The Hidden Language of Computer Hardware and Software

The book starts off very easy and understandable. At about chapter 10, when logic gates are introduced, I felt I was reading a text book, without the practice problems or variety of examples. The author's ability to write cohesive understandable statements diminishes at this point in the book. Assumptions begin to be made about circuit diagrams, and it is extremely easy to become lost. The book is not easy to read at all post chapter 10ish, and this why EE and CE's get paid 100k+ per year. Code has great merit, but the reality is the subject matter is tough to understand. Those of you who give this book 5 stars claiming they were completely enlightened are full of it. Just because you took the time to read the words doesn't mean you understood what they said. I wouldn't be surprised if less than 40% of the book was understood by most readers. Those with an EE or CE degree (hopefully) understood it all, but they didn't need to read the book to learn anything new.

This book gives a clear understanding of core concepts the computer is built on. Everything is explained in the subtlest details making this book appropriate for an ordinary person without any technical background. Excellent!

This is a pure gem. The author basically takes you on a journey of code and computer evolution through different periods and different applications. It's definitely a joy to read. If you know a lot about computers (I'm a software engineer), then you might not learn a whole lot of new concepts, but that does not mean that you are not going to enjoy reading this -- it's just one of those great reads, period. I'll bet that even more knowledgeable individuals will pick up some fascinating things from this book. I am not exaggerating when I say that this is one of the best computer science related books I've ever read in my entire life. The writing style is so incredibly approachable, with amazingly clear and simple examples and explanations. I wish some of my textbooks while getting my Computer Science degree were as good as this. I'm simply blown away and sad, at the same time, because it's so hard to find such amazing books.

I'm sure many people, faced with a computer (or another high tech gadget) wonders how it really works. Parts of its functioning are explained in the popular press, but you almost never get the whole picture: to many people (even highly educated people) the functioning of a computer must be something akin to magic. Petzold's book tries to remedy this by trying to explain how the computer works from the bottom up. The book is fascinating stuff, and is easy to follow at first. He easily explains concepts such as the binary code, logical gates, switches, the merging of boolean algebra to electrical engineering (this was first considered in a master theses by Claude Shannon, and its probably the great breakthrough that led to modern computing), the roles of transistors, microprocessors, etc. Inevitably, the complexity rises in the later chapters, and if you are not a physicist or an electrical engineer, you would be unable to understand everything. But it is nevertheless a good, recommended read.

This book ties multiple college courses together - from basic math to cpu design to machine language to computer architecture and organization to finally operating systems and high level programming concepts. It's a good overview on all the concepts but being a college grad with comp sci degree this book has little to offer.

Ordered "Code" by Charles Petzold. It is a great book that starts with the basics. I received the book faster than I expected. It was in like new condition. Couldn't be more pleased with the service and the product.

Started off ok, and then I went to sleep halfway though. Goes to show why I'm not a developer.

Reminds me of Godel, Escher and Bach, actually. I find the actual topics fascinating, and I like the way the connections are made through the various concepts ... until the point I get lost and am never found again.

Still a great book in 2015. Relatively little has changed about the fundamentals of computers aside from the numbers of gigabytes and megahertz.

Petzold explains how the complexity of computers arises from simple relays (or transistors these days). You learn how to make the necessary logic gates and assemble them into the basic parts of a computer.

As you learn how the logic gates are assembled, you learn how to program in machine code (and assembly language--they are two sides of the same coin). After you've learned assembly language for the imaginary computer you've built throughout the book, you learn the basics of how higher level languages and operating systems are built on top of the machine instructions.

It would have been nice if Petzold had been in-depth a bit more with higher-level language compilers and operating systems, it didn't get the same treatment as building the CPU received. He waited until the end and sort of glossed over the basics of these topics. Maybe that is the job of another book.

This book is easier to understand than a textbook and the average reader should be able to get through it as long as he/she has the motivation to keep going. In truth, the concepts are complicated--this stuff has taken the world's greatest minds 50 years to figure out--but Petzold explains it as simply as possible with minimal jargon.

I recommend that anyone who is interested in computers read this book, you will enjoy it. Even if you aren't able to understand 100% of the material, you'll learn something important.

Code is a history of the personal computer told from the point of view of the skilled amateur technologist. Most histories are a recitation of events and their effects - "In 1931, Dr Smith assembled the first electro-modulated adding machine, which was used to calculate tax tables". Here we are presented with the technical challenges of each era and walked through how the technology works, then given a short project to explore what could be derived from this technology.

For example, the chapter on telegraphy only briefly touches on inventor Samuel Morse before diving right into the mechanics of how telegraphs worked to enable near instantaneous communication across miles of wire. Earlier chapters on braille and semaphores explored the concepts of encoding - breaking words into binary units that could be consistently decoded. The telegraph chapter covers the main failure of that tech (the signal strength fades after a few dozen miles over wire) and the solution - relays which strengthen the signal and allow for hundreds of miles of range. The next chapter picks up on the relay and what new devices could be built with them. By the mid-point of the book, the author shows how you could build a simple functional computer using telegraph era technology.

Computer legend Charles Petzold (author of some of the major programming guides to Windows and the ancient OS/2) wanted a practical history of computers that shows how the tech evolved step by step.

The writing is clear and fairly crisp, with plentiful diagrams and examples. This is more a backgrounder than anything else, but its a fast read and a handy introduction for the skilled amateur.

I'm a senior in software engineering, so I was hesitant to invest time in reading a book that seemingly would only result in re-hashing much of what I already studied in college. I'm very happy I decided to look into CODE, and only wish that I could have been exposed to it earlier in my career.

A short summary of the book could be "how a computer works, from the ground-up." Much of the knowledge contained here will be familiar to those in computer science/electrical engineering and associated disciplines. The value that I found was in its ability to connect the different discrete concepts into one cohesive whole. I've taken many courses that have gone over these individual concepts, but it always seemed I was left with a gap between them. Petzold does an impressive job of making each piece of the computer accessible through analogies or light introductions and then connecting all of the individual parts together to make explain a computer in its entirety.

I've taken a whole course on digital logic circuits, and even managed to get a decent grade at the time. But I always knew that my understanding was only ankle-deep and I didn't properly understand the interaction of logic gates into integrated circuits, and eventually, microprocessors. This specifically was an extremely valuable piece of CODE that has resulted in a much deeper understanding. And this happened frequently within the book: for example, I've been familiar with the IEEE 754 standard, but its introduction as a mimicking of scientific notation didn't occur to me until I read the explanation in the book.

I'm not sure the book is as accessible as it may claim, however. Even though it is well-written, the information contained within isn't trivial to grasp, even with the great explanations. An interested reader would have to be quite dedicated to get through the book and understand all the concepts. If you believe you're such a reader, and especially if you've studied/worked in a career that's close to hardware & software, I think reading this book could do more than taking a college course on computing.

Code was recommended to me by a programmer friend with over 30 years industry experience after I expressed to him my interest in learning to program video games. He only first read it himself a few years ago, and despite all his long years as a programmer he found the book extremely valuable. His advice was to make this book the first thing that a beginning programmer should read. After reading it myself, I agree 100%.

Reading this book was the single most valuable learning experience I encountered in the past three years which I spent studying the skills of game-making. Basically, it explains how computers work on a fundamental level, but in a way that I have not encountered anywhere else. I think so many programmers learn to code without having a full understanding of the underlying technology of how the system they are using works. This book gave me that understanding.

It's a little dry in parts and requires some mental heavy-lifting. Ultimately, it is understandable and the author does an excellent job of explaining the evolution of computing hardware in an sequential way. Most of it was fun for me to read, although certain chapters were very difficult for me to get through since I have trouble with math stuff. I just kept going over and over the passages I didn't understand until I got it. Referring back to earlier sections of the book and further research on Wikipedia helped me get through the tough spots. In the end I grasped about 99% of the concepts.

The end result is a deep understanding of how computers work at the most basic level. I think this is helping to accelerate my learning of programming because everything makes sense now. Thanks to this book, when I am trying to learn a new programming concept, I see connections everywhere to concepts I read about in the book.

I can't sing this book's praises highly enough. It is helpful to anyone who is interested in computer programming, no matter what their experience level is.

Charles Petzold is an amazing teacher and communicator, taking the complexities and chaos of computer programming, and distilling it for a general audience. His is an eclectic mind, and he mixes math and history to tell a compelling story. Unfortunately, as the complexity grows, Petzold loses his patience, and thus his clarity. As well, the issue with computers is that only after a few years the book is horribly antiquated.

Years ago I read a book called, "Inside COM." It was unusual in that it didn't merely explain how COM worked and how to use it, but much more interestingly it explained why COM was the way it was through a compelling progression of ideas that begin with first principles. This set the book apart from virtually every other technical book I had ever read, and I had not come across another like it until I read "Code". Code begins with the basic notions around how and why we encode information, and walks the reader step-by-step through the fundamentals of logic gates and how they can be assembled into programmable computers. The pacing is fast enough to keep you turning pages, but patient enough to ensure that just about anyone can follow along. And, even if you already know 90% of the subject matter, you'll keep turning the pages as you enjoy watching the author assemble these ideas into a complete picture.

I picked this book up for something to read during a recent long trip; I had heard good things about it, so I decided to give it a chance. When I read the preface, I started to get worried, though: "After finishing this book, you'll have an understanding of computing systems that rivals that of many professional programmers". Oh, great, I thought - I've been a professional programmer for decades. I doubt there'll be anything interesting to me. How wrong I was! Of course, the discussions of logic gates and ASCII vs. EBCDIC were review for me, the way the author ties everything together in its historical context make the book worth it even if you already know everything in it (and trust me, you probably don't). Most of the book is the development (on paper, anyway) of an electromechanical computer using magnetic relays so that it's obvious at any point exactly what's going on. Hightly recommended for anybody of any experience level.

I'm really glad that i read this book. I honestly had given up on ever finding a book like this- and i'm so glad to know there ARE people out there who want to know how the amazing things around them work! Anyway- about the book- it starts from the very basics- introducing binary systems and the binary code that computers use, and it is explained so that ANYONE who is interested can understand it. The diagrams are all very clear and helpful. The book then goes into very basic circuits and how the differences in wiring can create logic circuits, and it is fascinating stuff. All of it, as i've already mentioned, is very neatly illustrated. Then he covers programming- and how the circuitry and programming go together! he does this all with plentiful information, obviously from many areas.

This book is the best book i've ever read. To be able to put this much information into one small book is no small feat. Thank you, Charles Petzold.

A masterpiece. From number theory to an overview of historical messaging and encoding/decoding system, building simple circuits and basic CPU architecture, Code makes understanding the the fundamentals of computer science, computer architecture and software fun, interactive and relatable. The theory is grounded in wonderful vignettes about kids using flashlights to communicate at night and fascinating historical context around Morse code, Braille and other language systems.

The book is never dry, boring or hard to follow. This book will deepen your understanding of the world around you. A must read.

Code was recommended to me by a programmer friend with over 30 years industry experience after I expressed to him my interest in learning to program video games. He only first read it himself a few years ago, and despite all his long years as a programmer he found the book extremely valuable. His advice was to make this book the first thing that a beginning programmer should read. After reading it myself, I agree 100%.

Reading this book was the single most valuable learning experience I encountered in the past three years which I spent studying the skills of game-making. Basically, it explains how computers work on a fundamental level, but in a way that I have not encountered anywhere else. I think so many programmers learn to code without having a full understanding of the underlying technology of how the system they are using works. This book gave me that understanding.

It's a little dry in parts and requires some mental heavy-lifting. Ultimately, it is understandable and the author does an excellent job of explaining the evolution of computing hardware in an sequential way. Most of it was fun for me to read, although certain chapters were very difficult for me to get through since I have trouble with math stuff. I just kept going over and over the passages I didn't understand until I got it. Referring back to earlier sections of the book and further research on Wikipedia helped me get through the tough spots. In the end I grasped about 99% of the concepts.

The end result is a deep understanding of how computers work at the most basic level. I think this is helping to accelerate my learning of programming because everything makes sense now. Thanks to this book, when I am trying to learn a new programming concept, I see connections everywhere to concepts I read about in the book.

I can't sing this book's praises highly enough. It is helpful to anyone who is interested in computer programming, no matter what their experience level is.

Charles Petzold is an amazing teacher and communicator, taking the complexities and chaos of computer programming, and distilling it for a general audience. His is an eclectic mind, and he mixes math and history to tell a compelling story. Unfortunately, as the complexity grows, Petzold loses his patience, and thus his clarity. As well, the issue with computers is that only after a few years the book is horribly antiquated.

Years ago I read a book called, "Inside COM." It was unusual in that it didn't merely explain how COM worked and how to use it, but much more interestingly it explained why COM was the way it was through a compelling progression of ideas that begin with first principles. This set the book apart from virtually every other technical book I had ever read, and I had not come across another like it until I read "Code". Code begins with the basic notions around how and why we encode information, and walks the reader step-by-step through the fundamentals of logic gates and how they can be assembled into programmable computers. The pacing is fast enough to keep you turning pages, but patient enough to ensure that just about anyone can follow along. And, even if you already know 90% of the subject matter, you'll keep turning the pages as you enjoy watching the author assemble these ideas into a complete picture.

Wow. Before I read this book, I already knew about logic gates, but I did not know (1) how electric and electonic devices can in the real world perform the function of logic gates and (2) how by arranging logic gates wisely one can perform addition and subtraction and (3) more complicated mathematical operations can be performed by doing "a lot of" additions and subtractions. Now I (kind of) know.

All these are gratifying.

Starting from Chapter 17, however, the speed and depth of the book changes gear quite a bit (at least to me). From that chapter onward, it is about the relatively detailed working of a modern computer - e.g. how integrated circuits (chips) work, what microprocessors are, etc. In Chapter 18, for instance, the author answered the question in the preface: "why can't you run Macintosh programs under Windows?". It is quite rewarding to understand why.

Different readers will have different views towards this book. By profession I am a physician and have no experience in serious computing, so I myself find Chapters 21 and 22 particularly difficult. But overall I think I have learned a lot from this book. Five stars.

I picked this book up for something to read during a recent long trip; I had heard good things about it, so I decided to give it a chance. When I read the preface, I started to get worried, though: "After finishing this book, you'll have an understanding of computing systems that rivals that of many professional programmers". Oh, great, I thought - I've been a professional programmer for decades. I doubt there'll be anything interesting to me. How wrong I was! Of course, the discussions of logic gates and ASCII vs. EBCDIC were review for me, the way the author ties everything together in its historical context make the book worth it even if you already know everything in it (and trust me, you probably don't). Most of the book is the development (on paper, anyway) of an electromechanical computer using magnetic relays so that it's obvious at any point exactly what's going on. Hightly recommended for anybody of any experience level.

I'm really glad that i read this book. I honestly had given up on ever finding a book like this- and i'm so glad to know there ARE people out there who want to know how the amazing things around them work! Anyway- about the book- it starts from the very basics- introducing binary systems and the binary code that computers use, and it is explained so that ANYONE who is interested can understand it. The diagrams are all very clear and helpful. The book then goes into very basic circuits and how the differences in wiring can create logic circuits, and it is fascinating stuff. All of it, as i've already mentioned, is very neatly illustrated. Then he covers programming- and how the circuitry and programming go together! he does this all with plentiful information, obviously from many areas.

This book is the best book i've ever read. To be able to put this much information into one small book is no small feat. Thank you, Charles Petzold.

A masterpiece. From number theory to an overview of historical messaging and encoding/decoding system, building simple circuits and basic CPU architecture, Code makes understanding the the fundamentals of computer science, computer architecture and software fun, interactive and relatable. The theory is grounded in wonderful vignettes about kids using flashlights to communicate at night and fascinating historical context around Morse code, Braille and other language systems.

The book is never dry, boring or hard to follow. This book will deepen your understanding of the world around you. A must read.

This is probably the most useful book on computing I've ever read. Yes books on assembly language and higher level languages such as C/Perl/Python are more immediately practical but working through this book will completely demystify concepts such as memory segments, integer arithmetic, pointers, so forth and so on that have to be accepted "at face value" if you only deal with them at more abstract levels. Which, considering that the book begins with a discussion of circuits at the electron level, is pretty much machine code on up.

One suggestion: use a simulator such as LogiSim and take the time to work through the circuits the author presents in the text. As well as the discussion - I found it added to the interest of the book to work out, as exercises, modifications to circuits the author describes in words but does not depict fully in the form of circuits. It's also gratifying to use LogiSim to catch the author occasionally oversimplifying matters as with his discussion of the simplified adder (kindle location 4836), which does not work correctly as the author presents it - but the reader CAN make it work with a bit of time and thought.:)

Good stuff.

Every Computer Science book I have read basically brushes off the internals of machine language especially when dealing with the higher-level languages as they move to compiler to machine language. "Abstraction" is usually the excuse (albeit a necessary one when trying to focus a book on a specific technology) but sometimes trying to put a program together or understand a particular aspect of the language feels like trying to solve a puzzle without seeing the overall picture while trying to put it together. This book, in my humble opinion is the box with the puzzle art and the corner pieces. Without it, trying comprehend how computers talk, programs talk, the fundamental properties of language, etc. has been extremely difficult. How does one work a puzzle without knowing what the definition of a puzzle is? I strongly encourage you to add this to a collection (even if you are a seasoned programmer) as it touches on a little bit of everything and is a nice steady read without being boring!

To be fair, Charles Petzold simplified the idea of Code and software programming languages to the best of his ability and to be honest it really is simplified. Howweevvveerrr...it isn't for the novice. I began reading this book before I learned how to program and after...the second time I tried it was soo much easier and the concepts stuck well. I think the only thing wrong here is that, it's a bit misleading in that sense. It's still an awesome book nonetheless. Just know, that if you don't know anything about computers....You will be confused...otherwise it's a great read.

I have been an IT professional for 20 years, but I never knew what the switches on the front panel of the Altar computer were for. I do now.

In fact, because of this book, I know many things about how a computer really works that I never did before. I think this book is great for anyone, except Electrical Engineers who would be bored. Having some background in computers probably makes this book easier to get through, but Petzold assumes nothing and starts from scratch. He does a good job of making potentially dry subjects fairly interesting.

I think an update to this book would be great, because the discussion of 1999 capacity and pricing makes the book feel dated. Also, the last chapter seemed rushed and not as well focused as the rest of the book.

So, if you want to know how any computer really works, read this book.

I wanted to write a review for this book for the past few weeks, but held off until I finished reading it completely, in case there was some disappointment at the end. Thankfully that is not the case - the book is excellent from start to finish.

You can see the amount of love and care that the author has put into this work. From the easy to read font, thought-out diagram and image layouts that never make you flip-back the pages - to the excellent teaching-like style with which the author gradually tackles the topic. It is amazing. I found myself holding off reading too much of the book at once, because I wanted to prolong the pleasure!

I recommend this book to anyone. The first seven or eight chapters should be accessible to anyone, regardless of their technical background, and are alone worth the price of the book. This book should be enjoyed from start to finish, just like a novel. Unlike a novel this book not only provides the reader with the pleasing reading experience, but also with some very useful lessons and fundamentals.

I like the author's approach so much that I have purchased his next book "The Annotated Turing". I will post my impressions of that when I am done.

The last chapter alone is worth the price of admission. A bit difficult at times, you have to think about it. Crazy I know. It is a book you read bits (pun) at a time. It reminded me often of my college years (Electrical / Computer engineering). It even helped me figure out a few things I missed way back then. Get it, Read it, Enjoy it. Just don't do it in a single session.

Many people enter the world of IT - especially software development - using terminology, tools, fashionably following best practices de jour and spending huge amount of time and energy trying to make computers follow instructions with more or less success. By time, each one of us gains experience and we become better and better at what we do.

I highly recommend this book to every person who work in the IT field. By going back in history and learning how our instructions are understood and performed at the hardware level we become better at what we do.

Charles is top notch technical writer and knows how much stress certain topic can give to our minds. I see reading his book more as a pleasant journey where I consolidated my knowledge and understood everything I know about computing much clearer then before.

I am a general reader with 'some' interest in computer programming. I also have 'some' knowledge and interest about almost anything in this world. I found this book when I was looking for a programming related book in our local bookstore. I picked it up since it interested me initially due to its reference to morse code etc. I used to be intrigued by morse code (which I had found in one of my dad's telegraphy books) and used to even use it with a friend while keeping our language a secret.
I must say that I found the book really amazing which is why I am writing the review. I also feel that it should be classified in more of general interest books (the bookstore had it under the software books as I mentioned earlier). I believe there might be other readers with general non-fiction interest who might miss this excellent opportunity just because they were not looking for some software book.
Finally, I want to put a note of appreciation here for whoever designed the cover (I tried looking on the inside jacket). It is amazing while being strikingly simple. That is actually the first thing that caught my attention. Seems like a summary of all the design theories you ever read about. Highest degree of simplicity achieved by conscious thought and effort. Very intellectually provoking.

As a hobbyist programmer, I had wondered for years how a computer worked at its most internal level. I had even had a couple of unsuccessful encounters with other "How Computers Work"-type books that left me mainly with the dissatisfied impression that the machine was an impenetrable black box.
Petzold's book was not like this. While other books started with flashy graphics of internal designs all flowcharts with little in the way of explanation, Code starts off simply, with two flashlights and the goal of communicating at night. This problem, of course, would be easy solved by anyone who knows of Morse code. Yet, from Petzold's pen it becomes an illuminating and amusing journey with attempts to deal with similar scenarios of every increasing complexity until I realized two-thirds of the way through that given a sufficient time and space, I could, at least in theory, build a computer. This is the greatest success of Code, in my opinion. Rather than attempting to peel away the mysteries of the system a layer at a time like an onion, it delves directly to the core and builds upon its ideas in a fashion like that of the original computer designers, until everything forms into a cohesive whole. Petzold does an excellent job of capturing his excitement for the material, making the progressive developments a joy to read about.
With my uneven background knowledge, there were a few sections that I felt that I could skim through, but also many a passage that I had to carefully scrutinize. Overall, I'd recommend this book for anyone interested in computers, from beginner to expert: Petzold provides enough explanation for a determined newcomer to understand all of the concepts, but enough breadth to still entertain and educate those with more experience in the area.

I recall the book being split into three parts:

The first third of this book is a crash-course in various "codes" used for communicating -- Morse code, Braille, and eventually Binary/Octal/Decimal/Hexadecimal. The author simply explains how to communicate messages using only 2 signals (on/off). This

The second third of the book delves into the history of computing, automated machinery, using electrical signals to convey messages (starting with the telegraph), and eventually working up to "Switches" -- the basic building block of a computers. From there, the author explains, very slowly and clearly, how to build a rudimentary computer. Even if you are not interested in the logical diagrams of circuits, you could easily skip past these sections and still find a wealth of information in the book.

In the third part of the book, after building our basic computer, the author goes into Processors: when they were popular and mass-produced, how people programmed with them, what each chip does, etc. The author explains how newer computers had different processors, and how the x86 chip is still commonly used in PCs today. The author also explains how advances in technology are trending.

The book is a little dated -- my edition was only current up to the year 2000. However, not much has changed in how a computer is made and powers itself on since 2000. This is a must-read for anyone interested in being a programmer or computer electrical engineer. It's also vital for anyone who really wants to know how a computer works.

It's not often I willingly give money to Microsoft, but I bought this book in hardcover. I don't care if Petzold is a hardcore Windows guy or not; this book is as deserving of immortality as the Lions book or "Godel, Escher, Bach".
Why? Because it lays it all out. Though it goes a bit light on the actual electronics, preferring to focus on the telegraph relay as its main way of understanding what's going on, this book takes the reader from square one -- sending messages to a friend with a flashlight -- to the structure of a modern microprocessor. It's an incredibly detailed yet easily accessible look at the internals of a computer system.
Flaws? A couple -- no index, and as I said it gives short shrift to what may be the single biggest invention of the 20th century, the transistor. But by and large Petzold has written the ultimate book to explain the mysteries of the computer to the layperson. This book is a must-buy.

Even though this book was published almost a decade ago, it is a wonderful, fascinating read. If you have ever wondered about the codes (broadly speaking) that make computer hardware and software work the way they do, how the many inventions of mankind that have made our lives more productive work, read this book. The fact that it was printed in 2000 did not stop me from buying it. I was initially intrigued by the title and after reading a few pages, I decided it is a book I MUST have for my personal library. Three chapters caught my eyes particularly: Chapter 3 - Braille and Binary Codes. You could not find a better chapter/book on Braille and how it came about. Chapter 18 - From Abaci to Chips. Here you will find a great account of the evolution of the calculating machine, from abacus to the modern calculator. (being Chinese, I learned how to use abacus from my dad/and in school) Finally, the last chapter. Chapter 25 - The Graphical Revolution. As someone who is not a technie but someone into art/photography, this chapter is priceless, it takes the reader from the very beginning of computing, the evolution of how graphical information is presented, CRT, TV, GUI, Vector and Raster graphics, jpegs, gifs. I am so pleased to have bought the book. Highly recommended.

There are plenty of reviews extolling the virtues of this book. Instead of repeating what has been said, I just want to say that even though Code was published in 1999, it is not at all out of date.

Sure, there are a few places where Petzold mentions specific numbers such as the current price of RAM, typical hard drive sizes etc. Of course those numbers are out of date 12 years later. But those numbers are not at all essential to the story. Even though computers have become faster, smaller, and more ubiquitous since 1999, they still work the same way.

If you want to understand computers, this book is just as relevant now as it was in 1999.

How come I never read this book when I was an undergraduate in electrical engineering major during 1999-2001? Just beat me! I took the liberty to write the review specifically for students majoring in computer science and electrical engineering.

Now a days, the computers are so prevalent and seem so complex that we think it is a complicated machine, but it's quite the opposite. This book beautifully explains it and keeps a perfect balance with historical perspective.

Most textbooks on logic design and electronics do not teach the historical motivation why things in computer came into beings as such, but this book does. For example, it explains why the binary system was such an essential idea for computer revolution. At the time people were still trying to use decimal system to create the computing machines.

Not only you get the historical motivation why computer came into being, but you also get the thought process. On the way you learn how UPC code works? How relay works? How digital electronics work? How logic gates work? How logic gates are combined to form more complex subsystem such as Multiplexor, Decoder, Adder, Subtractor, RAM. And ultimately, how computers hardware and software works? All this is done in a clear and lucid manner and just the right tone.

You continue your journey through how computer represent computer graphics, floating point arithmetic and operating system. This book also touches on why high-level languages are required.

In conclusion, you get basic essential engineering concepts that are required in future and more advanced courses in an absolute clear manner which, in my opinion, is unmatched by any other book on computer fundamentals.

I can't say enough good things about this book. I've recommended it to friends of mine coming from all levels of understanding. Few times have I been as enthusiastic about a book as I have about this one.

CODE is perfect except for the end. For 3/4 of the book, everything is meticulously and wonderfully detailed. However, in the last quarter, Petzold explicitly focuses on limiting his book to a certain number of pages and gives us a whirlwind tour through some really interesting topics. I'd like to see another 1 or 2 books explaining these to the same degree of detail as all of the early chapters.

This is the college textbook that was never recommended.

It gives easy to understand examples to explain difficult to grasp concepts (especially for beginners)

An example would be the use of cartoon hands to explain octal base, flippers to explain binary base. Powerful imageries used on difficult to understand topics. Two thumbs up!

This book cleared up some fuzzy areas that I have always been interested in but never really had the time to pursue. I have been developing software since 1980, and got this book because of the sample chapter that I read from the MS website. Now that I have read the book, I am able to better understand the electrical system on my plane (a surprise side effect of reading the book, I expected it to be more high level)
I would recommend this book to all software developers, and also anyone that has any technical hobbies. It has much technical information, but is also very easy to read.
Steve

This book is precisely what the doctor ordered; truly, there is no other book that even comes close to this one, in terms of actually capturing the most elegant, explicit essence of what the computer actually is, and does.

This is the standard that all other computer books must now live up to, and I'm sure that no small number of rival authors are a little green with envy. After all, nine years after its original publication in 1999, this book is #27,439 on the store... a score that easily outranks the majority of newer books!

It's a classic. I only hope Petzold does updated and, even, illustrated versions of this book. It is the "Cosmos" and "A Brief History of Time" of the computer industry.

Myself being a graduate Computer Engineering major couldn't help but love this book. I agree with other reviewers out there who think this book is not all for a novice. I wish i had this book with me when i started as an undergrad major in Computer and Electronics as a handbook or guide to put things in clear perspective (why i had to learn the list of subjects for this particular field and when and where do they fit into the progression of technology). Much better investment than visiting the computer history museum in Silicon Valley.

I am an engineer and I have studied the topics covered by this book but reading it I couldn't help to understand the concepts much better and to wonder aboout the smarts of all this devices and systems. Everybody can follow this book and it takes you from the basics of signal and information to the real "guts" of modern computers and programing step by step and with rich methaphors and illustrations.
A great book to understand the origins of Information Systems and a great book to refresh concepts for the pleasure of it.
The only weak chapter in my opinion is the assemblage of memory. The treatment is uniform but this subject is soo dry that in my opinion taking some distance would have been better.

This is one of the best books I have ever read!! This author is absolutely brilliant!! I would suggest any person going into electrical engineering or computer engineering, more for electrical engineers who want to understand digital systems this book is it. In every book there is always a couple pages explaining what is happening intuitively. This entire book is that. He explains exactly how computers got to be, and really electronics and digital systems. He exlpains flip flops, relays, and how to go from boolean algebra to digital logic better than anything I have ever read, even better than dare I say Mims and Malvino. This is so good it is scary. Please read!!!! He also explains the entire computer history, and you really get a good appreciation of how brilliant some people really are. This author also has two other books that are really best sellers. He ties in so many different ideas and explains things so simply. His starting off with the telegraph and moving from there is amazing. This author is extremely gifted in writing. One of the best books I have ever read.

After reading this book, I wrote an email to Charles Petzold. Here's an abridged version:

-=-=-=-=-=-=-=-=-=-=-=-=-

Dear Mr. Petzold,

Thank you. Thank you for writing this book! I just completed it, and am happy to say that I feel strengthened in my understanding of how computers really work. I enjoyed the examples, the humor and the simple, straightforward explanations. It is amazing to see what can be built by combining simple, tangible objects with novel ideas.

Sincerely,

Adam Monsen

-=-=-=-=-=-=-=-=-=-=-=-=-

This book is not for the easily distracted. I had to read over some of the examples many times before I felt like I really "got" them. The effort was well worth it, and I'm glad I discovered this book! If you're ready to dig in and really understand how the computer works, check it out.

This book might be thought of as a "beginner's tutorial to assembly language". Many pages are spent explaining the purpose and fuction of machine language and data.

I'm currently a hobbyist programmer and computer enthusiast who plans to move to professional. I play mostly with C, and Python but have recently been dipping into Assembly.

This book provided me with the underlying foundation of how and why a computer works. If I had one phrase to describe this book it would be "de-black magic computers". The knowledge it provided has been fundamental in my diving into deeper parts of assembly, C and computers in general.

I absolutely loved this book and would recommend it to anyone who wished to understand what is actually happening inside of a computer. If you have a geeky or semi-geeky teenager this book provides a great method of letting them truly understand computers.

This is the best introduction to the fundamental concepts behind computer science that I've ever read. That said, I'm not talking about a textbook for a Master's level Comp Sci treatment - but this IS the most complete, well-written, and accessible treatment of the subject that I know of. If I were trying to introduce a reasonably intelligent individual to these concepts, I'd not hesitate to direct them to this volume.

The average person who uses a computer to surf the web or type letters has so little knowledge of the underlying technology he or she is using that it may as well be magic. Even programmers, who typically spend their days solving problems with the high-end abstractedness of object-orientation, may be more than a little unclear about what's actually going on inside the box when their compiled code is running.
Petzold attempts, and largely succeeds at, writing a book that leaves the reasonably intelligent layperson with a thorough comprehension of each layer that comprises a modern electronic computer (binary coding -> electronic representation -> transistors -> logic gates -> integrated circuits -> microprocessors -> opcodes -> assembly language -> high-level language -> applications). At times, the reader must follow along carefully, but Petzold tries to avoid needless complication.
Code is a well written and very entertaining explanation of the digital electronic technology that has become an integral part of our daily lives. Short of getting a degree in electrical engineering, this book is your best bet to understand how it works.

Charles Petzold a does an outstanding job of explaining the basic workings of a computer. His story begins with a description of various ways of coding information including Braille, Morse code, and binary code. He then describes the development of hardware beginning with a description of the development of telegraph and relays. This leads into the development of transistors and logic gates and switches. Boolean logic is described and numerous electrical circuits are diagramed showing the electrical implementation of Boolean logic. The book describes circuits to add and subtract binary numbers. The development of hexadecimal code is described. Memory circuits are assembled by stringing logic gates together. Two basic microprocessors are described - the Intel 8080 and the Motorola 6800. Machine language, assembly language, and some higher level software languages are covered. There is a chapter on operating systems. This book provides a very nice historical perspective on the development of computers. It is entertaining and only rarely bogs down in technical detail.

As a person who is mathematically inclined, but never took a computer science or computer engineering class, I had always wondered how computers really work. Yes, we all know "it's binary", or "transistors" but there is a great divide between on/off and IBM's Watson. Rightfully so, as the author goes through the history of computer hardware development beginning with the telegraph, and explains that 150 years of technical development has taken place from the on/off concept to modern computing. He takes us step-by-step and shows how very simple things such as switches can create gates, circuits, and ultimately the computing machine that you're reading this on. This book has been enlightening and it gets the highest marks for quality of explanation, for staying interesting and on topic, and for value. I could not put it down, and I've since used it as a reference. I fully recommend.

I failed. Without any background or education in computer science, I tried to learn HTML, CSS, Python, PHP, Java script because I simply like the logic. I tried to use APP builders to create APP. I tried to run Ubuntu in my laptop. I tried very hard but I failed. I failed to be good in this. I can see myself never able to be exceptionally good in it. Because I don't do it structurally, because I give up too soon, because ultimately I dun understand the fundamentals. Secretly, I think I'm stupid.

OK. I hold a master degree in Philosophy. I cofound a company running fairly. Maybe I'm not so stupid. Maybe it's because I'm learning in a wrong way. After I downloaded the sample and read it, I immediately know that this is the book that will open the gate to computer science in my language - layman (me!), yet shows the why behibs

Just finished the book and it was great! This is exactly what i was looking for! I'm a webdev, but i hardly understood how computer operates under the hood, how we got where we are now with all this modern technologies, operating systems and other stuff like that. How the first programs were build and how they were executed. This book is the answer. The explanation of how the computer operates internally are really good. This is the must know minimum for developers and a good start if your want to go deeper and learn some more advanced stuff. Modern computers are more complicated than those described in the book, but most of principles are still kept true i believe and will be kept for a long time. Ones you know the basics and understand how a simple computer can be built and operate you can then go for some advanced topics.

Many books on technical subjects are either too technical or sweep too much under the rug so you either get bored half way through or you get through it but learn nothing. Charles Petzold manages to balance things just right so you are thoroughly engaged and nothing is being swept under the rug so you actually learn something without being bored to tears. If you've ever wondered how all the bits and pieces of modern computers fit together to accomplish their magic then this book should definitely be on your reading list.

Code is a fantastic read for anybody interested in different aspects of computer science. Petzold explains the history of the computer and how simple switches eventually evolved to handle extremely complex tasks that computers can handle today. It covers all major aspects of today’s computer hardware and software technology. This is a great read because it allows anyone to learn extensive amounts about computer science with prior knowledge.

This book is a true creation of art. It is a must have for anyone who wants to understand how computers work at the lowest of the levels. It starts off with "What is electricity?" and builds up on the design of a truly working modern computer.

Plus, you don't have to be an electrical engineer or have any knowledge on electronics, since the author assumes no previous knowledge on the field. No one but Charles Petzold could have ever written such an amazing master creation aimed at both the knowledgeable individual and the total newbie.

Charles Petzold's writing style is delightful and attractive; it couldn't have been any better. Also as I read further into the bowels of the system, eventually I got these thrilling sensations like "No way anyone could have ever thought about this" or "No way this is possible". The way the text is put together allows for such moments of amazement.

The book is loaded with diagrams. Every single step into the woods is clearly explained and illustrated.

Charles Petzold a does an outstanding job of explaining the basic workings of a computer. His story begins with a description of various ways of coding information including Braille, Morse code, and binary code. He then describes the development of hardware beginning with a description of the development of telegraph and relays. This leads into the development of transistors and logic gates and switches. Boolean logic is described and numerous electrical circuits are diagramed showing the electrical implementation of Boolean logic. The book describes circuits to add and subtract binary numbers. The development of hexadecimal code is described. Memory circuits are assembled by stringing logic gates together. Two basic microprocessors are described - the Intel 8080 and the Motorola 6800. Machine language, assembly language, and some higher level software languages are covered. There is a chapter on operating systems. This book provides a very nice historical perspective on the development of computers. It is entertaining and only rarely bogs down in technical detail.

As a person who is mathematically inclined, but never took a computer science or computer engineering class, I had always wondered how computers really work. Yes, we all know "it's binary", or "transistors" but there is a great divide between on/off and IBM's Watson. Rightfully so, as the author goes through the history of computer hardware development beginning with the telegraph, and explains that 150 years of technical development has taken place from the on/off concept to modern computing. He takes us step-by-step and shows how very simple things such as switches can create gates, circuits, and ultimately the computing machine that you're reading this on. This book has been enlightening and it gets the highest marks for quality of explanation, for staying interesting and on topic, and for value. I could not put it down, and I've since used it as a reference. I fully recommend.

I failed. Without any background or education in computer science, I tried to learn HTML, CSS, Python, PHP, Java script because I simply like the logic. I tried to use APP builders to create APP. I tried to run Ubuntu in my laptop. I tried very hard but I failed. I failed to be good in this. I can see myself never able to be exceptionally good in it. Because I don't do it structurally, because I give up too soon, because ultimately I dun understand the fundamentals. Secretly, I think I'm stupid.

OK. I hold a master degree in Philosophy. I cofound a company running fairly. Maybe I'm not so stupid. Maybe it's because I'm learning in a wrong way. After I downloaded the sample and read it, I immediately know that this is the book that will open the gate to computer science in my language - layman (me!), yet shows the why behibs

Just finished the book and it was great! This is exactly what i was looking for! I'm a webdev, but i hardly understood how computer operates under the hood, how we got where we are now with all this modern technologies, operating systems and other stuff like that. How the first programs were build and how they were executed. This book is the answer. The explanation of how the computer operates internally are really good. This is the must know minimum for developers and a good start if your want to go deeper and learn some more advanced stuff. Modern computers are more complicated than those described in the book, but most of principles are still kept true i believe and will be kept for a long time. Ones you know the basics and understand how a simple computer can be built and operate you can then go for some advanced topics.

Many books on technical subjects are either too technical or sweep too much under the rug so you either get bored half way through or you get through it but learn nothing. Charles Petzold manages to balance things just right so you are thoroughly engaged and nothing is being swept under the rug so you actually learn something without being bored to tears. If you've ever wondered how all the bits and pieces of modern computers fit together to accomplish their magic then this book should definitely be on your reading list.

Code is a fantastic read for anybody interested in different aspects of computer science. Petzold explains the history of the computer and how simple switches eventually evolved to handle extremely complex tasks that computers can handle today. It covers all major aspects of today’s computer hardware and software technology. This is a great read because it allows anyone to learn extensive amounts about computer science with prior knowledge.

This book is a true creation of art. It is a must have for anyone who wants to understand how computers work at the lowest of the levels. It starts off with "What is electricity?" and builds up on the design of a truly working modern computer.

Plus, you don't have to be an electrical engineer or have any knowledge on electronics, since the author assumes no previous knowledge on the field. No one but Charles Petzold could have ever written such an amazing master creation aimed at both the knowledgeable individual and the total newbie.

Charles Petzold's writing style is delightful and attractive; it couldn't have been any better. Also as I read further into the bowels of the system, eventually I got these thrilling sensations like "No way anyone could have ever thought about this" or "No way this is possible". The way the text is put together allows for such moments of amazement.

The book is loaded with diagrams. Every single step into the woods is clearly explained and illustrated.

This is a great read for anyone who, like myself, is involved with computers, but never took computer science classes.
Parts of the book were very detailed, and I ended up skimming over them (a few parts from chapter 17 on). This is no fault of the author, but the nature of the subject is very complex. This didn't impair my overall comprehension of the concepts in the book...I'll re-read the difficult parts in time.
Overall, I highly recommend this book. My goal was to fill in the gaps in my computer science knowledge, and the book met that goal to my satisfaction.
I debated whether to give this 4 or 5 stars...I'd probably have gone with 4.5 if that option was available. The book gets off to a bit of a slow start, and I thought it could have used some more information on networking and modern computing. But for the price of the book and the clarity of the information, I'll give it 5 stars. Outstanding value.

Stellar text, the information contained in this book singlehandedly has defined how a computer works. His approach of beginning with simple circuits and building up towards logic gates and eventually assembly language and the like is extraordinary. I would highly recommend this book for anyone interested in computing systems.

It's not often that you come across a book that deals with complex topics in language that the layman can understand.
The organisation is excellent - Petzold explores one topic at a time, giving you the chance to absorb one concept before moving on to the next. And each chapter builds on what you have read before.
If you are just curious about what goes on inside your PC, or if you are involved in IT but lack an understanding of the actual box that does all the work, then this book is for you.

I, myself am a fairly seasoned programmer and more accurately often serve as someone who performs application security assessments/code review professionally. However, my entire existence is not encircled by highly technical people and especially over the past few months with a new significant other with children who are highly non-technical trying to answer questions without a proper base of education often just serves to frustrate and confuse.

I ran across this book randomly recently and was floored by how perfect it was in explaining a lot of the basics of technology and how well written it was. I've been working with my significant others 14 year old daughter on web development/design and will be likely moving into 'real' programming in the near future. As such, this book has been absolutely indespensible.

My only regret is that the book is worth so much more than the slashed price here on the store. Furthermore, I only gave 4 out of 5 stars out of pure pedantry and refusal to deal in absolutes, nothing is perfect, which is what 5 stars represents to me.

A note to the author:
It will quite likely be a long time if ever that I am in Redmond again as I have left Seattle and no longer work as a consultant (product security now). I am however in the Seattle area semi-frequently and if we should ever happen to somehow end up in the same place at the same time (likely if you find yourself at some security related event), please make yourself known to me, I'd like to buy you a drink for your fine efforts.

As a merchant marine officer for many years I always enjoyed using a sextant and calculating some formulas to determine my position on the face of the earth to within a half mile. It just seemed like magic until one day I sat down and really thought about what was happening when I used a sextant and calculated these formulas, and finally it all made sense. I could see how there was a logical method to what initially seemed like magic. This book will reveal a similar enlightenment to the reader who feels that computers are magic (as I did). My only beef is that the book did not have a comprehensive index. That would have certainly been a big plus because I can see myself referring to this book in the future. Also, I kept waiting for an explanation of how a million transistors can fit onto a single silicon chip and it never came. Guess I'll have to find another book to explain that bit of "magic". But I recommend the book for anyone, neophyte or professional.

This book starts out by explaining how batteries produce electricity, then goes into the telegraph and the light bulb, and then based on that moves into explaining how computer logic gates work, how computer memory works, how different parts of the computer communicate over the buss. I've learned at the lowest level, all the way down to the electrons, those fundamentals that I have been seeking to understand for 12 years.

If you buy no other computer book this year, and you have the same yearning as I do to know the lowest of details without having to understand complex mathematics than you should buy this book. It is an absolute master piece of technical literature. It will teach you how electricity works and flows, how computers turn that electricity into bits and bites and running programs. It will help you to easily understand the lowest levels of computers.

Outstanding book. I think this book makes for a great companion book to 'But how do it know?' by J Clark Scott. Read both of these books, and your understanding of how computers work down at the 'ones and zeros' level should be solid.

Are you computer illiterate, or suffer with a near phobia about technology and its continuing advancement? Well then calm down and do yourself a favor and read this book! Petrzold writes well and has a good sense of humor. He wisely starts the book off with people who influence the design of the computer, and then goes into the basic mathematics the computer uses. If you don't know nothing about the computer (that includes if you don't know how to turn the computer on!) you will by the end. Relax and enjoy!

This is a book that will work your mind, and give you a lot of insight into the deeper workings of computer hardware and software. I recommend it to anyone with a strong interest in computers, but I would dare call it a necessary read for computer science students.

Want to know how computers work -- like, really? Petzold's book explains it all, tracing the evolution of computer circuitry from the telegraph to the machines we know today, in intricate detail. Heavy on electrical engineering (which was great for me, with my relative ignorance of it), and a fun, if somewhat thick, read -- Mr. Wizard for computer nerds, you might say.

I've heard the words "labor of love" used to describe this book. The description fits perfectly. Highly recommended.

Yes, that's right! CODE is the greatest book on the face of the earth!
Why? Here's my story, and go judge for yourself.
I'm using computers for around four years. My question was always "How is this thing doing it's stuff?". Although I have no idea how other electronic stuff work, the computer did bothered me more then anything else because the computer seems to do some kind of THINKING, that's why it triggered my THINKING. This question kept on staying in my head until two weeks ago. It really bothered me. All along this four years I was looking for an answer to my question. I bought books, went to the library a thousand times, but nothing helped me. I learned a few programming languages along my journey, but it did not clarify how it really works. So I decided to learn Assembly Language because I taught that that's where I'm going to find the answer to my question. I must admit that it did helped me out quite a bit, but not to the extent I expected. I used a great book called "Assembly Language Step-by-Step" by Jeff Duntemann, which is a great book, but since the subject of the book is not to teach you how computers work, it didn't helped me enough to satisfy my desire for the answer to my question. I contacted Jeff Duntemann, the author of the book and I told him my problem. He referred me to this book CODE. So I rushed and bought this book. The rest of the story is self-understood, the book made my day and my life. And that's why I'm restating "This is the greatest book on the face of the earth".

This book is a gem. It's not a textbook, but rather, fun and easy read into a very complex topic. If you want to understand computer hardware and logic, this is the place to start. You could start reading this book with zero knowledge about the workings of computers, and by the end of it, you would be well equipped for going forward at a rigorous level.

"Code" is a well-written, easy to follow and compelling book on technology in general. The book focuses on how, over time, the manner in which technology has changed how data and information are processed.

Through highly illustrative examples and well-crafted illustrations, Charles Petzold has written an excellent book that should appeal to anyone with an interest in technology.

This book reminded me of "Connections". If you are unclear about the difference between binary, hex, and decimals, or what an opcode is, and what it does for you, this is a great book. He has written it like a guidebook.
I liked this book very much and have recommended it to several of my friends.

I read this remarkable book when I was 50. I only wish it had been around when I was 20. This book could change your life. In his book " In The Beginning Was The Command Line" Neil Stephenson described this digitally dominated world as being like the future world in Wells' "The Time Machine"; populated be the Eloi, who occupy the surface and live pampered lives, and the Morlocs, who live under ground building and operating the machines that keep the Eloi alive so that they can eat them. If you want to be a Morloc, and truly understand and be able to control these electronic brains and not just use and be used by them, then this book is where you should start.

I hold a bachelors degree in computer science, but it has been 11 years since I have studied it seriously. This book has rekindled my interests, and I am now considering returning to school to get my masters degree. Charles Petzold is a very gifted author. He made several topics in his book much clearer than any professor or lecturer ever did. I recommend that anyone with an ounce of curiosity about the inner workings of computers read this book from cover to cover. Its destined to be a home library must-have.

This book is a fun overview of the evolution of computing as we know it today. Starting with basic building blocks from years past (relays, telegraph, etc.) we move to the present (transistors, ICs). With a little motivation one could build a functional logic computer from the knowledge gained by this book.

The book is written in a very accessible manner, I would recommend it highly to a high school graduate considering pursuing a college career in any electronic engineering discipline.

As the author states, this is not another book of how computers work. I had been looking for a book that explained how a microprocessor does what it does. And with this book I got that and much more. I should also say that this book is good only if you love computers, because otherwise, it would be a little bored, especially because it goes beyond software into hardware and talks a lot about digital electronics and logic gates. But to me, it is very very good and I recommend it to everyone who has a real interest in computers.

From turning on a flash light to coding, this book covers all history in programming in a very interesting way. This is not a book tell you how computer works. It is a story about how we get there. This one is a must-read for people interested in computer science and computer engineering.

The books starts off great, but later drowns in tedious details about the construction of complex circuits. I can't be too critical since it is apparently the purpose of the book to give such details, and I'm glad it didn't have the opposite problem of dumbing it down too much, but I think it could have been done better with the intended audience in mind.

This book is just superb and that is what I want to inform others. This is just the kind of book I was desperately looking for. All it beautifully teaches is that how computers work in the very fundamental way and the interaction between hardware and software. You will get example to build your own computer(virtual one).

So, even if you are a Great programmer or a novice, you just shouldn't miss this book. Buy it or get it from a Library, but read it. A must read.

The book's content was exactly what I was expecting and wanted. "Code" gives a very good overview of computer language from the most basic fundamental level up to briefly describing higher languages. I received this product very quickly and was happy with the service that "Daily Deals" gave.

V/R
Nick

My undergrad was Human Resource Management. As a programmer, I was missing some of the nuts and bolts of computer science. This book filled in some gaps. The most exciting part for me was chapter 24. The author takes you through machine code, assembly, and finally ALGOL.

This is a fantastic explanation of how computers work, from the ground up. Petzold is thorough enough to let his readers understand much of what goes on in computres and other digital logic systems, but doesn't go in deep enough to confuse them.
I'm a software engineering student; so computers are no stranger, but I still learned quite a bit from this book - I even used it as a reference in a computer engineering course on a few occasions. On the other hand, my non-technical family has had pretty good success in comprehending Petzold's expert explanation.

Beginning with flashlights and the telegraph, you'll soon find yourself with a miniature Computer Science degree :) Highly readable and very enjoyable. I purchased copies for a number of folks this Christmas.

This is the book you would give to your manager and cohorts (non-technically inclined) to know more about the basics for computing. I have been an avid reader of his other articles and books from the earliest editions (on Windows Programming which is considered to be a "classic"). I was much surprised to see this book lacking information on Object-Oriented technologies - which has to be the major paradigm developed in the past two decades.

This book was absolutely excellent. It is quite possibly the only book of its kind, as it combines an easily understandable style with a highly technical subject. Petzold explains not only the workings of a simple processor, but also the history of its design and the theory behind it. For anyone who wants to learn how a microprocessor works without buying a college text, this is the book to buy.

This book was really easy to understand thanks to the way that the author had for explaining how computers actually work. Only by starting from the basics of a circuit, does the author managed to successfully create an interesting "manual" for the reader. Excellent shipping.

For me and it looks like for many others, Mr. Petzold literally helped unlock the mystery of one of the greatest achievements of mankind. I go from one book to another rarely being captivated enough to stick it out to the end. On the contrary this book pulls you in, you can't not want to read it. I can't do it justice by words so i'll leave it at that. Hope Mr. Petzold smiles reading these reviews.

This is a great book! A individual that has a desire comprehending the computer and the way it works would find this book very satisfying . One other similar book that I read was, Introduction to Microprocessors by John Crisp available by the store and highly recommended .

This book is an excellent overview of the inner workings of the computer. Petzold does a great job of explaining everything from the origin of circuits to binary numbers and digital electronics. This is a must book for anyone that wants to take computers seriously!

I absolutely loved this book. I couldn't put it down once I start reading it, and I don't think I did much else for the next 2-4 weeks other than playing with chips and stuff that I'd never layed hands on before. It was the beginning of a great hobby!

I picked up back on Ch.4 after the bus station stop. Very well done, Charles. A labour of love, indeed, very well crafted. I still don't know if Thevenin's theorem is for pure calculation purposes of being. The two parallel puzzle bc. Exit

Well I will have to give 2 stars even though I am at the very beginning of the book. I will be updating my review later but I must say this book includes false (or misleading) information. In the first 10 pages I have read the author says: "Morse code is said to be a binary code." but Morse Code is not binary, it 'can be represented' by binary. This is a very important information.

Also in the beginning of the book the author says 2 friends try to communicate with just flashing the light the number of times where the character is found in the Alphabet. Like one friend will flash the light 1 time and wait to say 'A' and flash it 3 times and wait to say 'C'. Now THIS IS BINARY. You either 'flash' or 'do not flash'. 1101110means BC ,where I represented this by Binary, but for Morse Code I will need 'space' like: 10 111 (or whatever).

This is a book that will work your mind, and give you a lot of insight into the deeper workings of computer hardware and software. I recommend it to anyone with a strong interest in computers, but I would dare call it a necessary read for computer science students.

If I was teaching a intro to computer science class for people who are new to computers or non-technical backgrounds, this would be required reading. It is a easy book to read, and ties the concepts which form computers to real world examples. Highly recommend this one.

Wow. Before I read this book, I already knew about logic gates, but I did not know (1) how electric and electonic devices can in the real world perform the function of logic gates and (2) how by arranging logic gates wisely one can perform addition and subtraction and (3) more complicated mathematical operations can be performed by doing "a lot of" additions and subtractions. Now I (kind of) know.

All these are gratifying.

Starting from Chapter 17, however, the speed and depth of the book changes gear quite a bit (at least to me). From that chapter onward, it is about the relatively detailed working of a modern computer - e.g. how integrated circuits (chips) work, what microprocessors are, etc. In Chapter 18, for instance, the author answered the question in the preface: "why can't you run Macintosh programs under Windows?". It is quite rewarding to understand why.

Different readers will have different views towards this book. By profession I am a physician and have no experience in serious computing, so I myself find Chapters 21 and 22 particularly difficult. But overall I think I have learned a lot from this book. Five stars.