Code by Charles Petzold
Thursday, December 29, 2011 at 11:18AM
Have you ever bought a book that you knew you were interested in only to leave it on your bookshelf for moths before ever picking it up again? Let me tell you about one of those books.
Code: The Hidden Language of Hardware & Software (you can find it here on Amazon.com for pretty cheap) is a book that was written by Charles Petzold and published in 1999. The fact that it flew under the radar for so long was surprising to me, but as a simple google search for the author's name might indiate, what's even more surprising is the fact that Petzold is probably more famous for his works on software development and computer programming for Windows. But Code is something completely different.
In the foreword of Code, Petzold provides his motivation for writing the book
Code rattled around in my head for about a decade before I started writing it. As I was contemplating Code and then writing it, and even after the book was published, people would ask me, "What's the book about?"
I was always reluctant to answer this question. I'd mumble something about "a unique journey through the evolution of the digital technologies that define the modern age" and hop that would be sufficient.
But finially I had to admit it: "Code is a book about how computers work."
As I feared, the reactions weren't favorable. "Oh, I have a book like that," some people would say, to which my immediate response was, "No, no, no, you don't have a book like this one." I still think that's true. Code is not like other how-computers-work books.
I would certainly agree. Code is nothing like any other book I've ever read on the subject of computing, and I think the reason for that is that a lot of time when people say they want to learn about computers, what they really mean is they want to learn about how computers do what they do. They ask questions like, "What's the difference between ROM and RAM?" and, as Petzold points out "What's the difference between storage and memory?" These questions certianly have answers but often require the reader to understand the nitty-gritty of digital computing. This leads to more quesitons, often ones that ask about binary code and its relationship to hardware operation etc. This is where most people stop caring, because this is where things get complicated. But, this is where Code diverges from the beaten path.
What is a code and why do people use them? Better yet, why do computers use them? Petzold does one hell of a job answering this question. I think the reason I enjoyed this book so much was beacuse the author did not assume that his reader had a Master's in computer engineering. The examples in the book are highly illustrated, and Petzold's commentary is focused and engaging. He begins the book by talking about other types of code and how they have been used throughout history to provide informaiton to the people that use them, namely Morse code as a means of transmitting information over large distances, and Braile as a way of providing the blind with a means of reading withought sight. Each of these forms of codes relies on the notion of binary, the idea that things are either on or off, 0s or 1s, true or false; Petzold doesn't even present the notion of bits, however, until much later in the book. He really makes sure that his audience understands the basics before he moves on.
Petzold really takes his time to outline not only the history of traditional codes such as the ones mentioned above, but he also explains how thoes types of codes lend themselves to the world of digital computing. He goes into detail later on in the book explaining what a computer does and how exactly it does it and provides intuitive examples of how simple circuitry can be built to do amazing things such as add two (or more) numbers together and remember data for later use. He tells you everything you need to know, even if you've never operated a modern computer nor taken a single course in Information Technology, discrete mathematics, or electrical engineering. –– If you're curious about computers, Code is a great book.
If you have any questions about the book or wish to share your comments, feel free to comment on this post or send me a message by email at me[*at]jtgralka[*dot]com. As is with any great book, no blog article can do Code justice. I encourage you to flip through this book the next time you're browsing the shelves of your favorite bookstore. (Or, just buy the book online from Amazon or any other online retailer.) If you're at all interested in what Petzold has to say, 369 pages goes by quickly; maybe your copy won't collect as much dust as mine did!
