This, and "Understanding the Apple II" by Jim Sather are two of my favorite books. It's a lot of fun to open up my Apple 2 (it's a clone but the motherboard is 99% identical), and imagine all the different ICs doing their specific tasks, and the relations between those task, with these books as a guide.
I had both versions of the Sather book, for the II and //e. I bought the Apple when I decided these computer thingies were catching on, and I wanted to learn how they worked. I had to drop back to Don Lancaster's TTL Cookbook to get a basic understanding of logic blocks.
I always found it useful to have a question in mind when you start tearing into something. In my case, it was "how does it know that an "A" on this TV should be composed of just those dots? Why can't I have other fonts? You can't search for only these answers, or you'll miss the important stuff. Eventually, I learned mostly how it worked (the A2D2 Disk Interface card was a revelation).
Then I decided to close the loop on my question, and modify the Character Generator ROM to use a typeface of my own choosing. The chars were stored backwards, due to how the bits were clocked out of the ROM. So I had to do a bit of fiddling to get everything right, then I burned it into an EPROM (2708, IIRC). The stock ROM used a 2500 series PROM, and the enable pins were different. So I wired up two sockets, jumpering the 3 enable pins to line up for the EPROM. The entire mobo was socketed, which made this sort of hardware hacking easy. After a couple of tries, it was working. My //e still has my own custom font on it to this day.
So I was able to learn at a good time. But I missed out on learning about big systems, which were still the mainstream at the time. I even worked with some of them (a Data General Nova at work, and an IBM System/3 to learn FORTRAN IV), but did not realize they were an opportunity to get in to the scene early. Others my age, who lived in more affluent areas, were able to learn early machines, even being paid to program them.
The past always looks better, or simpler, or more understandable, but it never is. The "Good Old Days" never were. You can learn things with today's systems that I will probably never be able to understand. And that's the proper way of things.
