

Photographs by DWL.
Stainless steel
CITIZEN  9140A AKA [CSCW]
9140A
NONE
100 USD ??
[SS]
RELEASED  1978
This is the holy grail of all Calculator watches. As the "big brother" version to the more common Citizen Round Calculator Watch, it is scientific in nature. In terms of durability, it is second to none. In terms of functionality, it has all the scientific functions of a basic scientific calculator. This calculator calculates the 4 operations(+,,x,/ of positive and negative numbers), pi value, sine, cosine, tangent and their inverses, log x and its inverse, ln x and its inverse, squares and square roots of real numbers, 5 significant figure/full string value convertor and calculation of reciprocal, value y to the xth powers, xth root of value y and cube root, conversion of a decimal number to degreeminuteseconds, rectangular to polar coordinates (pseudo complex number calculations), standard forms, exponentials and factoral. It can even perform statistical calculations ! It is perhaps the ONLY scientific calculator watch that is able to do statistical calculation. The CFX40/CFX400, although boasts having boolean and baseN calculation capabilities lacks the statistical functions. In the statistics mode, this watch calculates summation, mean, standard deviation, sample and population distribution of a sample data of ANY size ! (limited by your patience in keying the data in) It can perform trigonometry calculations in degree and radian mode, It has a memory key, a memory clear and recall key as well as a register swap key. During calculation, some functions are accessed by a "2nd Function" key. One can also do a calculation edit by using the "CE" button, which clears the current value typed in. The "C" key does an ALLCLEAR to the calculation but maintains the value stored in memory. The grand "SW" key switches the calculator on and off and clears all memory during each activation. Each button is at most double mapped and no more. A total of 41 buttons surround the bezel of this watch. Buttons though small, are easy to depress and very sensitive. Contrary to common belief, a stylus is not required when using the calculator as the buttons can easily respond to a light touch with our fingernails. It is noteworthy to know that under certain suitable spotlighting, the 41 buttons actually glitter like small diamonds encrusted around the bezel. This moderates the "geekish" look of the watch and adds to its aesthetic appeal! There are no buttons at the sides of the watch giving it a very clean design. It is perhaps the most complete scientific calculator watch ever made by a digital watch company. Estimated less than 200 pieces were made. Few people have seen it and even fewer people owns a working piece of it. BookPrice range : $950 USD (?780 GBP)  Unknown. (Depending on availability and seller's quote)
WATCHES WITH MODULE 9140A