HP-12C

The HP-12C is a financialcalculator made by Hewlett-Packard (HP) and its successor HP Inc. as part of the HP Voyager series, introduced in 1981. It is HP's longest and best-selling product and is considered the de facto standard among financial professionals. There have been multiple revisions over the years, with newer revisions moving to an ARM processor running a software emulator of the original Nut processor. Critics claim that its 1980s technology is antiquated, but proponents point out that it is still the de facto and de jure standard in finance.