Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7, was an important early release of the

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser 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 ...

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

. V7, released in 1979, was the last

Bell Laboratories Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mul ...

release to see widespread distribution before the commercialization of Unix by

AT&T Corporation AT&T Corporation, originally the American Telephone and Telegraph Company, is the subsidiary of AT&T Inc. that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agen ...

in the early 1980s. V7 was originally developed for

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unti ...

PDP-11 The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were so ...

minicomputers and was later ported to other platforms.

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. Development of the

Research Unix 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). History The term ''Resear ...

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 Plan 9 or Plan Nine may refer to: Music * Plan 9 (band), a psychedelic rock band from Rhode Island * ''Plan 9'', an album by Big Guitars From Memphis with Rick Lindy * "Plan 9", a song on the 1993 album ''Gorgeous'' by electronica band 808 Stat ...

. V7 was the first readily portable version of Unix. As this was the era of

minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

s, 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 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sect ...

) ran a V7 port by UniSoft; the first version of Xenix for the

Intel 8086 The 8086 (also called iAPX 86) is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus (allow ...

was derived from V7 and

Onyx Systems Onyx primarily refers to the parallel banded variety of chalcedony, a silicate mineral. Agate and onyx are both varieties of layered chalcedony that differ only in the form of the bands: agate has curved bands and onyx has parallel bands. The c ...

soon produced a

Zilog Zilog, Inc. is an American manufacturer of microprocessors and 8-bit and 16-bit microcontrollers. It is also a supplier of application-specific embedded system-on-chip (SoC) products. Its most famous product is the Z80 series of 8-bit microp ...

Z8000 The Z8000 ("''zee-'' or ''zed-eight-thousand''") is a 16-bit microprocessor introduced by Zilog in early 1979. The architecture was designed by Bernard Peuto while the logic and physical implementation was done by Masatoshi Shima, assisted by a ...

computer running V7. The VAX port of V7, called

UNIX/32V 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. Overview Before 32V, Unix had primarily run on DEC P ...

, was the direct ancestor of the popular 4BSD family of Unix systems. The group at the

University of Wollongong The University of Wollongong (abbreviated as UOW) is an Australian public research university located in the coastal city of Wollongong, New South Wales, approximately 80 kilometres south of Sydney. As of 2017, the university had an enrolment ...

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. 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. 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. The number of

system call In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, acc ...

s in Version 7 was only around 50, while later Unix and Unix-like systems continued to add many more:

Released as free software

In 2002, Caldera International released V7 as

FOSS Fos or FOSS may refer to: Companies * Foss A/S, a Danish analytical instrument company *Foss Brewery, a former brewery in Oslo, Norway * Foss Maritime, a tugboat and shipping company Historic houses *Foss House (New Brighton, Minnesota), United ...

under a permissive BSD-like

software license A software license is a legal instrument (usually by way of contract law, with or without printed material) governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both sour ...

. Bootable images for V7 can still b
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. Paul Allen maintained 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. *Programming tools: lex,

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, and make.

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

Ritchie Ritchie may refer to: People Surname *Adele Ritchie (1874–1930), singer – comic opera, musical comedy and vaudeville *Albert Ritchie (1876–1936), governor of Maryland 1920 to 1935 *Alistair Ferguson Ritchie (1890–1954), crossword compiler ...

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. *New commands: the

Bourne shell The Bourne shell (sh) is a shell command-line interpreter for computer operating systems. The Bourne shell was the default shell for Version 7 Unix. Unix-like systems continue to have /bin/sh—which will be the Bourne shell, or a symbolic link ...

, at, awk, calendar, f77, fortune,

tar Tar is a dark brown or black viscosity, viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic matter, organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. ...

(replacing the tp command), touch *Networking support, in the form of

uucp UUCP is an acronym of Unix-to-Unix Copy. The term generally refers to a suite of computer programs and protocols allowing remote execution of commands and transfer of files, email and netnews between computers. A command named is one of the ...

and Datakit *New

s: access, acct, alarm, chroot (originally used to test the V7 distribution during preparation), exece, ioctl, lseek (previously only 24-bit offsets were available), umask, utime *New library calls: The new stdio routines, malloc, getenv, popen/system *

Environment variable An environment variable is a dynamic-named value that can affect the way running processes will behave on a computer. They are part of the environment in which a process runs. For example, a running process can query the value of the TEMP env ...

s *A maximum file size of just over one

gigabyte The gigabyte () is a multiple of the unit byte for digital information. The prefix '' giga'' means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte is GB. This defini ...

, through a system of indirect addressing

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 In Unix and Unix-like computer operating systems, a file descriptor (FD, less frequently fildes) is a process-unique identifier ( handle) for a file or other input/output resource, such as a pipe or network socket. File descriptors typically ...

, which could be used to communicate with the process that created the multiplexed file. Mpx files were considered experimental, not enabled in the default kernel, and disappeared from later versions, which offered sockets (BSD) or CB UNIX's IPC facilities (System V) instead (although mpx files were still present in 4.1BSD).

References

External links

Unix Seventh Edition manual
(Bell Labs)
Browsable source code

PDP Unix Preservation Society
{{Unix-like Bell Labs Unices Berkeley Software Distribution Discontinued operating systems Free software operating systems 1979 software