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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.