As a side note, reading "But How Do It Know" for a total beginner like me can help to scratch the itch of understanding the basics. I really loved the book and will buy my 3rd copy (lost one and gave away another).
Another popular book "An introduction to microcomputers" by Osborne, Adam, 1980 also has great detail on this topic..... Its on the internet archive https://archive.org/details/introductiontomi00adam/mode/2up