# Jaap's Mechanical Calculators Page

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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.

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.

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.
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.

VI 6x6x12 8x8x16 10x10x20 12x8x20 Electric motor Keyboard Double register Multiplier keyboard

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 8x9x16 or 8x9x18 9x9x16 or 9x9x18 11x9x16 or 11x9x18 Electric motor Keyboard For English currency Multiplier keys 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:

Reg. Size 12 8x6x12 16 8x8x16 20 10x10x20 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) 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) G Restyled version

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
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.

### 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.

## Patents

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

PatentFiling datePublish dateNameDescription
DE 72,87023-12-189211-01-1894Otto SteigerCalculator
CH 51,30504-09-190904-09-1909Heinrich Daemen-SchmidKeyboard input
CH 52,74717-08-191017-08-1910Otto SteigerReversing gear
CH 53,46711-08-191011-08-1910Otto SteigerInput mechanism
DE 271,30823-04-191209-03-1914Erwin JahnzCarry mechanism
DE 277,82920-09-191211-09-1914Erwin JahnzAutomatic carriage shift in division
DE 264,42822-09-191223-09-1913Erwin JahnzSliding carriage without lifting
CH 80,84712-07-191816-08-1919H. W. Egli A.-G.Keyboard testing apparatus
CH 116,61728-08-192501-10-1926Erwin JahnzCarry mechanism
CH 129,92506-07-192702-01-1929H. W. Egli A.-G.Multiplication register
CH 131,51407-12-192701-05-1929H. W. Egli A.-G.Multiplication register
DE 524,93914-12-192723-04-1931H. W. Egli A.-G.; Heinrich SuterCalculator with electric carriage shift
DE 519,66816-04-192912-02-1931Erwin JahnzReversing gear
DE 519,17617-07-192905-02-1931H. W. Egli A.-G.Carry mechanism
DE 587,74101-02-193026-10-1933Erwin JahnzKeyboard
CH 141,36216-09-192931-07-1930H. W. Egli A.-G.Shifting input
DE 536,92323-11-193008-10-1931H. W. Egli A.-G.; Heinrich SuterCarry mechanism
US 2,089,77027-10-193310-08-1937Heinrich Suter; Alfred GrasshofFull carry
DE 624,18123-02-193419-12-1935Erwin JahnzPrinting mechanism
DE 622,32603-08-193407-11-1935Karl Locke; Rudolf BrunhuberClearing mechanism
CH 180,72709-01-193501-02-1936Erwin JahnzStore input for repeat
CH 182,76522-02-193516-05-1936Erwin JahnzKeyboard locking mechanism
DE 673,91928-02-193516-03-1939Erwin JahnzMain shaft
DE 725,47505-05-193606-08-1942Karl Locke; Rudolf BrunhuberCarry mechanism
CH 195,37608-01-193716-06-1938H. W. Egli A.-G.Dividend set-up
DE 745,78322-12-193816-12-1943Karl Locke; Rudolf BrunhuberCarry mechanism
CH 218,92321-02-194116-09-1947H. W. Egli A.-G.Transfer mechanism
CH 217,53913-05-194116-06-1942H. W. Egli A.-G.Carry mechanism
CH 237,65210-07-194216-08-1945H. W. Egli A.-G.Keyboard
CH 232,66107-11-194216-01-1945Erwin JahnzInterlock mechanism
CH 236,04907-05-194316-05-1945Erwin JahnzKeyboard clearing mechanism
CH 256,01216-10-194316-02-1949H. W. Egli A.-G.Calculator
CH 240,25005-06-194401-04-1946H. W. Egli A.-G.Storage register
CH 240,83621-06-194416-05-1946H. W. Egli A.-G.Input display register
CH 243,87512-07-194401-02-1947Erwin JahnzTotal and Subtotal mechanism
CH 245,41817-01-194501-09-1947Heinrich SuterContinuous carry