Quoted from EalaDubhSidhe:As far as I'm aware, Flash Gordon was the first released game with the Squawk 'N Talk board and Eight Ball Deluxe was the second. As good as Xenon's sound was for the time, I don't count it here since the speech is all sample-based, not synthesized with its own dedicated board.
The early FG had the sounds plus and vocalizer as Xenon did. Not sure when they actually went to the S&T. I had an early game serial 1047 and it had a blue cover on the manual with the sounds plus schematic inside. The later FG came with the red cover manual with S&T schematic. I never did find out if the boards were interchangeable within the game without having to change the wiring.