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Texas Instruments TI-55-II (Taiwan)

Date of introduction:  August 1984 Display technology:  LCD
New price:   Display size:  8 + 2
Size:  5.8" x 2.8" x 0.85"    
Weight:  3.5 ounces Serial No:  1471966
Batteries:  2*LR44 Date of manufacture:  mth 12 year 1984
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  11 Integrated circuits:  TP0456 (CD4555), TP0456 (CD4556)
Memories:  1-8    
Program steps:  56-0 Courtesy of:  Luís Pereira

This TI-55-II could be called a rare calculator. Actually it is a TI-55-III from the first production runs and uses still the TI-55-II designation. Currently we know TI-55-II with production codes between October 1984 and March 1985.

If you search the differences to the later US or Italy built TI-55-III, concentrate on the description below the "=" key.

TI-55_PCB.jpg (129123 Byte)The picture on the right gives you an inside view of the three different TI-55-II and TI-55-III discovered up to now. From left to right you find:

TI-55-II manufactured in the year 1981 in US. 
Known for the bouncing keyboard introduced with the slimline calculators.
TI-55-II resp. TI-55-III manufactured in the year 1985 in Taiwan. 
Uses two PCB's, one for the keyboard.
TI-55-III manufactured in the year 1986 either in US or Italy. 
Uses far-east keyboard technology with conductive rubber together 
with contact fingers on a flexible PCB.

 



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

© Joerg Woerner, December 5, 2001. No reprints without written permission.