In a tribute to all the good that has come from the American experiment, with respect for the scientific and technological fruits of western civilization, and with just a bit of mocking of knee-jerk patriotism, we dedicate this robotic kinetic sculpture on this day, the Fourth of July, 2002. website 
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An Atmel AVR Tiny12 microcontroller generates two channels of pulse width modulated control signal for a pair of Airtronics 94102 servo motors. Custom subroutines interpret moves in polar coordinates using a four quadrant fractional multiply and table lookup transcendental functions.
Here is a script excerpt from "Reverse Flaring Spiral":
spiral: ldi t,0 ldi r,0 ldi v,-3 spi1: ldi p,10 spi2: rcall polar add t,v dec p brne spi2 inc r cpi r,120 brne spi1