Jaap's Mechanical Calculators Page


Diehl EVM

My Diehl EVM 18
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Diehl EVM 18

The Diehl EVM is an electrically driven mechanical calculator with a stepped drum mechanism, a full keyboard, and which features fully automatic division and semi-automatic multiplication. It was made from 1954 until 1962. It has 18 digits in the register, and 9 digits in the counter and on the keyboard.

Most of the controls are obvious, except for the division buttons.

← →Move carriage left or right.
- +Subtract or add the input to the register
. : ⋮Clear register, counter, or input.
× +Select whether to automatically clear input from keyboard. Also pauses automatic division.
.Start automatic division
≠ .Reverse direction of counter. Usually pressed simultaneously with division button
Left columnMultiply by chosen digit and shift carriage right
Unmarked leverAbort automatic division

On this version the register's carry mechanism is in the body of the machine so does not extend to any part of the carriage that sticks out to the left. In about 1956 the carry mechanism was redesigned and put in the carriage itself. Also, the division abort lever was moved next to the division buttons. My machine is therefore a relatively early one.

Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM

On the bottom is a plate showing the model and serial number. Its serial number is 26,373. In the hole near the side is a slider that releases any buttons that may have been pressed accidentally when moving the machine about.

Diehl EVM
Diehl EVM
Diehl EVM

The carriage is very easily removed. Pushing the little metal tab on top of the carriage releases a catch which allows you to pull out the rod that the carriage is attached with. When the carriage is removed, you have access to a voltage selection switch, 110 or 220 volts. It has a universal electric motor.

In a normal stepped drum mechanism there is a single sliding gear that engages with each stepped drum. The problem with that is that to select a 9 the gear has to move much further than when selecting a 1. In the Diehl the single sliding gear is replaced by two sliding gears, halving the amount of travel needed. In this way the all the number keys in a column need approximately the same small amount of force to be pressed.

Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM
Diehl EVM


Here is a video where I demonstrate the Diehl EVM.


Archimedes calculators had been produced since 1906 in Glashütte, a town in Germany, South of Dresden and close to the border with Czechia. It was a centre for the manufacturing of precision mechanics with many watch and clock manufacturers based there. Near the end of the second world war, the Archimedes factory was completely destroyed. When the war ended it was soon rebuilt, but it was located in the Russian zone. Ulrich Eichner, the son-in-law of the Archimedes founder Reinhold Pöthig, together with Wilhelm Kiel and a few other Archimedes engineers moved to West Germany, taking with them many patents and pending patents. There they developed a new machine, and negotiated with Diehl to put it into production.

Diehl was a metalworks company founded in 1902 by Heinrich Diehl and his wife Margarete in Nuremberg. It started as a small foundry and craft workshop, casting art pieces and other bespoke items, and as it grew they shifted to mass production of door knobs and fittings. In the first world war they made copper parts that other manufacturers would use to make bullet casings. Diehl would then continue to cast and press semi-finished products for other industries, for example supplying parts for the rail industry, and making pipes. In the second world war they again made ammunition, so much of their production line was destroyed, or dismantled immediately after the war.

Diehl had to rebuild its production, and not only went back to making many semi-finished products and precision parts, but also started producing clocks. When Eichler and the other Archimedes engineers came to Diehl with a calculator design it was a large and ambitious project to take on, as the proposed calculator had about 2600 precision parts. However, the Archimedes brand name was valuable and Eichner still had contacts with former Archimedes distributors who would be able to sell such a machine immediately, so this was a reasonable step for Diehl to take. After two years of development, the Diehl model A began production in 1952. By the end of the year the model B appeared, which was a more expensive model that included multiplier keys. Further similar models were developed and sold until about 1965. A 10-key listing calculator called the Diehl Transmatic, first released in 1963, soon became the more popular calculator, and variations of this were developed and sold until 1972.

Diehl tried to switch calculator production towards electronic desk calculators, but this was not so successful. The company was easily able to withstand such a setback because it was large and diverse, still making many semi-finished products, ranging from pipes and alloys to parts for white goods. The company still exists today.


Diehl made several series of stepped drum, full keyboard calculators. The series varied in the amount of extra functionality, and hence in price. Below is a table listing the various models and the functionality that they have. All models were sold in two register sizes, 8×7×15 and 9×9×18.

ModelYears Input
A 15/18 1952-1953×- - ----
B 15/18 1952-1954×- K ----
BN 15/18 1954-1957×-/×K ×---
D 15/18 1954-1958×-/×K ××--
DS 15/18 1956-1957×× K ×××-
DR 15/18 1957-1959×× K ××-×
DSR 15/18 1957-1961×× K ××××
E 15/18 1954-1962--/×- ----
EVM 15/18 1954-1962--/×K ----
EVMS 15/18 1957-1962-× K --×-
EVM 15s/18s1960-1962-× Kr-×--
FR 15/18 1958-1960×× K -×-×
FR 15s/18s 1960-1962×× Kr-×-×
KR 15/18 1960-1964×× K ××-×
V 15/18 1959-1964×× A ××--
VR 15/18 1960-1963×× A ××-×
VSR 15/18 1961-1965×× A ××××

The functions listed in the table are:

Input DisplayAn extra display register showing the keyboard input
Full Carry A carry mechanism over the full length of the main register. This was introduced in 1956, and added to existing models as well.
Multiply (K) Multiplier keys, (Kr) Multiplier keys with left to right entry, (A) Automatic multiplication
Negat Mult Negative multiplication, i.e. the multiplier keys can subtract instead of add
Div Tab Division setup and tabulation, i.e. place dividend in register with one button press, and set number of digits to calculate
Extra Reg Extra storage register. Denoted by S in the model name
Back Trans Back transfer from register to keyboard. Denoted by R in the model name

Not listed in the table is automatic rounding functionality, and machines that could do this had A/A appended to their model designation. Also not listed is the EVMH, a special version of the EVM which had a detachable hand crank for use when a blackout occurs. These were especially made for the German armed forces.

In 1963 Diehl began to make a 10-key listing calculator. It was so capable that soon their other calculators were discontinued. In the US these machines were rebranded and sold by SCM (Smith Corona Marchant).

Transmatic 1963-1966
Transmatic S 1965-1967
Transmatic DM1965-1969
Decima 1967-1970
Decima S 1967-1970
Producta 1971-1972

Diehl then began making electronic desk calculators, called the Combitronic and Algotronic. They used a narrow strip of punched paper tape for its internal programming, but they were not so successful as they were already outdated when they were released.


Archimedes Diehl Vom Arithmometer zum druckenden Rechensystem
Harald Schmid
Copyright 2014
Verlag W. Sünkel
208 page softcover book
210mm × 297mm × 9mm

This book details the history and mechanisms of Archimedes and Diehl calculators, with many photographs. Available from the Wehrtechnik Museum.

Archimedes-Diehl book
Archimedes-Diehl book
Archimedes-Diehl book
Archimedes-Diehl book
Archimedes-Diehl book
Archimedes-Diehl book

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Here are some advertisements and articles that I found in online archives of newspapers and magazines.

1957-11-18 Birmingham Daily Post (UK)
1958-09-11 New Scientist
1959-01-30 The Guardian (London UK)
1959-02 Banking
1959-06-02 Daily Herald (UK)
1959-08-19 The Sydney Morning Herald (Australia)
1959-12 Varsity Graduate
1960-05-12 New Scientist
1960-05-28 National Post (Toronto Canada)
1960-12-07 The Tennessean (Nashville Tennesee)
1961-03 Business Education World
1961-05-20 National Post (Toronto Canada)
1961-06-16 UCLA Daily Bruin
1961-11-28 De Telegraaf (Netherlands)
1961-12-06 Fort Worth Star Telegram (Texas)
1961-12-10 Pensacola News Journal (Florida)
1961-12-12 Het vrije volk (Netherlands)
1961-12-15 Het vrije volk (Netherlands)
1967-03 Business Education World
1968-03 Business Education World


Here is the list of later patents from Archimedes, which were probably licensed to Diehl and may have partly contributed to the Diehl machines.

PatentFiling datePublish dateNameDescription
DE 651,56710-02-193530-09-1937Reinhold PöthigShortcut multiplication (Model KT)
See also: CH 189,683
DE 671,52306-04-193526-01-1939Ulrich Eichler; Reinhold PöthigShortcut multiplication on electric calculation with multiplier keys (Model vM)
See also: CH 189,907 US 2,215,263
CH 185,71302-09-193515-08-1936Reinhold PöthigClear keyboard after multiplication/division (Model GEMRZ)
DE 691,44522-09-193530-04-1940Reinhold PöthigBack transfer
See also: CH 203,473
DE 681,95404-08-193614-09-1939Reinhold PöthigCarriage shift buttons (Model KT)
DE 895,54120-02-193715-06-1939Wilhelm Kiel; Reinhold PöthigSimplified input for divisions (Model L)
DE 697,82324-04-193726-09-1940Karl Berthold Wilhelm Kiel; Reinhold PöthigShortcut multiplication (Model vM)
DE 702,30124-04-193709-01-1941Reinhold PöthigElectric shortcut multiplication (Model vM)
DE 696,70231-10-193729-08-1940Reinhold Pöthig; Karl Otto Reinhold HenzelmannBack transfer
See also: CH 206,225, US 2,305,780
CH 201,32902-02-193830-11-1938Reinhold PöthigMotorised carriage
DE 696,70323-01-193829-08-1940Reinhold PöthigBack transfer (Model LR)
See also: CH 208,576
DEA 86,189 AZ18-03-193827-11-1941Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigShortcut multiplication (Model vM)
See also: CH 209,385
DE 693,89015-04-193820-06-1940Reinhold PöthigBack transfer
CH 206,22425-04-193831-07-1939Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigBack transfer
DE 731,15429-05-193831-12-1942Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigMultiplier input
See also: CH 209,676
DE 894,46728-06-193811-02-1943Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMultiplier display (Model vM)
See also: CH 211,691
DE 745,61418-09-193816-12-1943"Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigBack transfer
DE 882,31925-10-193823-10-1941Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigClearing mechanism (Model L)
See also: CH 213,080
DEA 88,766 AZ12-01-193911-03-1943Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigBack transfer
See also: CH 214,217
DE 919,78421-02-193914-05-1942Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMotorised carriage
See also: CH 214,650
DE 698,75609-07-193917-10-1940Karl Berthold Wilhelm Kiel; Reinhold PöthigElectric machine with shortcut multiplication (Model vM)
See also: CH 209,192
CH 211,51727-07-193930-09-1940Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMotorised carriage
DE 749,09613-08-193927-04-1944Karl Berthold Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigProportional drive
See also: CH 214,941, US 2,378,560
CH 213,46412-02-194015-02-1941Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigBack transfer
DE 760,10216-07-194023-11-1944Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigDisconnect during carry operation
See also: CH 222,290
DE 746,16602-10-194023-12-1943Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigPrinting calculator with motorised carriage movement
See also: CH 224,683
DE 746,50631-10-194006-01-1944Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigPrinting calculator with back transfer
DE 746,50827-06-194106-01-1944Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigExtended carry mechanism
See also: CH 225,815
DE 894,46728-06-193826-10-1953Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMultiplier keys with display
DE 895,54120-02-193705-11-1953Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMotorized carriage shift
DE 916,47502-02-194131-12-1952Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigShortcut multiplication
See also: CH 224,684
DEA 93,422 AZ12-05-194101-11-1948Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigUse of multiplier register as memory
DE 745,99219-07-193923-12-1943"Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigAutomatic clearing (Model L)
See also: CH 224,997
DE 918,78327-08-194210-07-1952Karl Berthold Wilhelm Kiel; "Archimedes" Glashütter Rechenmaschinenfabrik Reinhold PöthigClearing mechanism
DE 919,78421-02-193904-11-1954Wilhelm Kiel; Archimedes Glashütter Rechenmaschinenfabrik Reinhold PöthigMotorised carriage shift

Here are patents specifically for the Diehl calculators.

PatentFiling datePublish dateNameDescription
DE 913,47917-06-195114-06-1954Wilhelm Kiel; Ulrich Eichler; Metall-Guß- und Preßwerk Heinrich DiehlCarry correction
See also: CH 304,773
DE 915,15817-06-195115-06-1954Wilhelm Kiel; Ulrich Eichler; Metall-Guß- und Preßwerk Heinrich DiehlCarry correction
See also: CH 311,074
DE 933,66517-06-195129-09-1955Wilhelm Kiel; Ulrich Eichler; Metall-Guß- und Preßwerk Heinrich DiehlKey column module with display
See also: CH 305,459
DE 973,16321-07-195117-12-1959Wilhelm Kiel; Ulrich Eichler; Fa. DiehlControl mechanism
See also: CH 307,673, US 2,936,952
DE 975,66116-11-195112-04-1962Wilhelm Kiel; Ulrich Eichler; Fa. DiehlControl mechanism
See also: US 2,780,411
US 2,969,91108-08-195231-01-1961Wilhelm K.B. Kiel; Ulrich T.R. Eichler; Metall-Guß- und Preßwerk Heinrich DiehlActuator and carriage control
DE 1,001,02606-11-195217-01-1957Wilhelm Kiel; Ulrich Eichler; Diehl GmbHAdd/subtract switching
DE 973,55607-11-195231-03-1960Wilhelm Kiel; Ulrich Eichler; Fa. DiehlPlus/Mult switch
DE 1,094,49904-04-195308-12-1960Wilhelm Kiel; Ulrich Eichler; Diehl GmbHMultiplier keys with shortcut multiplication
DE 973,88219-04-195307-07-1960Wilhelm Kiel; Ulrich Eichler; Fa. DiehlPlus/Mult switch to interrupt division
DE 1,144,51221-04-195328-02-1963Wilhelm Kiel; Ulrich Eichler; Fa. DiehlBack transfer
DE 1,086,46515-05-195304-08-1960Wilhelm Kiel; Ulrich Eichler; Diehl GmbHDividend entry and tab
DE 934,20420-08-195313-10-1955Wilhelm Kiel; Ulrich Eichler; Metall-Guß- und Preßwerk Heinrich DiehlDividend entry
DE 1,020,47012-01-195405-12-1957Wilhelm Kiel; Ulrich Eichler; Diehl GmbHExtended carry mechanism
DE 1,027,43409-04-195403-04-1958Wilhelm Kiel; Ulrich Eichler; Diehl GmbH-
DE 958,88019-06-195428-02-1957Wilhelm Kiel; Ulrich Eichler; Diehl GmbHDrive train
DE 1,134,22721-06-195402-08-1962Wilhelm Kiel; Ulrich Eichler; Diehl GmbHAutomatic division
DE 1,157,01126-06-195407-11-1963Wilhelm Kiel; Ulrich Eichler; Fa. DiehlAuto-aligning divisor
See also: CH 336,625, US 2,937,809.
DE 1,023,25610-07-195423-01-1958Wilhelm Kiel; Ulrich Eichler; Diehl GmbHCarry mechanism in register
DE 1,087,38214-10-195418-08-1960Wilhelm Kiel; Diehl GmbHMultiplier keys shift lever to multiply mode
DE 1,695,789 U15-01-195531-03-1955Ulrich Eichler; Fa. DiehlKey column module
DE 1,037,73222-07-195528-08-1958Wilhelm Kiel; Diehl GmbHCarry mechanism
DE 1,108,95726-01-195715-06-1961Wilhelm Kiel; Diehl GmbHFully automatic multiplication
DE 1,135,21826-04-195823-08-1962Kurt Kollman; Fa. DiehlTransmatic
DE 1,149,92803-11-195806-06-1963Gottfried Burkhardt; Fa. DiehlFully automatic multiplication with display
DE 1,667,645 U31-07-195926-11-1963Ulrich Eichler; Fa. DiehlMultiplier keys


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