Naomi Dualbiosmod

OldFoo · Post by **OldFoo** » Fri Jun 01, 2007 3:44 pm

joshua3dg wrote:Umm... That's what I said. :smt104

?? :smt017 ?? :smt102

Really? My bad. :smt016

OldFoo · Post by **OldFoo** » Fri Jun 01, 2007 6:12 pm

Doing a triple wouldn't be hard at all but I don't see any reason for it. The main problem is space but placing the eproms underneath would fix that problem.

As Andy mentioned the naomi won't boot a 322 so the dualbios with bank shifting isn't possible (until someone figures out how to get the naomi to accept the 322).

When and if that happens doing a one chip dualbios ala the STV dual is very easy. Until then, this is the way to go. I'm very pleased with the external switch as I mainly have GD games.

OldFoo · Post by **OldFoo** » Tue Dec 02, 2008 8:39 am

hi,

is it possible to have the wiring diagram about this dual bios

setting????

It could be very nice.....

thanks

OldFoo · Post by **OldFoo** » Thu Oct 08, 2009 6:40 am

Hello,

I write an private message to starke about dual bios but It seems that he doesn't go anymore here. I would like to install an dual bios on my naomi 2 (I already have the two bios chip) but I didn't find how to link this two chips.

anyone can explain how to do ?

Thanks a lot.

OldFoo · Post by **OldFoo** » Thu Oct 08, 2009 5:02 pm

Nobody knows or there is an omert? about how done dual bios ?

OldFoo · Post by **OldFoo** » Mon Oct 12, 2009 11:04 am

:smt009

Nobody can help me ?

OldFoo · Post by **OldFoo** » Mon Oct 12, 2009 2:08 pm

Well,

Stop and think about it and you can figure it out.

You can't use a single 32Mb EPROM since it has been reported to not work. This means you can't use a bigger EPROM and simply switch the highest address line to high or low to choose the image you want to boot with.

So this means you have to use 2 individual EPROMs.

Now, with that said, how do you choose which one is active? In other words, what are the control lines on the EPROM?

Go find a data sheet for the chip you have and see what you can figure out. I'll even give you a start:

http://www.datasheetarchive.com has the data sheets...

http://newlifegames.net/nlg/index.php?topic=18.0 has information on the control lines.

Good luck!

RJ

OldFoo · Post by **OldFoo** » Mon Oct 12, 2009 3:10 pm

I heard there might be possible to-do a region free bios.

There is already a bios chip that is region free, but it is a fairly old one. You see the Naomi Bios has a CRC at the end of it, so you can't alter the region (making the region byte FF makes it region free), but you need to update the CRC.

OldFoo · Post by **OldFoo** » Mon Oct 12, 2009 3:37 pm

channelmaniac wrote:Well,

Stop and think about it and you can figure it out.

You can't use a single 32Mb EPROM since it has been reported to not work. This means you can't use a bigger EPROM and simply switch the highest address line to high or low to choose the image you want to boot with.

So this means you have to use 2 individual EPROMs.

Now, with that said, how do you choose which one is active? In other words, what are the control lines on the EPROM?

Go find a data sheet for the chip you have and see what you can figure out. I'll even give you a start:

http://www.datasheetarchive.com has the data sheets...

http://newlifegames.net/nlg/index.php?topic=18.0 has information on the control lines.

Good luck!

RJ

Hello,

I think there is an mistaken probably due to my very bad english.

I don't want to make an single chip with two bios, I just want to do the same thing as shown at the first picture of this thread, link with wires two naomi bios.

I wrote an pm to starke but I have no answer. So I ask in this thread how link two bios chips together.

OldFoo · Post by **OldFoo** » Mon Oct 12, 2009 5:37 pm

youpla wrote:
channelmaniac wrote:Well,

Stop and think about it and you can figure it out.

You can't use a single 32Mb EPROM since it has been reported to not work. This means you can't use a bigger EPROM and simply switch the highest address line to high or low to choose the image you want to boot with.

So this means you have to use 2 individual EPROMs.

Now, with that said, how do you choose which one is active? In other words, what are the control lines on the EPROM?

Go find a data sheet for the chip you have and see what you can figure out. I'll even give you a start:

http://www.datasheetarchive.com has the data sheets...

http://newlifegames.net/nlg/index.php?topic=18.0 has information on the control lines.

Good luck!

RJ

Hello,

I think there is an mistaken probably due to my very bad english.

I don't want to make an single chip with two bios, I just want to do the same thing as shown at the first picture of this thread, link with wires two naomi bios.

I wrote an pm to starke but I have no answer. So I ask in this thread how link two bios chips together.

And I gave you a start on what you need to read to do it yourself.