DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Exactra 21 by Texas Instruments
| Date of introduction: | March 1974 | Display technology: | LED-stick |
| New price: | Display size: | 8 | |
| Size: | 5.1" x 2.9" x 1.3" 130 x 74 x 34 mm3 |
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| Weight: | 5.1 ounces, 144 grams | Serial No: | 2100297344 |
| Batteries: | 3*AA | Date of manufacture: | wk 09 yr 1975 |
| AC-Adapter: | Origin of manufacture: | USA | |
| Precision: | Integrated circuits: | TMS0803 | |
| Memories: | |||
| Program steps: | Courtesy of: | Joerg Woerner |
The
Exactra 21 with it's brown keyplate uses a 8-digit display and similar
electronics to the TI-1500 and TI-2500-II calculators. All three were available
in the same period, this gives you an idea of the positioning in the marketing
of each calculator:
| • Datamath solid and well established since 1972
• TI-1500 modern and stylish • Exactra 21 young and cheap |
Even this cheap looking keyboard relies on the proven Klixon™ keyboard technology.
The
printed circuit board (PCB) of the Exactra 21 makes use of the TMS0803
single-chip calculator circuit and a tiny display driver. The remaining parts
form a small power-converter to use the 3 AA-sized batteries instead a 9V
battery block.
Don't miss a rare prototype of the Exactra 21 manufactured in early in 1974,
probably only few weeks before the formal market introduction. Main difference
to this late serial model is the display construction.
If you are interested in the Exactra series you should view
the remaining sibblings Exactra 19, Exactra
20, Exactra 22 and Exactra
23. Complete the line with the TI-2000 and Exactra
31.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.