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Texas Instruments TI-1200 (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:  1081178
Batteries:  9V  Date of manufacture:  wk 48 year 1975
AC-Adapter:  AC9180 Origin of manufacture:  USA (LTA)
Precision:  8 Integrated circuits:  TMS0952
Memories:      
Program steps:   Courtesy of:  Joerg Woerner
    Download manuals:   (US: 1.3M Bytes)
  (EU: 3.5M Bytes)

The original design of the TI-1200 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.

Dismantling the featured TI-1200 with Date code 4875 LTA and manufactured in November 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.

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 2, PCB Type 2 and Product Label Style 2, 7-Digit.

 

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

Joerg Woerner, May 29, 2021. No reprints without written permission.