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CPS3 EPROM security cart and stopping settings loss and other fun.

willkaotix

willkaotix

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I was lucky enough to have an A cart that can take a 28f400. Seeing as I wanted to have easy bios swapping I went with the 40pin zif as a 27c4100 is pin for pin compatible with the 28f400 it was a simple task.
I wanted to post this to show it works with an eprom(I used a 120ns same speed as the original bios). Also to say that I can test new software with little effort and would love to help out.
I also wanted to be able to experiment with editing the bios as I was not fond of the region menu, and that if accidentally picking the wrong region you could lose settings. So I wanted to lock the region but also be able to run it CD or NOCD at will.
I think my plan if I ever get another cart that can take a 28f400 would be to use a 28f800 and mount a little switch on the cart for bank switching. So I could have both the regular UNI to select games, but then able to run it nocd and no region menu as well so if I take the pcb somewhere for some 3S or JOJOBA I dont need to drag around the drive and cables and no risk of someone killing the settings.
A little ugly, but works.

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Will be tricky get that to work, because it's the games which wipe the eeprom when they detect it was not initialized by themselves (they check the game ID on the eeprom and if it's not it's own ID it formats and inits the eeprom).

Keep in mind those boards were not designed to swap games in a daily basis.
 
I have no interest or ability to try and keep a game from wiping the memory from game to game.
What did bother me was when you saved settings in JOJOBA for USA and then pick japan it would format the memory.
I dont want to play in any region other then USA or have the menu or have to have the drive connected all the time. Was simply solved by locking region and no region menu and making it NOCD.
 
That's because when you change the region the game is programmed to deem that the game was exchanged by a different title.

Each game has a designated four characters code which identify the game. Regional variations change the first character of that sequence that is stored on the EEPROM. If the sequence mismatches what the game expects (at the current region setting) it will format the EEPROM and set defaults.

So it's not possible to do what you want, without heavily hacking the games, as it's not done by the BIOS but by the game itself, as when you change the region it doesn't acknowledge the EEPROM data as it's own anymore.

All Capcom games actually do that when region modded, regardless of the platform (CPS1, CPS2 or CPS3).
 
I already did it is I guess what I was trying to say. It was very little hacking but a pain in the ass to find. No adverse affects that I have noticed yet.

l_oliveira said:
That's because when you change the region the game is programmed to deem that the game was exchanged by a different title.

Each game has a designated four characters code which identify the game. Regional variations change the first character of that sequence that is stored on the EEPROM. If the sequence mismatches what the game expects (at the current region setting) it will format the EEPROM and set defaults.

So it's not possible to do what you want, without heavily hacking the games, as it's not done by the BIOS but by the game itself, as when you change the region it doesn't acknowledge the EEPROM data as it's own anymore.

All Capcom games actually do that when region modded, regardless of the platform (CPS1, CPS2 or CPS3).
Click to expand...
 
Well, considering the usage these boards were supposed to have, it's not an annoyance, you see.

It would suck a lot more if you had to manually init the defaults every time you actually changed the game on original battery protected hardware.

But good, you solved your problem. Share with us the patches maybe?
 
If darksoft does not mind me spreading around how to manipulate his code sure. Its minor mods but I am no expert and barely understand what I did so it may have negative effects to the code for all I know (works just fine for my uses though).
If darksoft does not like people doing this to his work I do not want to disrespect him.
But in a nutshell it looks like darksoft modified the game code to look for region info at a different location in memory that the region menu can write to. I just changed where the program looks for region info back to the bios, at least that is what it looks like I did.
 
willkaotix said:
If darksoft does not mind me spreading around how to manipulate his code sure. Its minor mods but I am no expert and barely understand what I did so it may have negative effects to the code for all I know (works just fine for my uses though).
If darksoft does not like people doing this to his work I do not want to disrespect him.
But in a nutshell it looks like darksoft modified the game code to look for region info at a different location in memory that the region menu can write to. I just changed where the program looks for region info back to the bios, at least that is what it looks like I did.
Click to expand...
I don't think you should restrain yourself as the community has only to win from it. Means more interest in general and of course I don't think DarkSoft would mind anything like that.

Back when those behaviors were defined there were some sort of mentality on the community about making it possible to discern hacks from real original hardware. With the key writing hardware from Arcade Hacker, that argument went "poof" and dissipated as thin smoke.
 
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Mitsurugi-w said:
Yes but he's talking CPS3 not CPS2. Can't rewrite keys to CPS3 yet.
Click to expand...
I'm saying that in general terms. As in how the argument of the need for having hacks identify themselves as hacks with modified logos or different behaviors.


To put it bluntly, I don't bootleg games, but I simply don't care about what effect the ROMs I decrypt have on the collectors market. :thumbsup:
And I am telling the OP that he should not, as well.

I heard recently that Japanese collectors have been using my decrypted sets (of Japanese versions) on their hardware to get rid of the leaky batteries. That's what preservation is about. :)
 
willkaotix said:
If darksoft does not mind me spreading around how to manipulate his code sure. Its minor mods but I am no expert and barely understand what I did so it may have negative effects to the code for all I know (works just fine for my uses though).
If darksoft does not like people doing this to his work I do not want to disrespect him.
But in a nutshell it looks like darksoft modified the game code to look for region info at a different location in memory that the region menu can write to. I just changed where the program looks for region info back to the bios, at least that is what it looks like I did.
Click to expand...
Be my guest :)
 
This is for the original custom SH2 version of the multigame. Search the "10" program file of the games from the custom uni-cd in a hex editor for 02 07 f0 00 it may show up more then once but changing the first should be all you need to do. Replace it with 00 01 fe cb
The region menu comes from the unibios, so simply dont use it. Use the older ONERULING bios and hex edit it to whatever region you want and no cd if you want, everyone probably already knows how to do this, but its documented in the mame source.
This is where bank switching a larger chip would come into play instead of the socket I used. Run the uni to change games, the older on nocd will boot anything in memory without the drive attached.
 
Warzard (forgot the non Japanese game) though won't work without a drive. The game actually pings the drive by itself and if the drive isn't connected it freezes in a black screen.
 
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