Code: The Hidden Language of Computer Hardware and Software, Charles Petzold, Microsoft Press, 2000.
It’s safe to assume you will never be called on to build a computer out of relays. But if you were, this book would give you a chance. Starting from relays, he constructs logic gates, flip-flops, and other devices on his way to creating a real CPU. He has less compelling discussions of numbers, codes, 8080/6800, and programming languages. The book doesn’t give you a broad view of architecture, but that’s not its goal. Rather, its charm is in providing that it’s bits all the way down. (Reviewed Jan., ’04)