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
1 ounces, 144 grams
|Batteries:||3*AA||Date of manufacture:||wk 48 yr 1974|
|AC-Adapter:||AC9160||Origin of manufacture:||USA|
|Program steps:||Courtesy of:||Joerg Woerner|
|Download manual:||(US: 1.9 MByte)|
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 22 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.
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© Joerg Woerner, December 5, 2001. No reprints without written permission.