Geniac was an educational toy billed as a "computer" designed and marketed by Edmund C. Berkeley from 1955 through the sixties. The name stood for "Genius Almost-automatic Computer."

Basically a rotary switch construction set, the Geniac contained six perforated hardboard wheels into which brass jumpers could be inserted. It had no active elements at all--no relays, tubes, or transistors. All sequencing was performed manually by the operator, sometimes following fairly complicated printed directions (turn this wheel in this direction if this light lights, etc.)

The instruction book gave jumper positions and wiring diagrams for building a number of "computers." Current from a dry cell was routed through the rotary switches to light one or more flashlight bulbs. The kit allowed for the realization of fairly complicated Boolean equations, so the behavior of the "computer" could sometimes be interesting.

A typical project was a "masculinity-feminity tester." The user was instructed to answer ten questions, such as "Which makes a better toy for a child: a) a doll, b) a toy truck." For each "a" answer, one wheel was turned one position clockwise; for each "b" answer, another wheel was turned one position clockwise; and the wiring diagram lit up a "more masculine" or "more feminine" bulb depending on which wheel had been turned further.

Widely advertised in science and electronics magazines, the Geniac provided many youths with their first hands-on introduction to computer concepts and Boolean logic.