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Texas Instruments TI-1250 (Version 3, Style 4B)

Date of introduction:  March 1976 Display technology:  LED-stick
New price:   Display size:  8
Size:  5.5" x 2.8" x 1.4"
 138 x 70 x 35 mm3
   
Weight:  3.9 ounces, 110 grams Serial No:  B 0252166
Batteries:  9V  Date of manufacture:  wk 49 year 1976
AC-Adapter:  AC9180 Origin of manufacture:  USA (LTA)
Precision:  8 Integrated circuits:  TMS0972
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner
    Download manuals:   (US: 2.5M Bytes)
  (EU: 3.5M Bytes)

The TMS0952 introduced with the original design of the TI-1200 and TI-1250 was soon replaced with the TMS0972, a pin-compatible design dropping the additional resistors and capacitor and further reducing themanufacturing costs of the TI-1200 series.

Dismantling the featured TI-1250 with Date code 4976 LTA and manufactured in December 1976 in Lubbock, Texas reveals a very efficient and cost-optimized design with a single-sided printed circuit board (PCB) centered around a TMS0972 single-chip calculator circuit based on the TMS1000, the World's first Microcomputer.

The final step of cost reduction of the TI-1200/TI-1250 family was introduced just a few months before its discontinuation and included a smaller encapsulation of the TMS0972 Chip. While the original design was using a 0.6 wide 28-pin DIP (Plastic Dual In-line Package with a 0.1 / 2.54 mm lead pitch) encapsulation, switched the final design to a 0.4 wide 28-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07 / 1.778 mm lead pitch) encapsulation.

Learn more about the evolution of the TI-1250 between June 1975 and its discontinuation in 1977.

Learn more about the different Product Labels used with the TI-1250 - here at the Datamath Calculator Museum we classify the featured TI-1250 as Hardware Version 3, PCB Type 2 and Product Label Style 4, B-Series.

 

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If you have additions to the above article please email: joerg@datamath.org.

Joerg Woerner, June 28, 2021. No reprints without written permission.