There were multiple designs floating around the BBSes at the time. I don't remember the Scream Tracker one but they should be fairly similar. That kind of DACs

There were multiple designs floating around the BBSes at the time. I don't remember the Scream Tracker one but they should be fairly similar. That kind of DACs were compatible with Covox, which has a schematic on wikipedia: https://en.wikipedia.org/wiki/Covox_Speech_Thing https://en.wikipedia.org/wiki/Covox_Speech_Thing