DATAMATH

DATAMATH CALCULATOR MUSEUM

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.

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.

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