HP 12C Calculator
This Hewlett-Packard calculator was donated by Kristian Nergaard of San Francisco, California. Mr. Nergaard was hired by HP as a corporate trainer in 1981 and spent almost 20 years working for the company in Northern California's "Silicon Valley" before taking early retirement at age 53.
Most of his career was spent in employee and management development, and he was also a process and quality consultant for many years. He collected a number of HP items during his career, including these calculators used by some of the engineers and employees working for him.
The HP-12C is HP's longest and best-selling product, in continual production since its introduction in 1981. Due to its simple operation for key financial calculations, the calculator long ago became the de facto standard among financial professionals. Its popularity has endured despite the fact that even a relatively simple, but iterative, process such as amortizing the interest over the life of a loan – a calculation which modern spreadsheets can complete almost instantly – can take over a minute with the HP-12C. The 1977 October edition of the HP Journal contains an article by Roy Martin, the inventor of the simple method of operation used in HP financial calculators, which describes, in detail, the mathematics and functionality built by William Kahan (from UC Berkeley) and Roy Martin that is still in use today.