Manufactured by V.E.B. Büromaschinenwerk Sömmerda, the Soemtron branded range of ETR22x calculators encompassed three variants, the ETR220, ETR222 and ETR224 (a model with printout capabilities). A possible fourth calculator, the 221, was seen in various sales literature of the period and does show and describe the type 221 printing calculator, but it is believed now to have only existed as a single machine for a publicity release (December 2009) in the Büromaschinen Lexikon, a German publication of the 1960s. That one machine was possibly the one delivered to Office and Electronic Machines (OEM) in London, the UK importers.
Welcome to the only complete collection of Soemtron model ETR22x calculators, a collection which came into being after an old piece of equipment was received from Prague in the Czech Republic, following a Google search for “core memory” one day during some research into the PDP-7 range of computers manufactured by the now defunct Digital Equipment Corporation. The unit duly arrived, but it was found to be in a very poor state, dirty, rusty and missing its power supply and covers (photos). After a few days more research and translating some German text off of the baseplate, we worked out what this old dirty corroded hulk was – a Soemtron ETR220 calculator, which turns out to be a very interesting piece of early electronic calculator history from 1960’s and 70’s German Democratic Republic.