The Votrax Type-n-Talk. This is Votrax's first text to speech device, as far as I know. It uses the SC-01 speech synthesizer chip which was Votrax's main product at the time. This chip is found in various arcade PCBs (notably Q*Bert). For whatever reason, Votrax saw fit to pot the 6802, ROM, and the memory decoder in a little bit of epoxy on the board. I have seen "software security" cited as the reasoning for this before. Whatever the reason, it offers very little security. I have unpotted it and I dumped the ROM and replaced it with an EPROM.
HERE is a slide show of the unpotting.
After unpotting it, I traced out the circuit and dumped the ROM on this unit. Theoretically, this is enough information to construct a Type-N-Talk yourself on some perfboard or whatever. Schematic of this board. (note: clicky for larger)
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