Sega-Naomi

I recently bought a GD ROM setup & wanted to hook it up to my Naomi 1 mobo. I tried it and I get this error



"this gamesboard is not compatible "



My questions are



Does it matter what region the mobo or GD ROM is?

Are the GD Roms multi Region?

Could be a number of things:



1) Dimm board not installed correctly, make sure it has good contact.

2) Dimm board has damaged pins.

3) Naomi 1 has Bios older than Rev E, will require a Rev E bios or later