With this calculator, Hewlett Packard tried to conquer new fields of use. With the HP 16c it was for informatic engeneers possible to calculate like their computers.

There were different number systems available, like binary, octal, decimal and hexadecimal. You could change at every point the visual display into another number system or change between the number systems. The calculation operations are equal to the basic operations from processors. You can test programs up to 200 steps. 

The user can also define the register length between 8 and 64 bits and can decide if calculation should be with algebraic or binary complement.

With my first assembler programs, the HP 16c helped me a lot. The development tools in that time were not as comfortable as the actual ones - in no way! To find errors was pretty lame. There it was great if you could know for sure, that parts of the program worked well.

It was also possible to calculate like with a normal calculator, but only the basic functions. That was the reason why I always used this calculator in combination with the HP 15c.

A very special feature of this calculator is the power-need. I use this model since 25 years (state 2008) nearly every day and had not changed the battery once.

Together are both leprechauns an invincible team!