||This article is incomplete. (January 2014)|
Unconventional computing is computing by a wide range of new or unusual methods. It is also known as alternative computing.
Historically, mechanical computers were used in industry before the advent of the transistor. Mechanical computers retain some interest today both in research and as analogue computers. Some mechanical computers have a theoretical or didactic relevance, such as billiard-ball computers or hydraulic ones,. While some are actually simulated, others are not; no attempt is made to build a functioning computer through the mechanical collisions of billiard balls. The domino computer is another theoretically interesting mechanical computing scheme.
Unconventional computing is, according to a recent conference description, "an interdisciplinary research area with the main goal to enrich or go beyond the standard models, such as the Von Neumann computer architecture and the Turing machine, which have dominated computer science for more than half a century". These methods model their computational operations based on non-standard paradigms, and are currently mostly in the research and development stage. This computing behavior can be "simulated" using the classical silicon-based micro-transistors or solid state computing technologies, but aim to achieve a new kind of computing engineering inspired in nature.
The following types are based on computation with an unconventional medium or material:
- Physical objects (billiard ball computer, domino computation) These are unintuitive and pedagogical examples that a computer can be made out of almost anything.
- Light (optical computing)
- Molecules (molecular scale electronics)
- Molecular dynamics (DNA computing, peptide computing, biocomputing, chemical computing)
- Mechanical computer
- Neurons (wetware computer)
- Human computer
The following are unconventional styles of computing:
- Quantum computing
- Biologically-inspired computing/natural computing
- Neuromorphic computing
- Software agents acting under a special set of rules (e.g. cellular automata)
- Continuous-valued electronics or fluidics, etc. (e.g. analog computer although these may also be implemented mechanically)
- Ternary computing
- Amorphous computing
- Reversible computing
- Chaos computing
- Stochastic computing
- Penrose, Roger: The Emperor's New Mind. Oxford University Press, 1990. See also corresponding article on it.
- "Unconventional computation Conference 2007".
- "Unconventional Models of Computation 1998".
- C.S. Calude. "Unconventional Computing: A Brief Subjective History, CDMTCS Report 480, 2015".