Classic 80s Text-To-Speech On Classic 80s Hardware

Those of us who were around in the late 70s and into the 80s might remember the Speak & Spell, a children’s toy with a remarkable text-to-speech synthesizer. While it sounds dated by today’s standards, it was revolutionary for the time and was riding a wave of text-to-speech functionality that was starting to arrive to various computers of the era. While a lot of them used dedicated hardware to perform the speech synthesis, some computers were powerful enough to do this in software, but others were not quite able. The VIC-20 was one of the latter, but thanks to an ESP8266 it has been retroactively given this function.

This project comes to us from [Jan Derogee], a connoisseur of this retrocomputer, and builds on the work by [Earle F. Philhower] who ported the retro speech synthesis software known as SAM from assembly to C which made it possible to run on the ESP8266. Audio playback is handled on the I2S port, but some work needed to be done to get this to work smoothly since this port also handles the communication with the VIC-20. Once this was sorted out, a patch was made to be able to hear the computer’s audio as well as the speech synthesizer’s. Finally, a serial command interface was designed by [Jan] which allows for control of the module.

While not many of us have VIC-20s sitting at home, it’s still an interesting project that shows the broad scope of a small and inexpensive chip like the ESP8266 which would have had a hefty price tag back in the 1980s. If you have other 80s hardware laying around waiting to be put to work, though, take a look at this project which brings new vocabulary words to that old classic Speak & Spell.

34 thoughts on “Classic 80s Text-To-Speech On Classic 80s Hardware

  1. Pretty sure there was a small version of SAM for the VC20 (SAM/Reciter was quite popular on the C64) … it did create quite understandable output, and by this to me seemed superior to a lot of PC software coming out much later.

  2. I built a ham radio repeater controller that used the General Instruments SP0256 speech chip to produce almost comprehensible voice prompts on our repeater. This was at Data General in the late 80s. The first processor we used was a Motorola 6802, which was replaced by an Intel 8085 in a very clever multitasking controller designed by James Lee.

    1. I was a bit later to the scene (1983) and built a custom SPO256 (often mistyped SP0256) cartridge to plug into a Amstrad CPC6128.

      I laughed when I first used it and realized it had an American accent.

    2. Prior to that (1978 – 79) I wrote my first attempt at software speech recognition and synthesis on a Tandy TRS-80 with 48k RAM using the cassette port and PWM (PWM wasn’t even a thing then).

      In my first failed attempt, spoken “my god how board we are today” came back as “Huberrb-ah rebore baybem bar”.

      I was the laughing stock of the computer users for a while even though it was probably an achievement for the time.

  3. I remember when I was a kid they had a bunch of bbc micros setup in a play area with text to speech
    they’d masked out all the interesting words, but it was easy to get around, just mispell the word :)

    1. Definitely record them to digital and upload them. If you don’t have what you need to do that then go and mention them on a site for retro software restoration or just retro computing. Someone will help you for sure. They’re priceless now if there the last remaining copies.

    2. Recording Commodore tapes with audio equipment isn’t really the best approach, you would need to iterate several times before getting an accurate dump.

      I’ve built this a few months ago: which only requires a Datassette, very easy to find online for a few bucks.

      Otherwise, I could dump them for you. I’ll drop a message on the Gmail account you have on GitHub, feel free to get back to me; I think we live in the same town ;)

    3. If you have a casette deck, start by making audio files of them, then upload them somewhere, so people can decode their contents. Maybe start an account on for easy collaboration?

  4. Always surprised there aren’t more retro speech synthesis projects. I’ve got a bunch of spare TI 99 synth modules and a Toshiba chip or two. Should do something interesting with them. System independent synthesizer or something.

      1. You end up with oddball stuff, keep it around until the rest washes up, and eventually get rid of it because the rest never materialized.

        The HP-150 because no drives or keyboard. The IBM PC jr because it arrived with no keyboard. That Processor Technology S-100 16K ram board.

    1. It was hard. A difficult concept. There was much trial and error trying to work out which phonetics were best to use. The answer was rarely obvious and different dialects or accents, and even differences of how “you” talk, made it even harder.

  5. I still have the Atari 800 and Software Automatic Mouth laying around here on diskette and the Indus GT we ran it from. You could get much better speech from SAM if you fed him words in phonetics, but of course you’re then limited to those words. SAM on an interactive DTMF voice response dialup was pretty cool.

  6. Just what my Ghost of Hawking WIFI controlled wheel chair campus Rover needed. Don’t know if it’d be done by Halloween though.
    Couldn’t say 8266 overkill. Under-utilized maybe. Then again I have one to operate WiFi coffee pot. Not likely to find VC/SC-01( and A and -02 -the Votrax Speech Chip – )anywhere but can get SP0256-AL2 China Mart. Haven’t tried on yet to see if Microchip clone worthy. If indeed it is a Microchip. Possibly snag SC-01 out of a Hero Robot or ancient Vending machine. Very likely have to write a TTS (Text to Speech) too so likely best go with SAM like was done. Votrax was heavily overpriced to begin with. TMS 5520- and variants but again need TTS. There are some overpriced newer allophone but for same to slightly more intelligible 80’s sound -not worthy. Also FPGA around.
    There is a 1000 word ‘roll your own’ in Arduino library that says will go on ye ol AVR328 but havent tried it. yet.
    8266 with SAM simpler and cheaper. I like the idea. Nice work up with bit o history. Good work J. Derogee.

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