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Recovering the Lost Apollo 10 LM Software [video]

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Re: Recovering the Lost Apollo 10 LM Software [video]

#4

Post by morcheeba »

Summary: they found a document with checksums for each of the 36 banks of the missing software. This let them know that two banks had changed. Working from an earlier and later source listing versions, they had to recreate only some of the changes. Luckily, they found memos describing the changes - mostly in a newer gravity model. All that was left was to put the code in the proper places, and some obvious guesses (e.g. new constants at the end of existing constants) -- and it worked!

A fun watch.

Re: Recovering the Lost Apollo 10 LM Software [video]

#6

Post by sonofgod »

est31 wrote: post #3

We aren't printing out our source code any more. Which means that such recovery methods won't work in the future. Has archival of such historic stuff improved since?

There's some projects. Like arctic archival of github repos: https://archiveprogram.github.com/

Granted, this is only a snapshot, and preservation is a big problem. And you can't easily preserve gigabytes of data in dead tree format...

Generally the best approach is "Lots of Copies Keep Stuff Safe" but moves to streaming media and game rental services worry me.

There also needs to be a recognition that what we see is often a very small fraction of what existed... most things won't survive, unless successive generations of people continuously care sufficiently about them. Or they're ubiquitous that we'll find at least one...

Re: Recovering the Lost Apollo 10 LM Software [video]

#7

Post by kevin_thibedeau »

sonofgod wrote: post #6
est31 wrote: post #3

We aren't printing out our source code any more. Which means that such recovery methods won't work in the future. Has archival of such historic stuff improved since?

There's some projects. Like arctic archival of github repos: https://archiveprogram.github.com/ Granted, this is only a snapshot, and preservation is a big problem. And you can't easily preserve gigabytes of data in dead tree format... Generally the best approach is "Lots of Copies Keep Stuff Safe" but moves to streaming media and game rental services worry me. There also needs to be a recognition that what we see is…

Lots of copies on flash chips are all going to be gone in 100 years.

Re: Recovering the Lost Apollo 10 LM Software [video]

#8

Post by WalterBright »

kevin_thibedeau wrote: post #7
sonofgod wrote: post #6

Earlier quoted context omitted.

There's some projects. Like arctic archival of github repos: https://archiveprogram.github.com/ Granted, this is only a snapshot, and preservation is a big problem. And you can't easily preserve gigabytes of data in dead tree format... Generally the best approach is "Lots of Copies Keep Stuff Safe" but moves to streaming media and game rental services worry me. There also needs to be a recognition that what we see is…

Lots of copies on flash chips are all going to be gone in 100 years.

I don't trust flash chips at all.

My older media is all pretty much unreadable for one reason or another. My solution is to buy new drives every year and copy everything forward. Fortunately, the capacity keeps rising so that works out rather well.

Re: Recovering the Lost Apollo 10 LM Software [video]

#9

Post by rdc12 »

est31 wrote: post #3

We aren't printing out our source code any more. Which means that such recovery methods won't work in the future. Has archival of such historic stuff improved since?

In many cases it will prove difficult to even be able to build or run software that hasn't been touched in 10+ years. Preserving the computational environment is a whole another concern for future software archeology.
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