Turtle inversion, Graphite and conté on acid-free paper, 1.8 x 1.5 m
From the original Turtle Geometry, Computer Assembly Language dot-matrix computer paper based on an early algorithm developed by Hal Abelson, a professor in the computer science department at MIT (and an activist for internet freedom). Abelson has been a founder and director of such public interest groups as Creative Commons. The Turtle, a key early code, responds to 4 basic commands (as does much of early coding and algorithms):
•FORWARD d: The turtle moves forward d steps in the direction of its current heading, and draws a line from its initial position to its final position.
•MOVE d: Same as FORWARD d without drawing a line.
•TURN a: The turtle changes it heading by rotating in the plane counterclockwise from its current heading by the angle a.
•RESIZE s: Changes the turtle step size by the factors.