Links to other people's websites

The online reference "par excellence" for everything calculator-related, and the online version of Martin's famous book is

Another very useful website is

John Wolff is a fellow collector and excellent technician, who documents his restorations meticulously. His website is a joy to behold for everyone who loves these little mechnical wonders.

Herbert Schneemann, sadly deceased, used to have a varied collection of antique mechanical calculators.

Walter Szrek is a collector of mechanical calculators in the US.

Stephan Weiss has a website full of interesting articles and original manuals for the use of many calculators.

Rick Furr is the reference where Curta calculators are concerned

...together with Jack Christensen

...and Jan Meyer. is a beautifully designed website with all sorts of rare and never-seen-before documentation and pictures of Herzstark's Curta. Highly recommended!

A page on the Adix calculators, summarizing the most important features.

Valéry Monnier is a French collector of Thomas arithmometers, who has gone to great length to set up a database and collect all sorts of information on them. Since Valéry is a man of many interests, he also has a website on other 19th century calculators, which contains a lot of obscure and unknown machines. Very much worth a look! is the web reference for the Swiss MADAS calculators, with lots of interesting model, technical and company info, constructed and run by Gerald Saudan.

Serguei Frolov documented the Russian calculator history - lots of machines here that are seldom found outside of the former USSR.

Kevin Odhner is the great-grandson (or at least family) of Wilgodt T. Odhner, and took up an interest in these iconic calculators.

The Swedish Typewriter Page contains a few tidbits on calculators as well, including the definitive visual reference on Odhner models.

Freddy Haeghens is a fellow Belgian collector.

Detlev Bölter is one of the most talented restorers who has seen many rare and even unique machines pass through his workshop. Reading through his website -now preserved at the rechnerlexikon- is a true delight.

dr. Erhard Anthes was a professor (now emeritus) at Ludwigsburg University's Institut für Mathematik und Informatik, and creator of the MMM, the Mathematisches Maschinen Museum.

Christophe Méry is a French collector of mechanical calculators. He has recently built a site on the history of TIM and UNITAS machines.

W.J. Wang is one of the rare Chinese collectors of mechanical calculators - his blog is unfortunately in Chinese.

Eduardo Guillem collects typewriters and calculators in Alicante, and has made this beautiful site.

Friedel Schmitt has a collection which is much larger and more varied than what is on his website!

Mark Glusker collects mainly electromechanical calculators, but did build a replica of Fowler's balanced ternary calculating machine. Very much worth a look! Also see Kevin Twomey's documentary on Mark's collection here.

Wilfried Denz is a very ambitious collector who collects everything related to calculating without electricity. A beautiful site with interesting pictures, and in full development.

Georgi Dalakov owns a beautiful site oriented to the inventors and their patents and inventions - all related to calculating aids and machines. Warmly recommended!

Kees Nagtegaal is yet another Dutch collector, mainly of small calculating aids, but his website contains a section on pinwheel calculators as well.

Gonzalo Martin is a French/Spanish collector of anything that calculates. He made this website to "scratch a virtual itch".

Yves Serra is a french collector of mechanical calculators and has an online cabinet of curiosities, including not only machines, but also mathematics and philosophy.

Maarten Mittendorf is a new collector of mainly Brunsviga machines in the Netherlands, who has started a fledgling website about them.

John Scriven is one of the very few UK collectors of mechanical calculators, but his website is well worth a visit!

Prof. Antonio Pérez-Prados has a beautiful collection of calculating aids and machines, with some truly exceptional machines in the collection. Highly recommended!

Thomas Kirchhof is also a prolific collector and restorer of mechanical calculators, who meticulously documents his collection on his webpage. Worth more than a single look!

Ed Rupp is (among other things) a calculator afficcionado from Colorado, who videos his restorations and puts them on his youtube channel, The ID of ED.

A somewhat atypical link, but very nicely done is the model of Chebyshev's calculator built from Fisher Technik parts. Very well worth a look, and the video is also worth watching.

Along the same lines are these working models of difference engines in Lego Technics and Meccano. Even more impressive!

A fantastic project is this digital version of the Thomas arithmometer, made by third year students in mathematics and informatics at the Université Grenoble-Alpes. Take the time to play with it, the detail is stunning!

Another very nice marriage of old and new technology is this Odhner type calculator, implemented on an Arduino by Diego Cueva.

A wonderful youtube channel by Robert Maøík, professor of mathematics and old calculator enthousiast(where the old pertains to the calculators, not the enthousiast ...). The videos are subtitled in English if you click on the subtitle icon.

The Computarium is a small museum of calculation and informatics at the Lycée classique de Diekirch, in Luxemburg, and well worth a visit.

ANCMECA is the French association for old technical devices, their website hosts Michel Bardel's list.

The IFHB is the German Association for the Historic Office-world.