Soemtron History

Sömmerda coat of arms

The German "Rheinmetall" heavy engineering works was established the engineer Heinrich Ehrhardt in Düsseldorf in 1889 as the "Rheinische Metallwaren und Maschinenfabrik Aktiengesellschaft" (Rhein Metalwares and Engine Works Corporation) and registered on May 7th 1889. In the same year production starts in rented accommodation in Dusseldorf's Talstrasse and almost within a year they are employing 1,400 people producing 800,000 bullets a day. Then in 1901 a munitions factory was acquired in Sömmerda, a small town near Erfurt in Thuringia, Germany, on the Unstrut river. Following the first world war the Sömmerda factory started producing office machines, making typewriters, mechanical calculators, adding and listing machines and continued to further develop their machines upto the second world war in 1939-45.

Following the second world war, the Sömmerda factory then found itself in the newly formed East Germany, with development and production now continuing as a state-run enterprise, but using the pre-war Rheinmetall name and logo. In 1957, a group of young electronics engineers under the collective direction of Heinz Skolaude brought V.E.B. Büromaschinenwerk Sömmerda into the age of electronics. In 1960 the name was changed to "Supermetall" and then later to the "Soemtron" name in 1962, when they exhibited at the Leipzig Fair of that year an electronic Fakturierautomaten - the model EFA 380. 1963 saw the next model the EFA 381 with magnetic core memory.

The new brand name "Soemtron" appeared, composed from "SOEM"merda and Elek"TRON"ik, the long running legal dispute with the Düsseldorf Rheinmetall Group to the trademark "Rheinmetall" was resolved, along with use of the company logo and patent rights. Previously to this, machines were sold under the trade name "Supermetal". In 1966 V.E.B. Büromaschinenwerk Sömmerda then released the first of three electronic calculators. These models, with germanium transistors and Ferritkernspeichern, were produced in several versions. Production of mechanical calculators ceased at the factory in 1967 with the firm moving over to full production of electronic calculators and computers right up until they finally ceased all production in 1991.

Manufactured from 1966 to 1977 by V.E.B. Büromaschinenwerk Sömmerda, the Soemtron ETR series of calculators are by modern standards very basic six and seven function calculators with a 15 digit Nixie tube display or mechanical print mechanism. Three different units (and possibly four) were produced in the eleven year production run of these increasingly rare early electronic calculators from the Eastern Bloc.

• The ETR 220 - with six functions and three temporary registers, it is the most common machine in the range even today, with over 155,000 produced by V.E.B. Büromaschinenwerk Sömmerda in the 11 years between 1966 to 1977. Technical information for the 220 is rare but manuals, circuits and information in several languages do turn up from time to time.
• The ETR 222 - with seven functions and again three temporary registers, just over 3,000 type 222 calculators were manufactured between 1970 and 1972, this machine is rarely seen on the open market, and to date no documentation for the 222 has been found.
• The ETR 224 - a very, very rare machine with just over 500 units being produced in the six years during 1968-1974. The 15 digit nixie display is replaced with a 16 digit mechanical printer mechanism (15 + decimal point). The Soemtron 224 electronics appears to be based on a heavily modified version of the 222 calculator, with additional control electronics for the printer. It appears that no technical information now exists for the 224, and no machines are known to exist in the wild, other than the only known example in the Sömmerda Historisch-technisches Museum im Dreyse-Haus Weißenseer, Sömmerda.

Rumors continue to surface about the existence of a fourth ETR type, the ETR 221, another printing variant like the 224 but split into two housings with a long umbilical cable. One machine apparently existed in London at the offices of the UK importers "Office and Electronic Machines". Further information about the 221 can be found on the 221 page.

Update Feb 2009 - two more rare Soemtron 224's found !

The Soemtron series of calculators were imported into the UK from the D.D.R. by a company called "Office and Electronic Machines", based in London, but with the advent of small calculators using logic chips or basic processors during the eleven year production run of the Soemtrons, their sales market and use was mainly restricted to Eastern Bloc countries.

Film -
A Soemtron 220 calculator appeared in a 1977 Russian film - "Office Romance" directed by Eldar Ryazanov. A Wikipedia entry for the film is here, and stills from the film showing the Soemtron 220 here.

Legal -
We have a copy here of an export permit that Bernard Green of Office and Electronic Machines used in 1967 to export various manuals and documentation from East Germany.

Advertising -
Bernard Green has sent in an advert that appeared in "Office Methods and Machines" July 1967, as a "New desk calculator with 15 digit capacity and three independent accumulators". A copy of the advert is here

The Soemtron 220 range also appeared in the "Büromaschinen Lexikon", a German publication covering office machinery and products. Soemtron branded products appeared in the 1962/63 to 1968/69 issues, but only three are available online below -

Personal -
We have started a small section here for personal thoughts and recollections of Sömmerda, the Soemtron brand and it's people. To kick this section off the first is from Bernard Green who was Senior Engineer at Office and Electronic Machines in London UK, importers / exporters of the Soemtron series calculators. Has sent us his recollections of his time at the factory and it's influence. here

If you know of or have any more history or information about the Soemtron 220, 222, rare 224, or the very rare 221, or you just know more about the Soemtron companies in general then please let us know, contact us here

Some of the information on this page has been derived from www.robotrontechnik.de with grateful thanks.

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