Naomi Dualbiosmod

OldFoo · Post by **OldFoo** » Sun May 27, 2007 11:38 am

No news that it's possible to do dualbioses for the naomi but as I built a couple of them today I decided to pamper my own motherboard with a little extra luxury, an external switch. Very handy when swapping between gd-roms, no need to remove the dimmboard, phew.

Here's what they normally look like:

And yes, I do sell these.

Now I'm off for some sweet radilgy action :smt020

OldFoo · Post by **OldFoo** » Sun May 27, 2007 5:00 pm

NICE :smt023

OldFoo · Post by **OldFoo** » Thu May 31, 2007 4:00 pm

Looking forward tri-bios

OldFoo · Post by **OldFoo** » Thu May 31, 2007 4:20 pm

Could a triple be done?!? :smt017

OldFoo · Post by **OldFoo** » Thu May 31, 2007 5:21 pm

not really

OldFoo · Post by **OldFoo** » Thu May 31, 2007 5:32 pm

bamarquez226 wrote:Could a triple be done?!? :smt017

Can it be done? It's possible. But, judging by what the above dual setup looks like, it would be quite a mess.

Speaking theoretically, it is conceivable to use a chip of the same family type but with more memory and store the bioses on one chip. Then use a switch to change the addressable memory range through the data pins. The method I am referring to is called 'address transposition'. The controller (in this case, the Naomi) would, for example, address memory position one, but the pin configuration starts at position 40, where the second bios might start. Keep in mind that this is theoretical as I have done this in Electrical Engineering class, but with different chips than used by the Naomi.

Before anyone asks, I don't have the time to figure this configuration out. But I posted this information for the purpose of someone with know-how to make the attempt.

OldFoo · Post by **OldFoo** » Thu May 31, 2007 6:13 pm

Even it were possible, wouldn't it be more wiser to try the dual mod on a single chip vs the double? Space where the socket is pretty tight.

OldFoo · Post by **OldFoo** » Thu May 31, 2007 6:29 pm

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

?? :smt017 ?? :smt102

OldFoo · Post by **OldFoo** » Fri Jun 01, 2007 9:07 am

would be easy to-do, but the Naomi will not boot using a m27c322 eprom, don't ask me why..

I believe the core OS, does a device ID check.

OldFoo · Post by **OldFoo** » Fri Jun 01, 2007 3:42 pm

AndyGeezer wrote:would be easy to-do, but the Naomi will not boot using a m27c322 eprom, don't ask me why..

I believe the core OS, does a device Id check.

I see what you are saying. My understanding is that UV types don't support ID commands. I did look into the differences/similarities through their datasheets. The pin configurations aren't exactly the same, even though they are both 40 pin devices. I think what kills it is pin 32. :smt009

I will take a look into what might work in my free time. :smt024