Once in college I found myself sitting in an extremely boring operating systems class, trying to think of something disturbing to do with my circa 1986 Casio fx-4000P calculator.

I programmed the calculator to assist me in ray-tracing a sphere by hand.

For each pixel, the calculator would display a number that indicated one of five gray levels, corresponding to the intensity of one of a set of art markers I purchased.

On graph paper, I would fill in the current square with the appropriate shade of gray, and then press a button on the calculator, which would display the intensity for the next square.

The 32 by 32 pixel image took about an hour to create.

8 by 8 inches, marker on graph paper

Return to Drew's Home Page