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Apollo program source code

ibiblio.org

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Re: Apollo program source code

#11

Post by Retric »

GnarfGnarf wrote: post #6
exDM69 wrote: post #3

Fun fact: the actual programs in the spacecraft were stored in core rope memory, an ancient memory technology made by (literally) weaving a fabric/rope, where the bits were physical rings of ferrite material. http://en.wikipedia.org/wiki/Core_rope_memory

"Core" memory is resistant to cosmic rays. The state of a core bit will not change when bombarded by radiation in Outer Space. Can't say the same of solid state memory. I worked on core memory computers in the 60's. You had 16K, tape drives (no disks) and FORTRAN. What a gas!

At a low level your correct, but you can use error correction and a lot of redundancy to prevent cosmic rays from corrupting solid state memory and still have a lot more than 16K of storage space for a long time.

Re: Apollo program source code

#12

Post by strangetimes »

exDM69 wrote: post #3

Fun fact: the actual programs in the spacecraft were stored in core rope memory, an ancient memory technology made by (literally) weaving a fabric/rope, where the bits were physical rings of ferrite material. http://en.wikipedia.org/wiki/Core_rope_memory

"Some programmers nicknamed the finished product LOL memory, for Little Old Lady memory."

LOL.

Re: Apollo program source code

#13

Post by Retric »

GnarfGnarf wrote: post #8

With the power of open source, "many eyes make all bugs shallow". Wouldn't be a hoot if someone ran this through a simulator, and discovered a bug that had eluded NASA?

I would not take an even bet that there is any meaningful bugs in that code that NASA was not already aware of.

Re: Apollo program source code

#14

Post by viggity »

andrewcooke wrote: post #4

hmmm. so the "bugger words" at the end of, for example, http://www.ibiblio.org/apollo/listings/Colossus249/MAIN.agc.... are checksums - see http://books.google.cl/books?id=3fKzL0HfJp4C&pg=PA232&#3... anyone know the etymology? is it just a shortened form of "debugger"? is "bugger" not common slang in american english? or is this a joke?

It isn't short for debugger. A computer "bug" originated when a small moth (aka bug) was caught in a physical relay on the Mark II. http://en.wikipedia.org/wiki/Software_bug#Etymology

"Debugging" came from the action of trying to find where the bug is at in a program (or, in the original case, the machine)

Re: Apollo program source code

#15

Post by jerf »

GnarfGnarf wrote: post #8

With the power of open source, "many eyes make all bugs shallow". Wouldn't be a hoot if someone ran this through a simulator, and discovered a bug that had eluded NASA?

I'd need a lot of convincing it wasn't rather a bug in the simulator. An attainable amount of convincing, but it would be my first thought.

Re: Apollo program source code

#16

Post by J3L2404 »

exDM69 wrote: post #3

Fun fact: the actual programs in the spacecraft were stored in core rope memory, an ancient memory technology made by (literally) weaving a fabric/rope, where the bits were physical rings of ferrite material. http://en.wikipedia.org/wiki/Core_rope_memory

Sort of an interplanetary quipu.

http://en.wikipedia.org/wiki/Quipu

Re: Apollo program source code

#17

Post by DanBC »

jerf wrote: post #15
GnarfGnarf wrote: post #8

With the power of open source, "many eyes make all bugs shallow". Wouldn't be a hoot if someone ran this through a simulator, and discovered a bug that had eluded NASA?

I'd need a lot of convincing it wasn't rather a bug in the simulator. An attainable amount of convincing, but it would be my first thought.

Why?

Bugs in code made it into space. These are documented.

Re: Apollo program source code

#18

Post by Create »

Retric wrote: post #11
GnarfGnarf wrote: post #6

Earlier quoted context omitted.

"Core" memory is resistant to cosmic rays. The state of a core bit will not change when bombarded by radiation in Outer Space. Can't say the same of solid state memory. I worked on core memory computers in the 60's. You had 16K, tape drives (no disks) and FORTRAN. What a gas!

At a low level your correct, but you can use error correction and a lot of redundancy to prevent cosmic rays from corrupting solid state memory and still have a lot more than 16K of storage space for a long time.

...and radhard designs.

Re: Apollo program source code

#19

Post by jerf »

DanBC wrote: post #17
jerf wrote: post #15

Earlier quoted context omitted.

I'd need a lot of convincing it wasn't rather a bug in the simulator. An attainable amount of convincing, but it would be my first thought.

Why? Bugs in code made it into space. These are documented.

Because the odds are that the simulator with which someone will run around yelling about the bug they found (which will get them links on HN and other fun perks) will have had less than 1% of the time spent on creating it than the code that was actually sent into space, and on the balance, given the observation of a defect in the combined simulator+Apollo code the highest probability locus is the new, untested code that was probably rushed out for publicity's sake and had no lives ever depend on it.

You seem to have misinterpreted my post as me saying I would never believe it was a bug in the Apollo code, despite me making very sure to explicitly disclaim that.

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