Here you see the building of the wanderer type machine factory. There is no Wanderer related activity anymore. The location is still marked with "Wanderer viertel" (Wanderer area).
I didn't 'find the building of the "Adding and listing calculator factory" on my visit in 2010.
The Wanderer museum in Chemnitz was on an other location, further on the same street. They are more specialized on cars and motor cycles at the time I visited them. When I started a conversation with one of the employees, they showed me an office, some where hidden in the building, where they kept a few Continental 9 and 9S machines. I was telling them my story how I became a collector, that I was visiting them from Holland and had fun to see the history of those machines. I saw it was a pleasant surprise for them. Their would for sure telling it to their parents, who all worked there.

As a nice surprise, our hotel, we had in Erfurt, was rebuild on the location of the VEB Optima plant. Optima is the name of the previous known AEG and Olympia werke. After WW II the name was given to the west German company Olympia in Willemshaven.
The hotel and the surrounding buildings were rebuild in style of the factory buildings. Very good looking area and wonderful that they kept what was possible to restore!!
On one floor of the hotel they had a small exhibition of their office machines. Machines of others manufacturers are showed as well. Of course the Mignon was exhibited.

One of the reasons to visit the museum was the model of a memory part of the Zuze mechanical computer Z1.

More to Mr. Conrad Zuze:

During our stay in the US (maternity visit, Aleydis ), we spend an afternoon visiting the Computer history Museum in Mountain View. The main purpose was to see one of the two on the worldwide rebuild difference engines (no I and especially number II) designed by Charles Babbage, the first more ore less programmable mechanical calculator. At the arrival of the museum, at the ticket office we were told that "the machine" was not in the exhibition to day, due to maintenance. When I introduce myself, and told them that we came from the Netherlands, Europe and showed them my web side, the guys turned out to be mech.calc. collectors themselves, we were asked to wait a moment and we got a special guide to show us the whole exhibition, including the two Babbage machines and a lot of interesting stories!! Thanks!!
The other mechanical calculators are the usual seen types. (see the second photo). A metal cased Millionaire was showed.
The link to more information

The purpose of the visit to this museum was my first photo camera, which was a Praktica LCC. One of the first cameras with light measurement with open aperture.
The museum was in one of the factory buildings known as the Ernemann building. Heinrich Ernemann (1850, +1928) was co founder and a driving person behind the camera industry in Dresden. Pentagon and Praktica products and the big cinema projectors are shown in the building which with the famous top. (Pentagon logo).

I was told by the nice people, at the Wanderer museum in Chemnitz, that at this museum in Dresden they had a computer and calculator floor as well. Indeed a large number of mechanical calculators are exhibited from various manufacturers, located in the former DDR.

During our 2011 autumn holiday we spend a morning in the famous Deutsches Museum in Munich. Last visit was 30 years ago with a school trip. On business trips I often visited Munich, but never entered the museum again. The museums outsides first impression was a little outdated. At the web side and at the entrance we got the information that it is in total reconstruction period. Among other attractions, the planetarium unfortunately was closed.
What left was the computer and photo exhibition floor which had our fascination. In accordance with this web side purpose, I limit myself here to the displayed mechanical calculator.

The picture above gives an overview of one of the mechanical calculators displays. In general all technologies are showed. A view in particular:

Optima Museum Erfurt, Thüringen, Germany (may 2010)
Wanderer / Continental Chemnitz, Sachsen, Germany (may 2010)
Technische Sammlung Dresden (may 2010)
Deutsches Techniekmuseum Berlin (may 2010)
Computer History Museum, Mountain View, California , USA (may 2011)
Deutsches Museum Munchen (okt-2011)
I visited this town in 2011, on our way back home from Prague. Glashütte, the calculator an watch town in the Ertzgebirge, had their glory years from 1900 till 1970. The important and successful manufacturers Burghardt, Archimedes en Saxonia had design and manufacturing plants in Glashütte.

Surprisingly we saw no remaining's those years in the town who played a so important role in early mechanical calculator history. Only a museum of clocks was left from those years.
Tübingen Badenwurtenberg (summer 2012)
We visit the town Tübingen, as a stop to our summer holiday in Italy, to see if there is anything to visit which remembers the first mechanical calculator, which is build in the town university, by Wilhelm Schickard. The current emphasis of the university is obviously not technical and "we" found no museum or a like. His friend Keppler is mentioned in much more locations in the town.
So we enjoyed the town and the castle, nicely situated on the Neckar river.

Arithmeum in Bonn Germany (sept 2012)
On the day I visited the Photokina in Cologne, I had some spear time in the afternoon and I decided to pay a visit to the Aritmeum in Bonn, from there a half an our drive. No regrets at all. It is the greatest collection of mechanical calculators I have ever seen.
The Aritmeum hosted the Department of Discreet Mathematics of the Bonn University. It is located in an very open and beautiful building. It has three floors, where the ground floor is having the mayor part of the machines. But don't forget the others. They have all the machines who considered as historical milestones.
I have made a lot of pictures. A selection I will add shortly.
I introduced myself at the entrance and met the man who is in charge of the restorations. We had a very nice chat and we decided to meet again!

Link to part of the museum collection
Heinz Nixdorf Museum in Paderborn, Germany (aug 2014)
On our way back home from our summer holiday, we seems to have a tradition to pay a visit to a mechanical calculator museum. This year the Heinz Nixdorf Museum in Paderborn Germany was on our list.
In this self claimed biggest computer museum, the first floor, is fully dedicated to mechanical calculation and - communication. A few very nice remakes of the first concept machines are showed in Bonn as well, exceptional are the special area's dedicated to punch card equipment, mechanical code and encryption and book keeping machines.
On the second floor the history of the computer was exhibited in various themes. That's perhaps the reason that the logical historical sequence, from transistor to chips etc, was not indicated very well (to my humble opinion)

Link to part of the museum collection
Xavier Thomas statue in Colmar, France (may 2015)
During our visit to the Elsass, France we visited Colmar and saw the statute of one of the important pioneers in the calculators history