Soemtron History

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 (1) 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" (3) - 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 and 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" (4), were produced in several versions, mechanical calculators ceased production in 1967 with the firm moving over to full production of electronic calculators and computers up until they ceased production in 1991.

The Soemtron ETR series of calculators are by modern standards very basic five and six function calculators with a 15 digit Nixie tube display. Three different units were produced in the eleven year production run of these increasingly rare early electronic calculators from the Eastern Bloc.

• ETR 220 - with six functions and three temporary registers. The most common machine in the range even today, with over 155,000 produced.
• ETR 222 - five functions and again three temporary registers. With just over 3000 222's manufactured, this machine is rarely seen on the open market.
• ETR 224 - a very very rare machine, all that is known about the 224 is that it had some form of printer mechanism. We presume the Soemtron 224 was based on the 220 calculator.

Manufactured from 1966 to 1977 by V.E.B. Büromaschinenwerk Sömmerda, the Soemtron ETR 220 (and latterly the ETR 222) are by modern standards very basic five and six function calculators but with a quite high digit count of 15. There were, apparently, over 155,000 Soemtron ETR 220's manufactured during the production run up until it ended in 1977, and just over 3000 of the Soemtron ETR 222's between 1970 and 1972. Apparently there was another machine in the Soemtron ETR series, the Soemtron ETR 224, produced during 1968-1974, but with just over 500 units being produced it appears that no technical information exists for the 224, and no machines are known to exist in the wild. Other odd snippets of information from around the web would seem to imply that the Soemtron ETR 224 used some form of printer for calculation results, rather than the 15 digit display. Some of the information here is derived from www.robotrontechnik.de with grateful thanks. 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.

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

1. V.E.B. = Volks Eigener Betrieb, or Peoples Owned Company.      back
2. Büromaschinenwerk = Office Machine Works.      back
3. Fakturierautomaten = Automatic Invoicing.      back
4. Ferritkernspeichern = Ferrite Core Memory.      back