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.
If you are looking for a maker activity that reinforces computer science, the CARDIAC looks like a great way to teach and practice what goes on inside of a computer. The build looks intimidating, but a lot of the work can be done beforehand, it depends on the age of the students.