What do you think of this fact?
In 1969, humans landed on the Moon. The spacecraft was steered by the Apollo Guidance Computer, and by today’s standards its specs are almost laughable.
The numbers
- RAM: about 4 KB
- Storage: about 72 KB
- Clock speed: around 1 MHz
For comparison: a single photo on your phone is about 3 MB, or roughly 3,000 KB. A current smartphone has millions of times more RAM and is many thousands of times faster.
Software that was woven
Here’s where it gets wild. The Apollo computer’s program wasn’t written to a disk. It was woven by hand. The memory was called core rope memory: copper wires were threaded either through or around tiny magnetic rings. Through the ring meant 1, around it meant 0.
The work was done mostly by women at a factory in Massachusetts, many of whom had worked in the textile industry. “Installing” a program took weeks. A bug meant weaving it again.
The software team was led by Margaret Hamilton, who is credited with popularizing the term “software engineering.”
And it worked
Moments before the landing, the computer threw several overload alarms with the codes 1201 and 1202. Mission Control in Houston had seconds to decide: abort or keep going? They said go. Because Hamilton’s team had built it to drop low-priority tasks, the landing carried on. Neil Armstrong set the lander down safely.
Your phone wants 2 GB for an update? Humanity flew to the Moon with a tiny fraction of that.