Development and Status of Unix

A Brief History of Unix

In 1965, Bell Labs joined a program of singular electronics (general Electric) and MIT (MIT) to build a multi-user, multi-tasking, multi-layered (multi-user, multi- processor, multi-level) of the Multics operating system. It was not until 1969 that the plan was stopped because of the slow pace of Multics's work. At that time, Ken Thompson (later known as the Father of Unix) already had a program called "Star Trek" running on GE-635 's machine, but the reaction was very slow, and he found an idle PDP-7 (digital host), Ken Thompson and Dernis Ritchie transplanted the "Star Trek" program to PDP-7. And this PDP-7 in the history of the entire computer has left a mark.

MULTICS is actually "multiplexed information and Computing System" abbreviation, in 1970, that PDP-7 but only two users, when, Brian Kernighan Jokingly joked that their system is actually: "Uniplexed information and Computing system", abbreviated as "UNICs", later, everyone to take its homophonic, called it "Unix". 1970 can be called the UNIX.

In 1971, they applied for a pdp-11/20, in the name of the application: to develop the instrument processing system. The proposal was adopted and they developed a system of clerical processing-the predecessor of the Nroff/troff, the UNIX operating system. Interestingly, it was not long before Bell Labs ' patent offices used the system as a tool for their documents, and the patent department at Bell Labs became the first official user of UNIX. At that time, the PDP-11/20 had only 0.5MB of disk space. The document describing the entire system is labeled "First Edition" and the version date is November 1970. From then on, the UNIX version is called by the version of the system file.

UNIX genealogy

The history of Unix began in 1969 when Ken Thompson,dennis Ritchie (the inventor of the famous K&g,c language) and a group of people worked on a PDP-7, and later the system became UNIX. Several of its major versions are:

V1 (1971): First edition of Unix, written in PDP-11/20 assembly language. Including file system, fork, Roff, Ed and other software.

V4 (1973): Written from scratch in C, which makes UNIX modifications easy and can be ported to new hardware platforms within a few months. Originally the C language was designed for UNIX, so C has a close relationship with UNIX.

V6 (1975): the first UNIX version that was widely circulated outside Bell Labs, especially in universities. This is also the starting point of the Unix branch and the popular start. 1.xBSD (PDP-II) is derived from this version.

V7 (1979): In the minds of many Unix gamers, this is "the last real Unix," This version includes a complete K&RC compiler, Bourne shell. V7 transplanted to the VAX machine is called 32V.

The company that is currently developing UNIX (System V) is the UNIX System Laboratories (USL). USL was acquired by Novell at the beginning of 1993. Novell transferred the registered trademark of UNIX to the X/open organization at the end of 1993.

So far, there are two major schools of Unix: the Unix OS System V released by Berkeley and the Unix version of BSD (software distribution) released by the University of California, Berkeley. SVR4 is the product of the fusion of the two schools. At the end of 1991, The Open Software Foundation, a rival to System V, launched the OSF/1.

A brief History of Unix development in Bell Labs

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Atlas of the development of Unix/linux (Jane)

Unix/linux Development Atlas (detailed)

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Unix/linux Development Atlas (detailed) Click to view larger image

There are several major versions of Unix:

AIX:IBM UNIX is based on SVR2 (recently out to SVR3.2) and part of the BSD extension, plus a variety of hardware support. Have a unique system management (SMIT).

386bsd:jolitz was transplanted from NET/2 software. Support Posix,32 bit.

freebsd:1.x from 386BSD 0.1, FreeBSD 2.x version is rewritten with 4.4BSD lite.

HP-UX: The old system is from the development of S-III (SVRX), which is now developed by SVR2 (4.2BSD) and is currently in the 10.x version.

Linux (x86): Compliance with POSIX,SYSV and BSD extensions, as you can see from the table on the previous page.

OSF/1 (DEC): Dec's transplant to OSF/1.

SCO Unix (x86): SVR3.2, currently affecting the larger PC UNIX.

SunOS (680x0,sparc,i386): Based on 4.3BSD, contains many things from System V. The main results of Sun are: Nfs,openlook GUI standard, later evolved to Solaris. This is also one of the most famous UNIX versions of the present.

Ultrix (DEC): According to 4.2BSD plus many 4.3BSD things.

Xenix (x86): Unix on the Intel hardware platform, based on SVR2, launched by Microsoft. Used more widely in China.

Now UNIX two schools of System V and OSF/1

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Introduction to Common BSD systems

　　freebsd system

derivative products: Pc-bsd, DesktopBSD, GHOSTBSD, Apple OS X and iOS.

　Bsd/os System

Bsd/os is a commercial version of the operating system, he is the work of BSDI company, in the server operating system occupies a certain share, because it is a commercial operating system so can get a certain hardware vendor support, these vendors may not want to provide their own hardware technology to the free operating system, which may be its advantage. In fact, it and FreeBSD have a deep yuan, its developers are actually the original BSD Unix part of the developers, not only in the technology has a wide range of cooperation in the commercial BSD company and the provision of FreeBSD services company also has a variety of business dealings.

NetBSD System

NetBSD is also a 4.4 BSD-based UNIX operating system. It is due to the products that researchers use on RISC workstations. Due to the system upgrade of workstations and the support of various vendors, researchers have developed the current operating system NetBSD by porting 4.4 BSD to these hardware platforms.

it actually and FreeBSD are brothers, in the early development of their development are the same, which caused the two systems have a lot of the same place. These two systems learn from each other, and you can find mosquitoes in each of the other systems. With the two systems of different hardware positioning, the two systems gradually shared, FreeBSD is mainly for personal computer design, Intel and its compatible hardware platform, we all know that the Intel chip is mainly running in the old PC, so, FreeBSD can also be said to be some of the PC platform ( Same as Windows). The development of NetBSD is to be used on RISC workstations, its design requires running in multi-system, has the greatest portability, to today it can support more than 30 kinds of hardware platform, is currently the largest number of supported platforms operating systems.

　OpenBSD system

This is actually a derived version of NetBSD, which is generated just to pursue the high security of the system. At the same time, in order to avoid the U.S. authorities security software and encryption algorithm export restrictions, they are in Canada for development and research work. The system is highly secure, so its various settings are the maximum security settings. The system is now slowly being recognized by the vast number of users. It is commonly used in the backstage of security equipment.

This article is from the "Mad Messenger" blog, please be sure to keep this source http://1193432.blog.51cto.com/1183432/1671058

Development and Status of Unix