CARDboard Illustrative Aid to Computation

CARDIAC (CARDboard Illustrative Aid to Computation) is a learning aid developed by David Hagelbarger and Saul Fingerman for Bell Telephone Laboratories in 1968 to teach high school students how computers work.

The kit consists of an instruction manual and a die-cut cardboard "computer".

The computer operates in base 10 and has 100 memory cells which can hold signed numbers from 0 to ±999.

Memory cells hold signed decimal numbers from 0 to ±999 and are written with a pencil.

A “bug” is provided to act as a program counter, and is placed in a hole beside the current memory cell.