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Texas Instruments TI-1795+ (1996 Cal-Comp)

Date of introduction:  January 1996 Display technology:  LCD
New price:   Display size:  8
Size:  5.1" x 4.2" x 1.0"
 130 x 106 x 26 mm3
   
Weight:  3.3 ounces, 94 grams Serial No:  
Batteries:  n.a. Date of manufacture:  mth 10 year 1995
AC-Adapter:   Origin of manufacture:  Thailand (C)
Precision:  8 Integrated circuits:  Sharp LI3154
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

At first glance looks this TI-1795+ almost identical to the first design of the TI-1795+, main differences are the slightly rounder design of the housing and a new layout of the keys in the left column.

Dismantling this TI-1795+ manufactured already in October 1995 by Cal-Comp Electronics in Thailand and a second unit from April 1998 reveals a clean design centered around a Sharp LI3154 single-chip calculator circuit soldered on a double-sided printed circuit board (PCB). We noticed this chip during our research about so-called Checkbook Calculators with the Radio Shack EC-455. Learn more about single-chip calculator circuits used in Account Manager Calculators.

The LI3154 is packaged in a standard Flat Pack (FP) housing, a very uncommon approach mid of the 90s. Most calculators of this era use "Chip-on-Board" (COB) technology, instead. Please compare it with a TI-1795+ and TI-7350 manufactured in China, too. Inventec Corporation on the other hand manufactured even in 2007 the BA-20 Profit Manager with a conventional Quad Flat Pack (QFP) housing.

Inspecting the PCBs of the two TI-1795+ calculator brought our attention to a small mark reading SD29-11, most likely a reference to Type Small Desktop 2nd Design 9 and Revision 1.1 of the design (schematics and layout). We spotted a very similar PCB-Mark already with the Radio Shack EC-2006A and Privileg SOLAR 31. We started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

The Second Generation of the TI-1795+ was introduced in January 1996 and an interesting journey around the Globe began:

TI-1795+ Second Generation Prototype Kinpo Electronics (Taiwan), June 1994
TI-1795+ Second Generation Cal-Comp Electronics (Thailand), October 1995 and April 1998
TI-1795+ Second Generation Nam Tai Electronics (China), May 1998
TI-1795+ Second Generation Kinpo Electronics (China), August 1998

A similar calculator with 10 digits of display capability was sold with the TI-1796+.

Press the X-RAY button and view the internals of a TI-1795+. 
 Look carefully and you'll notice the odd battery compartment!
 (Pictures provided by Edward Soudentas)



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

© Joerg Woerner, April 9, 2020. No reprints without written permission.