32nd International Meeting of Collectors and Researchers
of Slide Rules and other Historic Computing Instruments

The conference will be held on

The city of Mainz is not only easy to reach, but also a good start, intermediate or final stop for a holiday trip to Germany / Europe. So this conference is not only a chance to meet again fellow slide rule collectors again, but also an incentive for spending a pleasant vacation in Germany / Europe.

It has been a long time since we had an in personam meeting in Europe, and the time has taken its toll. Where we once had more than 40 participants, we must now expect a drastically reduced number. As we all get older, our ability to travel is declining, and a number of members of the slide rule collector community have died. We saw the effects at last year's IM2025 in the USA. So we do not know, how many participants we will have at the proposed event in Mainz, and if it will be viable. In view of this uncertaincy, we made the following decision of having two alternatives, as we cannot take the personal financial risks of only a few people coming:

• We will have an IM2026 in any case.
• We want to have it in person in Mainz, but we have to base that on commitments on a deadline, where we can still switch the format.
• If we do not have (a) at least 22 definite registrations and (b) a sufficient number of presentations at the deadline of Sunday 2026-07-26 noon CEST, the meeting in Mainz will be cancelled, and instead there will be an online ZOOM meeting at the same weekend, on Saturday/Sunday 2026-09-12/13, similar to those in recent years.
  For this reason it is also necessary that you send (a) your intention to come
  to Mainz and (b) your intention of giving a presentation as soon as possible
  by email to Karl.Kleine@eah-jena.de with subject "IM20026 pre-registration"
  for our practical planning as we urgently need key numbers.

Further details for the full registration and possible presentations follow below.

In case of any question about the meeting, write an email to Karl Kleine, who organizes it.

A key element of our life today is communication, in an incredible variety of forms based on a large spectrum of media. This web page is a first example, other (still) popular media are printed books, journals, newspapers, photos, posters, movies, records, radio and tv broadcasts, and many more media in multitudes of forms — just think of vinyl / CD-ROM / casette tape music records. The historic key invention by Johannes Gutenberg around 1450 in Mainz was the printed page based on its composition using movable letters, which allowed him to print many copies of a document instead of copying it by hand-writing. Gutenberg's invention triggered a cultural revolution and an avalange of communication forms and media. It is still going strong today, as evidenced by electronic messages, internet services, smartphones, etc, of recent decade — including this web page.

That's the first reason to have IM2026 in Mainz.

The second reason are the needs of various computations for all these types of media, starting with calculations to fit a given text in some predefined space on paper. This is just a first example; there are many more in printing, and obviously one this is here today as it was 500 years ago. Other media have tasks of such nature also, as well as many specific ones for the many types and forms of media. Therefore, it will not be a surprise that there are a number of calculating aids, in particular special slide rules and the like. Unfortunately, these specialities were often considered 'tricks of the trade' and not made public, or they were so special that only few were produced and thus remained largely unknown. But for some applications slide rules are still popular, like circular slide rules for copy-fitting or the reproduction of images by graphical artists and printers. Print is just one media type. There are many others, each with particular technology issues which require specific calculations aids and tools, or are highly desirable. Just think of anything with sound, from music to radio or tv news, and beyond. So we hope to see a number of most varied presentations on the motto of this IM, from short one to large surveys.

Last not least, we also have to issue of slide rules in the media. We will have a special section on that also, and we already have one on slide rules in the movies.

Finally, we are not limited to this theme / motto, and we will have presentations of all kinds on slide rules and other historic computing aids. At former International Meetings presentations about the theme / motto were in the order of about a third to half of the conference program.

• Friday, 2026-09-11
  15:00 Informal gathering, registration, coffee (in parallel with hotel check-in)
  15:30 Start of IM2026 programme, first talk(s) / technical presentations(s)
  16:30 'Talk and Swap' session for demos, sales, exchanges, inspection of objects, etc
  We arranged to have ample table space for this
  18:00 End of Friday conference programme
  19:00 (or 19:30) dinner at conference hotel

• Saturday, 2026-09-12
  09:00 IM technical presentations
  12:00 participant's lunch (part of conference package)
  13:30 IM technical presentations and organizational business of slide rule organizations, like the Ougthred Society Award and Fellowship announcement / presentation
  The times for the Saturday programme, including both morning and afternoon half hour coffee breaks, will be subject to change according to submissions received.
  19:00 conference dinner / evening at another location; weather and temperature permitting this will be an outdoor event (garden restaurant, with fall-back)

• Sunday, 2026-09-13
  Morning: Visit of the Gutenberg Museum, details pending.
  departure

For that we have prepared a set of forms to make it easy for you and for the organization, which you find on the IM2026 registration web page. Right now, we have a mandatory pre-registration, which we need as soon as possible. Once you have completed this, you are on a special email list for further detailled information, in particular the definite full registration, which must be completed before the deadline as outlined above.

Although the International Meetings, like this IM2026, are organized by a couple of slide rule organizations, any participation is free of any membership requirement. Everybody is welcome!

Conferences like the IM live from the technical contributions. So it even more important than getting you as part of the audience, is getting you as a speaker. Please contact Karl.Kleine@eah-jena.de as soon as you have an idea about the subject you might or want to talk about. We have to avoid duplicate papers on the same subject, and need to coordinate efforts for a well-balanced programme.

We are interested in all kinds of subjects next to the general theme / motto, but also in all lengths of presentation. In particular, do not shy away if you feel you only have a tiny or not so important subject. On the other hand, we are open to proposals involving more time or more pages in the proceedings as usually available in slide rule journals.

Last not least, our subject area is not just slide rules, as it was for many years, but also includes all kinds of historic calculation and computing instruments. Surprise us!

As we want to have a printed record of our meeting, details for the preparation of papers are discussed under the heading 'proceedings' below and in personal contact.

If you cannot come to Mainz, but would like to participate in an alternative online IM as described above, in particular as a speaker, please do write so in your email notice of intent, the pre-registration.

We will also provide you with some touristic information here.

We prepared a 'Guidelines for Authors' paper to help you (and us) with the preparation of your contribution. It is a set of rules and recommendations to make it easy for you and the editor to produce a high-quality typographical appearance of your article with maximum freedom for your writing. But most the important issue is:

More about the IM series of conferences is available on our IM history web page.

Impressum and privacy statement