Editing RSX-11 (section)

===Clones in the USSR and other Eastern Bloc countries===
In 1968,<ref name="Kepes">{{cite web
| url=http://web.itf.njszt.hu/23r4r23r/uploads/2012/09/Computers-behind-the-Iron-Curtain.pdf
| author= Gábor Képes
| title = Hungary: Computers behind the Iron Curtain
| page = 8
| access-date=12 December 2017}}</ref> the Soviet Government decided that manufacturing copies of [[IBM mainframes]]<ref>{{cite book
| url=http://www.sigcis.org/files/SIGCISMC2010_001.pdf
| author= Boris Nikolaevich Malinovsky
| title = Pioneers of Soviet Computing
| page = 25
| date=2010
| access-date=12 December 2017}}</ref>
and DEC minicomputers,<ref>{{cite book
| chapter-url=https://link.springer.com/content/pdf/bfm%3A978-3-642-22816-2%2F1.pdf
| author= John Impagliazzo
| author2= Eduard Proydakov
| editor= John Impagliazzo
| editor2= Eduard Proydakov
| title = Perspectives on Soviet and Russian Computing
| chapter= Preface
| publisher=Springer
| page = XIV
| date=2011
}}</ref><ref>
{{cite book|chapter-url=https://link.springer.com/content/pdf/10.1007%2F978-0-387-34741-7_11.pdf |last=Raffai |first=Maria |editor-last=Impagliazzo |editor-first=John |title=History of Computing and Education 2 |volume=215 |publisher=Springer |date=2006 |page=157 |chapter= Computing Behind the Iron Curtain and Beyond Hungarian National Perspective|isbn=9780-387-34637-3|doi=10.1007/978-0-387-34741-7_11 |series=IFIP International Federation for Information Processing }}</ref> in cooperation with other [[COMECON]] countries,<ref name="Kepes" /><ref name="SM-EVM_devel">{{cite book
| chapter-url=https://link.springer.com/content/pdf/10.1007%2F978-3-642-22816-2_9.pdf
| author1= N. L. Prokhorov
| author2= G. A. Egorov
| editor= John Impagliazzo
| editor2= Eduard Proydakov
| title = Perspectives on Soviet and Russian Computing
| volume= 357
| chapter = SM EVM Control Computer Development
| publisher=Springer
| pages = 69–73
| date=2011
| doi= 10.1007/978-3-642-22816-2_9
| series= IFIP Advances in Information and Communication Technology
| isbn= 978-3-642-22815-5
}}</ref> was more practical than pursuing original designs. Cloning of DEC designs began in 1974,<ref name="SM-EVM_devel" /> under the name of [[SM EVM]] ({{Langx|ru|СМ ЭВМ}} or {{Langx|ru|Система Малых Электронно-Вычислительных Машин|lit=System of Small electronic computing machines}}). As happened with [[ES EVM]] mainframes based on the [[System/360]] architecture, the Russians and their allies sometimes significantly modified Western designs, and therefore many SM EVM machines were [[Binary-code compatibility|binary-incompatible]] with DEC offerings at the time.

*'''DOS/RV''', '''{{langx|ru|ОСРВ-СМ}}''', '''ОСРВM'''<ref>ОСРВМ is the  model of ОСРВ-СМ for the SM-1425. See:{{cite web
| url=http://www.computer-museum.ru/histussr/sm1425.htm
| script-title=ru:СМ 1425
| date=2002-07-19
| archive-url = https://web.archive.org/web/20150502175304/http://www.computer-museum.ru/histussr/sm1425.htm
| archive-date = 2015-05-02
| language=ru
| access-date=2015-08-25}}</ref> – Three names for an unauthorised clone of RSX-11M  produced in the [[Eastern bloc]]. The name ОСРВ is an acronym for {{Langx|ru|Операционная Система Реального Времени|lit=Real-time Operating System}}.<ref>Not surprisingly, the six-character string 'OCPBCM' fits nicely in the same 16-bit [[RADIX-50]] word as 'RSX11M'</ref> This system appears to be an exact duplicate of RSX-11M except a different header in binary files. Differences between RSX and ОСРВ are due to hardware differences between SM and PDP computers and to [[Software bug|bug]]-fixing done by Soviet engineers.  However, the original RSX-11M was more used than its Russian clone ОСРВ,{{Citation needed|date=October 2009}} because the programmers modifying the original RSX-11M code were doing a better job, and patched RSX was more stable than ОСРВ. Other benefits included a faster update cycle for drivers and a larger choice of patches, made possible by a wider user community.{{Citation needed|date=December 2022}}

A clone of the RSX-11M [[operating system]] ran on the [[Romania]]n-made CORAL series family of computers (such as CORAL 2030, a clone of PDP-11).