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MADAS

MADAS Portable 12e

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:

1. Shift the carriage as far to the right as possible.
2. Set the dividend in the register, starting from the third keyboard column from the left. You can do this using the setting knobs above the register, or by entering it on the keyboard and adding it to a clear register.
3. Clear the counter.
4. Enter the divisor on the keyboard, starting from the third keyboard column from the left.
5. Push down the Rep button.
6. Switch to subtraction mode.
7. Set the other switch to DIV.
8. Press the motor button. The machine should repeatedly subtract until an underflow occurs.
9. Press the Correction button to correct the underflow.
10. Shift the carriage one step to the left.
11. Repeat the previous three steps until the carriage can move no further.
12. The result of the division is in the counter register, and the remainder of the division is in the main register.

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.

Video

Here is a video where I demonstrate the MADAS Portable 12e.

MADAS 16e

This is almost the same as the MADAS Portable 12e above. The main difference is that it has a longer carriage to house the larger register of 16 digits. This particular machine was however made much later, in about 1947, and by then they had dropped the "Portable" name. There are a few other subtle differences, such as the coloured column markers between the keys, and the fact that the semi-automatic division works in the left-most key column. The outer casing is made of four parts that can be removed separately rather than one single part.

Note that the keyboard clearing button has the wrong button top, as it should have a zero on it and not a minus sign. The Corr button is also not the original.

This machine has serial number 52,641, 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.

MADAS 20BZS

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:

1. Carriage release catch, Allows the carriage to be removed for maintenance.
2. Register III, Input display register.
3. Auto tabulation switch, set whether carriage returns to chosen tab position after multiplication.
4. Keyboard, keyboard for inputting 10-digit number. Entered number is shown in register III.
5. Transfer I→IV, Transfer number from main register to multiplication register.
6. Set dividend, Clears main register, shifts to chosen tab, adds input without affecting counter.
7. Auto-clear I, Select whether to clear keyboard after addition or subtraction.
8. Clear I, Clear main register.
9. Clear II, Clear counter register.
10. Clear III, Clear keyboard input.
11. Negative Multiplication, Multiply input with multiplication register and subtract from main register.
12. Clear IV, Clear multiplication register.
13. Auto-clear IV, Select whether to clear multiplication register after multiplication.
14. Tabulation, Select the default carriage location for multiplication or division.
15. Split, Split main register so clearing only affects lowest 9 digits.
16. Setting knobs I, Knobs for manually setting a value the main register.
17. Register I, Main register.
18. Register II, Counter register.
19. Counter disable, Disables counter register
20. Stop button, Immediately aborts division, including division by zero.
21. End division, End division after the current digit is calculated.
22. Negative division, Set direction of counter in division.
23. Division, Start division process, dividing main register by input, result in counter.
24. Reverse, Set direction of counter in addition/subtraction.
25. Subtract, Subtract input from main register.
26. Add, Add input from main register.
27. Carriage shift, Shift carriage to the left or right.
28. Column separators, Show a line between keyboard columns, for example for decimal point.
29. Multiplication, Set multiplication register from input (if clear), or multiply input by multiplication register and add to main register.
30. Register IV, Multiplication register
31. Setting knobs IV, Knobs for manually setting a value the multiplication register.

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.

Video

Here is a video where I demonstrate the MADAS 20BZS.

History

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.

Models

Millionaire

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. Some models were given codenames, but with the possible exception of Excelsior, none of those names were used outside of the company. These names are shown in the table below, for example model VIIIe TD was named Antonius.

From records it is known how many of each model was produced, as shown in the table below. In total 5,099 long Millionaire machines were made.

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.

John Wolff has gathered together many serial numbers of still existing machines in the register of Millionaire Calculators.

Long MADAS

The long MADAS was made from 1913 till about the mid 1930s. A similar naming system was used for these as for the Millionaire, with roman numerals indicating the capacity, possibly followed by 'e' for an electrically driven version, and capital letters denoting any extra functionality.

For the Millionaire, model VIII was by far the most popular, so at first they released a model VIII Madas, but by the time it came to extra functionality such as a keyboard (1922) only the other capacities had these applied. Most of these models had code names that were used internally by the company, as shown in the table below.

From records it is known how many of each model was produced, as shown in the table below. In total 9,325 long Madas machines were made.

The Millionaire and Madas machines did not really have separate serial numbers. Almost 3500 Millionaires had been made before the first Madas, so the Madas machines started with serial number 3501. About 1500 further Millionaires were made, which were given the ranges 4001-4500 and 6001-6500, and then various larger numbers on a seemingly ad hoc basis. The Madas serial numbers therefore go up to about 5099+9325 = 14424.

Here are the serial numbers that I have found online.

MADAS Portable

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:

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.

Books

Swiss Calculating Machines H.W. Egli A.-G. - A success story
Gérald Saudan
Copyright 2017
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. Gérald Saudan died in 2025, so it is not clear whether the book will remain available from his website at madas.ch.

Advertisements and Articles

The Millionaire and long MADAS

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 from 1925.

These are the entries for the Millionaire and MADAS in Organisations-Lexikon from 1930.

These are the entries for the Millionaire and MADAS in Moderne Büro-Maschinen from 1931.

The MADAS Portable

Patents

Here is the list of patents related to the Millionaire and MADAS machines.

Links

• Madas.ch is an extensive site by Gérald Saudan about H.W. Egli and their calculators. Sadly Gerald died in 2025, so the site will not be updated any further.
• 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.

© Copyright 2021 Jaap Scherphuis, mechcalc a t jaapsch d o t net.