May 19, 2026, 6:14 am | Read time: 4 minutes
In the early 1970s, the first pocket calculators hit the stores, and today a man from Solingen has one of the largest collections worldwide. Gerhard Wenzel has amassed more than 5,000 electronic calculating aids over nearly 50 years. TECHBOOK spoke with the passionate collector.
“I received my first pocket calculator as a gift from my father,” recalls Gerhard Wenzel from Solingen. “It was a device from Quelle’s own brand, Privileg, an 872 MD.” Naturally, the first item in his collection is also featured in his online collection.
Back then, the teenager was training to become an electronics technician. From an early age, Gerhard Wenzel was intensely interested in how electronic devices work in detail. “I took apart several calculators at the time. That’s when I even had the idea to build my own electronic calculating machine,” says the calculator enthusiast. He realized this dream decades later.
From Hobby to Passion
Alongside his training, Gerhard Wenzel helped friends with malfunctioning calculators. He was allowed to keep irreparable devices. Thus, the number of small calculating machines in his apartment gradually increased. At the same time, he developed the idea of collecting calculators intentionally and documenting technical data.
By then, the era of home computers had also begun. Yet, Gerhard Wenzel continued to devote all his collecting passion to his calculators. “The collection holds a very high ideal value for me. The pocket calculator was the first application of the microprocessor in the mass market, even before the computer wave,” emphasizes the calculator expert from Solingen, adding, “The processor generations can be traced back from the Intel I7, through Pentium, 80386, 8086, 8008, to the 4004, which was used in Busicom calculators.”
Entry in the Guinness Book of Records
Another special aspect: He runs his collection entirely privately. There are no sponsors, and Gerhard Wenzel prefers it that way. Because it is the largest private calculator collection worldwide, the Solingen collector received an entry in the Guinness Book of Records in 2013.
Today, there are more than 5,000 items. He no longer stores them in his house but has safely stowed and outsourced them in various storage boxes. On average, two new calculators are added each month.
“I find many calculators through specific online portals or analog at flea markets. Additionally, I occasionally receive a device as a gift from other interested calculator friends,” Gerhard Wenzel says, delighted about his growing collection.
Because new devices keep coming in, the 65-year-old retiree has calculators in his study almost daily. His current favorites are the TSI Speech++, the first talking calculator for blind people, and the extremely rare Soviet calculator Elektronika C3/27, “which I searched for over ten years.”
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Today, people rarely delve into the workings of technical devices. According to Gerhard Wenzel, this is not due to a lack of interest from the younger generation. “Out of fear of plagiarism, the technical details of electronic devices, such as circuit diagrams or block diagrams, are unfortunately no longer published.” As a result, people’s technical curiosity has been virtually trained away over the past decades.
This development does not change his enthusiasm for electronic calculating machines. For him, calculators also represent a technology that no longer exists today. “Calculators didn’t have updates. Each device ran from start to finish with the same software, fit in any pocket, and was therefore quickly at hand,” describes Gerhard Wenzel.
For the passionate collector, calculators live on in today’s smartphones in a modern form. “Still, I would wish for a technology today that works as naturally, reliably, and effortlessly as the good old calculator; without lithium batteries, updates, annoying ads, and subscriptions. And that over many decades, not just a few months,” Gerhard Wenzel reminisces about old technical times.
Also interesting: How Apple brought the calculator to the Mac over 40 years ago
Collector Welcomes Supporters
If portable AI calculators ever come into existence, “they will certainly be included in my private online museum,” says the calculator fan with a wink.
Anyone who wants to support Gerhard Wenzel in his collecting passion, the Solingen native welcomes any feedback. Old or defective calculators are also welcome. “Even if I already have a device, I can use duplicate models for exchange or as a spare parts depot.”