DATAMATH CALCULATOR MUSEUM

Texas Instruments TI-55 III (Taiwan)

Date of introduction:	1985	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:	2292623
Batteries:	2*LR44	Date of manufacture:	mth 04 year 1985
AC-Adapter:		Origin of manufacture:	Taiwan (I)
Precision:	11	Integrated circuits:	TP0456/CD4555, CD4556
Memories:	1-8
Program steps:	56-0	Courtesy of:	Joerg Woerner
Download leaflet:	(US: 0.9M Bytes)

The story of this TI-55 III manufactured in Taiwan is somewhat difficult. Texas Instruments introduced already in the year 1981 with the TI-55-II a successful scientific calculator in a slanted design. Due to quality problems of the keyboard and the high manufacturing cost in the US the calculator was redesigned and the production shifted beginning of the year 1985 to Taiwan. We know the rare TI-55 II (Taiwan) using still the calculator chips of the original TI-55-II in a new housing (2nd generation slanted calculators) with a greatly improved keyboard design. Marketing decided to change the name of this 2nd generation TI-55-II and we got this TI-55 III for the US market and the otherwise identical TI-56 elsewhere.

The Date code on the backside of this TI-55 III reveals a well known contract manufacturer: Inventec Corporation, Taiwan's largest company assembling electronic calculators.

Please notice the small screw inside the battery compartment of this TI-55 III, calculators manufactured by Compal Electronics in Taiwan avoid it.

Even the printed circuit boards (PCB's) of the two siblings manufactured in Taiwan differ completely. Inventec Corporation placed both Integrated Circuits (IC's) on one side, Compal Electronics used both sides of the PCB.

To make the story more confusing Texas Instruments decided to shift the production of the slanted calculators during the year 1986 back to US and Italy (European market). Don't miss the US manufactured TI-55 III and the Italian TI-55 III.

In the year 1986 the design of the 2nd generation slanted calculators was slightly changed:

• The TI logo moved from bottom left to the top right of the calculator
• The text of the „headline“ changed, for example the „PROGRAMMABLE CONSTANT MEMORY“ of an early TI-55 III changed to „CONSTANT MEMORY“ on the later ones.

We know from other TI consumer products like the entire Speak & Spell line a similar movement in the corporate identity during the year 1986.

Between 1985 and 1986 Texas Instruments created an amazing number of different designs in the "Second Generation - Slanted LCD" calculator series just by moving production to Original Equipment Manufacturers (OEMs) in Far East, moving manufacturing back to their own facilities and revising the design. Please click on the picture at the right as a switchboard to all known versions of the Second Generation Slanted LCD calculators.

The TI-55 III is featured in the Texas Instruments Incorporated bulletin CL-872 dated 1985.

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