When Neil Armstrong, Buzz Aldrin, and Michael Collins went to the moon 50 years ago this week, they had a large portion of the world’s computing power with them on Columbia and Eagle and behind them in Houston. One NASA engineer estimated that, between 1962 and 1967, the Apollo program had purchased 60 percent of all integrated circuits built in the US.
Today, however, that overwhelming proportion seems paltry in its aggregate power. The two Apollo Guidance Computers (AGC) onboard the spacecraft, for example, each contained 32 kilobits of random-access memory and 72 kilobytes of read-only memory. The AGCs had a primary clock running at 2.048 megahertz, and their 2,048 integrated circuits contained only several tens of thousands of transistors. They also weighed 70 pounds.
By comparison, today’s iPhone XS sports 32 gigabits of dynamic random-access memory, 256 gigabytes of storage, and a processor with 6.9 billion transistors running at 2.49 gigahertz. That’s a million times more memory, several million times more storage, and hundreds of millions times more processing power than the AGCs. All in a package one-hundredth the weight.Read More