DATAMATH CALCULATOR MUSEUM
|
DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-1250 (Version 2)
| Date of introduction: | August 1975 | Display technology: | LED-stick |
| New price: | $24.95 | 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: | 098962 |
| Batteries: | 9V | Date of manufacture: | wk 37 year 1975 |
| AC-Adapter: | AC9180 | Origin of manufacture: | USA (LTA) |
| Precision: | 8 | Integrated circuits: | TMS0952 |
| Memories: | 1 | ||
| Program steps: | Courtesy of: | Joerg Woerner | |
| Download manuals: | 
(US: 3.1M Bytes)
(EU: 3.5M Bytes) |
The original
design of the TI-1250 was only manufactured for a few months, Texas
Instruments changed the PCB slightly to accommodate four additional 330Ω resistors
to pull down the four keymatrix input lines of the
TMS0952 Chip to VDD. We recently discovered this
TI-1250 without the additional resistors populated, obviously a
little measure to reduce manufacturing costs of the calculator.
Dismantling the featured TI-1250 with
Date code 3775 LTA and manufactured in
September 1975
in Lubbock, Texas reveals a very efficient and cost-optimized design
with a single-sided printed circuit board (PCB) centered
around a TMS0952 single-chip
calculator circuit based
on the TMS1000,
the World's first Microcomputer.
The TMS0952 was soon replaced with the TMS0972,
a pin-compatible design dropping the additional resistors and capacitor and
further reducing the manufacturing costs of the TI-1250 series.
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 2, PCB Type 2 and Product Label Style 1, 6-Digit.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, June 28, 2021. No reprints without written permission.