Version 7 Unix
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Seventh Edition Unix, also called Version 7 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 in the early 1980s. V7 ran, amongst others, on Digital Equipment Corporation's PDP-11 minicomputers and on the Interdata 8/32.
Unix versions from Bell Labs were designated by the edition of the user's manual with which they were accompanied. The Seventh Edition was preceded by Sixth Edition, which was the first version to be widely released outside of the Labs. Development of the Research Unix line continued with the Eighth Edition, which incorporated development from 4.1BSD.
V7 was the first truly portable Unix version, and many ports were completed. The first Sun workstations ran a V7 port by Unisoft, and the first version of Xenix was an extended V7. The VAX port of V7, called UNIX/32V, is the indirect ancestor of nearly every Unix system in use today. The group at Wollongong University that produced the V6 port to the Interdata 7/32 ported V7 to that machine as well.
DEC distributed their own version of V7, called V7M (for modified), for the PDP-11. V7M, developed by DEC's original Unix Engineering Group (UEG), contained many fixes to the kernel for the PDP-11 line of computers including support for separate instruction and data spaces, significant work for hardware error recovery, and many device drivers. Much work was put into producing a release that would reliably bootstrap from many tape drives or disk drives. V7M was well respected in the Unix community. UEG evolved into the group that later developed Ultrix.
Due to its power yet elegant simplicity, many old-time Unix users fondly (and with a good amount of nostalgia) remember V7 as the pinnacle of Unix development and the last "true" Unix, an improvement over all preceding and following Unices [1].
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[edit] Released as Free Software
In 2002, Caldera Systems released V7 under a free software license.
Boot images for V7 can still be downloaded today, to be run on PCs using PDP-11 emulators.
[edit] New Features in Version 7
Many new features were introduced in Version 7. Many, such as online man pages as well as programming tools like lex, lint, yacc, and make, came from PWB/UNIX, which was largely unknown at the time outside of Bell Labs). Others, listed below, demonstrate the influence of Version 7:
- Notable new commands: the Bourne shell, at, awk, calendar, cpio (in the 32V port), f77, iostat, tar (replacing the tp command), touch, uucp
- New system calls: access, acct, alarm, chroot, ioctl, lseek (previously only 24-bit offsets were addressable inside programs), umask, utime
- New library calls: The new stdio routines, malloc, getenv/putenv, popen/system
