Unix OS has become popular since its inspection in 1969, and running on machines of varying processors.Unix Operating System was first described in 1974 by Ken Thompson and Dennis Ritchie in ACM Paper. The system is devided into two parts. the first part consists of programs and services. The second part consists of the Operating System that support these programs and services.
In 1965, Bell Telephone Laboratoties joind an effort with the GEC(Genral Electronics Company) and project of the Massachusetts Institute of Technology to develop a new Operating system called MULTICS. Its primary Goal is how to share the common processor in between omre than one Users. the primitive version of MULTICS was run on GE645 machine in 1969 it did not provide consequent services. After that by mades some amondaments it was moved on PDP-7 machine. Altho it was satisfied with comparision of early versions of UNIX OS it could not realize its potensial, the UNIX system was moved to a PDP-11 in 1971. It was characterised by its size and affordable features.
Thompson setout the new into FORTRAN compilor, but instead came up with the labguage B, influenced by BCPL. B ws an interpretive language, with performence drqwacks implemented by such languages, UNIX was rewritten in to 'B' after words it was moved into C language in the year 1973, later it gain the popularity through out the world. By 1977 grown upto 500 installations including Universities.
In the year 1984, there wore found about 1,00,000 UNIX system installations, in the world, running on machines with a wide range of computing power from small microprocessors to Large Mainframe systems.
Basic Features.
* The system was written High Level language, making it easy to read, understand, change, and move to other machines.
* It has simple user interface.
* It provides primitives that permits complex programs to be build from smaller programs.
* It uses a hierarchial file system that allows that allows easy maintenance and efficient implementation.
* It uses a consistant format of files, byte stram, making application programs easier to write.
* It provides a simple, consistant interface to peripheral devices.
* It is a multi-user, multiprocessor system; each user can execute several processes simultaniously.
* It hides the machine architecture from the user, making it easier to write programs.
The UNIX OperatingSystem and many of the command programs are written in C, UNIX systems supportther Languages like compilor and Interpretor oriented.
Architecture of UNIX Systems.
The hardware at the centre of the diagram provides the Operating System with basic services that will be described . The Operating System interacts directly with the hardware, providing common services to programs. Viewing the system as set of layers, the Operating system is commonly called system kernal which isolating from user programs. Because programs are independent of the underlaying hardware. programs such as shell and editors(ed and vi) shown in the outer layes interact with the kernal by invoking a well defined set of system calls. The system call instruct the kernal to do various operations for the calling program and exchange the data between the kernal and the program. Several other programs shown in above diagram are called commands, a.out is the standard output file . Other application programs to build on top of lower-level programs. Ex. the standard C compiler, cc, is in the outermost layer of the figure, it invokes a C preprocessor.
In 1965, Bell Telephone Laboratoties joind an effort with the GEC(Genral Electronics Company) and project of the Massachusetts Institute of Technology to develop a new Operating system called MULTICS. Its primary Goal is how to share the common processor in between omre than one Users. the primitive version of MULTICS was run on GE645 machine in 1969 it did not provide consequent services. After that by mades some amondaments it was moved on PDP-7 machine. Altho it was satisfied with comparision of early versions of UNIX OS it could not realize its potensial, the UNIX system was moved to a PDP-11 in 1971. It was characterised by its size and affordable features.
Thompson setout the new into FORTRAN compilor, but instead came up with the labguage B, influenced by BCPL. B ws an interpretive language, with performence drqwacks implemented by such languages, UNIX was rewritten in to 'B' after words it was moved into C language in the year 1973, later it gain the popularity through out the world. By 1977 grown upto 500 installations including Universities.
In the year 1984, there wore found about 1,00,000 UNIX system installations, in the world, running on machines with a wide range of computing power from small microprocessors to Large Mainframe systems.
Basic Features.
* The system was written High Level language, making it easy to read, understand, change, and move to other machines.
* It has simple user interface.
* It provides primitives that permits complex programs to be build from smaller programs.
* It uses a hierarchial file system that allows that allows easy maintenance and efficient implementation.
* It uses a consistant format of files, byte stram, making application programs easier to write.
* It provides a simple, consistant interface to peripheral devices.
* It is a multi-user, multiprocessor system; each user can execute several processes simultaniously.
* It hides the machine architecture from the user, making it easier to write programs.
The UNIX OperatingSystem and many of the command programs are written in C, UNIX systems supportther Languages like compilor and Interpretor oriented.
Architecture of UNIX Systems.
The hardware at the centre of the diagram provides the Operating System with basic services that will be described . The Operating System interacts directly with the hardware, providing common services to programs. Viewing the system as set of layers, the Operating system is commonly called system kernal which isolating from user programs. Because programs are independent of the underlaying hardware. programs such as shell and editors(ed and vi) shown in the outer layes interact with the kernal by invoking a well defined set of system calls. The system call instruct the kernal to do various operations for the calling program and exchange the data between the kernal and the program. Several other programs shown in above diagram are called commands, a.out is the standard output file . Other application programs to build on top of lower-level programs. Ex. the standard C compiler, cc, is in the outermost layer of the figure, it invokes a C preprocessor.
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