MADAS Model 20ATG, S/N 70052
Functions: ASMD, automatic multiplication and division, back transfer
Technology: Electro-mechanical, Leibniz wheel
Digits: 10 keyboard, 10 multiplier, 2x10 counter, 2x20 accumulator
Dimensions: 9-1/2"W x 12"D x 9"H, carriage width 15", weight 38 pounds
Manufactured: Switzerland, 1930s to 1950s.
Original Owner: The University of Sydney (ex A.G.Bromley collection)
These pages contain a series of detailed notes and photographs which illustrate the basic principles and the internal mechanism of the Madas fully-automatic desk calculators. They are presented here to further the understanding and preservation of these historic instruments.
The notes are based on over 40 pages of hand-drawn notes and sketches, and about 100 photographs, that I took to assist in the overhaul of Madas No. 70052 during 2002.
I am indebted to Mr Ray Mackay of Melbourne, a former Madas technician, for his assistance and encouragement with this project. Ray's "Recollections on the Madas Calculator" are available on the Web and should be read in conjunction with these notes.
While I believe my descriptions to be substantially correct, I offer no guarantees of accuracy, completeness, or applicability to any other machine. Do not dismantle a Madas in the expectation that these notes alone will tell you how to get it back together!
I would welcome advice of any errors, or suggestions for improvement.