expansion ram

Hello Can someone point me to the right direction as far as understanding the process of porting games from one console to another using Ghidra? I was told that that would be the best option when you don't have the original source code. I'm also curious about porting games into Saturn that...

Some earlier Action Replay cartridge models had a physical switch to select RAM mode, but recent ones are advertised as automatically selecting it, which is not technically documented. So does anyone have some technical informations (which register to write, etc) about how to configure expansion...