PDP-11s behind the Iron Curtain

The PDP-11, as the PDP-8 before it, was cloned and copied extensively behind the so-called Iron Curtain. A number of plants produced PDP-11 compatible systems in the Soviet Union, including Elektronika-79 (11/70) and several machines without direct DEC analogues (DWK-4 with proprietary video controller).

Nobody knows how much of these clones were issued by many of the plants in the countries of the Warsaw Pact, but I believe that the total amounts of units should counted by hundreds of thousands. AFAIK the following countries issued a DEC clones of computers and peripherals:

Not all clones had analogues at DEC product line, but most of them were very close to some model (not in quality though). All DEC software and Unixes runs on these computers without problems (in fact, Soviet users used adopted versions of software because the KGB stole ALL source codes for RT11 and RSX11 and made it freely distributed; after a while it was modified to have support for Russian language and some nonstandard devices/architectures, RT11 became RAFOS, FOBOS, and FODOS, and RSX11 became OSRV).


We can divide the clones into four categories:

Below is the list of clones we know of so far:


There were several chip-sets made, corresponding (usually) to what DEC produced.

More Information

More TPA-specific information may be found at http://www.telnet.hu/hamster/tpa/e_index.html.

More general Warsaw Pact PDP-11 information is available at http://www.telnet.hu/hamster/pdp-11/index.html.

Cyrillic and General Nomenclature

Information provided by Alexey Chupahin:

I've been told that the Cyrillic V is best represented as W in the Roman alphabet. Thus, you're referring to the DWK-*, right?

Yes, DWK and DVK is the same name.

I've gotten information on 1801BM*, 1801VM*, and 1801WM*. Are these all the same thing, or are the letters really different? I believe the WM and VM to be the same. What is BM?

Yes, VM (WM) is BM in Cyrillic. Chips, exported to German or other countrieswas marked as 'BM', if I remember, so I write 'BM' instead 'VM' or 'WM'. Unfortunately, I don't know (and my friends) what is 'BM' meaning. All russian processors (DEC or Intel compatible) are marked as 'BM'. The letter 'K' before processor model(number) means 'ceramic box'. K1811BM1 for example.

Can "MC" be interpreted as "machine"? As in, an MC prefix means this is a model/system designator, as opposed to being a chip designator?

Hmm this is very interesting question.The first line of computers ( IBM/360 compatible ) and peripheral devices designed for it was named EC in cyrillic.(ES in English). EC means 'United Series' in Russian. DEC minicomputers PDP-11 series and peripheral devices was named 'CM'.(SM) 'CM' - 'Small Series'. CM-3, CM-4 are first models., CM1425 - one of the latest, with 2MB-4MB of memory, processor 1831BM1 (J-11 analogue). CM5508 - is 10MB hard disk, CM5509 - 30MB hard disk, CM6329 - Epson compatible matrix printer.

Series 'MC' is another. Usually MC is "smaller" than 'CM'. 'MC' means personal computer equipment. MC0585 - Elektronika-85, MC0502 - DWK's.

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