Texas Instruments TI-1798

Date of introduction:  1985 Display technology:  LCD
New price:   Display size:  10
Size:  4.7" x 5.0" x 0.80"
 120 x 128 x 20 mm3
Weight:  3.7 ounces, 110 grams Serial No:  
Batteries:  LR41 + LR54 (30A) Date of manufacture:  mth 01 year 1985
AC-Adapter:   Origin of manufacture:  Taiwan (C)
Precision:  10 Integrated circuits:  Sharp LI3163
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Texas Instruments Instruments introduced in the United States of America in 1985/1986 a family of three very similar calculators:

TI-1796: Basic desktop calculator with 10 digits display capability and "Dual Power" feature
TI-1798: TI-1796 with added clock module
BA-20 Profit Manager: TI-1798 with 6 added keys for COST, SELL, MARGIN calculations

Dismantling this TI-1798 manufactured in January 1985 by Compal Electronics in Taiwan reveals a clean design centered around a Sharp LI3163 single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by four solar cells and a small LR54 (LR1130) backup battery.

Please notice the clock module used with the TI-1798 and BA-20 Profit Manager next to the calculator display is powered by its own small LR41 battery. Later designs like the stylish EUROPA 10 powered the clock module directly from the calculator electronics and omitted the extra battery.

Inspecting the PCB of this TI-1798 calculator brought our attention to a small mark reading IOTI1796-01A, we spotted this PCB-Mark already with the TI-1796. We started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

The next generation of the TI-1798 looks completely different.

The BA-20 Profit Manager is featured in the Texas Instruments Incorporated bulletin CL-885 dated 1986.


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If you have additions to the above article please email:

Joerg Woerner, April 12, 2005. No reprints without written permission.