Bit rot?

[it290]

Some of you may have read my last post in this forum, an assessment of the game Generations Lost. Well, I was playing that game last night, and at one point I cleared a level. There was a cutscene at the end of the stage, and afterwards, the screen went blank. I thought 'hmm, some kind of glitch or something?' and turned the Genesis off.

When I turned the Genesis back on today to play the game some more, the 'licensed by' screen didn't come up. So I took the cartridge out and checked the contacts. They looked squeaky clean, but I cleaned them off anyway. Still no luck - the game won't boot up. I checked the back of the cart and it was labelled 'assembled in USA'... I opened it up, and noticed that the board had a Tengen copyright. I have another Tengen game, Dragon's Revenge, also 'assembled in USA' that has the exact same problem. Someone else mentioned they were having trouble with their Grind Stormer cart a while back (another Tengen game). So my question is, is this just a bad batch of ROM chips, or what? And what would cause the chip to go bad in the middle of gameplay?

 

[Borisz]

afaik, bit rot happens only if the chips are exposed to heavy sunlight. As far as they are in the cartridge, I don't see how bitrot could happen.

All I could imagine for a problem would be some kind of electrical charge hitting the cart and messing up the data, but I don't see how could that happen.

 

[ExCyber]

EPROM WILL bit-rot even without exposure to sunlight or other radiation; the gate isolation mechanism is not perfect, so it's only a matter of time (as far as I've been able to gather, depending on manufacturer/family and how cleanly it was programmed this can be anywhere from 10 to 25+ years)..

If it's a mask ROM it could be latent manufacturing defects that finally manifested. Also it's possible (though not terribly likely) that the cart PCB could have been messed up by things like exposure to smoke or being submerged in water.

 

[Cloud121]

(as far as I've been able to gather, depending on manufacturer/family and how cleanly it was programmed this can be anywhere from 10 to 25+ years)..

Wha?!

Not even cartridges can last forever?!

 

[ExCyber]

Most cartridges use mask ROM, which is theoretically immortal (although realistically something else will probably happen to it within a few centuries). EPROM tends to be used on prototypes and very short runs.

 

[it290]

Well, neither cartridge appears to have an EPROM in it. And the PCB looks perfect. I think it can be chalked up to shoddy ROMs.