For our excitement this week, we went to a concert at Luhrmann Woods. Danita made a stunning dinner. You can see it for yourself if you visit the website.

I love cool calculators. Not all calculators, just the cool ones. The very first CC is the Antikythera mechanism. Made in about 100 BC, it uses intricate brass gears and at least two face dials to calculate the position of the planets. Moving to modern times, there are slide rules. I have over a dozen. They are cylindrical, round, 6″, 12″, metal, wooden, and even a tie clip. My favorite is my well-used yellow Picket that got me through four years of engineering studies. With 18 different scales, it could calculate seemingly anything. It comes with a case and belt loop, and it bumped against my leg on many trips across campus. Another favorite is a rule that was supposedly owned by an engineer in the Russian space program.

When it comes to coolness, I have a special spot for HP handheld calculators. They are extremely well built and amazingly long lived. The first ever scientific handheld calculator was the HP_35S (1972). There were plenty of HP scientific calculators, but they were big and expensive. When HP decided to offer a handheld scientific, the design teem asked Mister Packard (the “P” in “HP”) what the dimensions should be. He said the calculator had to fit in his shirt pocket. So they measured his pocket. That set the size of the 35S. It was amazingly cheap compared to the old desktop calculators, but still far too costly for me to buy one.

Just one decade later, I bought the classic HP-15C (1982). This supported dozens of scientific functions including complex numbers, an equation solver, matrices — and it’s programmable. (Not that it’s likely I will ever again use the advanced features). And it still fit in Mr. P’s pocket. My 40 year old unit still works perfectly and until recently, it was the calculator I reached for. The keyboard is very good. The case looks nearly new. It was so popular that in 2023 HP made a 15C Collectors Edition. This used newer and faster chips, but the point was a celebration of calculator coolness. You can still buy a 15C Collectors Edition new in the box, but I much prefer my 40-year old version. The 15C had some interesting siblings. If you need cash flow, net present value, and other financial functions, pick up a 12C. This baby is so cool you can still buy it new today. If you were a programmer bit banger, the 16C was the one to have.

By 1988, advances in electronics made it possible to have one calculator that could serve all three user groups. Ladies and gentlemen, I bring you the coolest handheld calculator ever made, the HP-42S . The calculator supports enhanced versions of all the features of the 15C, 12C, and 16C. It still fit in the pocket. The 15C has 39 buttons, many of them with three functions. Clearly the button count was at its practical limit. The 42S overcame this by using a larger 2-line display and grouping functions into a multi-level menu. It needs only 36 buttons, none of which have more than two functions. The layout and design of the calculating features is incredibly good. It would have been the calculator I use — if it had worked. Unfortunately, HPs legendary reliability fell short. Some keys in mine didn’t work, making it completely non-functional until …

Imagine my delight when I found out the keyboard can be fixed! Thanks to YouTube, I saw what was required, I immediately decided I needed to find somebody with a prior experience and a steady hand who would fix mine for me. The fixed calculator came back this week. It is a real beauty. I enjoy using it immensely.

You may ask why anybody would want a calculator when they have a computer. First of all, it’s fun knowing I am using one of the coolest machines of all time. Plus I can use a calculator without opening still another window in my computer screen. Still, it is a good idea to have a calculator app on my smart phone and computer, just in case. Unfortunately, every scientific calculator app I could find had irritating quirks. And that lead to another delight.

Somebody wrote an app the perfectly duplicates the operation of the 42S. It’s available for both computers and smart phones. I love the way it works, both with a mouse and keyboard and with a touch screen. The program is Free42. As the name implies, it is available for a donation. My 15C is relegated to the bench. Long live the 42S. I am completely “wiggle my toes” delighted.

I hope this finds everyone doing well.