DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Exactra 23 by Texas Instruments
| Date of introduction: | October 1974 | Display technology: | LED-stick w/o lens |
| 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: | 2300021274 |
| Batteries: | 3*AA | Date of manufacture: | wk 48 yr 1974 |
| AC-Adapter: | AC9160 | Origin of manufacture: | USA |
| Precision: | 8 | Integrated circuits: | TMS0803 |
| Memories: | |||
| Program steps: | Courtesy of: | Joerg Woerner | |
| Download manual: | 
(US: 1.9M Bytes) |
The
Exactra 23 could be called the fully loaded model in the cheap Exactra line. It
sports an 8-digit display, a %-key and a connector for an external power supply.
This position in the Exactra line is demonstrated to the customer with a
valuable golden line around the keyboard.
Dismantling
the Exactra 23 revealed two small surprises. First of all the LED-display found
in this particular calculator was manufactured by Bowmar. We know the Opto-stick
display with he small numbers already from the
TI-2500B.
Second
surprise is the TMS0803
single-chip calculator circuit known from the Exactra 21 and Exactra 22. But
these siblings miss the %-key - once again the "power of marketing".
Nevertheless the Exactra 23 uses a different layout of the printed circuit board
(PCB). At first glance the schematics of the calculators seem to be identical
with a tiny display driver and two additional transistors plus a
power-converter.
A similar calculator was sold as Citation M4993
by the distribution company Western Auto and by Montgomery Ward
with the TXI-8661A.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.