DATAMATH CALCULATOR MUSEUM
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"
147 x 72 x 22 mm3
|Weight:||3.0 ounces, 84 grams||Serial No:||1471966|
|Batteries:||2*LR44||Date of manufacture:||mth 12 year 1984|
|AC-Adapter:||Origin of manufacture:||Taiwan (I)|
|Precision:||11||Integrated circuits:||TP0456 (CD4555), TP0456 (CD4556)|
|Program steps:||56-0||Courtesy of:||Joerg Woerner|
TI-55 II could be called a rare calculator. Actually it is a TI-55
from the first production runs and uses still the TI-55
designation. Currently we know TI-55 II with production codes between October
1984 and March 1985. Please note the missing hyphen in the TI-55 II, the
original design was labeled TI-55-II.
If you search the differences to the later US or Italy built TI-55 III, focus on the description below the "=" key.
this TI-55 II manufactured by Inventec
Corporation in Taiwan late in 1984 reveals the CD4555 / CD4556 calculator
chips soldered on a typical far-east designed printed circuit board (PCB).
The picture on the right gives you an inside view of the three of the four different TI-55-II and TI-55-III discovered up to now. From left to right you find:
|• TI-55-II manufactured in 1981 in US.
Known for the bouncing keyboard introduced with the slimline calculators.
• TI-55-II resp. TI-55-III manufactured by Inventec Corporation in Taiwan between
1984 and 1985. The PCB used in Compal's calculators could be found here.
• TI-55-III manufactured in 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: firstname.lastname@example.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.