
Tales from the lunar module guidance computer (2004) - astdb
http://www.doneyles.com/LM/Tales.html
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codewritinfool
Don is working on a book, can't wait for that.

I'd also love to see a book by Allan Klumpp. He wrote the ultimate mic drop
review on Amazon:
[http://www.amazon.com/gp/review/R3VJW144Y9YDBQ?ref_=glimp_1r...](http://www.amazon.com/gp/review/R3VJW144Y9YDBQ?ref_=glimp_1rv_cl)

After stating that he hates the book, he writes, "I have mastered six
programming languages from language reference manuals, and my software has
been used at five planets and the moon, so I speak advisedly." Ouch.

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justin66
> struggling for seven years to learn Word Visual Basic using this book as a
> reference

On the other hand, the "struggling for seven years" part suggests that he
might not be a transdimensional supergenius, or at least might not be
brilliant about allocating his time. At some point you'd ordinarily just chuck
a bad book in the trash.

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Daneel_
My heart was in my mouth reading this; what a moment to have been alive. I
can't begin to fathom the emotions for all involved. It must have been terror
mixed with elation, doubt, fear, hope and wonder. Any small mistake from the
ground or space crew regarding any number of tiny details could have ended the
mission. I'm in absolute awe of the training and skill involved.

Does anyone else know of similar accounts of early spaceflights? I'd love to
know if the audio from the radio is available too.

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davedx
I'm currently reading "The Dream Machine" [1], about the first evolutions of
computing. At the moment it's describing the period during and immediately
after the Second World War, with computers like ENIAC. It blows my mind that
in the space of around 20 years, we progressed from computers that were
programmed by turning shafts and ran computations using systems of wheels and
mechanical relays [2] to the Lunar Module Guidance Computer with its pre-
emptive multitasking and automatic pilot.

Sometimes the rate of technological advance is just staggering.

[1] [https://www.amazon.com/Dream-Machine-Licklider-Revolution-
Co...](https://www.amazon.com/Dream-Machine-Licklider-Revolution-
Computing/dp/0670899763)

[2]
[https://en.wikipedia.org/wiki/Harvard_Mark_I](https://en.wikipedia.org/wiki/Harvard_Mark_I)

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spatulan
I thought the Lunar Guidance computer used cooperative multitasking.

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ekimekim
IIUC it was a bit of both. A unit of work was meant to be short lived, but if
a higher priority unit of work came along it would be pre-empted and its state
pushed out to a temporary store.

There's a full description in the article, though it's buried a bit far down.
Here's a snippet for grep-ability:

    
    
        if a low-priority job was executing and a high-priority job was scheduled, the low-priority job was suspended while the higher-priority job executed.

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13of40
"It would have been easy for us to adjust the parameter that controlled how
long the delta-V monitor waited before testing the engine — but nobody told
us."

Sleep-and-assume programming is the bane of automation. Ideally, the software
people should have gotten the hardware people to install some kind of sensor
to detect the right condition, but I guess it was either limited by what could
actually be done with the hardware, or maybe they didn't have enough influence
to get the design changed...

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avar
Or maybe all of this was being done for the first time, and we have the
benefit of 50 years of hindsight.

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joezydeco
Don was 27 years old when he wrote the Apollo 14 inflight patch. Chew on that
for a moment.

~~~
InclinedPlane
The average age of NASA engineers at the time of Apollo 11 was 28.

~~~
ddalex
I think this was instrumental in their success - older people are more
cautious their approach. Younger people don't know what can and can't be done
and are way more Liberal in taking risks.

I also think of this as related to the second system syndrome - Apollo was the
first system for a lot of these engineers, and doing lots of things for the
first time ever. People were bold and cautious at the same time. The Space
Shuttle was the second system - an way over engineered system that did not
reach the targets it was designed for, and was successful only through large
amounts of money being thrown at the problem.

