DATAMATH CALCULATOR MUSEUM
Texas Instruments TI-30 ECO RS (2013)
|Date of introduction:||August 2013||Display technology:||LCD|
|New price:||€11.95 (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 04 year 2013 (B)|
|AC-Adapter:||Origin of manufacture:||China (K)|
|Program steps:||Courtesy of:||Joerg Woerner|
What a surprise, Texas Instruments changed in July 2013 the design of the original TI-30Xa - introduced already in 1996 - dramatically. The original design was used for five different calculators:
TI-30Xa - replaced in 2013 with
this new design
TI-30Xa Solar - discontinued in most markets
TI-36X Solar - replaced in 2004 with a newly designed TI-36X Solar
BA Real Estate - discontinued long time ago
BA-35 Solar - discontinued long time ago
In Europe a solar powered version of the
TI-30Xa is sold as TI-30 ECO RS, it was upgraded to the new
design line, too.
Disassembling this TI-30Xa manufactured in March 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.
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 ex 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
n=109 should reveal a very close approximation of ex=2.71828183
(rounded to 9 digits) but this TI-30 ECO RS manufactured in 2013 still indicates 2.71919279.
Ready for a surprise? Texas Instruments fixed the logarithm bug in 2015 -
don't miss the revised TI-30 ECO RS.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, December 1, 2013. No reprints without written permission.