Recently I figured out from another forum that I can change the region lockout on Naomi 1 and 2 game carts.
I have a few carts that required a JPN BIOS to work which is a pain since I dont like removing the BIOS eprom back and forth on the Naomi (not alot of room to do it and lots of chances to bend legs on the BIOS). So after reading up on how to change the region (which is just a byte change on the IC22 eprom) I can now run the same carts with my US BIOS. Im sure this wont work on every game since some games required a newer BIOS then the version G that the US stopped at but I think it will work for most.
Here is the info on how to do it instead of looking through the other forums:
Dump the cart eprom (27c322) at IC22
Edit the file at offset 0x428 FF = Any Region ; 01 = Japan
If you are having this problem and can't reprogram your own eproms you can send me the cart or just the eprom(5.50 return shipping plus 5.00 fee). If you want to keep your original eprom and want to buy a replacement eprom to install in your cart I can sell you one for 30.00 shipped in US. I also sell the Naomi BIOS eproms if you want an updated BIOS eprom for 25.00 shipped
I have a few carts that required a JPN BIOS to work which is a pain since I dont like removing the BIOS eprom back and forth on the Naomi (not alot of room to do it and lots of chances to bend legs on the BIOS). So after reading up on how to change the region (which is just a byte change on the IC22 eprom) I can now run the same carts with my US BIOS. Im sure this wont work on every game since some games required a newer BIOS then the version G that the US stopped at but I think it will work for most.
Here is the info on how to do it instead of looking through the other forums:
Dump the cart eprom (27c322) at IC22
Edit the file at offset 0x428 FF = Any Region ; 01 = Japan
If you are having this problem and can't reprogram your own eproms you can send me the cart or just the eprom(5.50 return shipping plus 5.00 fee). If you want to keep your original eprom and want to buy a replacement eprom to install in your cart I can sell you one for 30.00 shipped in US. I also sell the Naomi BIOS eproms if you want an updated BIOS eprom for 25.00 shipped

