Before transistors or microchips, the earliest computers relied on vacuum tubes — glass bulbs that glowed like small light ...

Did you know that the first half of the 20th century was dominated by vacuum tubes? Be it radio, television, telephone networks or computers, vacuum tubes were the basic component for all electronics.

The telephone company had problems with vacuum tubes, too, and hoped to find something else to use for switching telephone calls. The idea of somehow using semiconductors (solid materials such as ...