(It was Trek on the TRS-80 though that put the hook in me.)

The instructional manual probably makes a lot more sense with the actual system that it describes in hand.

As I see it, the genius of CARDIAC is this (emphasis mine):

> You will serve as CARDIAC's control unit by visually following its internal flow chart. While doing so, you will perform all of the operations described above.

Human-as-datapath is a fantastic idea for learning the basics of not just programming, but of microarchitecture. Once you start thinking, "hey, I could make a machine/circuit/etc. to do all of this stuff that I'm doing by hand" then you are on your way.

"Paper to FPGA" sounds like a cool idea, though the point of CARDIAC seems to be that you perform the operations yourself (by carefully following its flowchart/control specification and manipulating the cardboard device.)

> (3) that the typical 12-year-old youngster has the interest, skill and basic knowledge necessary to build and understand simple working models of practically anything

Indeed.