Code: The Hidden Language of Computer Hardware and Software, First Edition

Chapter 11. Gates (Not Bill)

In some far-off distant time, when the twentieth century history of primitive computing is just a murky memory, someone is likely to suppose that devices known as logic gates were named after the famous co-founder of Microsoft Corporation. Not quite. As we’ll soon see, logic gates bear a much greater resemblance to those ordinary gates through which pass water or people. Logic gates perform simple tasks in logic by blocking or letting through the flow of electrical current.

You’ll recall how in the last chapter you went into a pet shop and announced, “I want a male cat, neutered, either white or tan; or a female cat, neutered, any color but white; or I’ll take any cat you have as long as it’s black.” This is summarized ...