DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-1200 (Repair Label)
Date of introduction: | March 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: | 1037019 |
Batteries: | 9V | Date of manufacture: | Factory repaired wk 27 year 1975 |
AC-Adapter: | AC9180 | Origin of manufacture: | USA |
Precision: | 8 | Integrated circuits: | TMS0952 or TMS0972 |
Memories: | |||
Program steps: | Courtesy of: | Joerg Woerner | |
Download manuasl: |
(US: 1.3M Bytes) (US: 1.3M Bytes) (EU: 3.5M Bytes) |
Texas
Instruments introduced the TI-1200/TI-1250
in 1975, right at the beginning of the
Calculator War. Prized in 1975 still around US $20, or about $65 in 2000's
money and a whooping $100 in 2020's money, these basic calculators were not yet
considered to be commodities and Texas Instruments consequently repaired them.
We feature this repaired TI-1200 due to its special label on the backside of the
calculator that omits the serial number and country of manufacturing.
Dismantling
the featured TI-1200 with Repair Date code 275 (July 1975) and manufactured
around May 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 and shows some obvious signs of repair.
Early calculators of the TI-1200 and TI-1400 family use a
keyboard with a 6*4 matrix having only 5 key-dome rows populated for a total of 20 keys. The unused key
is
hidden with the metal faceplate and removing it would add the missing [CS] or
[+/-] key.
Later the keyboard was cost-optimized to a 5*4 matrix. Find two of them in the Speak
& Spell introduced in the year 1976.
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-1200
series.
Learn more about the
evolution of the TI-1200 between March 1975 and its discontinuation in 1977.
Learn more about the different
Product Labels used with the TI-1200
- here at the Datamath Calculator Museum we classify the featured TI-1200 as
Hardware Version 1, PCB Type 1 and Product Label Style 5, Repair Label.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, June 29, 2021. No reprints without written permission.