from Hacker News

The Apollo On-Board Computers

by rayascott on 8/7/22, 10:44 AM with 9 comments

• by mshook on 8/7/22, 4:48 PM

  If you're into that kind of stuff I recommend:

  - watching https://www.youtube.com/c/CuriousMarc

  - reading Ken's blog/twitter http://www.righto.com/ / https://twitter.com/kenshirriff

• by itsjustjordan on 8/8/22, 3:19 AM

  The source code is available on GitHub along with a virtual version you can play with.

  - https://github.com/chrislgarry/Apollo-11

  - https://www.ibiblio.org/apollo/

• by compumike on 8/8/22, 6:52 AM

  You may also enjoy some of the historical photos here: https://wehackthemoon.com/tech/apollo-guidance-computer-agc-...

  A few highlights:

  - photo #2 shows the construction of literally hand-weaved read-only memory for the 36,864 words of fixed program memory. Literally weaving wires through (or bypassing around) tiny magnetic cores for each bit of storage. Must be re-weaved for a new "build"

  - photo #10 shows the prototype, occupying many many racks (not yet miniaturized!)

  - photo #20 shows characteristics of the machine (2048 words of writable memory; 575us for a double-precision multiplication)

  - photo #24 https://www.youtube.com/watch?v=_gIrELUMtp0 (32 seconds) shows large-scale breadboarding before the computer logic design was miniaturized

  - https://www.youtube.com/watch?v=F1-KBKaCiMM (4 minutes 28 seconds) gives a nice overview of the AGC challenges

• by shadowofneptune on 8/8/22, 4:57 AM

  The best presentation I have seen on the AGC architecture: https://youtu.be/xx7Lfh5SKUQ

  It does present addresses in hexadecimal, oddly. The computer was 15-bit and used octal in its display panel. I suppose the presenters thought the audience would understand hex better.

• by tatoalo on 8/8/22, 5:51 AM

  In addition to the fantastic ccc.de talk, I suggest this one related to the 1202 alarm: https://youtu.be/B1J2RMorJXM

  Great talk and overall super presenter IMHO.

• by james-redwood on 8/8/22, 6:19 AM

  I once met a first year engineering student who was the daughter of a friend of mine. When she complained that you can do nothing cool with small computers, I pointed her to an article about this.