HN Theater @HNTheaterMonth

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] https://www.youtube.com/watch?v=B1J2RMorJXM

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.

Mandatory

Light Years Ahead | The 1969 Apollo Guidance Computer

https://www.youtube.com/watch?v=B1J2RMorJXM

34C3 - The Ultimate Apollo Guidance Computer Talk

https://www.youtube.com/watch?v=xx7Lfh5SKUQ

⬐ shadowofneptune

The second one is interesting for using hexadecimal in its new syntax format, even though octal is a natural fit for a 15-bit word and was used in the display. The reverse was common back in the 70s and 80s, so I guess it's always been about which is understood rather than which is correct.

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: https://www.youtube.com/watch?v=B1J2RMorJXM&t=454s.

⬐ pengaru

> The AGC is a fascinating device. It used 60% of the ICs produced in the United States in 1963.

As written I interpreted this as saying the AGC used 60% of the kinds of ICs produced in the US in '63.

But it's not that, it used 60% of the production capacity. No, the AGC is not a machine utilizing over half of the IC designs produced at the time. This number says more about the nascent state of the industry the AGC was drawing from than anything else.

⬐ morsch

I think he has, in fact, shown a passing interest in the AGC in the past. ;) http://www.righto.com/search/label/Apollo

⬐ mulmen

Haha! I didn't look at the username!

I suggest watching this excellent presentation: https://youtu.be/B1J2RMorJXM.

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.

⬐ EvanAnderson

I'm not able to check out the video right now, but I certainly will. I enjoy all things related to the Apollo program.

My understanding is that the autopilot in the LEM was very capable of flying the spacecraft, but there wasn't adequate sensor or image processing technology to allow the spacecraft to precisely choose a landing site free of obstructions. The human pilot wasn't necessarily essential for the mechanical act of landing, but was (in the first missions, at least) necessary for selecting a safe landing site.

⬐ mulmen

I believe that is mostly correct. I think you will enjoy the video. It definitely taught me a lot.

It has been a while since I watched the video myself but here is my understanding:

The LEM had a “target” landing point and was fly-by-wire. There were two control modes, one for the descent and rendezvous (~”flight”) and one for landing. Both were fly by wire but one put the LEM in a desired orientation (as defined by astronaut input) and the second for landing.

In the landing configuration the LEM actually was landing itself and Armstrong was actually updating the target with the controls. Aldrin was instrumental in this process to manage literally everything else and calling out information for Armstrong who lined up the target point using special crosshairs on the window.

So in a sense all the LEMs “landed themselves”. Additionally they did have the capability to carry out (but not update) a pre-programmed landing. This was never done in reality but was simulated.

Required viewing: https://www.youtube.com/watch?v=B1J2RMorJXM

⬐ bediger4000

This is actually a really great video that explains the AGC. The AGC was apparently pretty odd, a mix of realtime system, and virtual machine interpreter, along with an odd human interface.

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] https://youtube.com/watch?v=B1J2RMorJXM

⬐ isolli

True, it's not all about computing cycles :)

⬐ cybert00th

A thoroughly absorbing talk - even the Q&A at the end was good

⬐ davegauer

This is a total gem. Entertaining and absolutely packed with the most lucid explanations of the Apollo systems I've ever heard.