How They Built the Software of Apollo 11

LinuxScribe tips a piece up at Linux.com with inside details on the design and construction of the Apollo 11 code. There are some analogies to open source development but they are slim. MIT drafted the code — to run on the Apollo Guidance Computer, a device with less grunt than an IBM XT — it had 2K of memory and a 1-MHz clock speed. It was an amazing machine for its time. NASA engineers tested, polished, simulated, and refined the code. "The software was programmed on IBM punch cards. They had 80-columns and were 'assembled' to instruction binary on mainframes... and it took hours. ... During the mission, most of the software code couldn't be changed because it was hard-coded into the hardware, like ROM today... But during pre-launch design simulations, problems that came up in the code could sometimes be finessed by... computer engineers using a small amount of erasable memory that was available for the programs. The software used a low-level assembly language and was controlled using pairs or segments of numbers entered into a square-shaped, numeric-only keyboard called a Display and Keyboard Unit... The two-digit codes stood for 'nouns' or 'verbs,' and were used to enter commands or data, such as spacecraft docking angles or time spans for operations." Reader Smark adds, "The Google Code Blog announced today that the Virtual AGC and AGS project has transcribed the Command Module and Lunar Excursion Module code used during the Apollo 11 moon landing. The code is viewable at the VirtualAGC Google Code Page."

Fake

[Yuioup]

Wow. They sure went out of their way to fake the moon landing. I bet the source-code is fake too :-P

Y

Space, Spacecraft *and* Code

[MrKaos]

I think I just had a geekgasm.

README.txt

[Norsefire]

For Vista, the following steps may need to be performed manually after installation:

1.
2.

-- README.txt [google.com]

Wow, even rocket scientists don't know how to make code work on Vista.

Re:Fake

[bAdministrator]

lol Cheyenne Mountain doesn't exist.

looking at the code...

[circletimessquare]

this is clearly a horrible case of bloatware

Amazing

[hamburgler007]

When you consider how many shitty programmers there are now who use variable names that take up nearly 2k.

Re:Proper Old Skool

[morgan_greywolf]

As some one old enough to enter raw hex in to a hex keypad on a machine with an LED display having hand assembled the code in the back of her math exercise book during a math lesson (when I should have been learning stats) this doesn't sound too different.

You kids and yer "raw hex keypads" and "LED readouts." Why, back in my day, we had toggle switches and light bulbs! And we liked it that way! Now you kids get off my law.....hey, wait...you're a girl? You can stay. :)

Re:Fake

[morgan_greywolf]

Wow. They sure went out of their way to fake the moon landing. I bet the source-code is fake too :-PY

No, they couldn't have written in Python as it wasn't even a gleam in Guido's eye yet.

Waist deep in snow, uphill both ways

[140Mandak262Jamuna]

In those days we had to program the computer the size of a school bus strapped to our backs while trudging through the waist deep snow, for five miles one way, uphill both ways, without mittens while the politicians were whipping us yelling, "you don't want the Ruskies to win, do you?", those were the days boys. Now these young whippersnappers are using laptops with 8 Gigs of RAM and still could not write a simple javascript engine with a just in time debugger without creating a buffer overflow vulnerability while fed very long unicode strings.... bah... now get off my lawn.

Re:Fake

[elrous0]

I sure hope it's not fake code. I'm a time traveling entrepreneur, and I'm going to make a FORTUNE selling this to the Russians in 1965.

Re:README.txt

[K. S. Kyosuke]

That's because Microsoft tries very hard to convince everyone by developing Visual Studio that programming for Windows isn't rocket science. Which is why rocket scientists can't program for Windows.

Re:!opensource

[bonch]

I agree. It was pretty annoying to see the author of the piece try to shoehorn the story into an open source angle multiple times. You could tell the interviewer asked, "Would you consider it open source?" and the guys responded, "Well, in the sense that the source was accessible to the other NASA engineers, sure..."