View Full Version : Will a magnet destroy cartridge data?

03-23-2003, 03:52 PM
Not that I am willing to test this on any of my own carts, but I am just curious. I know it destroys data on diskette, but would it destroy data in a cartridge?

03-23-2003, 05:05 PM
Game data are stored on ROM which can't be altered short of a direct lightening strike (satrong electricity can melt silicon) so it's safe from even the strongest magnet.

Save data on older games using battery and newer games via EEPROM are also not prone to magnet damage. They are store electronically and not magnetically like floppy disk and tape does.

03-23-2003, 05:23 PM
Thanks for the reply! This is good to know. I guess cartridges really can stand the test of time :)

03-23-2003, 09:22 PM
The only thing left to fear is fear itself, or maybe bit rot.

Does anyone know if bit rot is real?

03-23-2003, 10:30 PM
ROMs are made differently from EPROMs, which are prone to eventual erasure as they lose their individual states. ROMs, rather, are generally made in large batches at once, like a permanent imprint. Methinks the contacts of the cartridge will go out long before anything bad happens to the chips, outside of static shocks and such.

03-24-2003, 12:56 PM
Does anyone know if bit rot is real?

It is definately possible, the specs that people quote (10 years) for Eproms are based on testing at extremes. (Some new EEPROMs are rated for 100 year retention). If your cartridge has been stored at room temperature for 20 years you are probably still in good shape.

I would begin to worry if the cart spent a few years at a temperature extreme (typical IC max operating is at 85C, max storage 110C). Personally I have never seen or experienced bit rot, though technically it is possible.

03-31-2003, 08:14 AM
The only thing left to fear is fear itself, or maybe bit rot.

Does anyone know if bit rot is real?

On floppy disks, most definitely. Recently I've been transferring my Color Computer disks to PC for eventual CD storage. My OS-9 Level 2, BASIC09, OS-9 PASCAL, and a Deskmate disk are all garbage. They were all stored decently as well. Luckily the important disks, my game disks, are all okay.

My program tapes are also starting to show their age. Gotta get that stuff transferred quick too!

04-02-2003, 06:17 PM
Does anyone know if bit rot is real?

For EPROMs and magnetic media, yes, YES, a thousand times YES! (I'm not picking on you, but there are a lot of skeptics out there who don't believe it).

As to ROMs, it shouldn't happen but I think even then you can't rule it out. On the other hand, if ROMs start suffering bit rot, probably the case has already disintegrated...

08-01-2003, 11:36 AM
the only way to erase a ROM would be any type of EM radiation like an EMP (magnets dont produce the right type of EM radiation, but nukes do) since commercial equipment is often porly sheilded from EMP... on the otherhand if you want it to last forever you might consider buying a ROM for military purpose and flash it with the same rom =)

08-16-2003, 06:13 AM
Okay, here's a question for the panel. :)

Way back when, my little brother was screwing around (as little brothers will do) and he figured out that a magnet would stick to our NES Game Genie cart. I didn't think anything of it immediately. Then the next time I went to use it, I was shocked to find that it made the screen roll while I was inputting the first code (but it fixed itself for the second and third). It has done this ever since.

So, any theories? I don't think the Game Genie internals are based on EPROMs...are they?

Duncan :D

08-16-2003, 06:17 AM
hard to say what a game genie is made of more then the logical assumption like.. at least one cpu of some sort.. since if you open it up you wont see anything more then a small black blob with blackepoxy where the components reside..

08-16-2003, 03:16 PM
That's really strange... I know it wouldn't have harmed the chips inside (unless it was a VERY strong magnet that physically destroyed something), but since you said the magnet stuck to the cartridge, unlike most carts, the game genie must have some sort of shielding, like the RF shielding inside the NES (maybe since another cart plugs in there, so the video quality would suffer if it wasn't?).

My only guess would be that the RF shielding became magnetically charged and messes with the video, but why only on the first code, I have no idea (does it roll again if you go back to the first code?). And it is the first code no matter how long you leave it on there, and not just for 10 seconds or so which just happens to be how long you take to put in the first code. You should try taking another magnet to it and just wave it all around the outside of the cartridge, sorta like degaussing (or use a degaussing coil if you have one).


08-16-2003, 09:35 PM
I have a TV that constantly rolls when I use the Game Genie, but is fine when it's just the game alone. More than likely, it's just bad programming. I seriously doubt that the magnet had anything to do with it, but stranger things have happened. You could always remove the innards from the shielding and try running it that way.

08-18-2003, 04:18 AM
Haven't played with it in a while, but as I recall it does the same thing on several different TVs (older and newer). And since I tend to turn the system on before I search the codebook, I know that it keeps rolling until I put in a code.

Once the first code is in, the screen still wiggles a little but gets better as I plug in more letters. By the time I start on a third code, it's usually gone.

And I swear to God, I am not making this up. It's always been a mystery to me...

Duncan :D

10-04-2003, 05:04 PM
Con someone please explain the technical differences of a ROM and an EPROM to me?

And so basically, what you are saying is that all cartridges will lose their data given time? So given 5-10 years my Atari and NES carts will be nothing but plastic pieces of junk?

That rather turns me off of collecting cart based systems. :/

Also, if this is true with carts, is it possible that the chips inside the consoles themselves will degrade? That kind of turns me off of collecting as a whole :/

10-04-2003, 05:54 PM

ROM (or mask ROM) - Type of chip found in most mass-produced games. 27 years after their production, your Channel F games still suck, and they will continue to suck well into the future. The data was rather permanently set at the factory.

PROM - Programmable ROM - Write-once memory used in lower-quantity game runs. I have no idea if any game manufacturers used these, but it possible/probable. Should still be pretty robust for years.

EPROM - Erasable/Programmable ROM - Chip with little 'window - re-writable chip which is erased with a specific wavelength of light. You see these on arcade boards, homebrews, and bootlegs. More of a bit rot candidate.

EEPROM - Electrically Erasable Programmable ROM - Rewritable chip which is erased with a specific application of electricity. More of a bit rot candidate.

In short: Don't worry about it. Really. Buy carts. People can always make new chips. If you've got a genuine one-of-a-kind, then get someone to make a copy of it for you.

10-05-2003, 02:47 AM
Bit rot is real. Any rewritable media is volatile in the right conditions (whether that be age, magnets, light, lasers, shoes, etc). I have a few games that are pristine clean on the contacts that are starting to slip. I have a spider man clone from brazil (they used eproms a lot instead on roms, the cheap bastards, lol j/k). The game, obviousoly is old as shit, but it is very glitchy in the graphics department. It's the only game that does it and it gets worse over time. I should probably dump it and back it up.