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

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 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 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 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 workstations 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

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

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 * pwx * Q * query * queryexec * ranlib68 * rcs * rcsdiff * 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 * 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 *

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 * 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