Originally Posted by TheCyberDruid
There is a Sega Arcade Classics CD with 5 games on one CD. The games are the same as the cartridge versions, so I guess the key how to make cartridge games work from CD is on that CD
I also think that it might be quite difficult to reverse engineer that technique since it was not done yet...
That was an official release and so could have been done at the source code level... interesting to take a look though. You'd still have to hack it.
You can of course buy the older cartridge emulators for Sega Megadrive. They had either FDD in them or parallel port links to a host computer, but they are old and very slow compared to a modern flash card solution.