DATAMATH CALCULATOR MUSEUM
Radio Shack Spellmaster
|Date of introduction:||1986||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 31 year 1988|
|AC-Adapter:||AC9199||Origin of manufacture:||USA|
|Precision:||Integrated circuits:||TMC0271, TMC0281, CD2350|
|Program steps:||Courtesy of:||Joerg Woerner|
This Radio Shack Spellmaster introduced in 1986 is 100% identical with the later Speak & Spell.
Radio Shack Spellmaster) was manufactured in July 1988 by Texas Instruments in
the United States and
represents the last design iteration of the Speak & Spell family. The printed circuit board (PCB) itself is
much smaller than the
original Speak & Spell design but sports an almost
The main components on the PCB are:
Microcontoller: The microcontroller is derived from the TMS1000 series and adopted to control both the keyboard, the display and to feed the speech synthesizer. This Speak & Spell uses a TMC0271 which interprets as TMC0270, ROM-Code 1.
Speech Synthesizer: The Speak & Spell series uses with the TMC0280 the first one-chip LPC speech synthesizer. Later refinements to the Speak & Spell chips resulted in the TMS5100, 5200 and 5220 Voice Synthesis Processors for commercial products. This Speak & Spell uses a TMC0281 which interprets as TMC0280, Version 1.
Speech ROM: Speech data is stored in a 128k ROM chip with the designation TMC0350. This Speak & Spell uses a CD2350 which is actually an identical VSM (Voice Speech Memory) from a more recent manufacturing process.
In 1988 we knew a total of 10 different plug-in modules for
the Speak & Spell, a comprehensive overview including the wordlists could be
If you have additions to the above article please email: email@example.com.
© Joerg Woerner, August 13, 2010. No reprints without written permission.