Here's how to make a "computer on a card" from the 1960s

Michael Gardi says, "There were probably millions of CARDIACs (CARDboard Illustrative Aid to Computation) distributed to high schools and colleges in the late 60s and early 70s. Heck even my little high school in Northern Ontario got a bunch of them. But they are all but impossible to find now, so here is the next best thing."

The CARDIAC Instructable presented here is not a computer, it's a device to help you understand how a computer works. You the user will:

• decode instructions by sliding panels up and down,
• move the program counter "lady bug" from one memory location to the next,
• perform the duties of an arithmetic logic unit (ALU),
• read inputs from one sliding strip,
• and write output results to another (with a pencil).

Along the way you will you will learn the internal workings of a typical Von Neumann architecture computer. Some fairly sophisticated programs can be executed (by you manually remember) on the CARDIAC. Stacks, subroutines, recursion, and bootstrapping for example can all be demonstrated.

Image: Instructables

Previously on Boing Boing:

• CARDIAC: Bell Labs's old cardboard computer
• CARDIAC paper computer emulator
• CARDIAC paper computer unboxing
• New-old stock of Bell Labs's cardboard teaching computer, the CARDIAC