Texas Instruments SR-10 Version 1

Date of introduction:  November 1972 Display technology:  LED modules
New price:  $149.95 Display size:  8 + 2
Size:  6.3" x 3.1" x 1.5"
 158 x 78 x 38 mm3
Weight:  9.2 ounces, 262 grams Serial No:  12638
Batteries:  3*AA NiCd Date of manufacture:  1972
AC-Adapter:  AC9200, AC9130 Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0120
Program steps:   Courtesy of:  Joerg Woerner
    Download manuals:   (US: 4.0M Bytes)
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The SR-10 was introduced only few month after TI's first calculator, the famous Datamath or TI-2500. Today we wouldn't call it a Scientific calculator, but it used the scientific notation on the display. Texas Instruments targeted the slide rules, guess what the abbreviation "SR" in the designation stands for.

SR-10-V1_DISP.jpg (18223 Byte)The first series of the SR-10 shared the poor readability of the TIL-360 display known from the Datamath calculators. 

SR-10_Proto_DISP.jpg (27302 Byte)Texas Instruments experimented with different solutions and created some prototypes with lenses attached to the 6-digit LED-modules.

Later models used different LED-modules with an additional magnification lens. Don't miss the rare SR-10 Clear-Case Prototype and compare it with the SR-10 Version 2

SR-10_PCBB.jpg (129692 Byte)The SR-10 makes use of the TMS0120 single-chip calculator circuit derived from the TMS1802, better known as first
"calculator-on-a-chip". The remaining components found inside an early SR-10 are known from the Datamath, too. Two display-drivers each for the segments and digits of the LED-modules and a discrete power converter to generate the three different supplies inside the calculator.

Klixon™ type keyboard looks very similar to the Datamath calculator with some additional keys placed in the upper line. Later calculators like the SR-11 changed the style of keys but the extreme wedge-style of the housing consists nearly 2 years. Last modell in the wedge design was the SR-16. Don't forget to explore the huge wedge calculators SR-20 and SR-22.

The SR-10 manufactured in Italy for the European market introduced a slightly different design of the housing.

The SR-10 was sold with different nameplates, compare it with both the Radio Shack EC-425 and the Montgomery Ward P300.

Don't miss the TI-150, the only basic calculator using the silver trim around the display.

horizontal rule

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