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

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 ...

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 ...

. V7, released in 1979, was the last

Bell Laboratories Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several lab ...

release to see widespread distribution before the commercialization of Unix by

AT&T Corporation AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to busi ...

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 until ...

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

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 Research Unix refers to the 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 term ''Research Unix'' first app ...

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 Portable may refer to: General * Portable building, a manufactured structure that is built off site and moved in upon completion of site and utility work * Portable classroom, a temporary building installed on the grounds of a school to provide a ...

version of Unix. As this was the era of

minicomputer A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s, built significantly smaller and sold at a much lower price than mainframe computers . By 21st century-standards however, a mini is ...

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 The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

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 Sector ...

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

Xenix Xenix is a discontinued Unix operating system for various microcomputer platforms, licensed by Microsoft from AT&T Corporation. The first version was released in 1980, and Xenix was the most common Unix variant during the mid- to late-1980s. T ...

for the

Intel 8086 The 8086 (also called iAPX 86) is a 16-bit computing, 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-b ...

was derived from V7 and Onyx Systems soon produced a

Zilog Zilog, Inc. is an American manufacturer of microprocessors, microcontrollers, and application-specific embedded System on a chip, system-on-chip (SoC) products. The company was founded in 1974 by Federico Faggin and Ralph Ungermann, who were soo ...

Z8000 The Zilog Z8000 is a 16-bit microprocessor architecture designed by Zilog and introduced in early 1979. Two chips were initially released, differing only in the width of the address bus; the Z8001 had a 23-bit bus while the Z8002 had a 16-bit b ...

computer running V7. The

VAX VAX (an acronym for virtual address extension) is a series of computers featuring a 32-bit instruction set architecture (ISA) and virtual memory that was developed and sold by Digital Equipment Corporation (DEC) in the late 20th century. The V ...

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 PDP-11 ...

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

University of Wollongong The University of Wollongong (UOW) is an Australian public university, public research university located in the coastal city of Wollongong, New South Wales, approximately south of Sydney. , the university had an enrolment of more than 33,000 s ...

that had ported V6 to the Interdata 7/32 ported V7 to that machine as well.

Interdata Interdata, Inc., was a computer company, founded in 1966 by a former Electronic Associates engineer, Daniel Sinnott, and was based in Oceanport, New Jersey. The company produced a line of 16- and 32-bit minicomputer A minicomputer, or col ...

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 Ultrix (officially all-caps ULTRIX) is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations. History The initial development of Unix occurred on DEC eq ...

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 (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, accessing a hard disk drive ...

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 Caldera International, Inc., earlier Caldera Systems, was an American software company that existed from 1998 to 2002 and developed and sold Linux- and Unix-based operating system products. Caldera Systems was created in August 1998 as a spinoff ...

released V7 as

FOSS Free and open-source software (FOSS) is software available under a license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term encompassing free ...

under a

permissive Permissiveness may refer to: * Permissiveness (endocrinology), between hormones and cells. * Permissiveness (virology), between viruses and cells. Permissive may refer to: * Permissive society, a liberalization of social norms in a society. * ...

BSD-like

software license A software license is a legal instrument governing the use or redistribution of software. Since the 1970s, software copyright has been recognized in the United States. Despite the copyright being recognized, most companies prefer to sell lic ...

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

SIMH SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president, and has been in development in one form or another since the 1960s. History SIMH was based o ...

. An

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...

port has been developed by Nordier & Associates.

Paul Allen Paul Gardner Allen (January 21, 1953 – October 15, 2018) was an American businessman, computer programmer, and investor. He co-founded Microsoft, Microsoft Corporation with his childhood friend Bill Gates in 1975, which was followed by the ...

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, lint, and make. The

Portable C Compiler The Portable C Compiler (also known as pcc or sometimes pccm - portable C compiler machine) 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 ...

(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. *New commands: the

Bourne shell The Bourne shell (sh) is a shell command-line interpreter for computer operating systems. It first appeared on Version 7 Unix, as its default shell. Unix-like systems continue to have /bin/sh—which will be the Bourne shell, or a symbolic lin ...

, at, awk, calendar, f77,

fortune Fortune may refer to: General * Fortuna or Fortune, the Roman goddess of luck * Luck * Wealth * Fate * Fortune, a prediction made in fortune-telling * Fortune, in a fortune cookie Arts and entertainment Film and television * ''The Fortune'' (19 ...

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

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

uucp UUCP (Unix-to-Unix Copy) is a suite of computer programs and communications protocol, protocols allowing remote execution of commands and transfer of computer file, files, email and netnews between computers. A command named is one of the prog ...

and Datakit *New

s: access, acct, alarm,

chroot chroot is a shell (computer), shell command (computing), command and a system call on Unix and Unix-like operating systems that changes the apparent root directory for the current running process and its Child process, children. A program that i ...

(originally used to test the V7 distribution during preparation), exece,

ioctl In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular file semantics. It takes a parameter specifying a request code; ...

, lseek (previously only 24-bit offsets were available),

umask umask is a shell command that reports or sets the mask value that limits the file permissions for newly created files in many Unix and Unix-like file systems. A system call with the same name, , provides access to the mask value stored in the ...

, utime *New library calls: The new

stdio The C programming language provides many standard library functions for file input and output. These functions make up the bulk of the C standard library header . The functionality descends from a "portable I/O package" written by Mike Lesk at ...

routines,

malloc C dynamic memory allocation refers to performing manual memory management for dynamic memory allocation in the C programming language via a group of functions in the C standard library, namely , , , and . The C++ programming language includ ...

, getenv, popen/system *

Environment variable An environment variable is a user-definable value that can affect the way running processes will behave on a computer. Environment variables are part of the environment in which a process runs. For example, a running process can query the va ...

s *A maximum file size of just over one

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

, 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 In computer science, interprocess communication (IPC) is the sharing of data between running Process (computing), processes in a computer system. Mechanisms for IPC may be provided by an operating system. Applications which use IPC are often cat ...

: 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 h ...

, 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
at

Plan 9 from Bell Labs Plan 9 from Bell Labs is a distributed operating system which originated from the Computing Science Research Center (CSRC) at Bell Labs in the mid-1980s and built on UNIX concepts first developed there in the late 1960s. Since 2000, Plan 9 has ...

Browsable source code
at The Unix Heritage Society
PDP Unix Preservation Society
at The Unix Heritage Society
''Unix Archive'' Sites List
at The Unix Heritage Society {{Unix-like Bell Labs Unices Berkeley Software Distribution Discontinued operating systems Free software operating systems 1979 software