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Apollo 11 Guidance Computer source code for the command and lunar modules

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Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#11

Post by [deleted] »

davidw wrote: post #7
floatingatoll wrote: post #5

Earlier quoted context omitted.

Line 34: > At the get-together of the AGC developers celebrating the 40th anniversary of the first moonwalk, Don Eyles (one of the authors of this routine along with Peter Adler) has related to us a little interesting history behind the naming of the routine.

It's kind of frustrating to try and figure out what is actually the original, unaltered code, and what's been added. There is a BURNBABY routine, though, so I guess that's real.

[deleted]

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#13

Post by thewonderidiot »

davidw wrote: post #7
floatingatoll wrote: post #5

Earlier quoted context omitted.

Line 34: > At the get-together of the AGC developers celebrating the 40th anniversary of the first moonwalk, Don Eyles (one of the authors of this routine along with Peter Adler) has related to us a little interesting history behind the naming of the routine.

It's kind of frustrating to try and figure out what is actually the original, unaltered code, and what's been added. There is a BURNBABY routine, though, so I guess that's real.

Wherever we added modern comments, they are denoted by a double hashtag (##) at the beginning of the line. Everything else, minus formatting concerns, is directly from the original listing. You can see the scans we transcribed this from here:

https://archive.org/details/Comanche55J2k60

https://archive.org/details/Luminary99001J2k60

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#14

Post by thewonderidiot »

turbostyler wrote: post #4

Didn’t this get released a couple years ago? Or was that a different ship?

These files were originally put on GitHub in the VirtualAGC repository [1] in 2015. The code was publicly released and digitized into these source files in 2009, through cooperation with the MIT Museum.

[1] https://github.com/virtualagc/virtualagc

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#15

Post by rahuldottech »

osamagirl69 wrote: post #10
NikolaeVarius wrote: post #6

Title is incorrect, this has been available for quite a while

I would argue that It should have (2016) appended to it to match the HN style, but it is otherwise accurate.

My bad, didn't realize that it's been out for a while.

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#16

Post by RcouF1uZ4gsC »

bensochar wrote: post #3

>TEMPORARY, I HOPE HOPE HOPE https://github.com/chrislgarry/Apollo-11/blob/master/Luminar... ...it was not temporary

Was the hope that the code would be temporary, or that the external conditions the code was dealing with would be temporary? Remember this is flight control software. There might be transient conditions that the system can handle fine, but could lead to failure if they persist.

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#17

Post by thewonderidiot »

RcouF1uZ4gsC wrote: post #16
bensochar wrote: post #3

>TEMPORARY, I HOPE HOPE HOPE https://github.com/chrislgarry/Apollo-11/blob/master/Luminar... ...it was not temporary

Was the hope that the code would be temporary, or that the external conditions the code was dealing with would be temporary? Remember this is flight control software. There might be transient conditions that the system can handle fine, but could lead to failure if they persist.

That call to STOPRATE was there to zero out attitude rate commands at the moment the astronaut switches into the semimanual final descent program P66. It was removed in the final few revisions before the first, unflown release of the Apollo 14 software (Luminary 163 [1]) because it was preventing attitude control of the spacecraft when Rate-Of-Descent commands were skipped [2]. Skipping ROD commands wasn't normal, but was something that was added as part of the effort to make the computer more cleanly handle large unexpected additional load, like happened in Apollo 11.

[1] https://github.com/virtualagc/virtualagc/blob/master/Luminar...

[2] http://www.ibiblio.org/apollo/Documents/LUM156_text.pdf -- look for PCN 1037

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#18

Post by ForHackernews »

NikolaeVarius wrote: post #6

Title is incorrect, this has been available for quite a while

Also, if you want to get really really technical, it's _always_ been in the public domain because it's a work by the US federal government and thus ineligible for copyright: https://en.wikipedia.org/wiki/Copyright_status_of_works_by_t...

Re: Apollo 11 Guidance Computer source code for the command and lunar modules

#20

Post by thewonderidiot »

ryanmarsh wrote: post #12
bensochar wrote: post #3

>TEMPORARY, I HOPE HOPE HOPE https://github.com/chrislgarry/Apollo-11/blob/master/Luminar... ...it was not temporary

>NUMERO MYSTERIOSO https://github.com/chrislgarry/Apollo-11/blob/master/Luminar...

People frequently seem to think this is about the line number it's on (666), but that doesn't have anything to do with it. That line number is a totally modern construction; the original source code was on punch cards. That particular comment was punched onto card number 0562 in the LUNAR LANDING GUIDANCE EQUATIONS log section. The original developers only referred to code by punch card number, and page number in the listing. So it really is just a coincidence, and the "NUMERO MYSTERIOSO" is referring to whatever is in GAINBRAK,1.
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