Michael Wessel built Perfect Paul ][, a drop-in DECtalk emulator card for the Apple ][. DECtalk was DEC's high-end standalone speech synthesiser, famous as Stephen Hawking's voice and completely out of reach for anyone who owned an 8-bit machine in the 1980s. What they got instead was allophone-based chips like the SP0256. That gap is now closed.
The card uses an RP2040-based Raspberry Pi Zero, an I2S DAC, an amplifier, a speaker, and bus-interface logic. It maps to a fixed set of memory addresses. Sending DECtalk commands requires nothing more than a POKE. The schematic and source are on GitHub, and the bus interface design is generic enough to port to other 8-bit platforms.
Read the original for the technical breakdown of how Apple ][ bus timing was handled and watch the video to hear the card sing. The gap between what this costs to build today and what DECtalk cost in 1983 is the real story here.
[READ ORIGINAL →]