The first old adding machine I got was a Brunsviga 20. I bought it in 1987 at a flee market in Berlin for 30 DM (about 15 Euro). I just wanted to find out how it worked.

In my computer lessons at highschool I showed this machine to my students and asked them to design structure charts for using the machine for basic calculations. This was to practice algorithmic thinking to prepare programming computers. For this purpose I also used other calculating equipment like sliderules, Suan Pan and pocket calculators.

So I got more interested in old calculators and looked for them at flee markets (Resulta, Addiator). Neighbours and friends noticed my preference for those machines and brought me some equipment they had left. Once I saw an Comptometer at a flee market and could not imagine what this was. I did not buy it for it seemed to be too expensive. This was in 1991. I noticed that I already had a small collection of fifteen different types of calculators. But it seemed to me that there must be many more types.

Since that day I knew that I was collecting old mechanical calculating equipment. As often as possible I searched for new old machines at antique shops, flee markets, junk dealers and recently in the internet too. Some of them were very rotten. I always tried to reconstruct them to their original state. So all my machines work, maybe they move a little slowly. Some equipment I rebuilt myself from pictures and descriptions in books, journals or museums.

Now there are more than 350 devices you can use to study the history of different types of mechanical calculating equipment.

This description of my collection can be studied here since April 1998. It is periodically updated. If you find mistakes in my desciptions or have some hints or additions please let me know. If you have questions please look at the info page of this collection.

Have fun studying my colletion.

Wolf-G. Bluemich, 07/20/2020

© Wolf-G. Blümich, Stand: 20.07.2020