UNIX System V
Encyclopedia
Unix System V, commonly abbreviated SysV (and usually pronounced—though rarely written—as "System Five"), is one of the first commercial versions of the Unix
operating system
. It was originally developed by American Telephone & Telegraph
(AT&T) and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4. System V Release 4, or SVR4, was commercially the most successful version, being the result of an effort, marketed as Unix System Unification, which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features.
While AT&T sold their own hardware that ran System V (see AT&T Computer Systems
), most customers ran a version from a reseller, based on AT&T's reference implementation
. A standards document called the System V Interface Definition
outlined the default features and behavior of implementations. The most widely used versions of System V today are IBM
's AIX
, based on System V Release 3, and Sun
's Solaris
and Hewlett-Packard
's HP-UX
, both based on System V Release 4.
In the 1980s and early-1990s, System V was considered one of the two major "flavors" of UNIX, the other being Berkeley Unix
(BSD). During the period of the Unix wars
System V was known for being the primary choice of manufacturers of large multiuser systems, in opposition to BSD's dominance of desktop workstations. However, with standardization efforts such as POSIX
and the commercial success of Linux
, this generalization is not as accurate as it once was.
in January, 1983
(there was never an external release of System IV).
This first release of System V (called System V.0, System V Release 1, or SVR1) was developed by AT&T's UNIX Support Group (USG) and based on the Bell Labs internal USG UNIX 5.0. System V also included features such as the vi
editor and curses
from release 4.1 of the Berkeley Software Distribution
of UNIX developed at the University of California, Berkeley
(UCB); it also improved performance by adding buffer and inode
caches. System V ran on the DEC VAX
and PDP-11
machines. It also added support for inter-process communication
using messages, semaphore
s, and shared memory
.
functions and the SVID. New kernel features included record and file locking
, demand paging
, and copy on write.
The concept of the "porting base" was formalized, and the DEC VAX 11/780 was named for this Release. The "porting base" is the so-called original version of a Release, from which all porting efforts for other machines emanate. Maurice J. Bach's The Design of the UNIX Operating System is the definitive description of the System V Release 2 kernel.
Apple Computer
's A/UX
operating system was initially based on this release. The first release of HP-UX
was also an SVR2 derivative.
It included STREAMS
, the Remote File System
(RFS), the File System Switch (FSS) virtual file system
mechanism, a restricted form of shared libraries, and the Transport Layer Interface
(TLI) network API
. The final version was Release 3.2 in 1988, which added binary compatibility to Xenix on Intel platforms; SCO OpenServer
was based upon 3.2, as was INTERACTIVE Systems Corporation
(ISC) 386/ix
. The AT&T 3B2
became the official "porting base". IBM
's AIX operating system
is an SVR3 derivative.
System V Release 4.0 was announced on October 18, 1988 and was incorporated into a variety of commercial Unix products from early 1989 onwards. A joint project of Unix System Laboratories
and Sun Microsystems
, it combined technology from Release 3 as well as 4.3BSD
, Xenix
, and SunOS
. New features included:
The primary platforms for SVR4 were Intel x86
and SPARC
; the SPARC version, called Solaris 2 (or, internally, SunOS
5.x), was developed by Sun. The relationship between Sun and AT&T was terminated after the release of SVR4, meaning that later versions of Solaris did not inherit features of later SVR4.x releases. Sun would in 2005 release most of the source code for Solaris 10 (SunOS 5.10) as the open source
OpenSolaris
project, creating the only open-source (heavily modified) System V implementation available. The "Principal Publisher" for SVR4 on the Intel platform was ISC
.
Many versions of SVR4 appeared, because of hardware vendors (HP
, SGI
) adapting it to their platform, and because porting houses (SCO, Microport
, ESIX, UHC) sold enhanced and supported x86 versions. SVR4 was even ported to the Amiga
as Amiga Unix
and Atari
as ASV SVR4 Unix 1991. Other popular SysV derivatives include Dell
SVR4 and Bull
SVR4. A consortium of Intel based resellers including Unisys
, ICL, NCR Corporation
, and Olivetti
developed SVR4.0MP with multiprocessing
capability (allowing system calls to be processed from any processor, but interrupt servicing only from a "master" processor).
Release 4.1 ES (Enhanced Security) added security features required for Orange Book
B2 compliance and Access Control List
s and support for dynamic loading of kernel modules.
In 1992, AT&T USL engaged in a joint venture with Novell
, called Univel
. That year saw the release System V.4.2 as Univel UnixWare
, featuring the VERITAS File System
. Other vendors included UHC and Consensys. Release 4.2MP, completed late 1993, added support for multiprocessing and It was released as UnixWare 2 in 1995.
. Any operating system that meets the Single Unix Specification
(SUS), effectively a successor to the System V Interface Definition, may be granted Unix rights. The SUS is met by Apple's Mac OS X
, a BSD derivative, as well as several other operating systems not derived from either BSD or System V.
System V Release 5 was developed in 1997 by the Santa Cruz Operation (SCO) as a merger of SCO OpenServer
(an SVR3-derivative) and UnixWare, with a focus on large-scale servers. It was released as SCO UnixWare 7. SCO's successor, The SCO Group, also based SCO OpenServer
6 on SVR5, but the codebase is not used by any other major developer or reseller.
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
. It was originally developed by American Telephone & Telegraph
American Telephone & Telegraph
AT&T Corp., originally American Telephone and Telegraph Company, is an American telecommunications company that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies. AT&T is the oldest telecommunications company...
(AT&T) and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4. System V Release 4, or SVR4, was commercially the most successful version, being the result of an effort, marketed as Unix System Unification, which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features.
While AT&T sold their own hardware that ran System V (see AT&T Computer Systems
AT&T Computer Systems
AT&T Computer Systems is the generic name for American Telephone & Telegraph's unsuccessful attempt to compete in the computer business. In return for divesting the local Bell Operating Companies , AT&T was allowed to have an unregulated division to sell computer hardware and software.Prior to the...
), most customers ran a version from a reseller, based on AT&T's reference implementation
Reference implementation
In the software development process, a reference implementation is the standard from which all other implementations, with their attendant customizations, are measured, and to which all improvements are added...
. A standards document called the System V Interface Definition
System V Interface Definition
The System V Interface Definition is a standard that describes the AT&T UNIX System V behavior, including that of system calls, C libraries, available programs and devices...
outlined the default features and behavior of implementations. The most widely used versions of System V today are IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's AIX
AIX operating system
AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...
, based on System V Release 3, and Sun
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
's Solaris
Solaris Operating System
Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....
and Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
's HP-UX
HP-UX
HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
, both based on System V Release 4.
In the 1980s and early-1990s, System V was considered one of the two major "flavors" of UNIX, the other being Berkeley Unix
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
(BSD). During the period of the Unix wars
Unix wars
The Unix wars were the struggles between vendors of the Unix computer operating system in the late 1980s and early 1990s to set the standard for Unix thenceforth.- Origins :...
System V was known for being the primary choice of manufacturers of large multiuser systems, in opposition to BSD's dominance of desktop workstations. However, with standardization efforts such as POSIX
POSIX
POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...
and the commercial success of Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, this generalization is not as accurate as it once was.
SVR1
System V succeeded AT&T's previous commercial Unix called System IIIUNIX System III
UNIX System III was a version of the Unix operating system released by AT&T's Unix Support Group . It was first released outside of Bell Labs in 1982. UNIX System III was a mix of various AT&T Unixes: PWB/UNIX 2.0, CB UNIX 3.0, UNIX/TS 3.0.1 and UNIX/32V...
in January, 1983
(there was never an external release of System IV).
This first release of System V (called System V.0, System V Release 1, or SVR1) was developed by AT&T's UNIX Support Group (USG) and based on the Bell Labs internal USG UNIX 5.0. System V also included features such as the vi
Vi
vi is a screen-oriented text editor originally created for the Unix operating system. The portable subset of the behavior of vi and programs based on it, and the ex editor language supported within these programs, is described by the Single Unix Specification and POSIX.The original code for vi...
editor and curses
Curses (programming library)
curses is a terminal control library for Unix-like systems, enabling the construction of text user interface applications.The name is a pun on the term “cursor optimization”. It is a library of functions that manage an application's display on character-cell terminals .- Overview :The curses API...
from release 4.1 of the Berkeley Software Distribution
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
of UNIX developed at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
(UCB); it also improved performance by adding buffer and inode
Inode
In computing, an inode is a data structure on a traditional Unix-style file system such as UFS. An inode stores all the information about a regular file, directory, or other file system object, except its data and name....
caches. System V ran on the DEC VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
and PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
machines. It also added support for inter-process communication
Inter-process communication
In computing, Inter-process communication is a set of methods for the exchange of data among multiple threads in one or more processes. Processes may be running on one or more computers connected by a network. IPC methods are divided into methods for message passing, synchronization, shared...
using messages, semaphore
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type that provides a simple but useful abstraction for controlling access by multiple processes to a common resource in a parallel programming environment....
s, and shared memory
Shared memory
In computing, shared memory is memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Depending on context, programs may run on a single processor or on multiple separate processors...
.
SVR2
System V Release 2 was released in April, 1984. It added shellUnix shell
A Unix shell is a command-line interpreter or shell that provides a traditional user interface for the Unix operating system and for Unix-like systems...
functions and the SVID. New kernel features included record and file locking
File locking
File locking is a mechanism that restricts access to a computer file by allowing only one user or process access at any specific time. Systems implement locking to prevent the classic interceding update scenario ....
, demand paging
Demand paging
In computer operating systems, demand paging is an application of virtual memory. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it...
, and copy on write.
The concept of the "porting base" was formalized, and the DEC VAX 11/780 was named for this Release. The "porting base" is the so-called original version of a Release, from which all porting efforts for other machines emanate. Maurice J. Bach's The Design of the UNIX Operating System is the definitive description of the System V Release 2 kernel.
Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
's A/UX
A/UX
A/UX was Apple Computer’s implementation of the Unix operating system for some of their Macintosh computers. The later versions of A/UX ran on the Macintosh II, Quadra and Centris series of machines as well as the SE/30. A/UX was first released in 1988, with the final version released in 1995...
operating system was initially based on this release. The first release of HP-UX
HP-UX
HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
was also an SVR2 derivative.
SVR3
System V Release 3 was released in 1986.It included STREAMS
STREAMS
In computer networking, STREAMS is the native framework in Unix System V for implementing character devices.STREAMS was designed as a modular architecture for implementing full-duplex I/O between kernel or user space processes and device drivers. Its most frequent uses have been in developing...
, the Remote File System
Remote File System
The Remote File System was a distributed file system developed by AT&T in the 1980s. It was first delivered with UNIX System V Release 3 .Compared to NFS it made quite different design decisions...
(RFS), the File System Switch (FSS) virtual file system
Virtual file system
A virtual file system or virtual filesystem switch is an abstraction layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way...
mechanism, a restricted form of shared libraries, and the Transport Layer Interface
Transport Layer Interface
In computer networking, the Transport Layer Interface was the networking API provided by AT&T UNIX System V Release 3 in 1987 and continued into Release 4 . TLI was the System V counterpart to the BSD sockets programming interface, which was also provided in UNIX System V Release 4...
(TLI) network API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
. The final version was Release 3.2 in 1988, which added binary compatibility to Xenix on Intel platforms; SCO OpenServer
SCO OpenServer
SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
was based upon 3.2, as was INTERACTIVE Systems Corporation
INTERACTIVE Systems Corporation
INTERACTIVE Systems Corporation was a US-based software company and the first vendor of the Unix operating system outside AT&T, operating from Santa Monica, CA....
(ISC) 386/ix
INTERACTIVE UNIX
INTERACTIVE UNIX System V/386 is a port of the UNIX System V operating system for Intel x86 processors.The system was first released by INTERACTIVE Systems Corporation as 386/ix in 1985. At that time it was based on System V.3.0. Later versions were based on System V.3.2...
. The AT&T 3B2
3B Computers
The 3B series computers were a line of micro-programmable minicomputers produced by AT&T Computer Systems's Western Electric subsidiary.-High-availability processors:The original series of 3B computers include the models 3B20C, 3B20D, 3B21D, and 3B21E....
became the official "porting base". IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's AIX operating system
AIX operating system
AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...
is an SVR3 derivative.
SVR4
System V Release 4.0 was announced on October 18, 1988 and was incorporated into a variety of commercial Unix products from early 1989 onwards. A joint project of Unix System Laboratories
Unix System Laboratories
Unix System Laboratories was originally organized as part of Bell Labs in 1989. USL joined with the UNIX Software Operation, also a Bell Laboratories division, in 1990. It assumed responsibility for Unix development and licensing activities...
and Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, it combined technology from Release 3 as well as 4.3BSD
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
, Xenix
Xenix
Xenix is a version of the Unix operating system, licensed to Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually superseded it with SCO UNIX ....
, and SunOS
SunOS
SunOS is a version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems. The SunOS name is usually only used to refer to versions 1.0 to 4.1.4 of SunOS...
. New features included:
- From BSD: TCP/IP support, sockets, UFSUnix File SystemThe Unix file system is a file system used by many Unix and Unix-like operating systems. It is also called the Berkeley Fast File System, the BSD Fast File System or FFS...
, support for multiple groups, C shellC shellThe C shell is a Unix shell that was created by Bill Joy while a graduate student at University of California, Berkeley in the late 1970s. It has been distributed widely, beginning with the 2BSD release of the BSD Unix system that Joy began distributing in 1978...
; - From SunOS: the virtual file systemVirtual file systemA virtual file system or virtual filesystem switch is an abstraction layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way...
interface (replacing the File System Switch in System V release 3), NFS, new virtual memory system including support for memory mappedMmapIn computing, mmap is a POSIX-compliant Unix system call that maps files or devices into memory. It is a method of memory-mapped file I/O. It naturally implements demand paging, because initially file contents are not entirely read from disk and do not use physical RAM at all...
files, an improved shared library system based on the SunOS 4.x model, the OpenWindowsOpenWindowsOpenWindows was a desktop environment for Sun Microsystems workstations which handled SunView, NeWS, and X Window System protocols. OpenWindows was included in later releases of the operating systems SunOS 4 and Solaris, until its removal in Solaris 9 in favor of Common Desktop Environment and...
GUIGuiGui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...
environment, External Data RepresentationExternal Data RepresentationExternal Data Representation is a standard data serialization format, for uses such as computer network protocols. It allows data to be transferred between different kinds of computer systems. Converting from the local representation to XDR is called encoding. Converting from XDR to the local...
(XDR) and ONC RPC; - From Xenix: x86 device driverDevice driverIn computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....
s, binary compatibility with Xenix (in the x86 version of System V); - Korn shellKorn shellThe Korn shell is a Unix shell which was developed by David Korn in the early 1980s and announced at USENIX on July 14, 1983. Other early contributors were AT&T Bell Labs developers Mike Veach, who wrote the emacs code, and Pat Sullivan, who wrote the vi code...
; - ANSI X3J11 C compatibility;
- Multi-National Language Support (MNLS);
- Better internationalizationInternationalization and localizationIn computing, internationalization and localization are means of adapting computer software to different languages, regional differences and technical requirements of a target market...
support; - An application binary interfaceApplication binary interfaceIn computer software, an application binary interface describes the low-level interface between an application program and the operating system or another application.- Description :...
(ABI); - Support for standards such as POSIXPOSIXPOSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...
and X/OpenX/OpenX/Open Company, Ltd. was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology. More specifically, the original aim was to define a single specification for operating systems derived from UNIX, to...
.
The primary platforms for SVR4 were Intel x86
X86 architecture
The term x86 refers to a family of instruction set architectures based on the Intel 8086 CPU. The 8086 was launched in 1978 as a fully 16-bit extension of Intel's 8-bit based 8080 microprocessor and also introduced segmentation to overcome the 16-bit addressing barrier of such designs...
and SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
; the SPARC version, called Solaris 2 (or, internally, SunOS
SunOS
SunOS is a version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems. The SunOS name is usually only used to refer to versions 1.0 to 4.1.4 of SunOS...
5.x), was developed by Sun. The relationship between Sun and AT&T was terminated after the release of SVR4, meaning that later versions of Solaris did not inherit features of later SVR4.x releases. Sun would in 2005 release most of the source code for Solaris 10 (SunOS 5.10) as the open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
OpenSolaris
OpenSolaris
OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
project, creating the only open-source (heavily modified) System V implementation available. The "Principal Publisher" for SVR4 on the Intel platform was ISC
INTERACTIVE Systems Corporation
INTERACTIVE Systems Corporation was a US-based software company and the first vendor of the Unix operating system outside AT&T, operating from Santa Monica, CA....
.
Many versions of SVR4 appeared, because of hardware vendors (HP
HP-UX
HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
, SGI
IRIX
IRIX is a computer operating system developed by Silicon Graphics, Inc. to run natively on their 32- and 64-bit MIPS architecture workstations and servers. It was based on UNIX System V with BSD extensions. IRIX was the first operating system to include the XFS file system.The last major version...
) adapting it to their platform, and because porting houses (SCO, Microport
Microport
Microport created the first version of AT&T UNIX System V for the IBM 286 and 386 Personal Computers, as well as IBM's PS/2 systems...
, ESIX, UHC) sold enhanced and supported x86 versions. SVR4 was even ported to the Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
as Amiga Unix
Amiga Unix
Commodore-Amiga, Inc., in 1990, did a full port of AT&T Unix System V Release 4 for the Amiga computer family , informally known as Amix. Bundled with the Amiga 3000UX, Commodore's Unix was one of the first ports of SVR4 to the 68k architecture...
and Atari
Atari
Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
as ASV SVR4 Unix 1991. Other popular SysV derivatives include Dell
Dell
Dell, Inc. is an American multinational information technology corporation based in 1 Dell Way, Round Rock, Texas, United States, that develops, sells and supports computers and related products and services. Bearing the name of its founder, Michael Dell, the company is one of the largest...
SVR4 and Bull
Groupe Bull
-External links:* * — Friends, co-workers and former employees of Bull and Honeywell* *...
SVR4. A consortium of Intel based resellers including Unisys
Unisys
Unisys Corporation , headquartered in Blue Bell, Pennsylvania, United States, and incorporated in Delaware, is a long established business whose core products now involves computing and networking.-History:...
, ICL, NCR Corporation
NCR Corporation
NCR Corporation is an American technology company specializing in kiosk products for the retail, financial, travel, healthcare, food service, entertainment, gaming and public sector industries. Its main products are self-service kiosks, point-of-sale terminals, automated teller machines, check...
, and Olivetti
Olivetti
Olivetti S.p.A. is an Italian manufacturer of computers, printers and other business machines.- Founding :The company was founded as a typewriter manufacturer in 1908 in Ivrea, near Turin, by Camillo Olivetti. The firm was mainly developed by his son Adriano Olivetti...
developed SVR4.0MP with multiprocessing
Multiprocessing
Multiprocessing is the use of two or more central processing units within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them...
capability (allowing system calls to be processed from any processor, but interrupt servicing only from a "master" processor).
Release 4.1 ES (Enhanced Security) added security features required for Orange Book
Trusted Computer System Evaluation Criteria
Trusted Computer System Evaluation Criteria is a United States Government Department of Defense standard that sets basic requirements for assessing the effectiveness of computer security controls built into a computer system...
B2 compliance and Access Control List
Access control list
An access control list , with respect to a computer file system, is a list of permissions attached to an object. An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Each entry in a typical ACL specifies a subject...
s and support for dynamic loading of kernel modules.
In 1992, AT&T USL engaged in a joint venture with Novell
Novell
Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
, called Univel
Univel
Univel was a joint venture of Novell and AT&T's Unix System Laboratories that was formed in 1991 to develop and market the Destiny desktop Unix operating system,...
. That year saw the release System V.4.2 as Univel UnixWare
UnixWare
UnixWare is a Unix operating system maintained by The SCO Group . UnixWare is typically deployed as a server rather than desktop. Binary distributions of UnixWare are available for x86 architecture computers. It was originally released by Univel, a jointly owned venture of AT&T's Unix System...
, featuring the VERITAS File System
VERITAS File System
The VERITAS File System, , is an extent-based file system. It was originally developed by VERITAS Software. Through an OEM agreement, VxFS is used as the primary filesystem of the HP-UX operating system...
. Other vendors included UHC and Consensys. Release 4.2MP, completed late 1993, added support for multiprocessing and It was released as UnixWare 2 in 1995.
SVR5
The Santa Cruz Operation (SCO), developers of Xenix, eventually acquired the UnixWare trademark and the distribution rights to the System V Release 4.2 codebase from Novell, while other vendors (Sun, IBM, HP) continued to use and extend System V Release 4. Novell transferred ownership of the Unix trademark to The Open GroupThe Open Group
The Open Group is a vendor and technology-neutral industry consortium, currently with over three hundred member organizations. It was formed in 1996 when X/Open merged with the Open Software Foundation...
. Any operating system that meets the Single Unix Specification
Single UNIX Specification
The Single UNIX Specification is the collective name of a family of standards for computer operating systems to qualify for the name "Unix"...
(SUS), effectively a successor to the System V Interface Definition, may be granted Unix rights. The SUS is met by Apple's Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
, a BSD derivative, as well as several other operating systems not derived from either BSD or System V.
System V Release 5 was developed in 1997 by the Santa Cruz Operation (SCO) as a merger of SCO OpenServer
SCO OpenServer
SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
(an SVR3-derivative) and UnixWare, with a focus on large-scale servers. It was released as SCO UnixWare 7. SCO's successor, The SCO Group, also based SCO OpenServer
SCO OpenServer
SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
6 on SVR5, but the codebase is not used by any other major developer or reseller.
SVR6
System V Release 6 was announced by SCO to be released by the end of 2004, but was apparently cancelled. It was supposed to support 64-bit systems.External links
- PC-clone UNIX Software Buyer's Guide by Eric S. RaymondEric S. RaymondEric Steven Raymond , often referred to as ESR, is an American computer programmer, author and open source software advocate. After the 1997 publication of The Cathedral and the Bazaar, Raymond was for a number of years frequently quoted as an unofficial spokesman for the open source movement...
(posted to USENETUsenetUsenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
in 1994) - Unix FAQ - history
- A Unix History Diagram - The original and continuously updated version of the Unix history, as published by O'ReillyO'ReillyO'Reilly is the Anglicised form of the Gaelic Ó Raghallaigh. It is also the patronymic form of the Irish name Reilly . It is commonly found throughout Ireland, with the greatest concentration of the surname found in County Cavan followed by Longford, Meath, Westmeath, Fermanagh and Monaghan, and...