Domino computer

The two domino logic gates, from which all others can be built. The XOR gate is dependent on timing.

A domino computer is a mechanical computer built using dominoes^[1] to represent mechanical amplification or logic gating of digital signals. Because of the existence of multiple schemes, domino computer will be used in this article as a collective noun, denoting any particular scheme that uses the mentioned base phenomenon (of domino sequences) for building machines equivalent to a computer. This choice of terminology may be somewhat arbitrary, because only few resources write on this topic.^[2]

Basic phenomenon

Sequences of standing dominoes (so that each topples the next one) can be arranged to demonstrate digital concepts such as amplification and digital signals. It is some digital information that is conducted by a string of dominoes, thus this effect differs from phenomena

• where energy is conducted without amplification, thus it dissipates
• or where amplification is applied to non-digital signals, thus noise effects occur.

The Domino Day event shows many constructs, mainly with purpose of entertainment. Some constructs may remind people of digital circuits. Some of them suggest that not only telegraph-like tools can be shown, but also simple information processing modules can be built.

It is possible to use this phenomenon for constructing unconventional computing tools.^[1][2][3] The base phenomenon is sufficient to achieve this goal,^[2] but also sophisticated “mechanical synapses” can be used (see online ^[4]), to the analogy of electrical synapses or chemical synapses.

Logic Elements

The two logic gates XOR and OR are the easiest to make with dominoes. All other gates can be built from these ((A XOR 1 = Ā) and (A OR B) XOR (A XOR B) = A AND B). The XOR gate shown here is extremely dependent on timing, this dependence could be reduced by making the horizontal string of dominoes longer. These logic elements are one-use-only, as a domino cannot be reset.

See also

• Domino logic
• The concept is mentioned in the book I Am a Strange Loop

Notes

1. ^ ^{a b} Domino computer
2. ^ ^{a b c} Domino computers, a detailed description written by David Johnston
3. ^ James Maguire: IBM Creates Molecular Computer Circuit. NewsFactor Magazine Online, 2006. A topic in the intersection of molecular computing and domino computer
4. ^ Perrucci, Mike: Domino Toppling.

External links

• Kybernetikos, (kyb). "Domino Computation". http://kybernetikos.com/2007/03/01/domino-computation/.