Sega Saturn architecture: a practical analysis by Rodrigo Copetti
Welcome to the 3D era! Well... sorta. Sega enjoyed quite a success with the Mega Drive so there's no reason to force developers to write 3D games right now.
Just in case developers want the extra dimension, Sega adapted some bits of the hardware to enable polygon drawing as well. Hopefully, the result didn't get out of hand!
Rodrigo Copetti
These in-depth analyses by Copetti are always a treat, and the Saturn one is no exception.