DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-1250 (Version 4)
| Date of introduction: | April 1977 | Display technology: | LED-stick |
| New price: | Display size: | 8 | |
| Size: | 5.5" x 2.8" x 1.4" 138 x 70 x 35 mm3 |
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| Weight: | 3.9 ounces, 110 grams | Serial No: | A 1588990 |
| Batteries: | 9V | Date of manufacture: | wk 18 year 1977 |
| 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
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.
Dismantling
the featured TI-1250 with
Date code 1877 LTA and manufactured in
May 1977
in Lubbock, Texas reveals a very efficient and cost-optimized design
with a single-sided printed circuit board (PCB) centered
around a TMS972 single-chip
calculator circuit based
on the TMS1000,
the World's first Microcomputer.
While the original design
of the TMS0972 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 of the TMS0972 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.
Preparing our DCM-50A Platform
to allow the Characterization of Single-Chip Calculator Circuits
of the TMS0970/TMC0900 Family, we studied
a TI-1200 (Version 3) calculator manufactured in October 1976 and a TI-1250
(Version 4) calculator manufactured in August 1977.
Learn more about the different
Product Labels used with the TI-1250
- here at the Datamath Calculator Museum we classify the featured TI-1200 as
Hardware Version 4, PCB Type 3 and Product Label Style 4, A-Series.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, June 28, 2021. No reprints without written permission.