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EPR-23609B Bios on downloads section
Posted: Fri Oct 31, 2008 10:52 am
by OldFoo
Guys that bios is not Rev B,
Its a Rev A Japanese bios so the part number is incorrect too..
Posted: Fri Oct 31, 2008 11:10 am
by OldFoo
Thanks for the heads up!
Posted: Fri Oct 31, 2008 3:04 pm
by OldFoo
How do you know? It doesn't say in the test menu screen.
Posted: Fri Oct 31, 2008 6:03 pm
by OldFoo
If someone is kind enough to send me the correct dump i will fix it asap.
Posted: Fri Oct 31, 2008 9:11 pm
by OldFoo
joshua3dg wrote:How do you know? It doesn't say in the test menu screen.
Test screen shows Japan, I checked the code for the version... everything in the code matches the REV A bioses apart from the region info...
Posted: Sat Nov 01, 2008 1:38 am
by OldFoo
This post prompted me to compare the known bios roms to see how similar/different they are. I found that, in the same revision, all of the code is the same except a few hex codes. I think this is where bios region can be set/modified. I will study these differences a bit more to see if I can manipulate the region coding.

Posted: Sat Nov 01, 2008 3:35 am
by OldFoo
I'd like to have a NAOMI Uni-BIOS go Josh!!!! :smt020
Posted: Sat Nov 01, 2008 9:26 am
by OldFoo
You only need to change 1 byte to alter the region code.
2 second job.
Posted: Sat Nov 01, 2008 11:01 am
by OldFoo
DJ Infinity wrote:I'd like to have a NAOMI Uni-BIOS go Josh!!!! :smt020
It doesn't make it any easier to do! Id imagine a lot of people knew where the region info was. I know i've known for a long time and didn't realise most other people didn't
I suppose you would have to write a program for the Naomi to boot, then say copy the real bios to ram, then you select the region, your program patches the code in ram with the region info you selected and then launches the bios from Ram rather than rom.. Not sure how that would go as I'm no programer

Posted: Sat Nov 01, 2008 12:49 pm
by OldFoo
Ordyne wrote:DJ Infinity wrote:I'd like to have a NAOMI Uni-BIOS go Josh!!!! :smt020
It doesn't make it any easier to do! Id imagine a lot of people knew where the region info was. I know I've known for a long time and didn't realise most other people didn't
I suppose you would have to write a program for the Naomi to boot, then say copy the real bios to ram, then you select the region, your program patches the code in ram with the region info you selected and then launches the bios from Ram rather than rom.. Not sure how that would go as I'm no programer

With the price of Naomi 1 mainboards, it just as cheap and easier to have different Naomi's for different regions..
If we could use 27c322 we could at least have a switch like on the STV Bios, but it seems to want the vendor/device id to match.