Add NDS, N64, PS1 or option to add platform

[perrello]

I was playing around with nostalgist and it works great. One thing that i really miss is the possibilty to add these emulators.
It would be great if they were added or possibly a bridge to add it my self.

[arianrhodsandlot]

The built-in cores are grabbed from web.libretro.com now. In theory, we can compile cores other than them, but in practice it's not that easy to make them work properly and browsers are not good at compute-intensive tasks.

I know EmulatorJS supports platforms like N64/PS1. I'm also investigating the possibility of adding support for loading cores from EmulatorJS.

[perrello]

I tested a few cores and they run fine but need some small tweaks from the nostalgist side of things. For example melonds exports 2 streams for the screens. It is possible to build cores with support for multiple threads. These things make it possible to run on web (even mobile). There are projects like Afterplay that included it like this.

[arianrhodsandlot]

Are those cores compiled by you or you are using some pre-compiled ones, like https://www.npmjs.com/package/@emulatorjs/core-melonds?
I would suggest not introduce any compile steps into Nostalgist.js and keep it to be a pure lean JavaScript layer rather than a all-in-one solution like EmulatorJS. But I'm okay with adding compatibility for loading different kinds of pre-compiled cores.

[perrello]

I agree, that would be the best thing for this project imo. It comes down to this: some cores offer more functionalities (like having multiple output streams for ds emulation). That combined with having the ability to load "threaded cores" and broader mapping (#58) would be a nice addition.