Bit Rot

[digitalpress]

I have a presentation next week and one of my slides will address "bit rot". The concept is familiar enough and I think many who doubted this years ago have probably all been hit with a first-hand case of this data disease by now.

I've got some good examples of this going on in EPROM data (cartridge prototypes) but I have never personally experienced a CD with bit rot. I know I've seen or heard people in this community talk about it before.

Do you have any specific examples of this happen, and was there an obvious culprit (heat, humidity, excessive light, etc) that caused a once working disc to go bad without ever having been used in the interim?

[Parodius Duh!]

Ive never had a problem with carts or game cds. Only Audio CDs and DVDs Ive had rot, most likely due to cheap materials used to make the discs themselves.

[megasdkirby]

Yes, it has happened to me, but not with games, but with cheapass optical media.

In fact, ever since I purchased two BDRE drives on my computer, I've started to backup files extensively, specially when I encountered some of the first few CD's burnt to be pretty much screwed up with bitrot. These CD's are from the year 2000 or so, so yeah, they are old. Generic media doesn't help either, though to be honest, generic media isn't always generic as people think...

Anyway,I've noticed that the conditions in which the discs are located in play a very important role in bit rot development. In a sealed environment, with little or no humidity, bit rot was practically non-existent. But when exposed to the elements...bit rot was just ONE of the problems to plague optical media. Others include fungus, stains, obviously scratches, peeling from the label side...and much, much more.

I'm pondering about putting small silica packets in certain games/locations to help prevent this as much as possible. Or at least slow down it's progress.

[kai123]

Never had one before fail.

[Tupin]

I've only ever gotten this on CD-Rs, and I would assume they are a lot more common on them than on pressed discs.

It may not be relevant to your interests, but LaserDiscs often had laser rot, especially ones manufactured by Sony in the 90's. LaserDiscs had to be made in a very sterile environment otherwise they would be messed up.

[treismac]

I have a Castlevania cart for the NES that has bit rot. The character falls right through the floor and dies even in the attract scene when you just let it play it self. No amount of cleaning fixed it so that is what I assumed it was.

Dude, make a video of this and post it to youtube, then drop us a link. I want to see this "bit rot" in action.

I've never heard of this before. While I'd hate for any of my carts to have bit rot occur to them unintentionally, I wouldn't mind purposely causing it to happen to a duplicate cart or two (I'm looking at you, Mario/Duck Hunts!). I really dig video games flipping out as their universe collapses in on itself like when certain Game Genie codes are entered. Cory Arcangel created a movie with Paper Rad about this kind of deterioration of the world of a video game as it ages. I am certain I've posted it on DP before, but screw it...


http://www.youtube.com/watch?v=_2vjnBF_oXY

[Kitsune Sniper]

I've only ever gotten this on CD-Rs, and I would assume they are a lot more common on them than on pressed discs.

It may not be relevant to your interests, but LaserDiscs often had laser rot, especially ones manufactured by Sony in the 90's. LaserDiscs had to be made in a very sterile environment otherwise they would be messed up.

You know how much music I buy. A lot of stuff from the 1990s and earlier now has disc rot. Even one CD I bought that was fine experienced rot a few years later, and this is why I now back everything up to FLAC ASAP.

I don't believe I've ever encountered a single console game with disc rot - Sega and Sony's manufacturing plants were pretty good at what they did. However I have found a few PC games that have died due to it.

[Rickstilwell1]

You know how much music I buy. A lot of stuff from the 1990s and earlier now has disc rot. Even one CD I bought that was fine experienced rot a few years later, and this is why I now back everything up to FLAC ASAP.

I don't believe I've ever encountered a single console game with disc rot - Sega and Sony's manufacturing plants were pretty good at what they did. However I have found a few PC games that have died due to it.

Is FLAC really any better than .WAV or .AIFF? I hear those are lossless as well

[Kitsune Sniper]

Is FLAC really any better than .WAV or .AIFF? I hear those are lossless as wellThe filesize is about half as big, sometimes a bit less.

[jb143]

Is loss of data on EPROM really considered "bit rot" since they were only guaranteed by the manufacturers to last 10 years or so? And even then I think you can rewrite them and they'll save that data for a good long time. More slowly erasing rather than rotting.

[Rickstilwell1]

The filesize is about half as big, sometimes a bit less.

Ah, I guess I'll stick with sacrificing disk space for ease of compatibility and access.

[Panzerfuzion]

are you guys saying 25 years from now nes and snes games will be worthless?

[Gameguy]

You know how much music I buy. A lot of stuff from the 1990s and earlier now has disc rot. Even one CD I bought that was fine experienced rot a few years later, and this is why I now back everything up to FLAC ASAP.

I don't believe I've ever encountered a single console game with disc rot - Sega and Sony's manufacturing plants were pretty good at what they did. However I have found a few PC games that have died due to it.
With early CDs I've heard it could be caused because of the paper insert in the front of the case. The paper can be acidic, when the case is closed it's pressed against the top of the disc and can eventually damage it. Some places say to store CD cases on edge in a bookcase like books instead of flat to prevent the booklet from sagging down onto the disc. I'm not sure how serious this type of problem is though as most CD storage racks seem to store them flat. Newer discs might be better sealed on top too.

I've found a Sega CD game with some pinholes in it, I'm not sure if it got ruined as it still played fine though I never beat the game to make sure(it's that Power Rangers game). I've also found a few PC games like that, I can't really recall coming across too many discs like that but it's not like it only happened once or twice either. I just make sure to check discs before I buy them.

[badinsults]

I've dealt with a few prototypes that clearly were bitrot. They had varying levels of corruption. Not much you can do about it except back things up before it happens.

As for CDs/DVDs, I have never really had too much of an issue. I have some older cds in my collection that skip and stutter, but it could be due to scratches as much as corruption. I'd say that optical media is far more fragile than cartridges (despite issues with contacts), and will have a shorter shelf life. Tis the nature of the beast. Hopefully there will be people keeping backups of everything.

[Atarileaf]

are you guys saying 25 years from now nes and snes games will be worthless?

Nothing lasts forever. This is why emulation is so important.

[JSoup]

are you guys saying 25 years from now nes and snes games will be worthless?

To quote the Angry Video Game Nerd; "What's the point? It'll all be dust one day anyway."

[Atarileaf]

To quote the Angry Video Game Nerd; "What's the point? It'll all be dust one day anyway."

True, heck I'm 42, in 25 years I may not be around to play them anyway. :D

[treismac]

How sad it is to contemplate the gradual and inevitable demise of all the video games from our childhood. :(


The sound of the Gion Shōja bells echoes the impermanence of all things;
the color of the sāla flowers reveals the truth that the prosperous must decline.
The proud do not endure, they are like a dream on a spring night;
the mighty fall at last, they are as dust before the wind.

[BetaWolf47]

I have had a PSX game give me garbage video output before, like a dirty NES cart. I don't know if this was due to bit rot, or due to something in the system.

[Mayhem]

A couple of my audio CDs have rotted a bit, a couple of tracks refuse to play properly. But they are "early" CDs, from the late 80s or early 90s. My game discs are fine currently.

[jperryss]

I have a Castlevania cart for the NES that has bit rot. The character falls right through the floor and dies even in the attract scene when you just let it play it self. No amount of cleaning fixed it so that is what I assumed it was.


Dude, make a video of this and post it to youtube, then drop us a link. I want to see this "bit rot" in action.

X2. Not that I would definitely consider it bit-rot, but I would love to see this.

[digitalpress]

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!

[Tupin]

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.

[Shulamana]

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.

[Gameguy]

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.

[bunnyboy]

are you guys saying 25 years from now nes and snes games will be worthless?

The mask roms used in almost all licensed production NES/SNES games do not get bit rot. It only applies to flash or eproms. However that does include many unlicensed games, prototypes, competition carts, homebrews, and repros.

[Natty Bumppo]

I've only ever gotten this on CD-Rs, and I would assume they are a lot more common on them than on pressed discs.

It may not be relevant to your interests, but LaserDiscs often had laser rot, especially ones manufactured by Sony in the 90's. LaserDiscs had to be made in a very sterile environment otherwise they would be messed up.

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.

[rbudrick]

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

[jb143]

I guess the Brazilian humidity did a number on the EEPROMs.



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?

[rolenta]

It may not be relevant to your interests, but LaserDiscs often had laser rot, especially ones manufactured by Sony in the 90's. LaserDiscs had to be made in a very sterile environment otherwise they would be messed up.

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.

[rbudrick]

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?

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

[NayusDante]

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?

[jb143]

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.




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

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.

[BetaWolf47]

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.

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.