As is suggestive of its name, an operating system (OS) is a collection of programs that operate the personal computer (PC). Its primary purpose is to support programs that actually do the work one is interested in, and to allow competing programs to share the resources of the computer. However, the OS also controls the inner workings of the computer, acting as a traffic manager which controls the flow of data through the system and initiates the starting and stopping processes, and as a means through which software can access the hardware and system software. In addition, it provides routines for device control, provides for the management, scheduling and interaction of tasks, and maintains system integrity. It also provides a facility called the user interface which issues commands to the system software. Utilities are provided for managing files and documents created by users, development of programs and software, communicating between users with other computer systems and managing user requirements for programs, storage space and priority.

There are a number of different types of operating sys

[Accessed 3 September 1998].

[Accessed 6 September 1998].

Operating Systems Introduction, v 3.2. Central Institute of Technology.

http://osiris.staff.udg.mx/man/ingles/introduccion.html

UNIX was slow to catch on outside of academic institutions but soon was popular with businesses as well. The first five versions were part of an internal research effort of Bell Labs, and it was not until the sixth version, called UNIX Timesharing Sixth Edition V, that UNIX was widely distributed (Osiris, 1). Relatively recent developments are graphical interfaces (GUI) such as MOTIF, X Windows and Open View. UNIX has two major versions. One, jointly developed by UNIX Systems Laboratories (USL) and by AT&T researchers together with Bell Labs, generically known as System V, is the commercial version and is the most widely distributed by major manufacturers. The second, developed by the University of Berkley and Berkley Software Distribution (BSD), is the educational version and is completely focused on research. The USL version is now on its fourth release, or SVR4, while BSD's latest version is 4.4. However, there are many different versions of UNIX besides these two. The operating system has been licensed to several manufacturers who in turn developed their own versions of UNIX, based on System V or BSD, but adding new characteristics. Most versions of UNIX developed by software companies are derived from one of the two groupings and, recent versions of UNIX actually incorporate features from both of them. However, UNIX has had an unregulated history with over 200 versions (Berson, 16) existing today.

Some common words found in the essay are:
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Approximate Pages = 16 (250 words per page double spaced)