Thanks for reading and thanks for all the corrections, in glorious Hacker News fashion. It's definitely a pleasant surprise to see my project here. Putting the "You" in CPU is still very much a work in progress — I was hoping to polish it a lot more and even add some more content before posting on HN later next week :)
Some backstory on me: I'm 17 and left high school a year ago to work full-time at Hack Club (https://hackclub.com/). I've been programming for as long as I can remember, and started homeschooling about 6 years ago to focus more on that (and my other interests).
Since I'm entirely self-taught, I haven't taken any college systems classes — and while I had picked up a lot, I wasn't happy with my answer to "what happens when you run a thing." So I let myself spend a shit ton of time actually learning as much as possible. What I found was that:
1. Operating systems and hardware are really fun to learn about!
2. Wow, online resources on this stuff are terrible.
A decent portion of my research ended up at PDFs of lecture slides from 2014, or StackOverflow answers that were, in fact, incorrect or vastly oversimplified.
So, I wrote Putting the "You" in CPU to hopefully provide a better resource to people who wanted to start teaching themselves all this stuff! While I don't provide perfect coverage (still need to write a couple paragraphs on SMP), it's a lot better than most of what I've seen. I also had fun drawing and making diagrams for the first time, I think I definitely got progressively better and I'm really proud of some of the drawings in the latter few chapters.
P.S. The whole thing is open source on GitHub if you want to look under the hood: https://github.com/hackclub/putting-the-you-in-cpu