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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
Memories:      
Program steps:   Courtesy of:  Joerg Woerner

This Radio Shack Spellmaster introduced in 1986 is 100% identical with the later Speak & Spell.

The Radio Shack Spellmaster) was manufactured in 1988 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 identical design.

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 TMC 0280 the first one-chip LPC speech synthesizer. Later refinements to the Speak & Spell chips resulted in the TMS 5100, 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 TMC 0350. This Speak & Spell uses a CD62175 which is actually a double VSM (Voice Speech Memory) with 256k capacity.

In 1988 we knew a total of 10 different plug-in modules for the Speak & Spell, a comprehensive overview including the wordlists could be found here

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If you have additions to the above article please email: joerg@datamath.org.

Joerg Woerner, August 13, 2010. No reprints without written permission.