What computer provided guidance and navigation for Apollo 11?

The Apollo Guidance Computer provided Apollo 11's onboard guidance and navigation.

The AGC was installed in both Apollo 11 spacecraft: one in the command module Columbia and another in the lunar module Eagle. It helped calculate and control the spacecraft's guidance, navigation, and flight-control functions, while astronauts interacted with it through the DSKY, a numerical display-and-keyboard unit.

The computer was developed by the MIT Instrumentation Laboratory in the early 1960s and manufactured by Raytheon. Its memory and processing power were tiny by modern standards, yet its real-time software could prioritize critical tasks. That capability mattered during the lunar landing, when the computer issued 1201 and 1202 alarms caused by an overload of lower-priority work. The system continued handling essential guidance tasks, allowing the landing to proceed.

The AGC did not operate in isolation: NASA's ground computers also supported mission planning and navigation. The onboard computer was nevertheless the named Apollo spacecraft computer, not a Gemini computer, UNIVAC mainframe, or IBM System/360.