Texas Instruments TI-508

Date of introduction:  1991 Display technology:  LCD
New price:   Display size:  8
Size:  4.9" x 4.2" x 0.9"    
Weight:  3.0 ounces Serial No:  
Batteries:  n.a. Date of manufacture:  mth 07 year 1992
AC-Adapter:   Origin of manufacture:  Thailand (C)
Precision:  8 Integrated circuits:  Sharp LI3135MR
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Production of the TI-508 and its twin TI-1795 was shifted in 1991 from Taiwan to Thailand. The leading "C" in the Date code reveals Cal-Comp Electronics as manufacturer of these small desktop calculators.

TI-508_C0792_PCB.jpg (61720 Byte)Dismantling this TI-508 manufactured in July 1992 by Compal Electronics , an OEM (Original Equipment Manufacturer) in Thailand, reveals a clean design centered around a Sharp LI3135 single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by solar cells. We known this chip already from the TI-502.

Inspecting the PCB of this TI-508 calculator brought our attention to a small mark reading SD9T-10, most likely a reference to Type Small Desktop 9, Texas Instruments and Revision 1.0 of the design (schematics and layout). We spotted this PCB-Mark already with the first TI-1795 and its near identical offspring Radio Shack EC-2006A and started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

Within a few month the TI-508 PLUS replaced the TI-508.


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Joerg Woerner, December 5, 2001. No reprints without written permission.