EDIT: For anyone unfamiliar, the MiSTer is a homebrew FPGA project originally built around a Terasic DE-10 Nano that can emulate in hardware a wide variety of consoles and computers, leading to extremely low latency and (often) higher accuracy than most software emulators due to it being easier/more efficient to recreate cycle-accurate effects in hardware. It’s extremely flexible, allowing for both HDMI and analog output (with scaler effects, if desired), as well as both modern USB/Bluetooth HIDs as well as adapters for original controllers. It’s a very cool project and worth checking out if you’re enthusiastic about such things - retroremake.co has had some well-liked clone/re-engineerings of the MiSTer hardware but they’re going through a big shipping backlog so I don’t know when they’re in stock; there were some decently regarded Aliexpress clones as well, but I don’t know what the status of those is. An authentic DE-10 Nano is an option too, it’ll just be more expensive and you’ll still need to get an SDRAM board to run most cores.

Exactly the first thought I had too. I know extremely little about FPGA development, but three things I noticed that came to mind re: difficulty:

- Alex used a Xilinx FPGA, the MiSTer uses an Altera Cyclone - dunno how portable code (if that’s even the right term for e.g. VHDL) is from one to the other. I know the MiSTer has a light framework for cores to plug into to get input handling, scalers, etc.; so maybe it’s more a matter of porting to the framework…?

- Alex mentioned the SCC didn’t have a pre-made FPGA core so they used a real one. I don’t think serial handling would be critical but I do suspect you’d at least need a dummy to get the OS to pass self-tests and boot properly. Possible that maybe the Mac core has already handled this, though.

- What little I know of RAM and the MiSTer would lead me to think the SDRAM card a MiSTer setup typically needs wouldn’t be a problem over the SRAM Alex used, and that either the framework or the wiring of the RAM card handles the details for you - but I definitely don’t know that.

On the plus side I suspect/hope maybe a bunch of stuff from the classic/original Mac core could be borrowed to get it up and running.

There’s definitely plenty of cores that haven’t yet been developed on the MiSTer… for instance there isn’t a color 68K Mac core, only recently have people started on 3D0 and CD-i and Apple IIgs cores, the Saturn core was pretty shaky until a recent overhaul, etc. I think what’s there is just a function of what was either already developed for an FPGA or what had the biggest demand from their respective communities.