The calculating devices and adding machines are ordered according to the criteria suggested by Ernst Martin in his book. You can look for a special calculating device by searching the index or the alphabetic catalog. A bibliography, a list of operating instructions and service manuals and links to other calculator collections in the Internet can be found in the end.

In the introduction of each section you can get information about the working principle of the machines together with further references. Within the section the machines of one producer are grouped together. If known further information to the producer is given.

To each indivdual instrument and to every single machine all those pieces of information are given which enable to identify and differentiate the various items. In most cases some operational descriptions are included. The calculating capacities follow the notation used in Martin's book: "I x C x A". I, C and A are the numbers of digits of the input device, the counter and the accumulator. If there is no counter then C is omitted.

The numbers of the pictures in the collection correspond to my inventory numbers which follow the sequence of acquisition. The progess of this site is documented.

All the information given here have been carefully researched. If you should find mistakes or can add anything please contact me.

Sorry, but all the important information about producers, operation and attributes of the instruments and machines is only in German. Please feel free to send me an email: . if you have questions concerning my collection.