Version 7 Unix

Last updated
Version 7 Unix
Version 7 Unix SIMH PDP11 Emulation DMR.png
Version 7 Unix for the PDP-11, running in the SIMH PDP-11 simulator
Developer AT&T Bell Laboratories
Written in C, assembly
OS family Unix
Working stateHistoric
Source modelOriginally proprietary software, now open source
Initial release1979;45 years ago (1979)
Marketing target Minicomputers
Available in English
Platforms DEC PDP-11, VAX (32v), x86
Kernel type Monolithic
Default
user interface
Command-line interface (Bourne shell)
License Originally proprietary commercial software, now free software under a BSD-like license
Preceded by Version 6 Unix
Succeeded by Version 8 Unix

Version 7 Unix, also called Seventh Edition Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T Corporation in the early 1980s. V7 was originally developed for Digital Equipment Corporation's PDP-11 minicomputers and was later ported to other platforms.

Contents

Overview

Unix versions from Bell Labs were designated by the edition of the user's manual with which they were accompanied. Released in 1979, the Seventh Edition was preceded by Sixth Edition, which was the first version licensed to commercial users. [1] Development of the Research Unix line continued with the Eighth Edition, which incorporated development from 4.1BSD, through the Tenth Edition, after which the Bell Labs researchers concentrated on developing Plan 9.

V7 was the first readily portable version of Unix. As this was the era of minicomputers, with their many architectural variations, and also the beginning of the market for 16-bit microprocessors, many ports were completed within the first few years of its release. The first Sun workstations (then based on the Motorola 68000) ran a V7 port by UniSoft; [2] the first version of Xenix for the Intel 8086 was derived from V7 and Onyx Systems soon produced a Zilog Z8000 computer running V7. The VAX port of V7, called UNIX/32V, was the direct ancestor of the popular 4BSD family of Unix systems.

The group at the University of Wollongong that had ported V6 to the Interdata 7/32 ported V7 to that machine as well. Interdata sold the port as Edition VII, making it the first commercial UNIX offering.[ citation needed ]

DEC distributed their own PDP-11 version of V7, called V7M (for modified). V7M, developed by DEC's original Unix Engineering Group (UEG), contained many enhancements to the kernel for the PDP-11 line of computers including significantly improved hardware error recovery and many additional device drivers. [3] UEG evolved into the group that later developed Ultrix.

Reception

Due to its power yet elegant simplicity, many old-time Unix users remember V7 as the pinnacle of Unix development and have dubbed it "the last true Unix", an improvement over all preceding and following Unices. At the time of its release, though, its greatly extended feature set came at the expense of a decrease in performance compared to V6, which was to be corrected largely by the user community. [4]

The number of system calls in Version 7 was only around 50, while later Unix and Unix-like systems continued to add many more: [5]

Version 7 of the Research UNIX System provided about 50 system calls, 4.4BSD provided about 110, and SVR4 had around 120. The exact number of system calls varies depending on the operating system version. More recent systems have seen incredible growth in the number of supported system calls. Linux 5.15.0 has 449 system calls and FreeBSD 8.0 has over 450.

Released as free software

Screenshot of a PDP-11 booting Version 7 Unix in a simulator. Pdp11-unixv7.png
Screenshot of a PDP-11 booting Version 7 Unix in a simulator.

In 2002, Caldera International released [6] V7 as FOSS under a permissive BSD-like software license. [7] [8] [9]

Bootable images for V7 can still be downloaded today, and can be run on modern hosts using PDP-11 emulators such as SIMH.

An x86 port has been developed by Nordier & Associates. [10]

Paul Allen maintained[ when? ] several publicly accessible historic computer systems, including a PDP-11/70 running Unix Version 7.

New features in Version 7

Many new features were introduced in Version 7.

The Portable C Compiler (pcc) was provided along with the earlier, PDP-11-specific, C compiler by Ritchie.

These first appeared in the Research Unix lineage in Version 7, although early versions of some of them had already been picked up by PWB/UNIX. [11]

Multiplexed files

A feature that did not survive long was a second way (besides pipes) to do inter-process communication: multiplexed files. A process could create a special type of file with the mpx system call; other processes could then open this file to get a "channel", denoted by a file descriptor, which could be used to communicate with the process that created the multiplexed file. [13] Mpx files were considered experimental, not enabled in the default kernel, [14] and disappeared from later versions, which offered sockets (BSD) or CB UNIX's IPC facilities (System V) instead [15] (although mpx files were still present in 4.1BSD [16] ).

See also

Related Research Articles

The Single UNIX Specification (SUS) is a standard for computer operating systems, compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, and user commands. The core specifications of the SUS known as Base Specifications are developed and maintained by the Austin Group, which is a joint working group of IEEE, ISO/IEC JTC 1/SC 22/WG 15 and The Open Group. If an operating system is submitted to The Open Group for certification, and passes conformance tests, then it is deemed to be compliant with a UNIX standard such as UNIX 98 or UNIX 03.

troff, short for "typesetter roff", is the major component of a document processing system developed by Bell Labs for the Unix operating system. troff and the related nroff were both developed from the original roff.

man page Unix software documentation

A man page is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs, formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command.

<span class="mw-page-title-main">Ultrix</span> Series of discontinued Unix operating systems by DEC

Ultrix is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations.

<span class="mw-page-title-main">Pseudoterminal</span>

In some operating systems, including Unix and Linux, a pseudoterminal, pseudotty, or PTY is a pair of pseudo-device endpoints (files) which establish asynchronous, bidirectional communication (IPC) channel between two or more processes. The master provides means by which a terminal emulator process controls the slave. The slave emulates a hardware text terminal device. PTY are similar to bidirectional pipes.

Source Code Control System (SCCS) is a version control system designed to track changes in source code and other text files during the development of a piece of software. This allows the user to retrieve any of the previous versions of the original source code and the changes which are stored. It was originally developed at Bell Labs beginning in late 1972 by Marc Rochkind for an IBM System/370 computer running OS/360.

rm (Unix) Unix command utility

rm is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the del command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell.

UNIX/32V is an early version of the Unix operating system from Bell Laboratories, released in June 1979. 32V was a direct port of the Seventh Edition Unix to the DEC VAX architecture.

<span class="mw-page-title-main">UNIX System III</span> Discontinued UNIX variant

UNIX System III is a discontinued version of the Unix operating system released by AT&T's Unix Support Group (USG).

<span class="mw-page-title-main">Version 6 Unix</span> 6th Edition of Research Unix alias UNIX Time-Sharing System

Sixth Edition Unix, also called Version 6 Unix or just V6, was the first version of the Unix operating system to see wide release outside Bell Labs. It was released in May 1975 and, like its direct predecessor, targeted the DEC PDP-11 family of minicomputers. It was superseded by Version 7 Unix in 1978/1979, although V6 systems remained in regular operation until at least 1985.

<span class="mw-page-title-main">History of Unix</span>

The history of Unix dates back to the mid-1960s, when the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric were jointly developing an experimental time-sharing operating system called Multics for the GE-645 mainframe. Multics introduced many innovations, but also had many problems. Bell Labs, frustrated by the size and complexity of Multics but not its aims, slowly pulled out of the project. Their last researchers to leave Multics – among them Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna – decided to redo the work, but on a much smaller scale.

In computer networking, STREAMS is the native framework in Unix System V for implementing character device drivers, network protocols, and inter-process communication. In this framework, a stream is a chain of coroutines that pass messages between a program and a device driver. STREAMS originated in Version 8 Research Unix, as Streams.

The term "Research Unix" refers to early versions of the Unix operating system for DEC PDP-7, PDP-11, VAX and Interdata 7/32 and 8/32 computers, developed in the Bell Labs Computing Sciences Research Center (CSRC).

The Portable C Compiler is an early compiler for the C programming language written by Stephen C. Johnson of Bell Labs in the mid-1970s, based in part on ideas proposed by Alan Snyder in 1973, and "distributed as the C compiler by Bell Labs... with the blessing of Dennis Ritchie."

<span class="mw-page-title-main">Berkeley Software Distribution</span> Unix operating system

The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley. The term "BSD" commonly refers to its open-source descendants, including FreeBSD, OpenBSD, NetBSD, and DragonFly BSD.

<span class="mw-page-title-main">Unix</span> Family of computer operating systems

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, and others.

<span class="mw-page-title-main">Unix filesystem</span> Directory structure used by a Unix-like operating system

In Unix and operating systems inspired by it, the file system is considered a central component of the operating system. It was also one of the first parts of the system to be designed and implemented by Ken Thompson in the first experimental version of Unix, dated 1969.

On Unix-like computer systems, seq is a utility for generating a sequence of numbers.

The History of the Berkeley Software Distribution begins in the 1970s.

References

  1. 1 2 3 Fiedler, David (October 1983). "The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace". BYTE. p. 132. ISSN   0360-5280. OCLC   854802500 . Retrieved 2018-09-11.
  2. James W. Birdsall. "The Sun Hardware Reference, Part II". Sun-1's were the very first models ever produced by Sun. The earliest ran Unisoft V7 UNIX; SunOS 1.x was introduced later.
  3. Canter, Fred. "V7M 2.1 SPD" (PDF). Digital Equipment Corp. Retrieved 7 January 2012.
  4. Salus, Peter H. (2005). The Daemon, the Gnu and the Penguin. Groklaw.
  5. Stevens, W Richard. Rago, Stephen A. Advanced Programming in the UNIX Environment, 3rd Edition. 2013. p. 21
  6. Caldera releases original unices under BSD license on slashdot.org (2002)
  7. "UNIX is free!". lemis.com. 2002-01-24.
  8. Broderick, Bill (January 23, 2002). "Dear Unix enthusiasts" (PDF). Caldera International. Archived from the original (PDF) on February 19, 2009.
  9. Darwin, Ian F. (2002-02-03). "Why Caldera Released Unix: A Brief History". Linuxdevcenter. O'Reilly Media. Archived from the original on 2016-01-26. Retrieved 2016-01-19.
  10. https://www.nordier.com/#v7x86 Robert Nordier - UNIX v7/x86
  11. 1 2 3 McIlroy, M. Douglas (1987). A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 (PDF) (Technical report). Bell Labs. CSTR 139. Retrieved 2018-07-22.
  12. Thompson, Ken (1978). "UNIX Implementation". Bell System Technical Journal. 57 (6): 1931–1946. doi:10.1002/j.1538-7305.1978.tb02137.x. S2CID   19423060.
  13. mpx(2)    Version 7 Unix Programmer's Manual
  14. mkconf(1)    Version 7 Unix Programmer's Manual
  15. Leffler, Samuel J.; Fabry, Robert S.; Joy, William N.; Lapsley, Phil; Miller, Steve; Torek, Chris (1986). An Advanced 4.3 BSD Interprocess Communication Tutorial (Technical report). Computer Systems Research Group, University of California, Berkeley.
  16. Ritchie, Dennis M. (1984). "A Stream Input-Output System". AT&T Bell Laboratories Technical Journal. AT&T. 63 (8): 1897–1910. CiteSeerX   10.1.1.48.3730 . doi:10.1002/j.1538-7305.1984.tb00071.x. S2CID   33497669.