Fortune is running a story about the golden age of microchip graffiti is fading. But these images were never meant to be seen in the first place.

“I saw something that looked different from most other things on the chip,” Davidson recalls. He cranked up the magnification and looked again. “I saw this Waldo thing,” recalls Davidson, referring to the character in the Where’s Waldo? cartoon books. At first Davidson thought the microscopic Waldo served as a kind of anti-copying feature, but a few months later, on the same chip, he found a teeny tiny Daffy Duck. Now the hunt was on.

“As I looked at more chips, I saw more graffiti,” Davidson says. “I started seeing things out in the gutters, in pad rings, and things in areas that normally don’t have any [circuitry].” By 1998 he had found a dozen examples. He referred to them collectively as a “Silicon Zoo” and posted them on a website that was featured by Wired.com. “That’s when a lot of chip engineers started sending me designs,” Davidson says. His Silicon Zoo is now populated by more than 300 works of micrograffiti.

Many engineers merely printed their initials on their chips, as though they were signing a painting. Some etched corners of their chips with humorous word graffiti, such as this takeoff on a famous bumper sticker: if you can read this, you are way too close. But much of the chip art is in the form of images, among them cheetahs, buffalo, rabbits, sailboats, trains, space vehicles, Groucho Marx glasses-and-mustache masks, and even seductresses and con artists. One chip designer doodled a “can-o-worms” on the edge of a chip to represent the glitches that arose during the chip’s development. This one is reminiscent of the unauthorized and often humorous, lascivious, or subversive doodlings that medieval scribes sometimes added to the lavish embellishments for pages of the ancient works they were copying.

Here are some very interesting samples:

You can check out more images online here and here .