Ancient childhood computers
I never had anything as interesting as CARDIAC, but I do have fond memories of a few old computer-y things I’ve owned.
- A Radio Shack 4-bit microcomputer trainerwith around 64 bytes of RAM. Oddly, it had the usual springs-and-wires of a typical RS electronics kit, even though there was only one way to wire it up. Input was a hex keypad in the form of a matrix of cheap pushkey switches and output was some LED dots and an 8-segment display. The manual was pretty interesting and was not very dumbed-down. You really could learn some good assembly language concepts from it.
- I had another computer-y toy whose name has sadly completely slipped my mind. It was pre-fabricated and like the one above also had a simple keyboard — pushswitch keys (so a step up :-) that were at least a hex keypad, but maybe more additional keys. Output was a speaker, either one or two 8-segment LEDs and, fascinatingly, a 4×4 (or maybe 5×5 or 6×6) LED dot array. The keypad was on the main body of the thing and the output unit (speaker, array, 8-seg displays) was a separate piece that attached to the main body via a short stalk. I don’t recall the manual being as technical as the Radio Shack trainer was (this one was marketed more as a toy than as a trainer). I don’t even remember if it gave you enough information to write your own programs. But because of the LED array, the programs that the manual had you key in were much more interesting :-). There were programs that would draw moving patterns. I think there was a “don’t let the snake eat its tail” game. There was even an animation program — you could “draw” (by using keys to set/reset dots) five or six or so animation frames. I really loved this toy and wish I could just remember the name of it.
- Somewhere over the years I picked up an AMD microcontroller trainer. It has a 1969-era microcontroller on it, a few hundred bytes of RAM, some LEDs, and a set of toggle switches for toggling in bytes, single-stepping, etc. It’s all mounted on a one-foot-square PCB. You have to supply the 5VDC yourself. The manual even comes with instruction coding sheets so you can hand-assemble your program.
- I had the Radio Shack Digital Computer Kit which was a set of eight quintuple-pole double-throw switches and eight light bulbs, each in its own compartment. There was a set of opaques (well, they weren’t transparent :-) generally organized with input labels to the left and output labels to the right that would slide into place in front of the bulbs. The idea was that you’d slide the switches that lined up with the inputs to light up the inputs you wanted to activate, the “computation” would be performed courtesy of the particular wiring pattern you had been instructed to wire up for that particular “opaque”. Ironically, the kit really was more of an analog computer. The manual/opaques had instructions for the basic logic gates and then a bunch of trivia, etc. quizzes. You couldn’t do any real programming since it had no state at all (other than the state of the switches).