The cloudy crystal ball: Electronic devices for logic

The invention of the transistor revolutionized electronics and brought new attention to solid-state physics. Transistors soon replaced relays and vacuum tubes in the logic of computing machinery and have made computers with many millions of devices possible. In the half-century since the advent of the transistor, scientists have invented and extolled a variety of other devices as replacements for it in electronic logic circuits. None has had any impact on computing. Only transistors provide the high gain with three-terminal control that is essential to the working of very large digital systems.