HP-12C Programmable Financial Calculator 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. Later HP financial calculators are many times faster with more functions, but none have been as successful. The HP-12C's programming mode is very intuitive and works like a macro operation on a computer. Basically, the keys one would press in the calculating mode to arrive at a solution are entered in the programming mode along with logical operators (if, and, etc.) if applicable to the solution. After the programming is complete, the macro will run in the computation mode to save the user steps and improve accuracy. There are 99 lines of programmable memory. The calculator is in good condition with some user traces. The calculator will be packed carefully.