This is the simplest electric version of the MADAS Portable. It is a stepped drum calculator with a full 8-column keyboard and a main register with only 12 digits. The electric motor removes the need for a crank, and is activated by the big black button. There is a switch for selecting addition or subtraction. By default the keyboard is cleared automatically after an addition or subtraction.
The Repeat button (Rep) can be pushed in to disable the automatic keyboard clearing, allowing you to do repeated addition, i.e. multiplication, or repeated subtraction, i.e. division. With both addition and subtraction the counter is incremented. There is also a Correction button that does the inverse of the currently selected operation, and decrements the counter.
The movement of the carriage is not driven by the motor and still has to be done manually. This means that there can be no fully automatic division. It does have a DIV switch that will run the motor until an underflow (or carry) occurs from the third to the second column from the left. This gives semi-automatic division functionality through the following steps:
This machine has serial number 25,894, which means it was made in about 1934. To remove the carriage you have to unscrew the small metal indicator at the right of the input register, and then release the hidden catch that locks the carriage in place by pushing a pin through the small hole located at the top-left corner of the keyboard.
Here is a video where I demonstrate the MADAS Portable 12e.
The MADAS 20BZS is an electrically driven mechanical calculator that offers fully automatic multiplication and division. It was made in Switzerland by H. W. Egli A.-G. from about 1959 till 1967. There were several other variants of the model 20B, and here the Z means it has a carry mechanism throughout the whole register, and the S means it has tabulation functionality.
Here is a list of all the buttons, switches and registers, and what they do:
This machine has serial number 90,720, which means it was made in about 1960 or 1961. Many parts had become stuck with dried up oil, most of which I have been able to lubricate and free up again. The multiplication functionality however does not work, as I have not yet dared disassemble it far enough to find all the stuck parts.
Here is a video where I demonstrate the MADAS 20BZS.
Hans Walter Egli apparently founded his eponymous company in about 1893. It took several years for the engineer Otto Steiger and Egli to fully develop the Millionär calculator, and set up a workshop to produce them, so production did not really start until about 1898. The Millionaire was a calculator that could perform single digit multiplications with one turn of the crank, using a built-in multiplication table similar to the few machines made years earlier by Léon Bollée.
Although the Millionaire was good at multiplication, division was still a somewhat complicated manual process. In order to offer a machine that could do automatic division, a complete redesign was required. This was the MADAS calculator, a machine that was based on the traditional Arithmometer stepped drum design, but with several clever improvements to allow division to be performed fully automatically. MADAS stands for Multiplication, Automatic Division, Addition, Subtraction. This calculator still had the long rectangular shape, so is now sometimes called the long MADAS. It was released in 1914, and was the first commercially available calculator with automatic division.
Hans Egli died in 1925, but the company he founded continued on.
The Millionaire and (long) MADAS were large, heavy, and expensive machines, especially the electrically driven versions. By addressing these issues a different market segment could be served. The result was the MADAS Portable, released in 1931.
Many variations of the MADAS Portable were made. By 1934 some fully automatic versions were made, so that the long MADAS became redundant and was soon discontinued. The Portable tag was eventually dropped for the MADAS machines.
In the late 1960s the rise of electronics made the MADAS mechanical calculators obsolete almost instantly. H.W. Egli was not able to make the switch to electronics and the large scale production needed to make such a switch profitable. In 1967/1968 production ended, and the liquidation of the company was set in motion.
The Millionaire was made from the late 1890s until about 1930. The model versions were denoted by a roman numeral indicating the number of digits in the input register, with the letter e appended if it had an electric motor, possibly followed by one or more groups of capital letters to indicate extra functionality.
The most complicated version was the XIIe TD MT, which was electrically driven and had 12 digits of input, two registers of 20 digits, keyboard for the input and a set of multiplier keys. The most common version by far was the VIII, a manual machine with sliders for input.
The long MADAS was made from 1913 till about the mid 1930s. A similar naming system was used for these as for the Millionaire.
|VII||7x7x12, or with keyboard 9x7x12 or 9x7x14|
|VIII||8x9x16 or 8x9x18|
|IX||9x9x16 or 9x9x18|
|XI||11x9x16 or 11x9x18|
|E||For English currency|
|A||Multiplier keys, Multiplication bar|
The MADAS Portable was made in many variants from 1931 until 1968 when the company was liquidated. The first models to be introduced were the basic manual models in three sizes (12/16/20), and their electrically driven counterparts (12e/16e/20e). The electric drive only moved the crank, with a switch to select addition or subtraction. Shifting the carriage or clearing the registers was still done manually. Later slightly improved versions were made (12eN/16eN) in which addition and subtraction had separate buttons, and with buttons for shifting the carriage (though still not electrically assisted).
Versions with automatic division were introduced in 1934. The carriage shift and clearing was also now fully electric. These semi-automatic machines were only available in sizes 16 and 20. These models were denoted by an L instead of an e in the model name. At the same time fully automatic models were introduced too, and these had an extra register for storing the multiplier. The fully automatic models were only available in size 20. The automatic and semi-automatic models optionally had extra functionality indicated by the various letters appended to the model name.
In the 1950s these models were restyled, and those models had a G appended to the model name. In about 1958 the mechanism of the fully automatic machines was improved, with an extra button added for negative multiplication, and those were designated B instead of A.
So the full model name consists of the following:
|Base model||e/eN||Non-automatic, electrically driven, manual carriage shift (N with shift buttons)|
|L||Semi-automatic (automatic division)|
|A||Fully automatic (Automatic division; Automatic multiplication with multiplier register)|
|B||Improved fully automatic (As A above but with negative multiplication button)|
|Extras||Z||Carry over the full length of the main register|
|V||Division set-up key|
|S||Tabulator buttons on the carriage (will also have division set-up but V omitted)|
|T||Extra totals register (will also have division set-up but V omitted)|
Not every combination was available or even possible. Here is a list of the models that are confirmed to have been made:
Non-automatic: 12, 16, 20, 12e, 16e, 20e, 12eN, 16eN
Semi-automatic: 16L, 20L, 16LG, 16LS, 20LS, 20LT, 16LV, 20LV, 16LVG, 20LVG, 20LZS, 16LZVG, 20LZVG
Automatic A: 20A, 20AG, 20AS, 20AT, 20ATG, 20ATZ, 20ATZG, 20AV, 20AVG, 20AZS, 20AZV
Automatic B: 20BG, 20BS, 20BTG, 20BTR, 20BTZG, 20BVG, 20BZS, 20BZVG
In addition to the above there were the MADAS 8 and MADAS 10R. These were manual machines with automatic division, and in the latter case with back transfer. For some reason the numbers indicate the size of the input rather than the size of the register.
Swiss Calculating Machines H.W. Egli A.-G. - A success story
145 page hardcover book
210mm × 297mm × 9mm
This book details the history of H.W. Egli, and the mechanisms of the Millionaire and MADAS calculators, with many photographs. Available from the author at madas.ch.
Here is the entry in the book Modern Instruments and Methods Of Calculation, A Handbook Of the Napier Tercentenary Exhibition from 1915.
The following is from the 1921 book Illustriertes Orga-Handbuch erprobter Büromaschinen by Ludwig Brauner and Victor Vogt (archive.org).
Here is the entry for the Millionaire in Ernst Martin's book, Die Rechenmaschinen.
Here is the entry for MADAS in Ernst Martin's book, Die Rechenmaschinen.
These are the entries for the Millionaire and MADAS in Moderne Büro-Maschinen from 1931.
Here is the list of patents related to the Millionaire and MADAS machines.
|Patent||Filing date||Publish date||Name||Description|
|DE 72,870||23-12-1892||11-01-1894||Otto Steiger||Calculator
See also: CA 47,857; CH 6,787; US 538,710.
|CH 51,305||04-09-1909||04-09-1909||Heinrich Daemen-Schmid||Keyboard input
See also: FR 411,063; GB 1909/20,301; US 1,015,842.
|CH 52,747||17-08-1910||17-08-1910||Otto Steiger||Reversing gear|
|CH 53,467||11-08-1910||11-08-1910||Otto Steiger||Input mechanism|
|DE 271,308||23-04-1912||09-03-1914||Erwin Jahnz||Carry mechanism|
|DE 277,829||20-09-1912||11-09-1914||Erwin Jahnz||Automatic carriage shift in division
See also: AT 67,997 B.
|DE 264,428||22-09-1912||23-09-1913||Erwin Jahnz||Sliding carriage without lifting
See also: AT 65,805 B; US 1,081,310.
|CH 80,847||12-07-1918||16-08-1919||H. W. Egli A.-G.||Keyboard testing apparatus|
|CH 116,617||28-08-1925||01-10-1926||Erwin Jahnz||Carry mechanism
See also: DE 435,047.
|CH 129,925||06-07-1927||02-01-1929||H. W. Egli A.-G.||Multiplication register|
|CH 131,514||07-12-1927||01-05-1929||H. W. Egli A.-G.||Multiplication register|
|DE 524,939||14-12-1927||23-04-1931||H. W. Egli A.-G.; Heinrich Suter||Calculator with electric carriage shift
See also: AT 116,469 B; US 1,915,037.
|DE 519,668||16-04-1929||12-02-1931||Erwin Jahnz||Reversing gear
See also: CH 146,299.
|DE 519,176||17-07-1929||05-02-1931||H. W. Egli A.-G.||Carry mechanism|
|DE 587,741||01-02-1930||26-10-1933||Erwin Jahnz||Keyboard|
|CH 141,362||16-09-1929||31-07-1930||H. W. Egli A.-G.||Shifting input|
|DE 536,923||23-11-1930||08-10-1931||H. W. Egli A.-G.; Heinrich Suter||Carry mechanism
See also: US 1,900,776.
|US 2,089,770||27-10-1933||10-08-1937||Heinrich Suter; Alfred Grasshof||Full carry|
|DE 624,181||23-02-1934||19-12-1935||Erwin Jahnz||Printing mechanism
See also: CH 183,723; FR 785,855.
|DE 622,326||03-08-1934||07-11-1935||Karl Locke; Rudolf Brunhuber||Clearing mechanism
See also: AT 144,539 B; CH 182,115; US 2,106,807.
|CH 180,727||09-01-1935||01-02-1936||Erwin Jahnz||Store input for repeat|
|CH 182,765||22-02-1935||16-05-1936||Erwin Jahnz||Keyboard locking mechanism|
|DE 673,919||28-02-1935||16-03-1939||Erwin Jahnz||Main shaft
See also: CH 189,444.
|DE 725,475||05-05-1936||06-08-1942||Karl Locke; Rudolf Brunhuber||Carry mechanism
See also: AT 154,550 B; CH 213,461.
|CH 195,376||08-01-1937||16-06-1938||H. W. Egli A.-G.||Dividend set-up|
|DE 745,783||22-12-1938||16-12-1943||Karl Locke; Rudolf Brunhuber||Carry mechanism|
|CH 218,923||21-02-1941||16-09-1947||H. W. Egli A.-G.||Transfer mechanism|
|CH 217,539||13-05-1941||16-06-1942||H. W. Egli A.-G.||Carry mechanism|
|CH 237,652||10-07-1942||16-08-1945||H. W. Egli A.-G.||Keyboard
See also: FR 895,001.
|CH 232,661||07-11-1942||16-01-1945||Erwin Jahnz||Interlock mechanism|
|CH 236,049||07-05-1943||16-05-1945||Erwin Jahnz||Keyboard clearing mechanism|
|CH 256,012||16-10-1943||16-02-1949||H. W. Egli A.-G.||Calculator|
|CH 240,250||05-06-1944||01-04-1946||H. W. Egli A.-G.||Storage register|
|CH 240,836||21-06-1944||16-05-1946||H. W. Egli A.-G.||Input display register|
|CH 243,875||12-07-1944||01-02-1947||Erwin Jahnz||Total and Subtotal mechanism|
|CH 245,418||17-01-1945||01-09-1947||Heinrich Suter||Continuous carry
See also: US 2,558,631.
|CH 253,287||09-03-1945||16-11-1948||Heinrich Suter||Clearing mechanism
See also: US 2,614,753.
|CH 245,419||20-06-1945||01-07-1947||Erwin Jahnz||Positive/negative (sub)total mechanism|
|CH 254,295||12-11-1946||01-12-1948||H. W. Egli A.-G.||Carriage shift mechanism|
Madas.ch is an extensive site by Gérald Saudan about H.W. Egli and their calculators. Gérald Saudan's beautiful book can be ordered there.
John Wolff has an H.W. Egli page with many models detailed technical descriptions.
Rechenmaschinen illustrated has a MADAS page many models and manuals.
Rechnerlexikon has a page about MADAS, and separate pages about various models. There is also a Martin Reese article.
Rechnen ohne Strom has a few long MADAS models.
Cris Vande Velde has several long MADAS machines, namely VII, VII T, VIIe T, VIII, IX, as well as the Portable machines 10R and 20BTG.
Xnumber.com has an article about the MADAS Portable.
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