John Wolff's Web Museum

Calculating Machines - About this site


As a Professional Engineer, I have long been fascinated by the workings of mechanical and early electronic calculating machines. Although never setting out to "collect" calculators, I do seem to have acquired a fair selection from various parts of Australia over the past 50 years or so. As a hobby interest, I have frequently disassembled (and reassembled) machines to study and document their mechanisms. I have taken notes from books, manuals, advertisements, patents, and many related items to provide a technical and a social background to the machines, and to the companies and the people who built and used them. During the 1990s I started preserving some of this information in electronic rather than hard-copy form, and established this public web site in December 2002.

My aims in making this material accessible through this "web museum" are:


The machines in these pages are organised into categories according to their basic technology, with separate pages for manufacturers where there are sufficient examples. Each machine entry has a photo and a brief technical specification, with explanatory notes where appropriate. The photos on the listing pages have been kept small (8-10kb) for rapid browsing, but clicking on these images will generally bring up a more detailed version. A full Index by Make and Model is available on a separate page. Detailed technical descriptions are being added to the Technical and Reference section as the opportunity arises.

Navigation within the site is primarily from the main Calculating Machines page, which is accessible from the "Back" path at the bottom of every page. Please avoid creating bookmarks or links beyond the main entry page, as items may be moved or re-arranged as the site develops.


This web museum does not aim to provide a complete or comprehensive listing of all calculator makes and models. It consists primarily of machines which I have personally collected within Australia, and which were (to the best of my knowledge) originally sold and used within this country. The number of examples from each manufacturer may provide a rough indication of their relative popularity. In 2006 the museum incorporated a similar collection assembled by Mr John Blackler, a retired engineer from Sydney, Australia, and a number of machines from the collection of the late Professor Alan Bromley of The University of Sydney. Some of these latter machines were collected overseas. Donations of machines and documentation from individuals and visitors to the web site have also been gratefully accepted. Provenance is noted where appropriate.


The machines and technical information in this private collection are accessible to the general public primarily through this on-line "web museum". I also provide machines for public displays in local libraries and museums, and for use in theatrical performances. I give illustrated talks on calculator history and development to professional and community groups, and provide photographs for use in books and academic papers. Physical access to specific items can be provided to calculator collectors, researchers, and interested parties by arrangement.


The explanatory notes and technical descriptions in these pages were prepared initially for my own use, to assist me in understanding (and remembering) the details of the machines in my own collection. They are drawn primarily from my own observations, supplemented with material collated from a variety of published sources. The notes are presented in good faith, but with no guarantees of accuracy or completeness. No responsibility will be taken for any consequences arising from the use of these notes by others. Useful resources for further information are listed on the relevant pages.


This web site currently displays about 500 mechanical and early electronic calculators, with 180 HTML pages of explanatory notes and over 2500 illustrations. Original text and images in these pages are copyright ©, and may not be reproduced without permission. Permission will generally be freely given for private, educational, or non-commercial purposes. Larger or higher-resolution images for publication can be provided by arrangement.


I am happy to receive questions, comments, corrections, or further information via the Enquiry Form

Please note that this "web museum" is strictly a part-time hobby - it is not a business. The machines illustrated are all part of my personal collection, and are not for sale. I do not deal in calculators, although I may occasionally have spare or duplicate machines that are available to good homes. I regret that I am unable to offer repair services on a commercial basis, but I will try to answer technical queries by email. If you find errors or inaccuracies in these pages, or if you can offer further information, or if you were directly involved in the calculator industry (especially in Australia), I would very much like to hear from you. I am always happy to provide a home for unwanted calculators, instruction manuals, or calculator-related documents, and to share and exchange with like-minded enthusiasts. Don't be afraid to ask!

Original text and images Copyright © John Wolff 2002-2022.
Last Updated: 8 March 2022.
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