The homebrew scene is always coming out with ways to emulate old games on new hardware with as much fidelity to the originals as possible. Programmer Tom Murphy, otherwise known as Tom7, has been working on a slightly different project in his two most recent YouTube videos: figuring out a way to run SNES games on a vanilla NES console.
To enact this seemingly miraculous feat of video game engineering, Murphy doesn't modify the NES at all. Instead, he hacks the circuit boards of NES cartridges to outfit them with Raspberry Pi 3 mini-computers. All of the information from the SNES ROMs on the Pi then gets filtered through a program to translate the data into something the NES can understand and render on-screen via the hacked cartridge.
In effect, the Pi streams games to the NES, which Murphy has running on a slight delay to compensate for the latency of all this extra computing.
This unusual approach allows Murphy to control the inputs being fed into the NES. As a result, he can do some interesting things, like let games scroll faster than the system would normally allow and have more colour variation. The result is an opening level of Super Mario World that looks acid-washed and creepy.
Murphy has put together a number of other projects over the years, including writing a program that could teach itself how to play NES games, but there's something both glorious and eerie about seeing once future tech taken apart and reconstructed as a demake, a type of homebrew Murphy has dubbed "reverse emulation."
Murphy has even wilder ambitions, speculating at the end of his reverse emulation video about the possibility that humans might one day use a similar theoretical process to integrate their brains with more advanced technology. Who knows - maybe in the year 2048 being a homebrew cyborg will be the only way to get access to a Nintendo virtual console.
You can watch Murphy go into much more technical depth about this project in his second video here.