Tut, where are the supporting unit tests.
Source code for the Apollo 11 Guidance Computer
31–40 of 71 posts
Re: Source code for the Apollo 11 Guidance Computer
#32It's of cause fun to have this code to look at, but is it really useful? I don't mean it in a condescending way, but is this actually someone at, say SpaceX, looks at and goes: "Oh so that's how they did that"?
It would be cool to frame and display one them, like one for Automatic Maneuvers.
http://www.ibiblio.org/apollo/listings/Comanche055/AUTOMATIC...
Re: Source code for the Apollo 11 Guidance Computer
#33Wow. This is really impressive: assembler, real-time systems in space, mission-critical equipment, software that protects lives, etc.
Maybe that is too much, causing those writing the next "date finding" app to feel incompetent after reading this.
But at least we will know we are standing on shoulders of giants.
Re: Source code for the Apollo 11 Guidance Computer
#34Do the famous 1201 and 1202 error codes make an appearance here? My assembly skills aren't good enough to find them, I'm afraid.
Re: Source code for the Apollo 11 Guidance Computer
#35Also a lot of of good information in this document: http://www.ibiblio.org/apollo/hrst/archive/1029.pdf
(Much of the Apollo Guidance Computer and software was developed by the MIT Instrumentation Lab, the predecessor to Draper Lab.)
Re: Source code for the Apollo 11 Guidance Computer
#36Re: Source code for the Apollo 11 Guidance Computer
#37Earlier quoted context omitted.
That's great - I actually came here to say "this is cool in an abstract way but what the fuck am I looking at? I'd love to learn a little bit more about the system". Turns out space folks are great at sharing knowledge! By the way, last night I read the radio transcript from the time Neil and Buzz exited the lunar module: http://www.hq.nasa.gov/alsj/a11/a11.step.html (that site has loads of other Apollo transcripts t…
>Turns out space folks are great at sharing knowledge! I've read that one of the problems a new moon-or-beyond space program would have is that we are so far removed from the Apollo program that all institutional knowledge that was gained is gone because most of the engineers on those projects have passed away.
On the other hand, how much of that institutional knowledge is still useful? Certainly some of it is, but I think experience with the F1-B shows that new knowledge, like 3-D printing, means that parts of the old knowledge aren't needed.
Re: Source code for the Apollo 11 Guidance Computer
#38http://www.ibiblio.org/apollo/listings/Comanche055/PINBALL_G... >Filename: PINBALL_GAME_BUTTONS_AND_LIGHTS.agc Can someone explain what this is? I doubt they had an actual game of pinball in their guidance computer.
It appears to be the code for the controls: # THE KEYBOARD AND DISPLAY SYSTEM PROGRAM OPERATES UNDER EXECUTIVE # CONTROL AND PROCESSES INFORMATION EXCHANGED BETWEEN THE AGC AND THE # COMPUTER OPERATOR. THE INPUTS TO THE PROGRAM ARE FROM THE KEYBOARD, # FROM INTERNAL PROGRAM, AND FROM THE UPLINK. I think it's just someone with a sense of humor.
A rather dark one if "PINBALL GAME" could be interpreted as describing the expected outcome of a lunar landing ;)
Re: Source code for the Apollo 11 Guidance Computer
#39It's of cause fun to have this code to look at, but is it really useful? I don't mean it in a condescending way, but is this actually someone at, say SpaceX, looks at and goes: "Oh so that's how they did that"?
Probably not. Why?
- Today's processors and capabilities run circles around those of the Apollo. It might be interesting to know how they calculate a square root, not today.
- They have more sensors and inputs and have to think of new and advanced ways of making it all work together
Re: Source code for the Apollo 11 Guidance Computer
#40Earlier quoted context omitted.
https://news.ycombinator.com/item?id=4339999
WOW ! > I think they should use COBOL, it's built in :)
Those are standard restrictions for embedded real-time systems, especially if the language itself doesn't offer guarantees on tail-call optimization (like the ML family, Erlang and others do). You have to guarantee the behavior of the program, and recursion (especially unbounded memory usage as in many C implementations) can royally screw things up. You may still have infinite loops because of an error in a for loop's terminating condition, but without dynamic memory and exploding stack usage you'll at least have enough memory left to deal with it when the watchdog timer kicks in.