CARDIAC (Simulator)

Cardiac (CARDboard Illustrative Aid to Computation) was a learning aid developed by David Hagelbarger and Saul Fingerman for Bell Telephone Laboratories in 1968 (Copyright 1966, 1968) to teach high school students how computers work. The kit consisted of an instruction manual and a die-cut cardboard "computer".

The computer "operated" by means of pencil and sliding cards. Any arithmetic was done in the head of the person operating the computer. The computer operated in base 10 and had 100 memory cells which could hold signed numbers from ±0 to ±999. It had an instruction set of 10 instructions which allowed CARDIAC to add, subtract, test, shift, input, output and jump.