Try Bell Labs Cardiac the cardboard computer https://en.wikipedia.org/wiki/CARDboard_Illustrative_Aid_to_Computation https://en.wikipedia.org/wiki/CARDboard_I

Try Bell Labs Cardiac the cardboard computer https://en.wikipedia.org/wiki/CARDboard_Illustrative_Aid_to_Computation https://en.wikipedia.org/wiki/CARDboard_Illustrative_Aid_to_...