Someone opened an issue: "Check continuity on O2 cryogenic tanks before allowing stir" https://github.com/chrislgarry/Apollo-11/issues/3
LOL
Apollo 11 Guidance Computer source code
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Re: Apollo 11 Guidance Computer source code
#92Earlier quoted context omitted.
This one is better image quality https://www.youtube.com/watch?v=Jg80HZsv_js
Here's one with subtitles and interactivity http://www.firstmenonthemoon.com/
Wow ! Just saw the whole landing again. I have seen the video before , but I never understood who was saying what . This is the best way all those conversations could have been visualized !
Re: Apollo 11 Guidance Computer source code
#93Other than gaining satisfaction from the historical importance of this code is there any conceivable way we can get some use of it - like try it out. Even setting that aside, what is it I'm looking at? Assembly?
> Even setting that aside, what is it I'm looking at? Assembly? AGC Assembly. Here's the manual: http://www.ibiblio.org/apollo/assembly_language_manual.html
Fascinating. Thanks for the link.
Re: Apollo 11 Guidance Computer source code
#94What was the development environment like for this code?
People, processes, and environments like this:
http://www.wired.com/2015/10/margaret-hamilton-nasa-apollo/
https://en.wikipedia.org/wiki/Margaret_Hamilton_(scientist)
Also was among first to invent scheme that automated the coding and testing from specs for high-reliability. Her case is the only one I follow as I lack data on the rest.
Re: Apollo 11 Guidance Computer source code
#95I recommend reading Digital Apollo[0] about the development of the computer, and actually the entire man-machine interface of early spaceflight. The machines were made in the milieu where computer mediated control was highly controversial. (e.g. "A machine might work when everything is fine, but will never work in an emergency.") Essentially there was huge argument between pilots and engineers, about how much automation should be done. It was so bad, that pilots even tried to insist on flying the rocket into orbit. (If I recall correctly, in simulations in a centrifuge, only Armstrong was able to successfully not crash the Saturn V in a manually controlled ascent.)
The other recurring theme in the book is the disturbingly short MTTF for flight computers during the mid 1960s. Statistically, NASA had to plan for a computer failure in route to the moon, and so repair-vs-replace became a serious issue. (Yeah, they seriously considered soldering in zero-g.)
Re: Apollo 11 Guidance Computer source code
#96people could've really used a higher-level language compiling to optimized AGC(apollo computer) assembly. Is there any reason why they didn't develop one? It seems it would've helped tremendously with the productivity and verification (and a lot of the explanations and equations would be readable as code, not as an non-executed comment)
> Is there any reason why they didn't develop one? “Now you have two problems.” Edit: OK, maybe that deserves explanation. First, an optimizing compiler is a much bigger project than the AGC code. Second, current optimization techniques didn't exist in 1969, even assuming NASA had enough budget for machine(s) to run them. Third, you need to verify the binary anyway, and small source changes (in either the guidance co…
I still think it's easier to verify two isolated projects: the compiler(that can be reused) and the apollo code instead of mashing all of the equations code in assembly. I doubt the people were so used to assembly(especially scientists) that they they didn't require a magnitude more time to mentally parse/unparse logic and equations to machine code. (Also the compiler doesn't have to be very high level, even just a glorified macro-assembler with some syntactic sugar for math does seem not hard)
Re: Apollo 11 Guidance Computer source code
#97There's a simulator, if you want to run it.[1] But it's just a simulator for the computer; there's no spacecraft attached. There's a mod for Kerbal Space Program which gives it real solar system planets and dimensions. (KSP's world is way undersized so things happen faster.)[2] There's another mod for Kerbal Space Program to give it real dynamics.[3] (KSP doesn't really do dynamics right; the spacecraft is under the…
I'm really surprised there isn't a moon landing simulator based on the real code yet.
Re: Apollo 11 Guidance Computer source code
#98Re: Apollo 11 Guidance Computer source code
#99Watch the landing: https://www.youtube.com/watch?v=k_OD2V6fMLQ During the landing, you'll here mention of 1201 and 1202 alarms. Here's what that's about: http://www.hq.nasa.gov/office/pao/History/alsj/a11/a11.1201-... Here's 1201 being called: https://github.com/chrislgarry/Apollo-11/blob/dc4ea6735c4646... And 1202: https://github.com/chrislgarry/Apollo-11/blob/dc4ea6735c4646...
The high quality originals were taped over by NASA. https://www.theguardian.com/science/2009/jul/16/moon-landing...
See? These are the types of reasons why the-moon-landing-was-staged conspiracy theories keep cropping up.
Re: Apollo 11 Guidance Computer source code
#100So how did this guy get the source code and why is he the one publishing it?