nelson@m.cs.uiuc.edu (09/29/89)
This may seem a bit inappropriate for comp.arch, but where else would this go? We are interested in building something (possibly a Turing Machine) out of LEGO blocks. Various ideas have been popped around, but there seem to be limitations on putting it all together (mechanical mainly). The most pleasing idea thus far is using counter-/clockwise movement to indicate the state of a bit. My question: Are there any articles floating around discussing this as-yet- untapped field? (Yes, I know about the one in the new Scientific American.) Danke!
preston@titan.rice.edu (Preston Briggs) (09/30/89)
In article <3300071@m.cs.uiuc.edu> nelson@m.cs.uiuc.edu writes: >We are interested in building something (possibly a Turing Machine) out of > LEGO blocks. Various ideas have been popped around, but there seem to be I don't know of any helpful articles, but it reminds me that Danny Hillis (as in Connection Machine) once mentioned building a tinker-toy machine that played tic-tac-toe. I believe it lives in a museum in Arkansas. How's that for urban rumor-mongering? Keep us posted on the Lego design. Preston Briggs
jeff@visix.UUCP (Jeff Barr) (09/30/89)
In article <1801@brazos.Rice.edu>, preston@titan.rice.edu (Preston Briggs) writes: > In article <3300071@m.cs.uiuc.edu> nelson@m.cs.uiuc.edu writes: > >We are interested in building something (possibly a Turing Machine) out of > > LEGO blocks. Various ideas have been popped around, but there seem to be > > I don't know of any helpful articles, but it reminds > me that Danny Hillis (as in Connection Machine) once > mentioned building a tinker-toy machine that played > tic-tac-toe. I believe it lives in a museum in Arkansas. > How's that for urban rumor-mongering? > Unless there is more than one, I saw the Tinker-Toy (tm ?) tic-tac-toe machine in the Computer Museum in Boston, MA earlier this year. Its a cube about 1m on a side, filled with Tinker-Toys and string. Do you suppose they needed a log-ic analyzer to debug it (:-)? > Keep us posted on the Lego design. > > Preston Briggs Jeff /\ Jeff Barr \ / Visix Software, Inc. /\ 800-832-8668 \ / / \ uunet!visix!jeff \ / 1525 Wilson Blvd. / \ 703-841-5858 \ / / visix!jeff@uunet.uu.net\/ Arlington, VA 22209 / \ \/
roy@phri.UUCP (Roy Smith) (10/01/89)
I can see it now, a USENIX special workshop for "Unix on big plastic"
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
{att,philabs,cmcl2,rutgers,hombre}!phri!roy -or- roy@alanine.phri.nyu.edu
"The connector is the network"spencert@rpics (Thomas Spencer) (10/01/89)
In article <218@visix.UUCP> jeff@visix.UUCP (Jeff Barr) writes: >In article <1801@brazos.Rice.edu>, preston@titan.rice.edu (Preston Briggs) writes: >> In article <3300071@m.cs.uiuc.edu> nelson@m.cs.uiuc.edu writes: >> >We are interested in building something (possibly a Turing Machine) out of >> > LEGO blocks. Various ideas have been popped around, but there seem to be [All comments but the original querry deleted.] I'm not sure what constitutes a Lego computer, but the following results from automata theory might be useful: 1. a two stack PDA can simulate a Turing Machine. Thus, one can imagine a computer whose main storage consisted of two stacks of Legos. Of course, it is necessary that there be two possible kinds of blocks in each stack and the finite control needs to be represented somehow. The latter is a small matter of engineering. 2. A four counter machine can simulate a Turing Machine. Thus, if you are willing to provide 4 stacks of legos, the stacks can contain all the same kind of block. I hope that this helps. -Tom Spencer spencert@turing.cs.rpi.edu uunet!steinmetz!itsgw!spencert "First figure out what you are trying to do." -Me.
paulsc@radio_flyer.WV.TEK.COM (Paul Scherf;685-2734;61-028;692-4142;orca) (10/03/89)
In article <3300071@m.cs.uiuc.edu> nelson@m.cs.uiuc.edu writes: >We are interested in building something (possibly a Turing Machine) out of > LEGO blocks. Various ideas have been popped around, but there seem to be > limitations on putting it all together (mechanical mainly). The most > pleasing idea thus far is using counter-/clockwise movement to indicate > the state of a bit. >My question: Are there any articles floating around discussing this as-yet- > untapped field? (Yes, I know about the one in the new Scientific American.) While I was in college (a few years ago), a friend of mine and I were going to build a Turing machine. We also tried to find articles on such things. The professors we happened to ask, were all very nice about it, but most of them didn't understand at first. They would either draw a Turing machine "tape" with the little squares on the chalkboard, or explain that we only needed a short Pascal program. Then we got a chance to explain that we wanted to build a PHYSICAL Turing machine. No one knew of any articles, but if we succeeded in our quest, we were invited to give a colloquium for the department. We got quite far into the mechanical design. When we got far enough to start collecting parts and begin construction, we had to "take time out" to study for semester final exams and never got back to working on our Turing machine. (-: Paul Scherf, Tektronix, Box 1000, MS 61-028, Wilsonville, OR, USA 97070 paulsc@orca.WV.Tek.com 503-685-2734 tektronix!orca!paulsc
bls@cs.purdue.EDU (Brian L. Stuart) (10/03/89)
I really haven't thought much about doing this myself, but I would suggest that you start by studying Konrad Zuse's work. He developed a couple of machines that used mechanical logic and even had mechanical memory. It's really clever stuff; it's worth everyone's time to learn about it. There is a good article on his work in an issue of the Annals of the History of Computing. I don't remember what issue, but I think it's in Vol. 2. Anyone know the exact reference? Brian L. Stuart Department of Computer Sciences Purdue University
rod@venera.isi.edu (Rodney Doyle Van Meter III) (10/03/89)
I vaguely recall an article (Scientific American, perhaps?) from a few years ago that talked about mechanical computers, specifically some simple state machine. It was in the guise of some ruins found on a South Pacific island, I think, with ropes and logs changing and representing the state of the machine. I no longer even recall whether it was real or some fiction created for the purposes of the article. A quick scan of Dewdney's columns over the last three years might provide a clue. --Rod
gillies@p.cs.uiuc.edu (10/04/89)
There was an article in BYTE back when I had a subscription (about '77
to '80, I believe) on how to build a Turing machine.
They used a big 1-bit DRAM for a tape (sorry, only binary alphabets
were supported). But it was pretty fast; less than 1 microsecond per
instruction. Maybe you could hunt up the article for more information.
Don Gillies, Dept. of Computer Science, University of Illinois
1304 W. Springfield, Urbana, Ill 61801
ARPA: gillies@cs.uiuc.edu UUCP: {uunet,harvard}!uiucdcs!gillieskleonard@gvlv2.GVL.Unisys.COM (Ken Leonard) (10/04/89)
In article <9981@venera.isi.edu> rod@venera.isi.edu.UUCP (Rodney Doyle Van Meter III) writes:
*
* I vaguely recall an article (Scientific American, perhaps?) from a few
* years ago that talked about mechanical computers, specifically some
* simple state machine. It was in the guise of some ruins found on a
* South Pacific island, I think, with ropes and logs changing and
* ...
Hey, mon!, Wanna bet it was in the April issue?
------------
regardz,
Kenfwb@demon.siemens.com (Frederic W. Brehm) (10/04/89)
>I vaguely recall an article (Scientific American, perhaps?) from a few >years ago that talked about mechanical computers, ... >quick scan of Dewdney's columns over the last three years might >provide a clue. I vaguely recall (:-) that there is an article in the current Scientific American on a tic-tac-toe playing tinker-toy computer. There is also a tinker-toy computer on display in the Computer Museum in Boston. Fred -- Frederic W. Brehm Siemens Corporate Research Princeton, NJ fwb@demon.siemens.com -or- princeton!siemens!demon!fwb
david@indetech.com (David Kuder) (10/10/89)
In article <4792@orca.WV.TEK.COM> paulsc@radio_flyer.WV.TEK.COM (Paul Scherf) writes: >While I was in college (a few years ago), a friend of mine and I were >going to build a Turing machine. We also tried to find articles on >such things. The professors we happened to ask, were all very nice >about it, but most of them didn't understand at first. They would >either draw a Turing machine "tape" with the little squares on the >chalkboard, or explain that we only needed a short Pascal program. >Then we got a chance to explain that we wanted to build a PHYSICAL >Turing machine. No one knew of any articles, but if we succeeded in >our quest, we were invited to give a colloquium for the department. > >We got quite far into the mechanical design. When we got far enough to >start collecting parts and begin construction, we had to "take time >out" to study for semester final exams and never got back to working on >our Turing machine. (-: > >Paul Scherf, Tektronix, Box 1000, MS 61-028, Wilsonville, OR, USA 97070 >paulsc@orca.WV.Tek.com 503-685-2734 tektronix!orca!paulsc In introductory CS courses at CalTech they drag out a mechanical turing machine. The tape consists of a metal rack of three position sliders. A segment of "tape" had about 16 sliders on it. Several segments could be connected to form a longer tape. If they had more than three segments I never saw them. The bottom of the rack was geared so it could be moved past the read/write head. If I remember correctly the read was destructive: it was accomplished by shoving the slider to "off" and seeing how far it moved. A write pretty much reversed the operation of a read: shove the slider out 0, 1, or 2 notches. The rack could be moved left or right under the head. Both the head and the rack were driven by noisy relays. This thing was real loud and slow. Just right for holding the attention of freshmen :-). The finite state machine was built out of blocks. Each block represented one state. The blocks hooked together on a bus to drive the tape and read/write head. Its been a while but I think the blocks had arrows and by flopping them over you changed from left to right movement. The transition from state to state was done by plugging wires from 0, 1, or mark read holes to the input of the next block. Blocks were either color coded or had a switch to control what they wrote. It's been too long since I've seen the thing. If it still exists, perhaps someone in closer vicinity to it can describe it. -- David A. Kuder Comp.lang.perl, the time is now! 415 438-2003 david@indetech.com {uunet,sun,sharkey,pacbell}!indetech!david
leech@alanine.cs.unc.edu (Jonathan Leech) (10/10/89)
In article <4792@orca.WV.TEK.COM> paulsc@radio_flyer.WV.TEK.COM (Paul Scherf) writes: >While I was in college (a few years ago), a friend of mine and I were >going to build a Turing machine. We also tried to find articles on >such things. Someone built a mechanical Turing machine at Caltech some years ago (1960s, I think) which was still in use as of a few years ago, as a demonstration device in the freshman digital logic class. The tape was ~40 characters long. -- Jon Leech (leech@cs.unc.edu) __@/ ``Before I refuse to take your questions, I have an opening statement.'' - Ronald Reagan