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From: phillips@cs.ubc.ca (George Phillips)
Newsgroups: comp.theory.cell-automata
Subject: wireworld patterns
Summary: got any? want any?
Message-ID: <6713@ubc-cs.UUCP>
Date: 9 Feb 90 09:29:59 GMT
Sender: news@cs.ubc.ca
Reply-To: phillips@cs.ubc.ca (George Phillips)
Organization: UBC Department of Computer Science, Vancouver, B.C., Canada
Lines: 24

In the Jan. 1990 issue of Scientific American, A. K. Dewdney describes
the rules for a cellular automata called "wireworld".  For those that
haven't seen it, each cell has 4 possible states: space, wire, electron
head or electron tail.  Cells interact with their 8 neighbours by the
following rules:

- space cells forever remain space cells
- electron tails turn into wire cells
- electron heads turn into electron tails
- wire cells remain wire cells unless bordered by 1 or 2 electron heads

With these rules, electrons composed of heads and tails can move along
wires and you can build diodes, OR gates, NOT gates, memory cells,
wire crossings and so on.

After a couple of really cheap hacks, I played with wireworld on my PC
and Unix and was able to come up with a 6 cycle memory cell, a number of
logical gates and some pulsars which generate electrons at different
rates.  If anyone is interested, I'll post my patterns here and (hopefully)
someone can dazzle me with their discoveries.  If such postings (or
even this posting) are inappropriate here, I'm sure you'll inform me :-).

--
George Phillips phillips@cs.ubc.ca {alberta,uw-beaver,uunet}!ubc-cs!phillips