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Build Your Own Apollo Guidance Computer
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, $2,980 in cash, 2,500 hours of labor and 15,000 hand-wrapped wire connections with 3,500 feet of wire to build. It might be next Christmas before you could build one of your own to give as a gift, but he promises you can build your own for less and it will be better than his. The perfect gift for the space geek who has everything. This guy is my hero."
Now all he has to do is build his own apollo 11, and he's all set to go to the moon! He just has to pay a few hundred million to get the rockets to take it up.
[me] HI AUNT EDNA! Look what I built for you! Its an exact replica of the Apollo guidance computer!
[Aunt Edna] uh, thanks?
time is a perception of a being's consciousness
time is your 6th sense, the wierd ones are 7+
They had IBM 360s and other big iron on the ground to do the heavy-duty calculations. If you have a choice between doing something on the ground and doing it on board the spacecraft, it's almost always better to do it on the ground.
Mea navis aericumbens anguillis abundat
will it run Linux? ... or at least NetBSD?
Easy, they weren't bogged down with a GUI.
you see, I come from a time in the nineteen hundred and seventies
when computers where used for two things
too either go to the moon or play pong
and nothing inbetween, you see
and You didn't need a fancy operating system to play pong
and the men who went to the moon, god bless them
did it with no mouse
and a plain text only black and white screen
and thiry-two kilobytes of ram
Beyond that, this guy is lucky its christmas because with multiple 4-9 meg pdf files it would be a silent night for his server.
can't sleep slashdot will eat me
10$ says it's flashing "1202" right about now...
An emulator already exists. It has been released as free software under the GPL. It supports Linux and Windows.
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");
With that kinda money you could rebuild the sound stage they faked the first trip to the moon on!
-bbh
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.
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.
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
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.