Post#2 » Mon May 06, 2013 7:15 pm
The DC and Naomi are very very similar, but there's a quintessential difference that is hard written into the game code that needs to be changed in the code when games are ported.
The naomi loads an entire game into ram - even the naomi GDrom games operate in this way. For a gdrom game - you have the gd drive connected to a dimm board which is essentially a writeable naomi cartridge that will store the gdrom data on the board (as long as the machine is plugged in) as if it is a cart. The game does not spool off the gd drive during gameplay, rather the gd is read and the data is transferred to the dimm board for a couple of minutes when you first boot up the game. Then for the duration of gameplay, the gd drive is idle and no data is read off the gdrom. If you even look at the file structure of a naomi gdrom game, it is vastly different to a DC game's file structure - there might only be 2 or 3 files on the disc, each 200+ mb. Sega used the GDrom+dimm board combo so that it would be cheaper to manufacture and distribute arcade games (disc = cheaper than cart) and an arcade operator would only need one (dimm) cart for a machine, and not really for any other reason to my knowledge.
In contrast, DC games, including naomi ports, have been reprogrammed to store each scenario (whether it is a level, or a cutscene, or what) into chunks that will fit in the DC's 16mb of ram. Sometimes the game graphics needed to be modified to crunch it down to fit into the 16mb of ram - I personally don't notice it, but apparently some naomi>dc games like Crazy Taxi have lower res textures to accomplish this. Naturally, the games also have loading times as well, as the non-relevant data needs to be swapped out of the ram to make space for the newly relevant data of a new level or cut scene etc.
^Unfortunately, this tailoring and organization of the game to fit into the DC's ram and be spooled from a game during gameplay requires changes in the game code, and no one has the game code but the developers.