Perspex machine
The perspex machine is a theoretical computer with a single instruction that performs a geometrical transformation and a jump. The transformation is piecewise continuous, not digital, which makes the theoretical perspex machine a hypercomputer. Consequently a digital computer cannot emulate the theoretical perspex machine, but it can simulate one approximately. The co-ordinates of the transformation are transreal numbers which means that the theoretical perspex machine, or a digital simulation of it, has no arithmetical exceptions.
The perspex machine is commonly simulated in terms of a perspex, short for "perspective simplex" which, in turn, is commonly represented as a 4 x 4 matrix with column vectors x, y, z and t:
It is claimed that the perspex machine has various interesting properties, for example:
- The perspex machine is deterministic.
- Perspex programs are robust in the face of deleted or altered instructions.
- A perspex program can be approximated (badly) by a single perspex instruction, and the approximation can be gradually improved by adding instructions until the original program is reconstructed.