MD cartslot is highly 16bit memory chip friendly, you basically have traces going straight to chip pins in correct order.
I used a pair of 27C160 for that. Had to wire them to the board. Even used an pirate LO-ROM Super Famicon cart re-wired as HI-ROM for that. Ugly but fitted inside a cart just fine. Also three 27C160 makes up for Tales of Phantasia. It's a bit difficult to build because of it's weird addressing mode but once you figure how it works, it's easy peasy. Still.... Copying Mega Drive games is so easy it's not even funny.
I thought 27C160 was 16bit only? Or is it dual mode? It would certainly be alot easier if I could use two chips rather than 4. Did you still use the onboard MAD-1 as the decoder for the ROMs then?
27C160 is dual mode. I would keep the 320 ones for the Mega Drive because they can't do 8 bit without a ton of external logic... And yes I used the MAD-1 from a broken cartridge (the board broke but I could salvage the chips) mostly because it not only provides address decoding but it also does the watchdog job for the SRAM.
Ive used this exact trick numerous times, it definately works, and quite well i might add!!! The only excpetion is if the screw is really, really tight youll strip the plastic away before you actually loosen the screw.
