What is the deal with calculators
Table of contents
Hobbies hobbies hobbies
This is going to be a post about hobbies, and specifically about one that seems meaningless to the majority of people. So the question is, why do I even bother using a calculator?
In order to understand how this came about, we need to understand how calculators are connected to my other hobbies. For starters, I always liked calculators, even though I was not fascinated by them. When I was at school, I was taught to look up trigonometric functions in tables. A calculator made all this obsolete and was so much better.
But I am not one of those people who like maths for math’s sake. I am a tech geek, I like maths when they can be used for some practical purpose.
As a tech geek, I am obsessed by various forms of technology and engineering, not only digital technology but also analogue technology. I enjoy a well engineered artifact.
That means that I am interested in various aspects of engineering from architecture, to sculpture, cars and motorcycles, well-designed clothes as well as electronics and digital technology.
Digital technology is my main focus. I have all sorts of little gadgets around, from programmable soldering irons that run Linux to any number of Arduino and esp32 boards that are used for various projects. Also, we should not forget retro gaming and various Game Boy shaped retro game devices.
So if we think of a programmable calculator as an embedded programmable device, then it is obvious that this type of gadget is right up my alley.
What do I use it for?
University use
The first time I used a calculator that was very valuable to me was when I was a university student. Back then I had a Handspring Visor handheld and I had found a calculator app called RealCalc. This app today exists for Android, and it is every bit as feature rich as it was back then.
I loved this app. It helped me complete several really difficult university modules. The main feature I used was the permanent calculation memory it had. I could go back and revise previous calculations, review formulas etc.
Of course this is an outstanding calculator and can do way more than that, but back then I did not know much about calculator programmability, RPN and unit conversions. I thought that a calculator was just a device to do simple math, or in the best of cases find results for some trigonometric functions or logarithms.
Of course, I was wrong, but that was my view of calculators back then, with the valuable addition of calculation history and the ability to review previous calculations in full.
Professional use 1
The second time I used calculators in a professional set up was when I was working for a bank, where I had to add and verify several numbers. By that time the Handspring Visor was gone, and I had a simple Sharp scientific calculator that did not have permanent memory like RealCalc but could go back and review previous executions.
Of course, I had access to a computer and I had access to banking software that was specially designed for this kind of work, but I always had the calculator at hand using it to verify sums of numbers. It was almost as good as having a printing adding machine. We had one only for the cashier, and I was not a cashier.
Usually the computer was the primary machine I was reading number from, the numbers i was verifying. The reason why I needed a second device is that even though I could have an Excel open, I would have to go back and forth between the two programs, which is inefficient. With the calculator, I was a lot faster.
I could almost blindly type numbers in the calculator without leaving my eyes from the screen. I could also look at printouts and do the same for partial sums etc.
The calculation history was the reason why I was using a scientific calculator and not one of the four bangers the bank provided us with.
At that time I did not know that there is a whole category of financial calculators that could be used not only to verify sums, but calculate mortgages, certificate of deposits, interest rates and a lot of other cool stuff. These are only thing I learned about years after I left the banking industry.
Back then, I even created the TVM functionality in one of the programs I wrote that calculated cashflows and eventually TVM. Naturally, I am still interested in this functionality even though I am not a frontline bank employee any more.
Professional use 2
The third time I used a calculator in a professional set up was under a very restricted environment. I was once more working for a bank, but this time on the technology side of things, not on the financial side.
I had to calculate again and again storage usage of Kafka topics, and this requires a fairly simple multiplication of multiple variables in order to estimate capacity. Furthermore, I also had to convert between milliseconds and days multiple times per day.
Although these two operations are uncomplicated, if you have to type them in all the time they become quite tedious. We were working on lockdown systems that we could not install any tools and on single displays, which made switching between apps quite counterproductive.
It was then when I discovered Free42 and Emu48 and started reading about RPN, RPL and HP Programmable calculators. This was a game changer, because by using these two phone apps I was able to calculate my storage equation and do unit conversions quickly and efficiently.
That opened a window to a world that I never knew it existed. Even though I have been studying about computers for most of my life, nobody ever mentioned that there were these field programmable devices, that you could use as a calculator but were also versatile enough to use for all sorts of other purposes as well.
Some people used them as gaming devices, others used them as organisers, some used them to control lab equipment. All in a portable package.
Then I discovered that these devices are still available and there are communities around them that are still developing software for the calculators, but also evolving the calculator software and the mathematical algorithms themselves.
The quality of work that has gone into them, and the quality of the discussions regarding the algorithms used in the past but also in the modern implementations, is astounding.
Sure you can roll your own calculator in whatever language but when you are creating a solution for a common function like a square root, how sure are you that this solution is accurate? The algorithms used by these HP calculators were designed by people who were masters of their craft, and as I mentioned before, I really enjoy a well engineered project.
So what most people understand when I say I am into programmable calculators is that I am a weirdo who buys old calculators, which although true is missing the true meaning of the phrase.
The reason why i am buying these calculators is that I want to be able to use the algorithms designed by Professor Kahan who worked with HP in the design of their first programming calculator HP 35 a piece of computing history but also participated in the design of other models I also have, and the algorithms of more modern heroes of numerical analysis that are discussed in the HP Museum collectors community.
Of course there are many more people who played a fundamental role in the development of these machines such as Thomas Okken, creator of Free42 and Plus42 simulators of the original HP 42, the Christophe de Dinechin, personal site here who has revived RPL with his DB48x project, Bernard Parisse professor of mathematics in University of Grenoble, who is responsible for XCas/Giac computer algebra system, available for computers but also calculators, Tim Wessman and Cyrille de Brébisson who designed a lot of HP calculators I own and love and many more.
This is an amazing community.
Conclusion
I hope that it is clear by now that my calculator collection hobby is really about numerical analysis, how we can use computers in general to do math reliably and field programmable embedded devices.
On top of all these we also get these really well engineered and powerful devices that are field programmable, standalone, do not need an internet connection to perform their magic that can be used to crunch numbers and solve problems.
These devices would be cool even without been able to see their development in real time and read all the discussions of the geniuses that are working on them. There is real value in them as prototyping systems with robust scientific, statistical and financial libraries that can be used to validate algorithms and techniques used in our day-to-day work.
When I need to calculate availability and reliability values in the various systems I design and maintain at work, I use them to verify the results I am getting from the various systems we use because these systems are not really designed to do math out of the box.
I also use them to do statistical analysis and curve fitting of various datasets produced by those systems.
Eventually these formulas are embedded in various monitoring and alerting systems, but during their development and prototyping I always use my physical or virtual calculators to design them.