History of Unix Operating systems

In the middle of the 60, At&t Bell Labs joined a project to develop an operating system called Multics with General Electric and the MIT Mac engineering team. Multics's main design goal is to provide many users with the ability to support large-scale concurrent access to the computer, to support sufficient data storage capabilities, and to allow users to easily share their data when needed. Many of the people who later took part in early UNIX development were involved in the development of Multics at Bell Labs.

Although the initial version of the Multics system was put into operation on the GE645 computer in 1969, it did not provide general-purpose computing services as intended, nor did it understand when it was possible to achieve its development goals. To that end, Bell Labs withdrew from the Multics plan. However, due to the completion of the work of the Multics project, the working members of Bell Labs Research Center for Scientific Computing have lost the convenient interactive computing environment. As an attempt to improve its programming environment, Ken Thompson, Dennis Ritchie and other researchers developed a basic filesystem that later evolved into an earlier version of the Unix file system. The original version of the file system was developed by Ken Thompson on the PDP-7 machine.

In 1971, the At&t Patent Department used UNIX as a text-processing system on the PDP-11 machine, making Unix's work potential appreciated by most people. UNIX is also famous for its short sophistication, because the system is 16KB, user program 8KB, a 512KB disk, each file is limited to 64KB. After the first successful UNIX, people began to implement Fortran compiler for the system, but developed a new high-level language--c language, C language allows the production of machine code, description of data types and the definition of structure. The UNIX system was rewritten in 1973 using the C language. This implementation enables UNIX systems to be accepted by a wide range of users, which is also an important reason for UNIX to become an open system.

At&t could not sell Unix as a commodity because at&t was unable to enter the computer market area under U.S. antitrust laws. Therefore, at&t can only use and distribute it to the university's scientific research institutions for research and use. Still, Unix systems are becoming more popular, providing a good environment for program development, network transport operations services, and real-time services. UNIX was licensed for commercial use in 1977, and the first UNIX vendor,--interactive system, began selling UNIX systems for office automation. Similarly, 1977 marks the first time a UNIX system was "ported" to a non-PDP computer--interdata8/32.

At&t's UNIX Systems Lab (now owned by Novell) has developed subsequent versions of UNIX, and the UNIX research team in 1978 handed the Unix release work to the UNIX Support Group (Unix supportgroup), The group released a UNIX build of the programmer's work desk (programmer World抯 Workbench) in 1978. With the increasing popularity of microprocessors, other companies are porting UNIX systems to new machines, but its simplicity and clarity attract many developers to enhance their UNIX systems in their own way, resulting in several variants on the underlying system. By 1982, At&t Bell Labs had integrated a number of at&t variants into a single system, which is known as the ⅲ,1983 UNIX support group for commercial Systems and released System V, System V's two newest versions of System V version 3 (SVR3.2) and System V version 4 (the latest version of SVR4,SVR4 for SVR4.2) have been popular in computer operating systems.