Some of the external experiments that used the PC or Apple i/o cards were found during clean up. Above is a stepper motor driver controlled directly from an Apple II i/o card.
This is a temperature probe that uses op-amps and an A to D converter for rather accurate T measurements. The probe is a 2n2222 epoxied into the end of a pen barrel.
.... not sure but lots of familiar parts!
Digital dice made using wire wrap technology.
A binary number game. The black header holds a 7 segment display driven by a random number generator. The student would set the DIP switches to make the same number in binary and push the button. The circuit will indicate Too High, Correct or Too Low.
These circuits are now trash but the memory of making and using them in classes remains.