1973, D.M.Ritchie developed the system description language C, and rewritten UNIX originally written in assembly language with the new C. This is V5, which makes UNIX easier to modify and portable on different CPU platforms, which has become an important feature of UNIX. Since then, almost all UNIX operating systems and applications are written in C language, and only a C compiler is needed on the corresponding platform. There is a very close relationship between C and UNIX. In the same year, K.Thompson and D.M.Ritchie published the article "UNIX Time-sharing System" at the 4th Symposium on Operating System Principles of American Computer Association, and the Unix system was officially made public. This article was later published in the July issue of ACM magazine 1974.
V6 was introduced by 1975. Since then, Interactioe System Co (acquired by SUN) has become the first distributor of UNIX. UNIX has gone out of Bell Laboratories and started to spread widely on PDP- 1 1, especially on university campuses. Analyzing the structure of UNIX, correcting errors and improving it, and developing better application software have become the best topics for teachers and students of computer major and graduation project. At the University of California, Berkeley (UCB), some software technicians, led by Willian Joy, developed BSD from V6 and became new members of the UNIX family. BSD has been greatly developed in Berkeley. Until 1992, UNIX trademark holder USL(at & amp； T later opened a subsidiary) sued Berkeley for improper use of Unix licenses. Although USL finally lost the case, Berkeley also announced that it would not develop BSD in the same year. The final version of BSD, BSD 4.4BSD, is another story. Attached below are two major schools of UNIX, AT & amp； It is a schematic diagram of the development process of T UNIX and BSD respectively. In addition to UCB, the Mach plan of Carnegie Mellon University (CMU) has a far-reaching impact on the development of UNIX. Nowadays, many popular UNIX systems are related to Mach.
At&T Company. T was introduced in V6, and V7 was introduced in 1978, which contained more commands and supported large-scale files. V7 was later transplanted to VAX, called 32 V, 198 1 year, and system III, 1983, was developed, and system V suitable for education and easy to maintain was introduced.
In addition to the two main schools, there are also some UNIX-like operating systems developed by software and hardware manufacturers on different CPU platforms. Although these systems are implemented in different ways, their functions and operation management methods are similar to some versions of major universities. We call them "compatible" UNIX. The following table lists the compatible UNIX:
Naming company hardware platform function
AIX IBM RS6000 and POWER PC combine the characteristics of SVR2 and BSD, and have unique system management.
The latest version V5.x of IRIX SGI PC/ workstation is based on SVR4.
ULTRIX DEC PC has many features of 4.2BSD and 4.3BSD.
Sunos
(Solaris) SUN 68K, Sparc and X86 are all based on 4.3BSD, and a lot of contents come from the OPEN LOOK GUI standard developed by SYSTEM V, NFS and SUN.
HP -UX HP X86, developed HP workstation 4.2BSD.
Next, NeXTstep 68K, X86 is based on Mach core's 4.3BSD, which has a friendly user interface and conforms to the Openstep standard.
Xenix SCO/ Microsoft X86 is based on SVR2.
Scounix is the follow-up product of Scox86 Xenix, which has a great influence on PC UNIX.
UNICOS· Cray Cray Supercomputer
Dell UNIX Dell X86 based on SVR4
Minix's personal works are X86, Mac and Atari compatible with V7 and the originator of LINUX.
Interestingly, most of them are not called "UNIX", mainly because the trademark of UNIX is at &；; T (later its subsidiary USL),1in the spring of 993, NOVELL acquired USL, and the UNIX trademark was owned by NOVELL from then on. "In&; The name "T UNIX" has become history. 1994, NOVELL surprisingly gave up the "UNIX" trademark and sold it to X/OPEN in Britain, which made all operating systems that met the X/OPEN standard called "UNIX". However, NOVELL still retains the copyright of the original UNIX system code.
BSD version 4.4 came out because it was related to AT&; T sued the copyright and stopped the development (later, based on the work of BSD, some development members removed the code that had copyright problems with at&T and developed today's FreeBSD). The lawsuit was finally settled out of court, and then in&; T faced antitrust charges and sold the UNIX part to SCO. NOVELL sold the source code and their unixware products to SCO, and recently SCO sold part of their UNIX server to Linux vendor Caldera. ...
The two inventors of UNIX made outstanding contributions in the 1980s.
Won the Nobel Prize in IT field-Turing Award.