Original Equipment Manufacturers (OEMs)

Made in the USA - this is how Texas Instruments started in 1972 with the introduction of the famous TI-2500 Datamath, TI-3000, and TI-3500 calculators. The last TI calculator manufactured in Lubbock, TX? The TI-7000 II, TI-7140, and TI-7300 II manufactured in 1994 for Texas Instruments' US-built campaign started in 1989.

• Vertical Integration

When Jack S. Kilby, an Inventor of the Microchip, initiated in 1965 the Cal-Tech project, he and and two of his colleagues, Jerry D. Merryman and James H. Van Tassel started literally from scratch. There was no such thing like compact and power conserving LED displays or cost effective keyboards and Texas Instruments decided to develop all core technology other than the rechargeable batteries for the Cal-Tech project in-house.

Texas Instruments approached Canon Inc. (Tokyo) and arranged to coproduce a pocket calculator completely built with Texas Instruments parts. In April 1970, the Pocketronic appeared on the Japanese market; it was a four-function, entirely electronic calculator that retailed for about $400. Texas Instruments announced on September 17, 1971 with the TMS1802 a single-chip calculator circuit and offered it together with four integrated display drivers, two integrated LED display modules, a complete keyboard assembly and even schematics for a fully functional, battery operated calculators to various OEMS.

Bowmar announced in the same month the game-changing 901B "True-Pocket-Size" calculator based on the TMS0103 single-chip calculator circuit (a variation of the TMS1802), Texas Instruments' Klixon keyboard assembly, TI display drivers and their own LED displays. Dozens of other companies followed with more or less success before TI introduced on September 21, 1972 formally the TI-2500 Datamath.

A perfect example of Vertical Integration:

While Texas Instruments was a pioneer of early calculators based on thermal printer and LED display technology, were companies in Japan forerunners in combining both LC-Displays with single-chip calculator chips manufactured in low-power CMOS technology. Think about the groundbreaking Sharp EL-805 introduced in May 1973 and both Canon LC-1 and Toshiba LC-810 introduced in 1976 - almost one year ahead of TI's TI-1750. The TI-1750, introduced in April 1977, started an era of a productive cooperation with Toshiba that brought us not only the TI-1790 Datachron, TI-25 and TI's first solar cell powered calculator (TI-1766) but even the amazing TI-66 Programmable. Visually compare some Toshiba and Texas Instruments calculators. Texas Instruments could bridge their technology gap in CMOS technology with their cooperation with Toshiba before introducing in June resp. August 1978 basic, scientific, and financial "slimline" calculators sporting LC-Displays "Made in the USA": TI-1030, TI-50, and Business Analyst II.  

• Original Equipment Manufacturers (OEMs)

We wrote the year 1981 when Texas Instruments introduced with the TI-55-II the first product of a very sophisticated calculator line positioned above the "slimline" series from 1978. These calculators combined an innovative architecture with a Master and Slave CPU and an enhanced LC-Display with the keyboard technology from the original slimline series. Unfortunately led some cost reduction measures of the keyboard design to an extremely unreliable design and there was immediately a saying: "The -II designation was evidently for the number of keystrokes that were recorded with one button press".

Texas Instruments was during this difficult time already experienced with contract manufacturers in Far East - we noticed TI-1015 and TI-1020 calculators assembled in Taiwan with Date codes as early as 1980 - and it wasn't too big of a surprise to see the second series of the TI-55 II manufactured starting Summer 1984 by Inventec Corporation in Taiwan with a completely different "Asian-style" keyboard. Inventec was in 1984 the largest calculator producer in Taiwan and expanded soon into Malaysia to take advantage of competitive labor rates. In 1995 the first factory was established in Shanghai, China - manufacturing most of TI's graphing calculator line - before further expanding in China in 2004 to add even engineering services and a logistics center to the then 8 factories. Texas Instruments was and is working with other contract manufacturers, too - we know as of today:

Examples are this TI-1756 with serial number 8687189 and this TI-2200 Checkwriter with serial number 84249159. Dismantling these two calculators revealed a surprise, we located on the printed circuit boards (PCBs) small marks reading MK65 resp. 309T-10. We located similar PCB Marks on almost identical looking products from other brands and would call it "Badge Engineering".

The near identical offspring of the TI-1756, the IMA LC 688, Novus Electronics NS220 and Unisonic LC-7311BK consequently exhibit the MK65 PCB-Mark, too while we could trace back the 309T-10 PCB-Mark from the TI-2200 Checkwriter to the Radio Shack EC-306 sporting a 306 PCB-Mark.

Tracing back to Texas Instruments' OEMs is pretty straight forward for most calculators and related products manufactured in or after 1984 - the date codes on the back of the products display usually the contract manufacturer, e.g. I for Inventec Corporation Taiwan / Malaysia or P for Inventec Pudong Campus in Shanghai, China. The difficult part is with the numerous TI calculators introduced around 1982 sporting just a serial number, don't miss our tear-down of the TI-1755 SLR and its relative SL674CK from Technico, a brand of Inventa Electronics Co., digging even into the fonts used with the calculator keys.

Printed Circuit Board Marks (PCB-Marks)

We noticed during our research of calculators a huge variety of PCB-Marks and compiled a first overview (Work-in-Progress):