Code: The Hidden Language of Computer Hardware and Software

Im currently building my foundations in computers on a lower level one book at a time. I came into software engineering from a sales background. Over time, I’ve realised that while practical experience teaches you a lot, it can leave gaps in the deeper why behind how computers actually work and why software behaves the way it does. So I’ve been creating my own structured learning path to fill those gaps, starting from the ground up. The first book I chose is this one right here! It’s not a typical programming book. It starts with how humans first used codes to communicate through Morse code, telegraphs, and switches and slowly builds toward how those same ideas evolved into modern computers. What surprised me most is how much of computing is built on very simple logic. At its core, everything reduces to circuits making yes/no decisions and when you chain enough of those together, you get adders, memory, and eventually an entire processor. Reading it connected a lot of dots for me like how information becomes binary, how logic gates combine to perform arithmetic. It made computing feel less like magic and more like a long, logical sequence that starts with electricity and ends with the systems we work with every day. If you’re self taught, or you feel like you’ve jumped straight into frameworks and languages without really understanding what’s underneath, I’d highly recommend this book. It helped me see computers as one continuous chain of reasoning from Morse code to microprocessors.

Charles Petzold did the impossible: he managed to explain how the core of modern tech works in one book, in a simple way, starting off with a light bulb going all the way to loops. Highly recommended book for everyone, can be read even without prior technical knowledge. I only wish someone told me about this book earlier. P.S. I recommend the second edition as it has some nice additions, e.g. how a QR code works.

Clear explanation by the author. Walkthrough all the concepts without skipping any difficults part. Daunting task explaining the inner workings of a CPU but the author clearly succeeded.

Love this book however the reason for my rating is the build quality of the book is terrible. Thin translucent plastic-like pages with multiple creases and print issues throughout. As a result the print is also shiny. I returned the first one as these issues were so bad it was illegible, but there are still issues with the replacement. For a book of this price, you would expect much better build quallity overall.

I found this book to be both entertaining and extremely informative. The author takes you from understanding how humans have encoded information since before the age of computers, through electronic circuitry, all the way to an overview of how programming languages interact with this hardware. Definitely recommend

Code is one of those books written by someone who doesn’t assume anything about the reader. The author explain topics in a nice and polite way. No patronising. He clearly knows a lot but he doesn’t use that against the reader. Instead he elevates the reader such that it’s hard to put the book down. I was familiar with all the concepts presented and explained but after reading Code, they became even clearer in my mind. Buy it!

the author did phenomenal job in simplifying complex subject, it is interesting how he guide the reader from the early innovations that culminated into the "Code" we use for granted now.

Im loving every bit of this book, started with the digital version then after reaching chapter 4 I decided that i must get the physical copy, yes its that good. The author has a magical way of making complex subjects much easier to digest and understand. I’m a first year EEE student, but I highly recommend this book to every STEM student and not just those with electrical and computers/programming interests.

Interessting, great book

One of the best, if not the best, books on computing… nice touch with the colored diagrams

Good concise write up on how hardware and software interact inside an Intel 8080 cpu.

Great book for a curious child or adult who wants to know how computers work. Less hands-on than Nisan and Schocken's book. Ideally, get both!

I love how Charles wrote this book, I read it slowly throughout the year and was easily able to digest all the examples and illustrations provided and have got a better and broader understanding of Code, software, hardware, batteries, lightbulbs, history and much more!