Of all the silly ways to mine bitcoin, this is my favorite. [stacksmashing] used an old Game Boy connected to a Raspberry Pi Zero. In the video, he gives a good high-level overview of how bitcoin mining works.
From Hackaday:
[stacksmashing] does a great job of explaining the project, covering everything from the Game Boy's link port protocol to the finer points of the Bitcoin algorithm in explicit detail. For the technically experienced, everything you need to know to recreate the project is there. While the Game Boy manages just 0.8 hashes per second, trillions of times slower than cutting edge hardware, the project nonetheless is amusing and educational, so take that into consideration before firing off hot takes in the comments below. If you're really interested in the underlying maths, you can try crunching Bitcoin hashes with pen and paper.
The world would be a better place if bitcoin mining was legally prohibited on anything other than an original Game Boy.