DATAMATH CALCULATOR MUSEUM |

Texas Instruments TI-30Xa Solar School
Edition (Virgina 3^{rd} edition 2013)

Date of introduction: | August 2013 | Display technology: | LCD |

New price: | $11.99 (SRP 2013) | Display size: | 10 + 2 |

Size: | 6.0" x 3.0" x 0.6" 153 x 76 x 15 mm³ |
||

Weight: | 2.8 ounces, 78 grams | Serial No: | |

Batteries: | n.a. | Date of manufacture: | mth 05 year 2013 (B) |

AC-Adapter: | Origin of manufacture: | China (K) | |

Precision: | 12 | Integrated circuits: | |

Memories: | 3 | ||

Program steps: | Courtesy of: | Joerg Woerner |

What a surprise! Fellow calculator collector John Kleperis informed us in October 2015 that Texas Instruments quietly introduced the third generation of the famous TI-30Xa Solar School Edition sporting the design of the TI-30Xa.

Dismantling this TI-30Xa Solar School Edition manufactured in May 2013 by Kinpo Electronics, Inc. in China reveals no surprises. The printed circuit board (PCB) of the calculators sports still a prominent SR-30S logo - with a revision index of 10. A TI-30XA calculator manufactured four years earlier by Kinpo Electronics, Inc. carried a SR-30-12 designator.

Technically this calculator is identical with the
TI-30 ECO RS sold in Europe.

Since its introduction in 1996 we verify with each TI-30Xa
the presence of the Logarithm Bug
and - yes....

The
algorithm problem known as "Logarithm Bug" was implemented already
1991 with the TI-35X and TI-36X
SOLAR and floats around in various calculators.

The best way to demonstrate the logarithm bug could
be found with the exponential function, one of the most important
functions in mathematics. It is written as e^{x} and can be
defined as a limit of a sequence:

The calculation of this expression
will yield to unexpected results due to:
• The ln(1 + x) problem |

Using
n=10^{9} should reveal a very close approximation of e^{x}=2.71828183
(rounded to 9 digits) but this TI-30Xa Solar School Edition manufactured in May 2013 still indicates 2.71919279.

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

© Joerg Woerner, December 25, 2015. No reprints without written permission.