Sonic 3 cart on its own: ROM is enabled if access below $200000, SRAM enabled if access $200000 and above... no fooling around with !TIME.
This was made BEFORE I learned that Sonic&Knuckles was designed with a cart slot on it. If anyone wants, I can give you a schematic...
Sonic 2 and Knuckles wont work though.
It depends on a Flash chip how easily it could be used. And as Fonzie said, there isn't much RAM in MD for sectors. I guess it will be simpler to use EEPROMs, less hassling... or do like I did with S3 cart
