Code: The Hidden Language of Computer Hardware and Software, 2nd Edition

Chapter Seventeen

Feedback and Flip-Flops

Everybody knows that electricity can make things move. A brief glance around the average home reveals electric motors in appliances as diverse as clocks, fans, food processors, and anything that spins a disk. Electricity also controls the vibrations of loudspeakers, headphones, and earbuds, bringing forth music and speech from our many devices. And even if that’s not an electric car sitting outside, an electric motor is still responsible for starting up antique fossil-fuel engines.

But perhaps the simplest and most elegant way that electricity makes things move is illustrated by a class of devices that are quickly disappearing as electronic counterparts replace them. I refer to those marvelously retro ...