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Texas Instruments TI-25X Solar

Date of introduction:	1996	Display technology:	LCD
New price:		Display size:	8 (5 + 2)
Size:	4.6" x 2.5" x 0.40" 117 x 64 x 10 mm³
Weight:	1.8 ounces, 50 grams	Serial No:
Batteries:	n.a.	Date of manufacture:	mth 03 year 1997
AC-Adapter:		Origin of manufacture:	China (N)
Precision:	11	Integrated circuits:	Toshiba T6974
Memories:	1
Program steps:		Courtesy of:	Joerg Woerner

This TI-25X Solar manufactured in China is identical to the US-built TI-25 STAT. In Europa the calculator was sold as TI-30S giving some memories to the very first TI-30 with a red LED-display introduced in 1976.

Like all early TI-30 variants this TI-25X Solar uses an 8-digit display. This is for most calculations convenient but in scientific notation you'll get only 5 digits of mantissa.

Dismantling this TI-25X Solar manufactured in March 1997 by Nam Tai Electronics, Inc. in China reveals a printed circuit board (PCB) with a TI-30S designator and sporting a Toshiba T6974 single-chip calculator circuit. We know this calculator chip from some older calculators, e.g. the TI-31 Solar, the TI-35 SLR and even the TI-30 SLR introduced in 1984.

Dismantling a TI-25 STAT from a late production run (year 2000) revealed a small surprise: The original Toshiba T6974 single-chip calculator circuit was replaced with a T6F27 chip. This gave the T6974 a life span of almost 15 years.

The similar TI-25 SOLAR lacked the statistical functions.

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