Dutch Circle of Slide Rule Collectors
Founded in 1991, The Dutch Circle has grown into an informal group of
about 60 collectors,
These goals are pursued by issuing our periodical "MIR", by
The 27th International Meeting of Collectors and Researchers of Slide Rules and other Historic Computing Instruments
be held as a teleconference via the Internet on
September 11 & 12, 2021. This year's theme will be
Announcing a new Book for Slide Rule Collectors:
“THE ALRO CATALOGUE” …
… featuring for the first time all 52 currently known solid calculating discs and slide rules, plus the over a hundred slide charts, that were produced by the Dutch firm “ALRO” in the city of The Hague, from the mid-1930’s until the late 1990’s.
We proudly announce “THE ALRO CATALOGUE” (2020), in a hardback bound book format, with more than 200 pages of descriptions, tabular data, documentary annexes, a new coding system for identification, and – most importantly – the high-resolution colour images of each and every ALRO that is known today.
“THE ALRO CATALOGUE” is for sale at € 35.- + shipping costs