Citizen SR-270X

Date of introduction:  2008 Display technology:  LCD dot matrix
New price:   Display size:  3 * 15 characters
Size:  6.4" x 3.1" x 0.45"
 163 x 78 x 12 mm3
Weight:  3.5 ounces, 98 grams Serial No:  080602
Batteries:  Solar cells + LR44 Date of manufacture:  mth 05 year 2008
AC-Adapter:   Origin of manufacture:  China
Precision:  15 Integrated circuits:  
Memories:  7    
Program steps:   Courtesy of:  Joerg Woerner

Casio introduced with the fx-115ES already in 2005 an advanced scientific calculator with a 2-line Natural Textbook Display showing formulas and results exactly as they appear in the textbook.

Texas Instruments followed mid-2007 with the TI-30XS MultiView and Sharp joined the group with its EL-W531 series introduced late-2007.

Citizen Systems Japan Co., Ltd. introduced in 2008 with this colorful SR-270X a pretty close clone of the Casio fx-300ES but the calculator seems to be available only in the European market. In the United States an identical product is sold by Office Depot as Ativa AT-30SX.

In addition to the so called "Math Format" mode the calculator sports a traditional "Linear Format" mode.

Dismantling the Citizen SR-270X reveals a pretty common construction with a single printed circuit board (PCB). The PCB hides the single-chip calculating circuit under a small protection blob of black epoxy and drives the graphing display with a heat sealed fine-pitch connector. The prominent SR100 designation on the main PCB proves that this calculator was manufactured by Kinpo Electronics, Inc., a famous company located in Taiwan and doing calculator production for well established companies like Texas Instruments, Hewlett Packard, Casio, Canon and Citizen. 

Please compare the Citizen SR-270X with its competitors Casio fx-300ES, Sharp EL-W535B and Texas Instruments TI-30XS MultiView and understand that the it is 99% compatible with Casio fx-300ES!The remaining 1% are very ambivalent:

The algorithm of the Citizen SR-270X sport a higher precision and faster execution time.
The menu structure and keyboard functionality is identical but the layout of the keys is disturbing.
    Please notice for instance the odd grouping of the [sin], [cos] and [tan] keys and the out-of-place [Abs] and [log
ab] keys.
Both the Citizen SR-270X and Casio fx-300ES sport a dual power system with solar cells and battery,
    but the Ativa doesn’t turn on without battery, even in bright sunlight!

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© Joerg Woerner, March 6, 2011. No reprints without written permission.