Subject:
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Re: The latest rage in pneumatic computing
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Newsgroups:
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lugnet.technic, lugnet.robotics
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Date:
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Sat, 21 Jun 2003 23:07:16 GMT
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Viewed:
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1118 times
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In lugnet.technic, Robert Fay wrote:
>
> "Kevin L. Clague" <kevin_clague@yahoo.com> wrote in message
> news:HGup2n.7Jv@lugnet.com...
> > I created Mark Tarrabain's single pressure/single piston AND gate and have it
> > all four possible input states. In this case I use rubber bands to compress the
> > pistons, but this is not the only way to compress the pistons.
> >
> > http://www.brickshelf.com/gallery/kclague/Computing/mt-and-kmap.jpg
> >
> > Here is a picture of my additions to Mark's gate to make single piston/dual
> > pressure (works well with dual acting LEGO pneumatic pistons) AND gate. By
> > adding the two switches, I can create the pressure to close the pistons (without
> > using rubber bands).
> >
> > http://www.brickshelf.com/gallery/kclague/Computing/klc-and-kmap.jpg
> >
> > Here is my single piston/dual pressure OR gate. Same mechanics as the AND gate,
> > but with different connections.
> >
> > http://www.brickshelf.com/gallery/kclague/Computing/klc-or-kmap.jpg
> >
> > Here is my single piston/dual pressure XOR gate.
> >
> > http://www.brickshelf.com/gallery/kclague/Computing/klc-xor-kmap.jpg
> >
> > The AND and XOR can be driven by the same piston, so a full binary adder can be
> > created with three pistons, and 17 switches.
> >
> > Unfortunatly for me Mark can perform the same addition with 3 pistons and 13
> > switches plus rubber bands, or 3 pistons and 14 switches (one extra one to
> > pressure the gates closed.)
> >
> > PLUKWYT
> >
> > Kevin
>
> Good work, Kevin! I have not worked with AND OR & XOR logic for many years.
> The old discrete component Bendix DynaPath Numerical controls used AND & OR
> through out their systems. I think your pneumatic recreation is really
> interesting. I am having trouble visualizing the full adder. I will have to
> think about that a bit. Thanks for sharing your efforts.
You are welcome, and thanks Robert.
The full adder has three inputs A,B and carry in, and two outputs sum out and
carry out.
SumAB = A XOR B
Sum out = SumAB XOR Carry in
Carry out = (A AND B) OR (SumAB AND Carry in)
You need a total of 2 XOR gates, 2 AND gates and an OR gate.
Before Mark Tarabain showed me the how to make half an AND gate with 1 piston
(instead of two), it took me 14 pistons and 7 switches to make a full adder.
I've cut the number of pistons by 11, but increased the switches by 10. A
*huge* cost savings. Pistons are expensive.
I'm still thinking about a pneumatic computer...... Gotta buy more pistons and
switches though.
Kevin
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Message is in Reply To:
 | | Re: The latest rage in pneumatic computing
|
| "Kevin L. Clague" <kevin_clague@yahoo.com> wrote in message news:HGup2n.7Jv@lugnet.com... (...) it (...) compress the (...) piston/dual (...) By (...) (without (...) gate, (...) can be (...) 13 (...) Good work, Kevin! I have not worked with AND OR (...) (21 years ago, 21-Jun-03, to lugnet.technic, lugnet.robotics)
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