The VIC-20 Talk-Back was a speech synthesis electronics kit sold by Maplin way back in 1983. The board was designed by Mark Brighton. This was a home build kit that you could build to make your VIC-20 talk. The speech system had a GI SP0256-AL speech chip at its core. This chip provided some of the following features :
- A programmable digital filter which simulates the human voice tract.
- A 16K ROM which contains the data for the 64 allophones.
- A micro controller which controls the flow of speech data to the filter and the linking of allophones to produce words. A pulse width modulator.
There was no ROM on the PCB. You made it talk by POKEing it. So, this device did not take up any RAM – so you still have your 3k or more RAM! 🙂
There was a small demo piece of code that you tested the speech synthesizer with. Here is a copy of the code from the manual.
To save you some time, I have typed in the program into my VIC-20, tested it and saved it as a .PRG file. I have also put the file into a D64 disk image. There are several ways you can copy these files to a real VIC-20. A SD2IEC is a great device – and there are many more such systems out there.
You can also download the complete article from the March 1983 edition of the Maplin Magazine. The magazine includes all information you need to make the Talk-Back say anything you want. If you write any applications using the VIC-20 Talk-Back, be sure to let me know and I will put a copy of your code on this site.