I was at the Ontario Science Center with the kid today and came across one of the few bits of tech from when I was a kid, a machine that speaks the word “coffee”. It consists of six seemingly identical breadboards with mostly analog components, mostly some seemingly large caps and several small pots per card.
It seems the active component was a large “chip” labeled DOA 40. I'd like to understand what this might be - op-amp? noise generator? Google turns up nothing. Any ideas?