CARDiac stands for "CARDboard Illustrative Aid to Computation," and it was created in 1968 at Bell Labs as a way to teach high schoolers how computers worked. I wasn't anywhere near high school age (I think I was in third grade?) but the CARDiac was revelatory. The year before, I'd had access to a teletype terminal and acoustic coupler that let me operate a PDP machine at the University of Toronto, and I'd been endlessly fascinated with the possibilities.
2/
