Houston, we have some code. The Apollo 11 Guidance Computer source code is now available for free online, thanks to a NASA intern that uploaded it to Github.
In the 1960’s, MIT programmers wrote thousands of lines of esoteric code for Apollo 11's flight software. They invented “rope memory,” and created a special version of the assembly programming language.
Margaret Hamilton, Director of Software Engineering, standing next to the stack of code
The AGC code has since been available to the public for quite a while (it was uploaded by tech researcher Ron Burkey in 2003). He transcribed it from scanned images of the original hard copies MIT had put online. Burkey remarked, “It was scanned by a airplane pilot named Gary Neff in Colorado. MIT got hold of the scans and put them online in the form of page images, which unfortunately had been mutilated in the process to the point of being unreadable in places.”
Burkey had to reconstruct the unreadable parts and fill in the blanks for himself. He later managed to secure replacement scans and learned that he had filled in the blanks correctly. Despite Burke efforts’, the code remained rather obscure to modern coders. That was until NASA intern Chris Garry uploaded it to Github, finally making the code more available to the general public.
Coders began dissecting the software within hours of the upload. One developer noted, “A customer has had a fairly serious problem with stirring the cryogenic tanks with a circuit fault present.” He then listed steps to reproduce the problem.
Some of the most interesting discoveries, however, have been of the 1960’s references evident in the code. The file BURN_BABY_BURN--MASTER_IGNITION_ROUTINE is a reference to the 1965 Watt’s Riots. Another portion of the code references The Wizard of Oz with “OFF TO SEE THE WIZARD …”
To check out the code for yourself, click here.