Texas Instruments Speak & Maths (Type 1)

Date of introduction:  1980 Display technology:  Fluorescent
New price:   Display size:  9 alphanumeric
Size:  10.0" x 7.0" x  1.3" 
 254 x 177 x 34 mm3
Weight:  16.7 ounces, 474 grams Serial No:  
Batteries:  4*C cells Date of manufacture:  wk 36 year 1981
AC-Adapter:  AC9199 Origin of manufacture:  Italy
Precision:   Integrated circuits:  TMC0270/CD2704, TMC0280/CD2801, CD2392, CD2393
Program steps:   Courtesy of:  Joerg Woerner

Did you already noticed the small difference? This Speak & Maths sold in the United Kingdom is 100% identical to the Speak & Math sold in the United States of America. 

Please notice the gold lettered "Texas Instruments" on the display screen and the large "TI" logo on the keyboard. The original products changed the logo in the year 1986. Compare yourself with a newer US Speak & Math.

Dismantling this Speak & Maths manufactured in September 1981 by Texas Instruments in their Rieti, Italy facility for the British market reveals a design identical to the US version and centered around four Integrated Circuits:

TMC0270/CD2704: 4-bit microcontroller with 2k*9 Bits ROM and 9*64 Bits RAM
TMC0280/CD2801: TMS5100 VSP (Voice Synthesis Processor)
TMC0350/CD2392, TMC0350/CD2393: TMS6100 VSM (Voice Synthesis Memory) with 128k Bits, each

The Speech-ROMs of the Speak & Math vary depending on the production date. Starting in 1981 the overall capacity was significantly reduced, differences in the word list and voice tunes are not known:

1980: TMC0350/CD2392 + TMC0350/CD2393 for a combined 256k Bits
1981: TMC0350/CD2381 + TMC0355/CD2614 for a combined 160k Bits

An inside view of some dismantled Speak & Spell products could be found here.

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If you have additions to the above article please email:

Joerg Woerner, December 21, 2001. No reprints without written permission.