I see it's already mentioned upthread and you've added to your reading list - but I just want to add yet another recommendation here - Code by Charles Petzold i

I see it's already mentioned upthread and you've added to your reading list - but I just want to add yet another recommendation here - Code by Charles Petzold is so so good in it's early chapters when it gets to the program counter and the fetch/execute cycle. I'm sure you'd really enjoy it!