Code

Computers are everywhere --- most obviously in our laptops and smartphones, but also our cars, televisions, microwave ovens, alarm clocks, robot vacuum cleaners, and other smart appliances. Have you ever wondered what goes on inside these devices to make our lives easier but occasionally more infuriating? For more than 20 years, readers have delighted in Charles Petzold's illuminating story of the secret inner life of computers, and now he has revised it for this new age of computing. Cleverly illustrated and easy to understand, this is the book that cracks the mystery. You'll discover what fl ashlights, black cats, seesaws, and the ride of Paul Revere can teach you about computing --- and how human ingenuity and our compulsion to communicate have shaped every electronic device we use. This new expanded edition explores more deeply the bit-by-bit, gate-by-gate construction of the heart of every smart device - the central processing unit that combines the simplest of basic operations to perform the most complex of feats. Along with new chapters, Petzold has created a new website, CodeHiddenLanguage.com, that uses animated interactive graphics to make computers even easier to comprehend. From the simple ticking of clocks to the worldwide hum of the internet, Code reveals the essence of the digital revolution.

1. Best Friends 2. Codes and Combinations 3. Braille and Binary Codes 4. Anatomy of a Flashlight 5. Communicating Around Corners 6. Telegraphs and Relays 7. Our Ten Digits 8. Alternatives to Ten 9. Bit by Bit by Bit 10. Logic and Switches 11. Switches and Gates 12. A Binary Adding Machine 13. But What About Subtraction? 14. Feedback and Flip-Flops 15. Relays, Tubes, and Transistors 16. Bytes and Hex 17. Displaying Hex Digits 18. An Assemblage of Memory 19: Automating Arithmetic 20. Jumps and Calls 21. Computer 2.0 22. Characters and Decimals 23. Peripherals 24. Languages Low and High 25. Everything is a Code