Longines Symphonette  Electronic Calculator (Early B Series)

Date of introduction:  September 1972 Display technology:  LED-modules
New price:   Display size:  8
Size:  5.8" x 3.5" x 1.5"
 147 x 88 x 38 mm3
Weight:  6.7 ounces, 191 grams Serial No:  B 4996
Batteries:  4*NiCd AA Date of manufacture:  mth 10 year 1972
AC-Adapter:  unknown Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0103, 2*SN75491, 2*SN75492
Memories:   Displays:  DIS40, DIS95
Program steps:   Courtesy of:  Joerg Woerner

This boxy calculator does at first glance not look like a Texas Instruments product. Nevertheless is the proof rather simple, just read the label on the back side of the Electronic Calculator carefully: Custom manufactured for Longines Symphonette by Texas Instruments, Dallas, Texas. 

With Monsanto introducing the first commercial LED (Light Emitting Diode) display in 1970 and Texas Instruments announcing on September 17, 1971 the "calculator-on-a-chip", Bowmar/Ali Inc. of Acton, Massachusetts, USA launched the famous Bowmar 901B "True-Pocket-Size" calculator based on the TMS0103 with a suggested retail price (SRP) of $240.00.

It took less than one year before Texas Instruments announced the TI-2500 Datamath calculator in April 1972 with a SRP of only $149.95, its delivery in June 1972 to first customers in the Neiman-Marcus and Sanger-Harris department stores in Dallas, TX and its formally introduction on September 21, 1972. The SRP of the TI-2500 was reduced to $119.95 by the date of its introduction

Texas Instruments did not only provide to calculator manufacturers complete "kits" consisting of the TMS0100 single-chip calculator circuit, SN75491 and SN75492 display drivers, TIL360 Multi-Digit calculator LED displays and Klixon™ keyboards, they offered contract design and manufacturing of complete calculators, too. The first three products manufactured for retailers were:

Longines Symphonette EC
Montgomery Ward P800
Radio Shack EC-100

We noticed two different versions of the original Electronic Calculator design, the featured one with mostly black keyboard caps and a later one with mostly white keyboard caps. Don't miss the second version of the Longines Symphonette Electronic Calculator.

Within few month this Electronic Calculator was replaced with a well know design. Don't miss the second generation of the Electronic Calculator based on the Datamath.

Klixon™ is a trademark of Texas Instruments.

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