
What happens in WHATCHME.TOS ??

The program was written in assembler, of course.
It simulates the FREDKIN cellular automaton.

Most computer-users know today, what happens in LIFE.
The fredkin-automaton is a more general version of
a self-sustaining cellular automaton, and to my mind a
vastly more important one!








In this version the procedure looks for every pixel of the
screen at it's four adjoining neighbors to the north, east,
south and west:


               N
               |
             W-X-E
               |
               S

The living neighbors are counted and if the result is even 
(0, 2 or 4) the cell is assigned = 0 = dead for the next 
generation. 1 or 3 living neighbors means X=1 = alive.

There are 256000 pixels in the ST's screen.
How would you write a program to do the trick?

Using variables? For 4 bytes / variable this amounts to 1 megabytes!

Try to figure it out by yourself. The answer is found in the
program itself, just disassemble it! There is a command for the
Fredkin cellular automaton in the prosessors micro-code!

Or write me a letter with a stamp in it.

Heinrich Pesch
Tiistilnkuja 1 E 50
SF 02230 Espoo / Finland

July 29. 1988

