Texas Instruments TI-1755

In 1981/1982 Texas Instruments introduced not only cheap looking calculators manufactured in Taiwan like the TI-1015 or TI-1006 but some very stylish and thin calculators. 

The line covers the TI-1754 (credit card sized), TI-1755, TI-1756 (silver edition of the TI-1755) and TI-1757 (Music Card). All four models got an audible instead of a tactile feedback of the entries. The design was continued with the later TI-1755 SLR.

Dismantling this TI-1755 manufactured in 1982 by a non-disclosed OEM (Original Equipment Manufacturer) in Taiwan reveals a clean design centered around a Sharp LI3033MT single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by two LR54 (LR1130) batteries.

Inspecting the PCB of this TI-1755 calculator brought our attention to a small mark reading MK65-A, we spotted this PCB-Mark already with near identical offspring like the IMA LC 688, Novus Electronics NS220 and Unisonic LC-7311BK and suspect to locate it in the Technico MK-65, too. Plus the Asaflex MK 653, Benkson CAL-20, Levi MK 1652 (Fellow collector Marie Collas reported that her MK 1652 sports an IO065A04A mark!), MBO MK65, M-Office MK650, Olympia MK 65, Privileg Senator, Radio Shack EC-376, Satek MK 652 and Unisonic LC-7311M. Based on the PCB-Marks located with the TI-2130 and its twin Technico F-800 we are almost positive that the TI-1755 and its siblings were manufactured by Inventa Electronics Corporation of Taipei, Taiwan. We started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

The same housing was used with the later TI-1002 / TI-1036 4-function calculator and the TI-1757 II melody calculator.

An even smaller calculator was introduced already in 1979 with the rare TI-1760 DataCard.

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

© Joerg Woerner, January 3, 2002. No reprints without written permission.