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Texas Instruments TI-1780

Date of introduction:  1984 Display technology:  LCD
New price:  DM 17.30 Display size:  8
Size:  2.3" x 3.9" x 0.28"
 58 x 99 x 7 mm3
   
Weight:  1.3 ounces, 37 grams Serial No:  0050799
Batteries:  n.a. Date of manufacture:  mth 09 year 1983
AC-Adapter:   Origin of manufacture:  Taiwan (C)
Precision:  8 Integrated circuits:  
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

This TI-1780 looks like a TI-1706 in credit card format. You can't compare it with the stylish TI-1754 introduced a few years earlier.

Dismantling the featured TI-1780 calculator manufactured in September 1983 by a non-disclosed Original Equipment Manufacturer (OEM) in Taiwan reveals a very clean design centered around an unknown single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by four solar cells.

Inspecting the PCB of this TI-1780 calculator brought our attention to a small mark reading S4T-10, together with the leading "C" in the Date code of the calculator we assume that it was manufactured by Cal-Comp Electronics. We started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

Later credit card sized calculators like the TI-1786 sport an even simpler design.

Don't miss the Casio FILM CARD SL-800, a real credit card sized calculator with a thickness of only 0.030".



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

Joerg Woerner, September 29, 2002. No reprints without written permission.