I was under the impression that the FPGA was solely used for interfacing with the cart, and the actual gaming was all handled by emulation. I thought I had read something along those lines somewhere.
EDIT: Here it is, same interview Mega linked.
So hybrid emulation at its core is - we are running traditional emulation and that is the way that you would play games that are not inserted into the console. But what hybrid emulation is there’s an FPGA that’s also on the board and we have a custom memory controller that sits in between the FPGA and the CPU and what that does is it interprets cartridge data directly from the cartridge when it’s inserted. So if you have a game that has a special chip on it, like a Super FX chip, rather than trying to emulate that part of the cartridge, we are actually reading that chip directly off of the cartridge itself so that way we’re going to get a more accurate reproduction. You’re getting wider compatibility and all that sort of thing.
So it looks like the FPGA acts as an interpreter for the cartridge slot (and CD drive maybe?) to the CPU which is running a software emulator.
That said, I’m not against emulation at all (I use emulation as my main method of playing games at the moment), but I do doubt the claim about totally original, high quality emulation for over half a dozen systems in 3 years. I hope I’m wrong, but I just don’t see how it’s is possible without filching some existing code.
Then again, I have always wondered how great emulation would be if a company with real money invested in high-accuracy, full-featured emulators. Most existing projects have been done by minuscule teams (Higan), or in the devs’ spare time (Dolphin). With those projects being as great as they are, imagine if someone put real resources behind it.