A Brief History of Unix :: Computer Science

A Brief History of UnixThis enter is designed to deem people with no previous UNIXexperience some sense of what UNIX is. This enrolment will cover thehistory of UNIX and an introduction to UNIX.HISTORY OF UNIX AND CAUSES FOR ITS POPULARITYMost discussions of UNIX get under ones skin with the history of UNIX withoutexplaining why the history of UNIX is important to understanding UNIX.The remainder of this document will describe some strengths andweaknesses of UNIX and attempt to explain why UNIX is becomepopular. All of UNIXs strengths and weaknesses can be directlyrelated to the history of its development, because a discussion ofhistory is very useful.UNIX was originally developed at Bell Laboratories as a privateresearch project by a small classify of people starting in 1969. This conclave had experience with a number of different operating remainssresearch efforts in the 1970s. The goals of the group were to designan operating constitution to satisfy the following objectiv es wide-eyed and elegantWritten in a high level lyric poem rather than assembly languageAllow re-use of codeTypical seller operating systems of the time were extremely large andall scripted in assembly language. UNIX had a relatively small amountof code scripted in assembly language (this is called the vegetable marrow) andthe remaining code for the operating system was written in a highlevel language called C.The group worked primarily in the high level language in developmentthe operating system. As this development continued, small changeswere necessary in the kernel and the language to allow the operatingsystem to be completed. Through this phylogeny the kernel andassociated software were extended until a complete operating systemwas written on top of the kernel in the language C.UNIX industry PROGRAMMING INTERFACEMany proprietary operating systems have a simplified view ofapplication behavior. The typical application reads some info fromdisk, tape or a terminal and does s ome processing. Output is producedonto disk, tape, tape, terminal, or printer. The operating systemsgenerally provide easy to use well-implemented facilities to supportthese types of facilities.As applications become more sophisticated they need new features suchas network access, multi-tasking, and interprocess communications. Intraditional operating systems, these features are often problematic to use,not well documented, and only callable from assembly language. When abroadcast makes use of these features, the program may be much more colonial and much more difficult to maintain.In UNIX because the C language was written to be used to implement anoperating system rather than a traditional input-processing-outputapplication, use of these sophisticated features is quite easily donefrom the C language without writing any assembly language.