Votrax Type 'n Talk (1980)
Yay! I finally obtained a TNT on eBay after 34 years of waiting. Amazon even had a new-old-stock, "O1P-1224B," power supply for it. I've put up the contents of the owner's manual, which is impossible to find online in this format: Owner's Manual (PDF)
The TNT uses a Motorola 6802 CPU with 4K ROM and 1K RAM. It interfaces to the outside world via an onboard RS-232C connector capable of receiving data at eight different baud rates from 75 to 9600 (8-N-1).
In 1980, Votrax designed and manufactured an integrated circuit speech synthesizer called the SC-01. It was essentially Gagnon's discrete design mapped to silicon. The TNT leverages the SC-01. I find that a lot can be learned by looking at the data sheets for ICs, and here is the one for the SC-01.
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