Light Years Ahead | The 1969 Apollo Guidance Computer
Why Hacker News recommends it
HN calls it mandatory viewing on the AGC, praising the speaker's enthusiasm and the clear account of restartable, robust software design.
What it is
Robert Wills of TNMoC explains the Apollo Guidance Computer hardware and software, then walks through the Apollo 11 landing procedure step by step, including the 1202 alarms.
Recommended by 11 HN commenters across 11 different months, 2021 to 2026.
What Hacker News said
Strong rec mulmen · 2021-06 · on “A transistorized shift register box, built in 1965 for Apollo testing”
I suggest watching this excellent presentation: [this video] . He goes in to great depth in explaining how the LEM was in fact capable of landing itself. Automation was widespread in the development and execution of the Apollo program.
Strong rec Banana699 · 2022-05 · on “On rebooting: the unreasonable effectiveness of turning computers off and on”
Mandatory Light Years Ahead | The 1969 Apollo Guidance Computer [this video] 34C3 - The Ultimate Apollo Guidance Computer Talk [LINK]
Strong rec TremendousJudge · 2022-09 · on “Two hundred years ago, Jean-François Champollion deciphers the Rosetta Stone”
Yeah, a great example is this presentation[1] about the Apollo guidance computer. The guy is really, really into it and it just makes the presentation amazing. [1] [this video]
Strong rec kzrdude · 2023-11 · on “Translations of Russ Cox's Thompson NFA C Program to Rust”
That reminds me of the Apollo guidance computer talk (available on youtube [this video] ). "Everyone" might have seen this one, but if one hasn't, it's a gem.
Strong rec isolli · 2024-03 · on “NASA engineers make progress toward understanding Voyager 1 issue”
I can't recommend a book, but I watched this video a while ago, and I found it riveting: "Light Years Ahead | The 1969 Apollo Guidance Computer" [0] > Robert Wills introduces the amazing hardware and software that made up the Apollo Guidance Computer, walks you through the landing procedure step-by-step, and talks about the pioneering design principles that were used to make the landing software robust against any failure. [0] [this video]
Strong rec soferio · 2026-07 · on “Original Apollo 11 Guidance Computer source code for command and lunar modules”
For a superb video explaining what the AGC did and what WENT WRONG during the moon landing including the error codes:l, see: [this video]
Recommends alpaca128 · 2021-03 · on “Part of Wright brothers' first airplane on NASA's Mars chopper”
A bit offtopic but I recently saw a surprisingly interesting talk about the Apollo board computer[0], and it's incredible how carefully they engineered the whole thing. Software hardcoded in the wiring, error correction for every memory access, ability to restart the whole system in any situation without losing state...this thing might have been rudimentary in today's standards, but the quality of the software was a different beast. [0] [this video]
Recommends mulmen · 2022-02 · on “A look inside the chips that powered the landmark Polaroid SX-70 instant camera”
The AGC is a fascinating device. It used 60% of the ICs produced in the United States in 1963. If you are interested in the AGC I suggest this excellent video: [this video] .