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Lego Logic Gates
Thud457 writes "LEGO Logic Gates - It's like Babbage, but with bricks. All the gates except XOR are here, and he goes on to develop a clocked flip-flop. While practical mechanical computers may be out, even at the nanotechnological scale, nanomechanical memory may be in. "
can one create robots with these or is it only to create simple electronic circuits ?
I guess these could be combined with mindstorm, couldn't these ?
Trolling using another account since 2005.
There may be no obvious immediate use for mechanical analogs of digital circuits, when digital circuits are orders of maginitude faster than mechanical circuits, but dismissing the idea out of hand reminds me of old scientists telling the newspaper that "There's no need for flying machines here!"
Besides, a steam-powered computer would be really fun to build!
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Have a look - it's identical.
There is much friction inherent in these, and as shown, no "gain stages" to overcome these losses. So the "fan-out" would be appalling as implemented here. This would preclude their use to build anything other than the simplest logic constructs. However, I think it would not be too hard to add "gain stages" to act as "buffers", which could, for example, use falling weights to act as "supply rails" to increase "fan-out", thereby facilitating construction of far more complex circuits. Martin
"Absorbing your worst..."
As another poster mentioned, there's no gain in these devices, so after a few stages of friction loss and imperfections in the mechanisms, the whole thing will lock up. Electronic gates have inherent gain, and thus are resistant to noise and slight differences between gates.
Another problem is the way his clock works -- the clock has to go to zero before the set or clear bits can change. This won't happen in a real circuit -- generally everything changes just after the clock rises. One solution is some sort of two-phase system, where alternate flip flops use the rising and falling clocks, but I'm not sure how much this would limit the circuits you can build.
He mentions that "It is possible to build an edge detector for the clock signal. It requires a few more NAND gates. The advantage of doing this is that it no longer matters when the clock signal goes back to 0 and the indeterminant state is avoided." But I want to see it in action before I believe it.
Giving the gates gain may be possible, too, but it would require powering each gate, either with electrical power or some sort of funky mechanical setup.
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If it's good enough for Google then it's good enough for me. Although I'm guessing that in order to make it completely out of LEGO it will require quite a bit more space. Like maybe a stadium?
I would hate to see the instructions for it, and just imagine trying to find all the proper pieces. Wouldn't walk near it in the middle of the night either, man those things f'ing hurt.
Have a look:n kertoyComputer/TinkerToy.html
http://www.rci.rutgers.edu/~cfs/472_html/Intro/Ti
rmathew.com
here are some nice pictures of Hillis' tinker toy tic tac toe machine...It predates his work on the Connection Machine and Thinking Machines Inc.
Goes to show you how strong the mind can become with a little exerecise in logic. Other posters are right about how limited the potential circuits are with lossy elements but all the the same, kudos to Lego for hoping that at least some of us consider thinking a form of recreation.
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When I was a kid back in the 60's, I had a toy mechanical computer called 'Digicomp'. It was a funky conglomeration of springs-and-rods-and-plastic-things that you built from a kit, and programmed it by putting little pieces of tube over various tabs to affect the flip-flops.
To operate it, you pushed a sliding thing in and out (a clock cycle). You could add and subtract and multiply and divide in binary, albeit rather small numbers. Hard to describe this thing, but it was very cool!
Actually, the following year I got Digicomp II for Christmas, which ran by letting a stream of marbles flow through it by gravity, and these marbles toggled the flip-flops. Very cool again!
These toys came with excellent little books on Boolean Algebra, and sure taught me a lot about the interface between binary math and physical things. I felt right at home when I started programming 6502's and Z-80's in machine language back in the day...
Are these things, or anything like them, still around?
- sgage
Anyway, take a long brick, put it on a horizontal pivot. Use horizontal motion of other bricks to push either end of the brick in such a way that it trips some sort of switch. Put such a switch on either end. (If you don't want to use switches, find a way so that both ends can push simultaneously on something built like a space bar so when you push on either end, the center always goes down.)
When one end of the rotating brick is pressed, it goes down. When the opposite end, ditto. When neither end is pressed, it does not move. When both ends are pressed, the force cancels out and nothing is able to move.
Now find a piece that has some sort of spring tension to push both ends back to the neutral position when neither end is being pressed, and figure out a similar spring to serve as a buffer so that the failure to move the rotating bar doesn't cause the circuit upstream to wedge in weird ways, and you're done.
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