This old tech: The beloved Speak & Spell was a pioneer of popular computing

Built by Texas Instruments, the Speak & Spell electronic educational toy was the first mass-produced product to use digital signal processing.

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Credit: Benj Edwards

If one were to compile a list of the greatest electronic toys ever released, the Texas Instruments Speak & Spell would rank somewhere near the top—along with friends like Milton-Bradley’s Simon and Big Trak, Parker Brothers’ Merlin, and Mattel’s Football.

First released in 1978, the Speak & Spell pioneered digital signal processing techniques as the first mass-produced consumer product to include speech-synthesis capabilities. Ostensibly an educational tool, the Speak & Spell also served as a fun distraction thanks to its multiple built-in game modes and appealing robotic voice. In its main operational mode, the unit speaks out one word at a time, then challenges the user to type the word correctly using its built-in keyboard.

Back in 2008, prompted by the 30th anniversary of the Speak & Spell, I bought one of the very first models, still in its original box, on eBay. Not long after that purchase, I had a chance to interview Richard Wiggins, one of the four men who created the device (while simultaneously building its internal speech-synthesis circuitry) at Texas Instruments.

In the interview, Wiggins mentioned that during the device’s creation, the development team recorded a radio announcer named Hank Carr speaking hundreds, if not thousands, of phrases. They then chopped up the sounds into their constituent parts—and did not digitize them (a common misconception)—but used the audio to tune an electronic simulation of a human voice box to reproduce the sounds as accurately as possible. It was an impressive feat of engineering.

So here I am today with an original 1978 Speak & Spell. Let’s take a look.

speak and spell 2 Benj Edwards

The discrete plastic letter keys on the original Speak & Spell were replaced with a smooth membrane keyboard in later models.

Two screws and four plastic latches later, we’re inside the unit. The unit comes apart cleanly in two halves. One half (the front) has all the working business tucked inside; the back merely plays host to the battery compartment door.

speak and spell 3 Benj Edwards

All the internal components are clipped into place behind the the front of the toy. 

It’s hard to see from this view, but all the internal components are held in place using plastic snaps. To get a better look at the main circuit board, I needed to pry it out.

After gently bending back the snaps (the plastic is surprisingly resilient for being this old), I removed the main board, the two-part keypad assembly, and the speaker.

speak and spell 4 Benj Edwards

I added batteries to the unit to see if everything still works. It does.

With the board removed, you can see the backside of the plastic keyboard keys, an orange and red plastic insert that snaps behind the front of the case. The actual key sensors are packaged in two flat assemblies that contain the membrane-like key switches, which, in the picture above, flank either side of the circuit board.

Speaking of the circuit board...

speak and spell 5 Benj Edwards

Here we see the Speak & Spell's main board oriented upside down from its usual placement.

The smallest chip (TMCO281NL), on the right, is the speech-synthesis chip; the two chips next to each other (TMCO351NL and TMCO352NL) store the speech-pattern data; and the chip next to the VFD (vacuum fluorescent display—the glass panel that shows the letters) is the microcontroller brain (TMC0271N2L) that pulls it all together.

Regarding that brain, the Speak & Spell uses a version of the famous TMS1000 microcontroller that also served as the heart of the Milton-Bradley Simon, among dozens of other electronic toys from the late 1970s to early 1980s.

While we’re inside, I might as well mention that the small brown board on the right of the main board, is a power supply, which delivers the proper voltages to the chips. The array of metal contacts inside the rectangular notch in the main board (near the upper center of the photo) serves as a cartridge connector, which allows new speech data to be added via removable modules.

Overall, it’s a fairly simple design that requires surprisingly few electronic components—ideal for a mass-produced consumer product. And mass-produced it was, with the Speak & Spell most likely selling millions of units across all of its variations during its multi-decade run.

I just hope mine still works when I put it all back together, because I think my kids will love to play with it.

Did you have a Speak & Spell when you were younger? I’d love to hear from you in the comments.

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