labels on a couple so I could open the casings in order to better clean the contacts (getting some very odd artifacts in some games). Turned out, the carts used EEPROMS. They were suffering from bitrot for sure. I guess the Brazilian humidity did a number on the EEPROMs.
-Rob
The moral is, don't **** with Uncle Tim when he's been drinking!
I'm not sure how much of an affect humidity would have, but heat is sure to speed up the data loss. What happens in EEROMs is that bits are held high by an electric field(or low by the lack of one). That field slowly dissipates over time as electrons escape...which is sped up the hotter it is. This is why they were only guaranteed to last 10 years or so.
I would certainly hope that all proto-collectors are aware of this, though I'm pretty sure that most at least make personal ROM dumps right?
"Game programmers are generally lazy individuals. That's right. It's true. Don't let anyone tell you otherwise. Since the dawn of computer games, game programmers have looked for shortcuts to coolness." Kurt Arnlund - Game programmer for Activision, Accolade...
The original LaserDiscs, those manufacturerd by DiscoVision a subsidiary of MCA) suffered from Laser Rot because laserdiscs consisted of two platters that were glued together back-to-back. The glue used in the original LaserDiscs seeped through the alumnium causing the rot. I have an original Laser Disc that I bought in 1979 and it is now unwatchable.
Leonard Herman
The Game Scholar
Publisher of Historical Videogame Books
http://www.rolentapress.com
Phoenix 4 coming in 2014
Well, the contacts looked like total shit on these carts. I had to scrape oxidation off some of them (tin colored, not gold, heh). Once a light sanding was done and contacts checked with a multimeter, I was sure the contacts were in good shape. The two or three carts I saw this artifacting on all had EEPROMs, all came from Brazil, all had oxidized contacts. Coincidence? Well, possibly, I guess, but they seemed to have something to do with each other.
I would like to hear someone's opinion on how humidity could affect an EEPROM, because jb143 is right, it is unlikely when thinking intuitively, but as I've stated, I've been witness to such phenomena, um, maybe, heh.
-Rob
The moral is, don't **** with Uncle Tim when he's been drinking!
I have one copy of Mega Man 2 that works worse than another. The "bad" copy is the one I grew up with, and it's more likely to garble the graphics while playing. I've always wondered if it's a result of the ROM chips degrading or the connectors, but the connectors are pretty clean. At any rate, it's always funny to see the CHRROM calls get offset and all the text get cyphered. Then, the intro text often contains strong profanity. Considering how hard it was to get games to boot properly back then, I'm surprised there was never a controversy over kids seeing profanity in damaged games.
Theoretically, could data held on ROM chips be damaged by electrical spikes or overvoltage?
Not just theoretically. Most chips are designed to work right at 5V and anything over that can damage them. It's even possible to damage a ROM with the static built up from walking across a carpet. I'm not quite sure how likely it is to happen but it is possible.
Practically though, IC's tend to be a bit tougher than over-voltage and antistatic warnings would have you believe. It's more a case of better safe than sorry.
Well, the EEPROM itself is sealed...at least it certainly should be, so humidity alone shouldn't effect the contents of the data directly. It could however completely screw up the outside of the chip through corrosion and the like. Erasing an EEPROM typically takes a high voltage so that's not likely to occur from accidentally shorting or breaking something either, through moisture or corrosion for example. Though possibly from voltage spikes and static but that's more likely to "fry" it then erase it.
Last edited by jb143; 04-04-2012 at 11:51 AM.
"Game programmers are generally lazy individuals. That's right. It's true. Don't let anyone tell you otherwise. Since the dawn of computer games, game programmers have looked for shortcuts to coolness." Kurt Arnlund - Game programmer for Activision, Accolade...
You just reminded me, back when I was trying to get my age old NES to work again after about 12 years of inoperation, my copy of Super Mario Bros./Duck Hunt DID actually display a certain four letter word. Given the title of the latter game in the compilation, you can figure out what word.
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