While attempting to travel to the future to get a copy of Portal 3. I accidentally traveled to alternate-1987 and obtained a copy of Portal 1 for the Apple II!
In actuality I originally just planned to do the end credits. But the Apple II high-res mode has the perfect Aperture Science orange and blue colors, and one thing led to another...
If you look at the project webpage, the one picture of the Apple II has a Raspberry Pi3 and serial breakout sitting next to it, left over from when I was trying to help out with the hardware flow control problem.
You might also enjoy the webserver I wrote, also in Apple II Applesoft BASIC: applesoft webserver
That one cheats a bit more, as the ethernet card does TCP/IP offload so the BASIC program mostly just has to talk at the socket level.
In related news, streaming video using a SNES and two NESs. (One NES for each side of a stereo signal).
Have you seen the version of Portal for the TI-83 Plus calculator? It was not mentioned in the list of "Previously" links.
https://www.youtube.com/watch?v=SQvWa_q8OrI
I can't believe that when I had an Apple II i couldn't get decent graphics performance so I learned machine language. There were sprites built-in to Applesoft!!!
OT: Cyberdyne Systems announces at CES 2017 their 835 processor, with on-chip support for neural networks and machine learning.
https://youtu.be/QvnaBT79gn0