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Calculator Forensics (2002)
"Calculator forensics" is a term I've coined which seeks to answer the questions of who originally designed a particular calculator's chip set, what features of a particular calculator have been borrowed from earlier designs, and how has calculator technology spread among the manufacturers. The superficial answer to the first question is "open the calculator and look at the chip." With some calculators, this is a practical answer.
The calculator forensics process includes reviewing any published technical documentation, observing the physical attributes of the calculator (e.g. number of display digits, internal construction, cosmetic features), the keyboard layout, the key assignments, display font, and indirectly the embedded algorithms. The keystroke sequence (ignoring 2nd, INV, or ARC keys) is typically: 9, sin, cos, tan, arctan, arccos, arcsin. Some finagling is usually required to get at the hidden guard digits, and care must be taken to avoid the rounding of intermediate results as happens on some calculators (see hints and tricks).
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