One of our favorite hobbies is collecting pocket calculators. Explore time through the various versions of calculators in the following pages.

HP Calculators. Pocket calculators built by HP have a special place in the calculator history.

Aviation Calculators. A special breed of calculators, those used for aircraft navigation, have appeared in the early 70s as well. We will follow their history through these pages.

Non-HP RPN Calculators. HP was the master of RPN Reverse Polish Notation) calculators. However, others made attempts to use RPN in their calculators. Presented here are all those other manufacturers.

Other Calculators. Explore the technology of other pocket calculator manufacturers during the early 70s along with a series of mechanical calculators.

and finally...

Calculators Wanted. This is a list of calculators we are looking to add to our collection. If you come across any, please let us know.