Game Cartridge battery backup?

bokmeow

Ned's Ninja Academy Dropout
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Apr 11, 2002
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11,314
I'm putting the question out there for people who know anything about the battery backup on the Neo Geo Pocket game cartridges. I have seen clear game cartridges for the Gameboy, so I figure it would probably be a similar flat button battery that backs it up, but when I opened up my game cartridges in order to clean the contacts, I found nothing of the sort. for 8 megs to 16 megs it usually has one rom chip, for 32 megs there are two, but other than that I looked on the front and obverse side and had no look locating the battery. Is it a custom battery for the cartridge now? It doesn't even appear visible to the naked eye, and that's the only thing that was naked when I was examining the cartridge board, I swear.
 

2D

Galford's Armourer
Joined
May 12, 2002
Posts
451
I didn't think they had battery backup, although i am probably wrong. I was under the impression that any game data was saved to the actual console? <img src="graemlins/spock.gif" border="0" alt="[Spock]" />

I'd be interested to here about this one, as that would mean that the cart would have a limited life span unless the battery was changed.
 

Flavor

Saver,
Joined
Jan 2, 2002
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283
It doesn't use a battery.

The NGPC uses flash chips for it's carts. Those chips are writeable, and when the NGPC wants to save information, it just writes to the same chip that the ROM is stored on.

Don't worry, though. All the important information (the game itself) has been write protected. The chip knows what areas have been protected, and if the NGPC tries to write over something important, it won't be allowed.
 
S

snkneogeousaCTH

Guest
Okay, I **think** I can explain this.. The CR2032 battery in the system powers the saving, hence no onboard battery. each cart has a small amount of flash memory, which the battery powers a save to.

On a side note, I opened up about 4 of my carts, (2 black and white 2 ngpc) and the boards are all different. Funny stuff.
 

bokmeow

Ned's Ninja Academy Dropout
Joined
Apr 11, 2002
Posts
11,314
That makes sense. I know the ROM for the Neo Geo Pocket Color game cartridges are EEPROM (Electronically Erasable Programable Read Only Memory) so it would make sense that the consoles writes the saved information onto a flash memory. Very clever of them, now my game cartridges have an indefinite lifespan, what an advantage over Gameboy cartridges ^_^
 
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snkneogeousaCTH

Guest
Yes, it was quite clever of snk. Think of it, in ten years a gbc cartridge might have battery acid leaked all over it...but then again, who'd WANT to play a gbc game in ten years :p
 

Morden

Somewhere in Europe.,
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Jul 5, 2005
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711
kind of clever though.

The writable sectors in NGP games? I don't know ... I guess. The thing is, with Game Boy games, it's generally super easy to back up your save using a dumper of choice. Not that you can't do it for NGP, but Flavor's dumper will just dump the entire ROM, save data included.

Let's say you've dumped your game, along with the save data. You want to use an emulator to either progress or hack the save or whatever ... It's not as simple to write it back. Also, emulators automatically create separate files for saves, which is logical, since polluting ROM data with a save would be stupid. BUT ... That save file is usually only the difference in data between the raw blank writable sector, and not the whole sector itself, which makes injecting save data into a ROM a pain.

This also raises the question of how clean the ROM images available actually are. If the game was used, it could have written something to the writable sector on boot-up. Not that it matters much, but still. The way NGP games work, you're dumping everything, writable sector included.

I probably wouldn't have had so much to say about this, if it weren't for the adventures I've had with Neo Poke Kun and Faselei, which were games I dumped to use the save on an emulator to capture clean screenshots. I also wanted to write the saves back to the cartridges, but that wasn't as straight forward as I had originally hoped.
 
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xsq

Thou Shalt Not, Question Rot.,
Joined
Jan 17, 2013
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7,414
I was referring to the bump... but thanks for that interesting story anyways.
 
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