The Switch: Introduction

The history of nearly any technology, when examined closely, is a complex braid. What might appear on the surface to be a single ‘invention’ is revealed to be a series of often unrelated ideas and motivations, recombinations and repurposings, that coalesce at last, after decades, into something that we dub the sewing machine, or the…

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The Transistor, Part 3: Endless Reinvention

For over a hundred years the analog dog wagged the digital tail. The effort to extend the reach of our senses - sight, hearing, even (after a manner of speaking) touch, drove engineers and scientists to search for better components for telegraph, telephone, radio and radar equipment. It was a happy accident that this also opened…

The Transistor, Part 2: Out Of The Crucible

The crucible of war prepared the ground for the transistor. The state of technical knowledge about semiconductor devices advanced enormously from 1939 to 1945. There was one simple reason: radar. The single most important technology of the war, its applications included detecting incoming air raids, locating submarines, guiding nightfighters to their targets, and aiming anti-aircraft…

The Electronic Computers, Part 4: The Electronic Revolution

We have now recounted, in succession, each of the first three attempts to build a digital, electronic computer: The Atanasoff-Berry Computer (ABC) conceived by John Atanasoff, the British Colossus projected headed by Tommy Flowers, and the ENIAC built at the University of Pennsylvania's Moore School. All three projects were effectively independent creations. Though John Mauchly, the motive force…

The Electronic Age

We saw last time how the first generation of digital computers were built around the first generation of automatic electrical switch, the electromagnetic relay. But by the time those computers were built, another digital switch was already waiting in the wings. Whereas the relay was an electromechanical device (because it used electricity to control a mechanical…

Lost Generation: The Relay Computers

Our previous installment described the rise of automatic telephone switches, and of the complex relay circuits to control them. Now we shall see how scientists and engineers  developed such relay circuits into the first, lost, generation of digital computers. The Relay at Zenith Recall to mind the relay, based on the simple idea that an electromagnet could operate a…