CARDboard Illustrative Aid to Computation
learning aid
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" by means of pencil and sliding cards. Any arithmetic is done in the head of the person operating the computer. The computer operates in base 10 and has 100 memory cells which can hold signed numbers from 0 to ±999. It has an instruction set of 10 instructions which allows CARDIAC to add, subtract, test, shift, input, output, and jump.
The CARDIAC was also published in France as the Ordinapoche ("pocket computer", from ordinateur and poche) by Science & Vie in 1981.
Hardware
The “CPU” of the computer consists of 4 slides that move various numbers and arrows to have the flow of the real CPU (the user's brain) move the right way. They have one flag (+/-), affected by the result in the accumulator.
Memory consists of the other half of the cardboard cutout.
“CARDboard Illustrative Aid to Computation” enters the record as learning aid. Crown Archives preserves that source wording while asking what CARDboard, Illustrative and Computation can confirm, complicate or overturn.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated May 7, 2026. The linked authority identifier is Q5008796. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1968 and 1981.
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This entry incorporates text from “CARDboard Illustrative Aid to Computation” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.