A plastic platform with attached dominoes in different logical configurations.
These would be a lot easier to set up than regular dominos. Just turn the upside down, slide them into the breadboard and then flip over and you are ready to set the domino effect in motion to run any program you can design.
You would have to experiment with what regular size to make each square so that you could fit all of the logical operations on the same sized squares, so they would be interchangeable.
Then put them up on thingiverse so everyone can download them and print them out.-- JesusHChrist, May 31 2014 Domino logic https://www.youtube...watch?v=lNuPy-r1GuQ [tatterdemalion, Jun 01 2014] NAND gates could be a challenge. Someone needs to get to work on the donimo server platform...-- RayfordSteele, Jun 01 2014 Domino NOT gates in general would be difficult, unless you have some kind of grey-code.-- Hive_Mind, Jun 01 2014 A Google image search turns up many domino logic gates-- Voice, Jun 01 2014 //Domino NOT gates in general would be difficult, unless you have some kind of grey-code.//
I think domino NOT gates are conceptually equivalent to electronic NOT gates. In both you need a hidden supply of 'ones'.-- Loris, Jun 02 2014 NOT gates can be implemented as: a XOR 1 = ~a. That implements Loris's hidden supply of 1s. Or course implementing an XOR is tricky because it is timing dependent. Since each input and output can only change once from a 0 to a 1, the gate must have some delay after the first input goes to 1 during which receiving a second 1 will prevent the 1 from being sent out the output. And if the the XOR is after some other logic, the propagation times could be hard to predict. To deal with that, you could put both inputs through AND gates that are triggered by a 1 that is delayed longer than the expected propagation time of the other two inputs.
And after all that you're still restricted to combinational logic. Any state machine would require resetting the dominoes. One sort of work around is to simply create a full copy of your entire logic circuit for every cycle you'd like to perform.
One idea to implement state machines at the cost of possibly violating traditional domino restrictions would be to mount them inside a large rolling cylinder. Normal domino action would happen on the bottom, but as the domino modules rotated upside down they would get reset. The length of the cycle would of course need to match the circumference of the cylinder, and all the dominoes would need to be falling generally forward. Any domino path that tried to backtrack wouldn't get reset properly. This would also make timing easier because the domino propagation rate would actually be controlled by the cylinder rotation speed.-- scad mientist, Jun 02 2014 I too was thinking that if you knew exactly what logic you wanted then you could use a resetting device to allow loops. Suppose that you had each domino standing on a small plinth, then after falling it would be out of the way. I imagine a bowling-pin style resetting device, sweeping off the untriggered dominos before laying down the new set.-- Loris, Jun 03 2014 random, halfbakery