The computer that guided Apollo 11 to the Moon had only about 4 kilobytes of working memory and a processor running at roughly 1 MHz. Today, even the electronics hidden inside a USB charger can operate at comparable or higher frequencies, while the smartphone in your pocket has millions of times more computational capability.

The computer that guided Apollo 11 to the Moon had only about 4 kilobytes of working memory and a processor running at roughly 1 MHz. Today, even the electronics hidden inside a USB charger can operate at comparable or higher frequencies, while the smartphone in your pocket has millions of times more computational capability.

There is something almost comic about putting Apollo 11 beside a USB charger. One carried human beings across a quarter of a million miles and helped land them on the Moon. The other sits behind a desk collecting dust until somebody’s phone reaches 12 per cent. Yet the comparison is not invented. The Apollo Guidance Computer, or AGC, had roughly 4 kilobytes of erasable working memory and ran from a clock around 1 megahertz. Some of the digital c…