|
Home |
Soemtron ETR 220 Coming soon to a browser near you - the Soemtron ETR 220. This website is dedicated (in probably a very nerdy way !), to an old piece of calculator history received in 2007 from Prague in the Czech Republic, after a Google search for "core memory" 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 top covers (see the bottom picture). After a few days research and translating some German text off of the baseplate, we worked out what this old dirty corroded hulk was - a Soemtron ETR 220 calculator, which turns out to be a very interesting piece of early electronic calculator history from 1960's and 70's German Democratic Republic.
Over time we repaired and conserved our Soemtron 220 and eventually we hope to get into working order this interesting piece of Eastern Bloc calculator history from the 1960's (see the top picture). Bookmark this page and come back from time to time for a visit and see how we are getting on. We have published and are updating a full circuit diagram of the machine and its inner workings for those of you who are interested - not many probably !, but there again this is the Internet, see you again soon. The third picture (left) is of a very good condition Soemtron ETR 220 owned by calculator collector Serge Devidts, for more information see his website here Time line -
June 2009 - We are looking for a supplier of the keyboard microswitches used in the Sometron 22x series of calculators, said to be V23 microswitch ?. One of our machines, the 222, has several broken keyboard switches, which because of the connection arrangement, renders the machine unuseable. They may be of German origin, they have the triangle 1 quality mark, are rated at "220V~2,5A", and a "C2"mark. The manufacturers logo is an inverted V in a circle. May 2009 - Full time work on the Soemtron 220 has not resumed yet, but we have started on that Russian manual received from Gerhard Just back in July of last year. Some time was spent searching the web for a decent OCR program for Cyrillic characters and eventually we found one that does a very good job, so we have started on this bit of the project. Eighty six pages have been done to date, out of 214. Russian manual - 2.9Mb pdf March 2009 - Due to other pressing matters (we have to work !), work on our Soemtron 220 was suspended in January but is expected to resume in April/May. This is a bit of a shame as we had just got to the interesting bits, examining signals and relating them back to the circuits, never mind, we will be back soon. Meanwhile if you come across any other snippets of information about the Soemtron 220 / 222 /224 machines please let us know. February 2009 - January 2009 - December 2008 - Click here for previous events in the Soemtron website time line. |