Repairing N64 game save functionality, 4K EEPROM
Hi dudes,
A couple of weeks ago I bought a cheap NTSC-J copy of Goldeneye for my Japanese N64. I had been greatly enjoying playing the game over a number of separate gaming sessions, working my way through the various levels. However, calamity struck when I went to play the game again this weekend, and I found my save file completely gone! I hadn't removed the game from the system since my last session, and the contacts are clean etc. I figured it might be a fluke so I played the game a little more, turned off the system, and then the new save was gone too. (Actually in another test, it DID hold a save again for a little while, but very soon that was gone too). So, I figure that the 4k EEPROM inside is dying/dead, which means I intend to replace it. Couple of questions:
1. Does the EEPROM communicate in any way with the CIC chip inside the N64 cart? I know that a great majority of N64 games (including Goldeneye) use the 6102 CIC chip, but if I were to put in a donor EEPROM from a cart with a different CIC chip would that work? I may decide to put in a 4K EEPROM from a spare PAL game I have (uses different CIC), so I need to know if this CIC thing will be an issue.
2. Can a 4K EEPROM be replaced with a 16K EEPROM? Of course, I probably WON'T be doing this, but it is more of a theoretical question. Clearly a 16K EEPROM could not be replaced with a 4K one, but what about the other way round?
I have been doing some research on this issue all week, and I have only read about one reported case of someone attempting a 4K EEPROM transplant (which apparently WAS successful). This stuff is really on the edge of known information at the moment, so ANY information you have at all will be helpful before I attempt the transplant myself.
Comments
If I recall correctly from my days of experimenting with the Dr. V64, there are some games that recognize when an EEPROM is too large (a form of copy protection). I don't think Goldeneye would do that. The extra copy protection measures (beyond CIC) were typically later games like Donkey Kong 64 and Banjo Tooie. The CIC thing should not be an issue. I also have an NTSC-J copy of Goldeneye 007 somewhere around here...
Thanks for the info! Technically speaking, discounting any potential copy protection, would a 16K EEPROM function correctly in place of a 4K one in this case? I have a double of a Japanese N64 game (Robopon) that I don't mind sacrificing, but that uses a 16K chip. Other than that, I am thinking of taking the 4K chip from my PAL version of V-Rally 99 (because seriously fuck that game, lol). Just looking for options before I go through with the transplant.
(P.S. To anyone wondering why I am going to all this trouble for Goldeneye: apart from the fact that a game this awesome DESERVES to be saved, the Japanese version of Goldeneye is surprisingly expensive... I was kinda thinking that the reason I found this one so cheap was because of the save issue, perhaps, but then again it came with saves already on it and I was playing it on and off for more than two weeks before I ran into the issue, so perhaps not...)
Last year I transplanted Cruis'n' USA into QB Club 98 (IIRC). I could have got another copy of Cruis'n' for $3 but it was our original copy from 1996 and I wanted to see our old saves. The original had the edge connector snapped completely off! I booted it up without the EEPROM and this particular game seems to not mind (no error; behaves as if it was never intended for anything but Controller Pak saving). I then added the EEPROM and all my old saves/times showed up.
Two options: Get a donor with 4K EEPROM and move the EEPROM or find a 4K EEPROM donor cart with the right number of ROM chips, then move the ROM. If you don't get one with a 6102 CIC then you'll also have to move the CIC chip with option 2. I've seen plenty of games that have single and dual ROM variants inside so what you find may differ from what you see online. If something wrong with the PCB is causing your EEPROM to corrupt then option 1 isn't likely to fix it.
If I recall correctly from my days of experimenting with the Dr. V64, there are some games that recognize when an EEPROM is too large (a form of copy protection). I don't think Goldeneye would do that. The extra copy protection measures (beyond CIC) were typically later games like Donkey Kong 64 and Banjo Tooie. The CIC thing should not be an issue. I also have an NTSC-J copy of Goldeneye 007 somewhere around here...
Thanks for the info! Technically speaking, discounting any potential copy protection, would a 16K EEPROM function correctly in place of a 4K one in this case? I have a double of a Japanese N64 game (Robopon) that I don't mind sacrificing, but that uses a 16K chip. Other than that, I am thinking of taking the 4K chip from my PAL version of V-Rally 99 (because seriously fuck that game, lol). Just looking for options before I go through with the transplant.
(P.S. To anyone wondering why I am going to all this trouble for Goldeneye: apart from the fact that a game this awesome DESERVES to be saved, the Japanese version of Goldeneye is surprisingly expensive... I was kinda thinking that the reason I found this one so cheap was because of the save issue, perhaps, but then again it came with saves already on it and I was playing it on and off for more than two weeks before I ran into the issue, so perhaps not...)
I couldn't say for sure that the 16K EEPROM would work, but my hunch is that it will. I'd try it.
N64 PCBs are extremely consistent. Pretty much every game with no onboard save memory still has an EEPROM-capable PCB and the CIC has never been PCB-specific. Of course, you want a donor with EEPROM so you won't be transplanting the old one.
Last year I transplanted Cruis'n' USA into QB Club 98 (IIRC). I could have got another copy of Cruis'n' for $3 but it was our original copy from 1996 and I wanted to see our old saves. The original had the edge connector snapped completely off! I booted it up without the EEPROM and this particular game seems to not mind (no error; behaves as if it was never intended for anything but Controller Pak saving). I then added the EEPROM and all my old saves/times showed up.
Two options: Get a donor with 4K EEPROM and move the EEPROM or find a 4K EEPROM donor cart with the right number of ROM chips, then move the ROM. If you don't get one with a 6102 CIC then you'll also have to move the CIC chip with option 2. I've seen plenty of games that have single and dual ROM variants inside so what you find may differ from what you see online. If something wrong with the PCB is causing your EEPROM to corrupt then option 1 isn't likely to fix it.
He intends to transplant only the EEPROM initially. He's not moving his ROM + CIC to another board (unless maybe the EEPROM transplant is unsuccessful).
N64 PCBs are extremely consistent. Pretty much every game with no onboard save memory still has an EEPROM-capable PCB and the CIC has never been PCB-specific. Of course, you want a donor with EEPROM so you won't be transplanting the old one.
Last year I transplanted Cruis'n' USA into QB Club 98 (IIRC). I could have got another copy of Cruis'n' for $3 but it was our original copy from 1996 and I wanted to see our old saves. The original had the edge connector snapped completely off! I booted it up without the EEPROM and this particular game seems to not mind (no error; behaves as if it was never intended for anything but Controller Pak saving). I then added the EEPROM and all my old saves/times showed up.
Two options: Get a donor with 4K EEPROM and move the EEPROM or find a 4K EEPROM donor cart with the right number of ROM chips, then move the ROM. If you don't get one with a 6102 CIC then you'll also have to move the CIC chip with option 2. I've seen plenty of games that have single and dual ROM variants inside so what you find may differ from what you see online. If something wrong with the PCB is causing your EEPROM to corrupt then option 1 isn't likely to fix it.
He intends to transplant only the EEPROM initially. He's not moving his ROM + CIC to another board (unless maybe the EEPROM transplant is unsuccessful).
Yeah. That was the first option I mentioned but there's a chance that the board is responsible for the EEPROM corrupting/initializing.
Is there a chance that some of the other components, like the resistors or capacitor could be faulty, leading to lost saves?
If I recall correctly from my days of experimenting with the Dr. V64, there are some games that recognize when an EEPROM is too large (a form of copy protection). I don't think Goldeneye would do that. The extra copy protection measures (beyond CIC) were typically later games like Donkey Kong 64 and Banjo Tooie. The CIC thing should not be an issue. I also have an NTSC-J copy of Goldeneye 007 somewhere around here...
Thanks for the info! Technically speaking, discounting any potential copy protection, would a 16K EEPROM function correctly in place of a 4K one in this case? I have a double of a Japanese N64 game (Robopon) that I don't mind sacrificing, but that uses a 16K chip. Other than that, I am thinking of taking the 4K chip from my PAL version of V-Rally 99 (because seriously fuck that game, lol). Just looking for options before I go through with the transplant.
(P.S. To anyone wondering why I am going to all this trouble for Goldeneye: apart from the fact that a game this awesome DESERVES to be saved, the Japanese version of Goldeneye is surprisingly expensive... I was kinda thinking that the reason I found this one so cheap was because of the save issue, perhaps, but then again it came with saves already on it and I was playing it on and off for more than two weeks before I ran into the issue, so perhaps not...)
I couldn't say for sure that the 16K EEPROM would work, but my hunch is that it will. I'd try it.
Games are hard-coded to use a 4K or a 16K EEPROM. They are NOT interchangeable.
The games usually check right at start up for the EEPROM chip, and if it doesn't find the one it expects (or none at all) then saving is disabled or anti-piracy is enabled, or the game just doesn't boot. That part depends on the game.
For example, Mario 64 won't even boot up with a 16K EEPROM, as it's expecting a 4K one.
If I recall correctly from my days of experimenting with the Dr. V64, there are some games that recognize when an EEPROM is too large (a form of copy protection). I don't think Goldeneye would do that. The extra copy protection measures (beyond CIC) were typically later games like Donkey Kong 64 and Banjo Tooie. The CIC thing should not be an issue. I also have an NTSC-J copy of Goldeneye 007 somewhere around here...
Thanks for the info! Technically speaking, discounting any potential copy protection, would a 16K EEPROM function correctly in place of a 4K one in this case? I have a double of a Japanese N64 game (Robopon) that I don't mind sacrificing, but that uses a 16K chip. Other than that, I am thinking of taking the 4K chip from my PAL version of V-Rally 99 (because seriously fuck that game, lol). Just looking for options before I go through with the transplant.
(P.S. To anyone wondering why I am going to all this trouble for Goldeneye: apart from the fact that a game this awesome DESERVES to be saved, the Japanese version of Goldeneye is surprisingly expensive... I was kinda thinking that the reason I found this one so cheap was because of the save issue, perhaps, but then again it came with saves already on it and I was playing it on and off for more than two weeks before I ran into the issue, so perhaps not...)
I couldn't say for sure that the 16K EEPROM would work, but my hunch is that it will. I'd try it.
Games are hard-coded to use a 4K or a 16K EEPROM. They are NOT interchangeable.
The games usually check right at start up for the EEPROM chip, and if it doesn't find the one it expects (or none at all) then saving is disabled or anti-piracy is enabled, or the game just doesn't boot. That part depends on the game.
For example, Mario 64 won't even boot up with a 16K EEPROM, as it's expecting a 4K one.
Good to know. Kinda thought it *might* work with older games, but I guess it doesn't.
I've spent some time testing it out, saving and copying and deleting files in all the different slots. What I've found is that the game holds on to saves in some of the slots at random, while deleting others. But, unbelievably, it suddenly deleted all of the save files in all the slots WITHOUT turning off the console... I left the console to idle with the demo for just ten minutes or so, and when I pressed start to return to the game, everything was erased!
Maybe that is the EEPROM, maybe it isn't, I don't even know anymore. Clearly the game is screwed and I don't have the skills right now to repair it, so I think I'm just gonna start looking for a nice CIB replacement for the damn thing that actually works!
Right... I have no idea what is going on with my Goldeneye cart, I don't know if it even is the EEPROM chip actually that is broken!
I've spent some time testing it out, saving and copying and deleting files in all the different slots. What I've found is that the game holds on to saves in some of the slots at random, while deleting others. But, unbelievably, it suddenly deleted all of the save files in all the slots WITHOUT turning off the console... I left the console to idle with the demo for just ten minutes or so, and when I pressed start to return to the game, everything was erased!
Maybe that is the EEPROM, maybe it isn't, I don't even know anymore. Clearly the game is screwed and I don't have the skills right now to repair it, so I think I'm just gonna start looking for a nice CIB replacement for the damn thing that actually works!
If you want to swap, I have a cart-only Japanese copy of Goldeneye 007.
That's extraordinarily kind of you Ichinisan, thanks for the offer! I wouldn't feel right sending you a broken game in exchange for a working one, however. Maybe I would consider it, if I chucked a few other items in for you...
It's no loss to me. I have plenty of USA copies. I only bought the Japanese one out of curiosity because it was at a local shop (well, same state).
EEPROM has a limited amount of read/writes. Chances are that EEPROM has reached that limit, or is just faulty.
Your quickest option is to just swap out the EEPROM. You can use any EEPROM from any other game as long as its the 4K version (labelled as BU9850 usually).
It's definitely the EEPROM.
Jump to 1m 45s:
https://www.youtube.com/watch?v=WYjgHLFZMa0#t=1m45s