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Build Your Own Apollo Guidance Computer

Posted by michael on from the some-assembly-required dept.

PingXao writes "Well, if you can't exactly give the Moon you can give the gift of a computer to get you there. Almost a year ago this Slashdot story about the Apollo 11 Guidance Computer referenced a pretty cool Dr. Dobbs Journal article from their History of Computing series. Now there's this guy who built one in his basement! It took him 4 years, $2,980 in cash, 2,500 hours of labor and 15,000 hand-wrapped wire connections with 3,500 feet of wire to build. It might be next Christmas before you could build one of your own to give as a gift, but he promises you can build your own for less and it will be better than his. The perfect gift for the space geek who has everything. This guy is my hero."

26 of 218 comments (clear)

  1. Kinda makes you wonder, by DoraLives · · Score: 3, Insightful

    with those old boxes, how in hell did they ever make it to the moon and back alive.

    --
    Is it fascism yet?
    1. Re:Kinda makes you wonder, by Detritus · · Score: 4, Insightful

      They had IBM 360s and other big iron on the ground to do the heavy-duty calculations. If you have a choice between doing something on the ground and doing it on board the spacecraft, it's almost always better to do it on the ground.

      --
      Mea navis aericumbens anguillis abundat
    2. Re:Kinda makes you wonder, by Average_Joe_Sixpack · · Score: 5, Funny

      Easy, they weren't bogged down with a GUI.

    3. Re:Kinda makes you wonder, by UniverseIsADoughnut · · Score: 4, Insightful

      well, you could do it without computers, would just be even harder, plus astronauts would have one sucky time flying the craft by hand to the moon. But it could be done, there is always a way without a computer.

      The other thing is they took a very simple approach to thing, to do it today would be even harder because we would over complex thing thing with uber redundancy and sensors for everything and so forth. Thus why we could get to the moon, or russians get space stations, but the space shuttle and space station suck.

      Not that getting more computers involved is bad, it just makes it easier for things to crap out and not know why. Mechanical stuff is easy to figure out why it's not working, electrical not so much, and code and semiconductors very hard.

      I too look at how we did it, am are amazed it all worked. But then, look at a Model T or a Steam Locomotive, today it seams amazing people would trust those thing cross country or that they would be very durable, but they did it just fine.

      I'm pretty sure my powermac has failed on my more then my atari 800 ever did.

    4. Re:Kinda makes you wonder, by Glonoinha · · Score: 4, Insightful

      Heh.
      Most of us wear watches with more horsepower than a single System 360 of the time.
      I would imagine that every computation performed at all of NASA from T minus 10 until splashdown could grind through my desktop in less time than it took me to reply to this message.

      The difference wasn't in the hardware.
      It was in the people, their abilities, and in the working relationship those people had with each other.
      It was in the management of those people, putting success and excellence above all else.
      It was in the work - putting men on the moon wasn't just a job, it was an adventure and it was a dream.

      --
      Glonoinha the MebiByte Slayer
    5. Re:Kinda makes you wonder, by bigberk · · Score: 3, Insightful
      The difference wasn't in the hardware. It was in the people... it was an adventure and it was a dream.
      I agree with you. Look at the incredible computation abilities we now have, it really boggles the mind. We have made leaps forward in speed, miniaturization, and power usage. Materials science has also brought us an entirely new set of possibilities since then. Now, if we had a real goal -- like to start human exploration of space in earnest (longer missions, more frequent), I think we could really do some amazing things.

      Personally I think we're being really stupid by not funding more space exploration. Yes, I know people on earth are starving. But both you and I know that it's not the starving Ethiopians competing with NASA or ESA for funding...
    6. Re:Kinda makes you wonder, by fmaxwell · · Score: 3, Interesting

      well, you could do it without computers, would just be even harder, plus astronauts would have one sucky time flying the craft by hand to the moon. But it could be done, there is always a way without a computer.

      Actually, there is not always a way without a computer. Some modern fighter jets are inherently unstable (in order to provide faster response) and no human being in the world could react quick enough to keep those planes from wadding themselves into little silver balls. Their computers make multiple control surface adjustments per second.

    7. Re:Kinda makes you wonder, by GuruBuckaroo · · Score: 3, Insightful

      There's a Heinlein quote that I'm trying to think of, that goes something along these lines:

      There are three stages to the development of any technical project. In stage one, the device is simple, does only what it needs to, and works most of the time. In stage two, the device is vastly overcomplicated, overpowered, does far more than it needs, and works occasionally. In stage three, the "improvements" are thrown out, the device is again simple, does only what it needs to, and works all the time.

      I've been waiting for Stage Three for a long time now. My money is on Burt Rutan.

      --
      Poor means hoping the toothache goes away.
    8. Re:Kinda makes you wonder, by UniverseIsADoughnut · · Score: 4, Insightful

      well, they are unstable for the purpose of getting better performance, not to make the concept of planes to fly work. You can build a plane without a computer, and could achieve the same basic concepts, but it wouldn't do it as well.

      Also, planes like the Stealth Bomber are said to not be able to fly without a computer for reasons like you mentioned, especially landing it. But really it's a issue of it makes it practical, not needed. The Northrop flying wing worked in the late 40s and it obviously had no computers. The B2 is based off that planes design (actually has the exact same wing span), the computers just made it more feasible and overall better.

      In the case of going to the moon, it could be done without a computer, rockets went up without computers, plus people make a great computer. The computers for apollo did pretty straightforward stuff, and were mainly there so the astronauts didn't have to keep doing stuff non-stop. They could still sight stars and calculate there path and manual fire rockets to adjust (like they did in Apollo 13),

      The thing is we have all gotten so used to doing stuff with a calculator that we forget you can do it without. When was the last time you did a square root by hand (or even remember how). I think this is the kind of thing that causes people to wonder how things like the pyramids were made, people just can't think of how to do things without modern tools, cause thats all they know. To the Egyptians building them probably wasn't that hard to figure out.

  2. Fantastic by Icarus1919 · · Score: 4, Funny

    Now all he has to do is build his own apollo 11, and he's all set to go to the moon! He just has to pay a few hundred million to get the rockets to take it up.

  3. Give it as a gift? by Prophetic_Truth · · Score: 5, Funny

    [me] HI AUNT EDNA! Look what I built for you! Its an exact replica of the Apollo guidance computer!
    [Aunt Edna] uh, thanks?

    --
    time is a perception of a being's consciousness
    time is your 6th sense, the wierd ones are 7+
  4. Or... by binderhead126 · · Score: 3, Funny

    You could just hack a Gameboy Advance, and have even more horsepower! To the MOOOOOOOOOOOOON!!!!!!!!

  5. yea but... by mindwar · · Score: 5, Funny

    will it run Linux? ... or at least NetBSD?

  6. Every operating system sucks... by powerlinekid · · Score: 5, Funny

    you see, I come from a time in the nineteen hundred and seventies
    when computers where used for two things
    too either go to the moon or play pong
    and nothing inbetween, you see
    and You didn't need a fancy operating system to play pong
    and the men who went to the moon, god bless them
    did it with no mouse
    and a plain text only black and white screen
    and thiry-two kilobytes of ram

    Beyond that, this guy is lucky its christmas because with multiple 4-9 meg pdf files it would be a silent night for his server.

    --

    can't sleep slashdot will eat me
    1. Re:Every operating system sucks... by neuromortis · · Score: 4, Informative

      For those who don't know, the above excerpt comes from the comedy genius of Three Dead Trolls in a Baggie, specifically the track "Every OS Sucks".

      --

      I build model citizens.
    2. Re:Every operating system sucks... by powerlinekid · · Score: 5, Funny

      No no, you got it all wrong. The thing that looked like pong really was the guidance program. The first paddle was earth, the second was the moon and the little dot was the capsule.

      --

      can't sleep slashdot will eat me
  7. And now it's been linked to by Slashdot. by Nanoda · · Score: 5, Funny

    10$ says it's flashing "1202" right about now...

    1. Re:And now it's been linked to by Slashdot. by agtorange · · Score: 4, Funny

      Well then all he would have to do it flip it off and take the thing in on manual.

  8. Re:Emulators? by enosys · · Score: 5, Interesting

    An emulator already exists. It has been released as free software under the GPL. It supports Linux and Windows.

  9. FPGA by saned · · Score: 4, Insightful

    Not to undermine his job, which I think is a major accomplishment, not only by building it but by reimplementing the whole logic from diagrams. But looking at the logic, it seems it could fit easily in a Spartan 3 FPGA. So yes, it could be done cheaper and faster, but not with the degree of detail this guy put on.

    Kudos to him

    --
    signal_connect(0, "test_top.dut.my_sig", "clk");
  10. Sucker! by bbh · · Score: 5, Funny

    With that kinda money you could rebuild the sound stage they faked the first trip to the moon on!

    -bbh

  11. Your Palm Pilot is not radiation hardened. by gelfling · · Score: 4, Informative

    There are two reasons why spaceflight computers are relatively underpowered:

    Reliability under conditions your PC would fail, like radiation, shock, vibration, acceleration, heat and cold.

    Built to solve unique specialized problems for people who are not entirely computer expert.

    Navigation computers have to solve complex solid analytic geometry problems for people who are experts in solid analytic geometry but aren't experts in computers and don't have the luxury to spend lots of time to do that.

  12. Limits of simulation? by Tablizer · · Score: 3, Funny

    Can it simulate the part where the sensor loop queue was overloaded because they forgot to turn off the rendevous radar and the warning lights went crazy and Neil or Buzz wet his suit? (I have no official info that they did, but I bet at least one did but never told anyone.)

    --
    Table-ized A.I.
  13. No disrespect, but... by fmaxwell · · Score: 3, Insightful

    I have the utmost respect for the initiative, intelligence, and generosity of the man who built this computer. That said, he didn't build a replica of an Apollo Guidance Computer (AGC). He did not use the same parts, constructing it with higher integration 74LS parts that gave about a 10-to-1 IC package reduction. The original AGC prototype used core memory and his uses static RAM and EPROM. There are countless other differences.

    Again, he is deserving of high praise, but he did not replicate the original AGC I prototype. He created a working model which was very true to the original at the block diagram level.

  14. Re:OK, so Apollo can go home, but how about... by HermanAB · · Score: 3, Informative

    Nope, even Apollo is long gone. King Constantine retired all the old Gods in 325AD at Nicea near Naples and defined the Trinity to take their place. Only Zeus, Mercurius and Demeter survived - oh, and Isis - she survived too, Contantine didn't want to kill her and her cute little baby, but in return for continued worship, the Gods were morphed. Constantin caused such divine confusion, that the collective memory of the Western World still haven't recovered...

    --
    Oh well, what the hell...
  15. Documentation by Cryptnotic · · Score: 3, Informative

    What's the most important thing about what this guy did?

    Documentation. He documented every step of the way everything that he did. It's something that's lacking in a lot of geeky projects and it's something that I commend this guy at doing an awesome job at.

    --
    My other first post is car post.