Model: HP 10C
Type: Programmable scientific calculator
Picture: HP 10C
Batteries: LR44 x 3
Lifetime: Introduced: 1982
Terminated: 1984
Notes: This calculator is one of HEWLETT PACKARD’s landscape series of calculators, named the HP Voyager series. Extremely (and I mean extremely) robust calculators and some of them were quite successful too.

What I find really amazing about this calculator series is the design, which is actually quite timeless and very elegant. If one calculator series deserves a design award it’s this series. Only HEWLETT PACKARD can create heavy duty casing with such elegance.

The calculators in this series are:
  • HP 10C (this one)
  • HP 11C
  • HP 12C
  • HP 12C Platinum
  • HP 12C Platinum 25th Anniversary Edition
  • HP 12C Prestige
  • HP 15C
  • HP 15C Limited Edition
  • HP 15C Collector’s Edition
  • HP 16C
According to this article (link valid 2024-07-09), the HP 10C is not the first model of this series but rather the last one with more modern technology. It is also the only model of this series with just one shift key.

The HP 10C is a programmable scientific calculator. It does not have a large number of program steps. Program memory and register memory can be exchanged, for a maximum of 79 programming steps and zero registers. After clearing Program Memory there are 10 registers and 10 programming steps. When entering more than 10 steps the highest registers, starting at R9 are automatically converted to programming steps, 7 steps per register. The newly created programming steps are automatically filled with the "GTO 00" instruction, very practical. use the "MEM"-key to see how many programming steps and registers there are. When multiple memory locations are needed during a program this needs careful planning.

There are powerful flow control options available when programming such as "GTO" to jump to a specific program step. and conditionals to conditionally execute or skip the next programming step.

The Owners Handbook (with some corrections actually!) can be found here at hpcalc.org (link valid 2024-07-09).

Programs and data are stored in constant memory and are not lost when the calculator is switched off.

The display of the thousands separator, a "." or a "," can be set by switching the calculator on whilst pressing the "."-key. Another power-on key combination is holding the "-"-key whilst powering on, this completely resets its memory.

I found this specimen at a flea market at walking distance from my home, in a carton box filled with all sorts of metal tools. I was pleasantly surprised, this calculator is quite hard to find. The calculator however is quite scratched but it is still working beautifully.

I must stand corrected, by the way. For a long time, since I started this website actually, I was under the impression that the HP 10C was a non-programmable entry level model in this series. This was mentioned on the page for the HP 15C (now corrected).

For more information on this beauty please refer to the better sources, like The Museum of HP Calculators (link valid 2024-01-13) as referred to above.