Despite being neither a game developer nor a programmer, the technical minutiae of early game programming and graphics are endlessly fascinating to me. Here are a few channels that scratch this particular itch for me:
[Retro Game Mechanics Explained](https://www.youtube.com/channel/UCwRqWnW5ZkVaP_lZF7caZ-g) produces a savant-level series of videos that delves exhaustively (in all senses of the word) into the inner workings of the Super NES and also addresses several specific programming phenomena from older games and consoles. The videos are really second to none in terms of expertly produced visual aides, not to mention the soothing cadence of his voice. Here is one that particularly resonated with me dissecting the psychedelic enemy encounter backgrounds from _Earthbound_:
https://www.youtube.com/watch?v=zjQik7uwLIQ
[Modern Vintage Gamer](https://www.youtube.com/results?search_query=modern+vintage+gamer) produces consistent videos of a digestible size focused mainly on homebrew and investigating older means of copy protection. The topics really do run the gamut of interesting hardware and software quirks, though, and he can speak with some authority as an active contributor to the homebrew community. Here's a recent breakdown of the impressive SNES SF Alpha 2 port, which also addresses modern efforts to improve it even further:
https://www.youtube.com/watch?v=fB9GlZUYNUQ
[GameHut](https://www.youtube.com/channel/UCfVFSjHQ57zyxajhhRc7i0g) is created and maintained by Jon Burton, a founder of Travellers Tales with quite a programming [pedigree](https://www.mobygames.com/developer/sheet/view/developerId,53984/). His channel is updated only sporadically, but he goes into quite a bit of detail about the demoscene-level programming tricks incorporated into what would have been otherwise bland licensed games. For example:
https://www.youtube.com/watch?v=nt-AxAqlrOo
[Displaced Gamers](https://www.youtube.com/channel/UCWoSKWs8h6lFdiEDAjuIfpA) is another channel that really gets into the nitty-gritty with the programming of older games, down to examining and manipulating assembly code in games such as The Legend of Zelda. There is also quite a bit of technical discussion of video output, for example:
https://www.youtube.com/watch?v=3XDyQnY5GHI
Finally, this needs no introduction I'm sure, but the cream of the crop for me is the excellent [DF Retro](https://www.youtube.com/playlist?list=PLY9cZ8nX4xmlpd1RE8_toocbU9cND7U-A) series produced by John Linneman for Digital Foundry. Each of these video releases is an eagerly anticipated event for me--I especially appreciate how expertly he threads the needle between accessibility and technical completeness in his videos. As a specific example, I quite enjoyed the exploration of the quad-based rendering of the Saturn in this video, which included footage of what the game would look like if these quad transformations were completely disabled:
https://www.youtube.com/watch?v=VutzIK3DqZE
