Spartan universal computer-constructor

Spartan Universal Computer-Constructor
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Pattern type	Miscellaneous
Number of cells	27
Bounding box	17 × 7
Static symmetry	Unspecified
Discovered by	Adam P. Goucher
Year of discovery	2009

This is a Life implementation of a universal computer designed and built in 2009 by Adam P. Goucher.

Architecture

The computer contains 11 sliding-block memory registers capable of storing any positive integer (including zero). Three of these are directly used by the microcode; the other eight are freely accessible to the program.

In addition to this, eight gates (simple, two-state switches) are provided for fast boolean storage.

Finally, the computer has three tapes (program tape, data tape and marker tape). The program tape consists of eaters and is read-only, whereas the other two tapes consist of blocks and can be altered during run-time.

The machine also has a construction arm (by Paul Chapman and Dave Greene) capable of synthesising anything with a slow-salvo glider synthesis. Because the machine itself consists exclusively of still-lifes with seven or fewer cells, a sufficient program tape would allow the machine to self-replicate forever. This could emulate (in increasing difficulty) a puffer, a rake or a spaceship. Adam P. Goucher estimates that it will take

Comparison with other universal computers

Because of the architecture of the machine, it has several advantages over other universal computers:

• It is relatively easy to program, since the instruction set allows basic arithmetic operations, bitwise shifts and logical operations to be performed using a string of a few instructions.

• The main storage is in binary, meaning that it stores data exponentially more compact than an equivalent Resiter Machine.

• Conditional jumps are relative, rather than absolute, so a suborutine can be copied into a program without having to alter the pointers.

External Links

The zipped file of the U.C.C. at calcyman.co.uk