The V operating system (sometimes written V-System) is a discontinued

microkernel In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

that was developed by faculty and students in the

Distributed Systems Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different computer network, networked computers. The components of a distribu ...

Group at

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

from 1981 to 1988, led by Professors

David Cheriton David Ross Cheriton (born March 29, 1951) is a Canadian computer scientist, businessman, philanthropist, and venture capitalist. He is a computer science professor at Stanford University, where he founded and leads the Distributed Systems Group. ...

and Keith A. Lantz. V was the successor to the

Thoth Thoth (from , borrowed from , , the reflex of " eis like the ibis") is an ancient Egyptian deity. In art, he was often depicted as a man with the head of an African sacred ibis, ibis or a baboon, animals sacred to him. His feminine count ...

operating system and Verex

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

that Cheriton had developed in the 1970s. Despite similar names and close development dates, it is unrelated to

UNIX System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

Features

The key concepts in V are '' multithreading'' and ''synchronous

message passing In computer science, message passing is a technique for invoking behavior (i.e., running a program) on a computer. The invoking program sends a message to a process (which may be an actor or object) and relies on that process and its supporting ...

''. The original V terminology uses ''process'' for what is now commonly called a ''thread'', and ''team'' for what is now commonly called a ''

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management * Business process, activities that produce a specific s ...

'' consisting of multiple threads sharing an address space. Communication between threads in V uses synchronous message passing, with short, fixed-length messages that can include access rights for the receiver to read or write part of the sender's address space before replying. The same message-passing interface is used both between threads within one process, between threads of different processes within one machine, and between threads on different machines connected by a local

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

. A thread receiving a message is not required to reply to it before receiving other messages; this distinguished the model from

Ada Ada may refer to: Arts and entertainment * '' Ada or Ardor: A Family Chronicle'', a novel by Vladimir Nabokov Film and television * Ada, a character in 1991 movie '' Armour of God II: Operation Condor'' * '' Ada... A Way of Life'', a 2008 Bollywo ...

rendezvous. One common pattern for using the messaging facility is for clients to send messages to a server requesting some form of service. From the client side, this looks much like a

remote procedure call In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in a different address space (commonly on another computer on a shared computer network), which is written as if it were a ...

(RPC). The convenience of an automatic stub generator was lacking, but in contrast, the client can pass one parameter by reference, which is not possible with other RPC implementations. From the server side the model differs more from RPC, since by default all client requests are multiplexed onto one server thread. The server is free to explicitly fork threads to handle client requests in parallel, however; if this is done, the server-side model is much like RPC too. V was never an end in itself for the Stanford group; rather, it was used as a vehicle for many different research projects in distributed operating systems and networking. Much like other operating system efforts of its day (such as Sprite), V was a complete system that was mostly self hosting. Many students ran V as the only operating system on their diskless

SUN workstation The SUN workstation was a modular computer system designed at Stanford University in the early 1980s. It became the seed technology for many commercial products, including the original workstations from Sun Microsystems. History In 1979 Xerox do ...

s or

MicroVAX The MicroVAX is a discontinued family of low-cost minicomputers developed and manufactured by Digital Equipment Corporation (DEC). The first model, the MicroVAX I, shipped in 1984. The series uses processors that implement the VAX instruction se ...

workstations. Compiles could be done either on V, or on

VAX VAX (an acronym for virtual address extension) is a series of computers featuring a 32-bit instruction set architecture (ISA) and virtual memory that was developed and sold by Digital Equipment Corporation (DEC) in the late 20th century. The V ...

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

machines that provided file service in a more stable environment than the ever-changing research system. V did have some notable impacts. After the initial implementation on one computer, the Versatile Message Transaction Protocol (VMTP) was developed to extend the send-receive-reply system call semantics over a

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...

. The protocol included multicast support developed by

Steve Deering Stephen Deering is a former Fellow at Cisco Systems, where he worked on the development and standardization of architectural enhancements to the Internet Protocol. Prior to joining Cisco in 1996, he spent six years at Xerox's Palo Alto Research C ...

as a graduate student in the group. The

Internet Protocol The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP ...

layer to support this evolved into the

IP multicast IP multicast is a method of sending Internet Protocol (IP) datagrams to a group of interested receivers in a single transmission. It is the IP-specific form of multicast and is used for streaming media and other network applications. It uses speci ...

standard. The V-System was used for

graphical user interface A graphical user interface, or GUI, is a form of user interface that allows user (computing), users to human–computer interaction, interact with electronic devices through Graphics, graphical icon (computing), icons and visual indicators such ...

(GUI) research. The Virtual Graphics Terminal Service (VGTS) provided a modular windowing system for both local and remote applications. The little-known

W Window System The W Window System, or simply W, is a discontinued windowing system and precursor, in name and concept, to the modern X Window System. W was originally developed at Stanford University by Paul Asente and Brian Reid for the V operating system. ...

got its name because it was first hosted on the V operating system, and the better-known

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...

in turn got its name because its first version was based partly on W. V also spawned another pure microkernel effort at

Apple Computer Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Co ...

known as

Vanguard The vanguard (sometimes abbreviated to van and also called the advance guard) is the leading part of an advancing military formation. It has a number of functions, including seeking out the enemy and securing ground in advance of the main force. ...

, which added a number of improvements to the basic system. Vanguard later disappeared in a reorganization. The

Tektronix Tektronix, Inc., historically widely known as Tek, is an American company best known for manufacturing test and measurement devices such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. Originally an independent c ...

VM700 television measurement instrument was developed in a networked V environment in the late 1980s and ran a lightly modified version of the V operating system; this device was manufactured and sold for many years.

Ridge Computers Ridge Computers, Inc., was an American computer manufacturer active from 1980 to 1990. The company began as a builder of deskside workstations and workgroup servers and progressed to superminicomputers. They claimed to have produced the first ...

' Ridge Operating System (ROS) was a commercial system based on Stanford's V-System.

Commands

The following is a list of workstation

commands Command may refer to: Computing * Command (computing), a statement in a computer language * command (Unix), a Unix command * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Appl ...

that are supported by the V operating system version 6.0

command-line interface A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

.V-System 6.0 Reference Manual
/ref> * addcorr * amaze * ar * biopsy * bitcompile * bits * boise * build *

cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

* cc68 * cd * checkers * checkexecs * ci * clear * clock * co * cp * cpdir * cx * dale *

date Date or dates may refer to: * Date, the fruit of the date palm (''Phoenix dactylifera'') * Jujube, also known as red date or Chinese date, the fruit of ''Ziziphus jujuba'' Social activity *Dating, a form of courtship involving social activi ...

* debug * debugvgts * define * delcorr * delexec * destroy *

diff In computing, the utility diff is a data comparison tool that computes and displays the differences between the contents of files. Unlike edit distance notions used for other purposes, diff is line-oriented rather than character-oriented, but i ...

* do * domake * dopar * doseq * draw *

echo In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...

* fexecute * freemem * gftodvi * gftyoe *

grep grep is a command-line utility for searching plaintext datasets for lines that match a regular expression. Its name comes from the ed command g/re/p (global regular expression search and print), which has the same effect. grep was originally de ...

* hack * ident * instances * internetserver * iphost * killprog * listdir * listdesc *

login In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system or program by identifying and authenticating themselves. Typically, user credential ...

logout In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system or program by identifying and authenticating themselves. Typically, user credentials c ...

mail The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...

* memserver * mf * migrateprog * mon * name * newterm * pagemode *

password A password, sometimes called a passcode, is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of password-protected services t ...

* pc68 *

pwd pwd (print working directory) is a shell command that reports the working directory path to standard output. Although often associated with Unix, its predecessor Multics had a pwd command (which was a short name of the print_wdir command) from ...

* pwx * Q * query * queryexec * ranlib68 *

rcs RCS may refer to: Organizations Arts and entertainment * Radio Corporation of Singapore * Radcliffe Choral Society, a choral ensemble at Harvard University *RCS MediaGroup (Rizzoli-Corriere della Sera), an Italian publishing group *Royal Conserva ...

rcsdiff Version control (also known as revision control, source control, and source code management) is the software engineering practice of controlling, organizing, and tracking different versions in history of computer files; primarily source code t ...

* rcsmerge * rename * rlog * rm * sed * serial * show *

sleep Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain Sensory nervous system, sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with th ...

sort Sort may refer to: * Sorting, any process of arranging items in sequence or in sets ** Sorting algorithm, any algorithm for ordering a list of elements ** Mainframe sort merge, sort utility for IBM mainframe systems ** Sort (Unix), which sorts the ...

* startexec * storagestats * stuffboot *

tail The tail is the elongated section at the rear end of a bilaterian animal's body; in general, the term refers to a distinct, flexible appendage extending backwards from the midline of the torso. In vertebrate animals that evolution, evolved to los ...

talk Talk may refer to: Communication * Communication, the encoding and decoding of exchanged messages between people * Conversation, interactive communication between two or more people * Lecture, an oral presentation intended to inform or instruct ...

telnet Telnet (sometimes stylized TELNET) is a client-server application protocol that provides access to virtual terminals of remote systems on local area networks or the Internet. It is a protocol for bidirectional 8-bit communications. Its main ...

* telnetserver * testexcept * timeipc * timekernel *

tsort The tsort program is a command line utility on Unix and Unix-like platforms, that performs a topological sort on its input. It is part of the POSIX.1 standard. and has been since The Single UNIX Specification, Version 2. History According to i ...

* type * undefine * ved * vemacs * w * wc * wh * whi

References

External links

V-System documentation
at Bitsavers.org {{Distributed operating systems Microkernels Stanford University Discontinued operating systems Distributed operating systems Microkernel-based operating systems