March 9, 2024

I was listening to a spin-off episode of the Thoroughly Considered podcast where they take a single designed object chosen by a guest and consider its design. It started me wondering what object would I choose.

An then it was obvious…

The Platonic Ideal of the  calculator

I bought this calculator in the summer of 1983 just as I went into my second year of studying engineering. I think I’ve changed the batteries three times over that time!1

I can think of examples of designed objects that are arguably the one — the best examples of their type. My Kyocera ceramic cook’s knife, Airpods Max, Happy Hacking Keyboard, Gekkoso pencils from Japan. Or maybe a Jens Ansø Monte Carlo pocket knife?

When I asked myself what is the designed object I’ve been using the longest and have no desire to change, this HP-15C was the obvious answer. I’ve used it for over 40 years — sold it, bought it back again, seen more capable successors come and go — but this is one that I will hang on to and keep using.

I just love the landscape for factor and small size. This truly is a pocket calculator. The subtle colour coding and tactile feedback of the keys is perfect. I know how to program it quickly if needed even though I no longer need the built-in complex maths, and matrix functions that were so advanced when this product was first released. The financial version of this calculator (HP-12C) has remained in continuous production since it was released — so embedded is in the world of financial professionals

My engineering version lives in my desk drawer at work and will survive the Great eBay Massacre™ when I retire!

  1. The long battery life of the Voyager calculators is legendary.↩︎


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