Exactra 19 by Texas Instruments 

Date of introduction:  October 1974 Display technology:  LED-stick
New price:  $16.30 (The Ohio State Univ.) Display size:  6
Size:  5.1" x 2.9" x 1.3"
 130 x 74 x 34 mm3
Weight:  5.1 ounces, 144 grams Serial No:  1900039332
Batteries:  3*AA  Date of manufacture:  wk 44 year 1974
AC-Adapter:   Origin of manufacture:  USA
Precision:  6 Integrated circuits:  TMC0806
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US: 1.3M Bytes)

When The Ohio State University approached Texas Instruments early in Summer 1974 with the demand of Thousands of high quality calculators in the $15.00 to $20.00 range for a Classroom Experiment, they actually initiated the development of this Exactra 19.

Texas Instruments established with the Exactra 20 already a budget calculator with an SRP of $39.88 and the Exactra 19 was the result of a dramatic cost-reduction program:

Smaller keys without injection molded lettering.
Drop of the sliding switch to use either fix point or floating point notation.
Replacement of the double-sided printed circuit board (PCB) with a single-sided PCB.
Replacement of the TMS0135 single-chip calculator circuit with more cost effective TMC0806.

Texas Instruments obviously achieved their goals, the Exactra 19 was sold in the bookstores for $16.30 to the students of The Ohio State University.

The manufacturing costs of the keyboard could be reduced by dropping the double-shot injection molding process in favor of a simple-shot process. Please notice the 6-digit display already known from the Exactra 20. Did you notice the "bubble lens" to magnify the small LED display? One of the most sought part of any Exactra calculator - don't miss the Star Wars: Episode IV - A New Hope (1977) story and learn more about the Exactra Calculator LED Displays.

The keyboard assembly still has an opening for the sliding switch to select between fix point or floating point notation, but the switch itself is missing.

The single-sided printed circuit board (PCB) of the Exactra 19 makes use of the TMC0806 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.

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If you have additions to the above article please email:

Joerg Woerner, December 5, 2001. No reprints without written permission.