
 Software woven into wire: Core rope and the Apollo Guidance Computer - matt_d
http://www.righto.com/2019/07/software-woven-into-wire-core-rope-and.html
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kens
If anyone has questions about the Apollo Guidance Computer or our restoration
of it, I'm here to answer.

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chiph
I've enjoyed CuriousMarc's videos very much. Thanks for publishing them.

Here you guys are helping the AGC pass it's self-tests, which was an amazing
step.

[https://www.youtube.com/watch?v=HpIwQZaEvV0](https://www.youtube.com/watch?v=HpIwQZaEvV0)

I worked on a core memory device when I was in the Air Force, and got to
troubleshoot a problem with it (which was rare - it was usually very
reliable). One core had gone bad in a particularly poor location, which
corrupted the "end of message" indicator. So we'd get one message and it would
hang, waiting forever for the message to end!

[https://nara.getarchive.net/media/ssgt-anthony-j-mathis-
and-...](https://nara.getarchive.net/media/ssgt-anthony-j-mathis-and-sgt-
bryan-s-hammons-from-the-2048th-communications-947d8e)

(neither of them are me)

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xfitm3
Brilliant. I miss the days when software was so simple!

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lhoff
For anyone interested in the AGC itself I can recommend the "ultimative Apollo
guidance computer talk"

[https://www.youtube.com/watch?v=xx7Lfh5SKUQ](https://www.youtube.com/watch?v=xx7Lfh5SKUQ)

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geuis
Great short youtube series about core rope memory
[https://www.youtube.com/watch?v=WquhaobDqLU](https://www.youtube.com/watch?v=WquhaobDqLU)

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flyinghamster
I wonder if twistor memory would have been lighter in mass? It was developed
by Bell Labs, and mostly found use in (surprise!) telephone switches. It could
be made in both read-only and read/write forms, and its manufacture could be
heavily automated.

[https://en.wikipedia.org/wiki/Twistor_memory](https://en.wikipedia.org/wiki/Twistor_memory)

~~~
kens
Twistor memory looks like one of those technologies that was not quite
competitive with core for one reason or another and never really caught on. As
far as twistor ROM, it used a small permanent magnet per bit, so I expect that
its density was worse than core rope.

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mkesper
As core rope was manufactured by (black and white) women: Regarding how
NACA/NASA gave work to black women in times from world war ii until the moon
landing, "Hidden Figures" (the book) teached me more about american history of
that time than my whole school career. Technology always also influences
humans, forms society.

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LukeShu
A relevant comment from an old thread (2018):
[https://news.ycombinator.com/item?id=17689693](https://news.ycombinator.com/item?id=17689693)

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kens
That comment is from Mike, the expert on everything AGC, who is part of the
restoration team.

