Alt-BEAM Archive

Message #00716



To: Noam Rudnick rudnick1@cwix.com, beam beam@corp.sgi.com
From: Sean Rigter rigter@cafe.net
Date: Sat, 20 Feb 1999 21:00:02 -0800
Subject: [alt-beam] Re: associative memories



> Noam Rudnick wrote:
>
> oops, i guess i jumped the gun.

No, I was just slow!

In fact, if in your circuit you use 74HC14 gates with 2 identical
resistors connected together at one end and connected to the input of
each gate it forms 2 input "majority logic gates". If the voltage at the
other end of each of the 2 resistors is connected to input voltages the
output changes only if the majority of inputs is either one or zero. ie
0V at both inputs change the output to 1 If both inputs are 1 the output
is 0 if there is no majority of one or zeroes at the 2 inputs, the
output remains unchanged.

Actually one correction (my fingers are faster than my brain!)
I should have said the minimum neighborhood size for LIFE is 9 cells
with 8 surrounding the central cell. In large arrays each cell is
surrounded by 8 neighbors except at the edge of the array.

XXX
X0X
XXX

With non inverting majority logic gates the CA behaviour will be one
called "VOTE". Cells turn on if a majority of neighboring cells are on
or turn off when the majority are off. If there is no clear majority the
cell output remains unchanged.

Such a rule could also be used to control group behaviour of robots if
they are wired up with majority logic rules and can communicate with
each other.

Talk about peer pressure and conformity

Anyway I wrote a short article on this which you can find on my
absolutely unfinished web page

http://www.geocities.com/ResearchTriangle/System/8222/beamlife.html

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