Unix

An Overview

The UNIX* operating system was designed to let a number of programmers access the computer at the same time and share its resources.

The operating system coordinates the use of the computer's resources, allowing one person, for example, to run a spell check program while another creates a document, lets another edit a document while another creates graphics, and lets another user format a document -- all at the same time, with each user oblivious to the activities of the others.

The operating system controls all of the commands from all of the keyboards and all of the data being generated, and permits each user to believe he or she is the only person working on the computer.

This real-time sharing of resources make UNIX one of the most powerful operating systems ever.

While initially designed for medium-sized minicomputers, the operating system was soon moved to larger, more powerful mainframe computers. As personal computers grew in popularity, versions of UNIX found their way into these boxes, and a number of companies produce UNIX-based machines for the scientific and programming communities.

The Evolution of the Unix Time-sharing System*

IThe first version of UNIX was created in 1969 by Kenneth Thompson and Dennis Ritchie, system engineers at AT&T's Bell Labs. It went through many revisions and gained in popularity until 1977, when it was first made commercially available by Interactive Systems Corporation.

At the same time a team from the University of California at Berkeley was working to improve UNIX. In 1977 it released the first Berkeley Software Distribution, which became known as BSD. Over time this won favour through innovations such as the C shell.

Meanwhile the AT&T version was developing in different ways. The 1978 release of Version 7 included the Bourne Shell for the first time. By 1983 commercial interest was growing and Sun Microsystems produced a UNIX workstation. System V appeared, directly descended from the original AT&T UNIX and the prototype of the more widely used variant today.

Origins

1969 The Beginning The history of UNIX starts back in 1969, when Ken Thompson, Dennis Ritchie and others started working on the "little-used PDP-7 in a corner" at Bell Labs and what was to become UNIX.

1971 First Edition It had a assembler for a PDP-11/20, file system, fork(), roff and ed. It was used for text processing of patent documents.

1973 Fourth Edition It was rewritten in C. This made it portable and changed the history of OS's.

1975 Sixth Edition UNIX leaves home. Also widely known as Version 6, this is the first to be widely available out side of Bell Labs. The first BSD version (1.x) was derived from V6.

1979 Seventh Edition It was a "improvement over all preceding and following Unices" [Bourne]. It had C, UUCP and the Bourne shell. It was ported to the VAX and the kernel was more than 40 Kilobytes (K).

1980 Xenix Microsoft introduces Xenix. 32V and 4BSD introduced.

1982 System III AT&T's UNIX System Group (USG) release System III, the first public release outside Bell Laboratories. SunOS 1.0 ships. HP-UX introduced. Ultrix-11 Introduced.

1983 System V Computer Research Group (CRG), UNIX System Group (USG) and a third group merge to become UNIX System Development Lab. AT&T announces UNIX System V, the first supported release. Installed base 45,000.

1984 4.2BSD University of California at Berkeley releases 4.2BSD, includes TCP/IP, new signals and much more. X/Open formed.

1984 SVR2 System V Release 2 introduced. At this time there are 100,000 UNIX installations around the world.

1986 4.3BSD 4.3BSD released, including internet name server. SVID introduced. NFS shipped. AIX announced. Installed base 250,000.

1987 SVR3 System V Release 3 including STREAMS, TLI, RFS. At this time there are 750,000 UNIX installations around the world. IRIX introduced.

1988 POSIX.1 published. Open Software Foundation (OSF) and UNIX International (UI) formed. Ultrix 4.2 ships.

1989 1989 AT&T UNIX Software Operation formed in preparation for spinoff of USL. Motif 1.0 ships.

1990 1989 SVR4 UNIX System V Release 4 ships, unifying System V, BSD and Xenix. Installed base 1.2 million.

1991 1990 XPG3 X/Open launches XPG3 Brand. OSF/1 debuts. Plan 9 from Bell Labs ships. 1991 UNIX System Laboratories (USL) becomes a company - majority-owned by AT&T. Linus Torvalds commences Linux development. Solaris 1.0 debuts.

1992 1992 SVR4.2 USL releases UNIX System V Release 4.2 (Destiny). October - XPG4 Brand launched by X/Open. December 22nd Novell announces intent to acquire USL. Solaris 2.0 ships.

1993 1993 4.4BSD 4.4BSD the final release from Berkeley. June 16 Novell acquires USL Late 1993 SVR4.2MP Novell transfers rights to the "UNIX" trademark and the Single UNIX Specification to X/Open. COSE initiative delivers "Spec 1170" to X/Open for fasttrack. In December Novell ships SVR4.2MP , the final USL OEM release of System V

1994 1994 Single UNIX Specification BSD 4.4-Lite eliminated all code claimed to infringe on USL/Novell. As the new owner of the UNIX trademark, X/Open introduces the Single UNIX Specification (formerly Spec 1170), separating the UNIX trademark from any actual code stream.

1995 1995 UNIX 95 X/Open introduces the UNIX 95 branding programme for implementations of the Single UNIX Specification. Novell sells UnixWare business line to SCO. Digital UNIX introduced. UnixWare 2.0 ships. OpenServer 5.0 debuts.

1996 1996 The Open Group forms as a merger of OSF and X/Open.

1997 1997 Single UNIX Specification, Version 2 The Open Group introduces Version 2 of the Single UNIX Specification, including support for realtime, threads and 64-bit and larger processors. The specification is made freely available on the web. IRIX 6.4, AIX 4.3 and HP-UX 11 ship.

1998 1998 UNIX 98 The Open Group introduces the UNIX 98 family of brands, including Base, Workstation and Server. First UNIX 98 registered products shipped by Sun, IBM and NCR. The Open Source movement starts to take off with announcements from Netscape and IBM. UnixWare 7 and IRIX 6.5 ship.

1999 1999 UNIX at 30 The UNIX system reaches its 30th anniversary. Linux 2.2