The computers of our wildest dreams — and what it takes to make them a reality

One of the first electronic, programmable computers in the world is remembered today mostly by its nickname: Colossus. The fact that this moniker evokes one of the seven wonders of the ancient world is fitting both physically and conceptually. Colossus, which filled an entire room and included dinner-plate-sized pulleys that had to be loaded with tape, was built in World War II to help crack Nazi codes. Ten versions of the mammoth computer would decrypt tens of millions of characters of German messages before the war ended.

Colossus was a marvel at a time when "computers" still referred to people — women, usually — rather than machines. And it is practically unrecognizable by today's computing standards, made up of thousands of vacuum tubes that contained glowing hot filaments. The machine was programmable, but not based on stored memory. Operators used switches and plugs to modify wires when they wanted to run different programs. Colossus was a beast and a capricious one at that. Read more...