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?

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    Are you, by any chance, talking about the VODER (or a descendant), developed by Bell Labs and presented 1939. That consisted mainly of a tone and impulse generator and a large recombination of filter banks and was perfectly able to produce understandable, synthesized sentences (provided you could "play" it like an instrument). That beast was even able to sing recognizable songs with text.
    – tofro
    Apr 23 at 20:24
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    This machine was developed by Philips (I guess in their NatLab in Eindhoven, the Netherlands) and was part of a famous tech museum/exhibit called the “Evoluon”, also in Eindhoven. So, technically, the machine attempts to say “koffie”. ;-) Apparently, there were only two built. One of them was donated to OSC when the Evoluon exhibit was dismantled. There are several sources (and movies) about this machine that you can find online. Sorry, no idea how it was constructed. Just fond memories.
    – WimC
    Apr 24 at 5:34
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    @WimC - ok that found me a few bits and pieces - Evoluon was cool! - but that "chip" is the thing I'm trying to find here - perhaps just some op-amps? It had a dozen leads or so - should have taken a picture. Apr 24 at 17:22
  • That thing is still there!? I'm hoping it's the same board I remember. I think it's been 40 years since I saw that. The one I remember was a huge board, with lights for "C", "O", "FF", and "EE", and a knob for speed, and a knob labeled "!" and "?". Do they still have the storage-tube-based vector-graphics terminal that would draw pictures of a car?
    – supercat
    Apr 24 at 17:54
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    @MauryMarkowitz re: taking a picture, I can make out the 'DOA 40' text in youtube.com/watch?v=1A-L47cUnmY
    – Tommy
    Apr 24 at 18:45

1 Answer 1


Ok, WimC's lead on Philips was the key that led me to this techsheet on the DOA40. Yes, it is an opamp.

For posterity, here's a link to a video of it in action.

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