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NOS/VE (Network Operating System / Virtual Environment) is a discontinued operating system with time-sharing capabilities, written by Control Data Corporation in the 1980s. It is a virtual memory operating system, employing the 64-bit virtual mode of the CDC Cyber 180 series computers. NOS/VE replaced the earlier NOS and NOS/BE operating systems of the 1970s.

DeveloperControl Data Corporation
Working stateHistoric
Initial release1980s
Marketing targetMainframe computers
PlatformsCDC Cyber 180 series and successors


The command shell interface for NOS/VE is called the System Command Language, or SCL for short. In order to be callable from SCL, command programs must declare their parameters; this permits automatic usage summaries, passing of parameters by name or by position, and type checking on the parameter values. All standard NOS/VE commands further follow a particular naming convention, where the form of the command is verb{_adjective}_noun; these commands could be abbreviated with the first three characters of the verb followed by the first character(s) of all further words. Examples:

Full command Abbreviation UNIX command
display_catalog disc ls
display_working_catalog diswc pwd
change_working_catalog chawc cd
delete_catalog delc rmdir
copy_file copf cp
delete_file delf rm
create_connection crec telnet

Inspired by addressing structure-members in various programming languages, the catalog separator is the dot.

Subsystems like FTP integrate into the command shell. They change the prompt and add commands like get_file. Thereby statements like flow-control stay the same and subsystems can be mixed in procedures (scripts).


Commands could take parameters such as the create_connection command:

crec telnet sd=''

would connect you to IP address with telnet service.

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