Next up in our series of Rochester Electronics’ favorite 1970s semiconductors, is Texas Instruments’ first microcontroller: the TMS1000 series.

As the schools reopen for the new term, now is an ideal time to reminisce upon the popular “Speak & Spell” educational toy from the 1970s. This children’s hand-held electronic console toy was created by a small team of Texas Instruments engineers led by Paul Breedlove. This was the first of a series which also included “Speak & Read” and “Speak & Math.” Speak & Spell was originally advertised as a toy to help children aged 7 and above to learn to how to spell and pronounce over 200 commonly misspelled words.

Texas Instruments introduced the first microcontroller TMS1000 series in 1974 when they received their first patent for the single-chip microprocessor. Before the TMS1000, computing was implemented by a microprocessor, such as the Intel 4004 (the first single-chip microprocessor) and several additional chips for memory and inputs/outputs.

The TMS1000 technology was provided by P-Channel MOS 4-bit Central Processor Unit, 8192-bit Read-Only Memory (ROM), 256-bit Random-Access Memory (RAM) and Arithmetic Logic Unit (ALU) and 2 four-bit working registers all on chip. It allowed for conditional branching and sub-routines, offered 4-bit parallel data input and 11 or 13 latched control/data-strobe outputs based on either a 28 or 40-pin DIP package selection. The device also offered a choice between an on-chip oscillator or external synchronization. It operated off a 15V power supply which was a hit with the battery manufacturers of the era.

Looking back, the release of the “Speak & Spell” can be considered the start of the personal consoles, speech synthesis, and solid-state speech revolution, which lead the way to Siri®, Alexa®, and Google®.

(Speak and spell product image: © Bill Bertram 2006, CC-BY-2.5 — Attribution)