7th Class Computers Science Understanding Basic Concepts of Operating System Introduction to UNIX

    Introduction to UNIX

UNIX is one of the time sharing operating systems primarily intended for program development and document-preparation environment. The first version of UNIX was written by Ten Thompson, later joined by Dennis Ritchie. It was a single user system written for the PDP-7 computer written in assembly language. Several specialized versions of UNIX, such as the programmer's Workbench, UNIX/ PWB and Writer's Workbench, UNIX/WWB are also available.  

  Some of the major features of UNIX are the following:

• Hierarchical file system.
• Device Independence.
• Multi-user operation.
• Tools and tool-building utilities.
• Probability.    

• In 1985 the first version of Windows was released in market.
• iPod, iPhone, and iPad all are developed by Apple.
• Steve Jobs established Apple in April 1976.  

• Multiprocessing: It supports in running a program on multiple CPUs.
• Multitasking: Generally it allows more than one program to run at the same time.
• Multi-user: It allows more than one user to run the program at same fraction of time.
• Multithreading: It permits all different modules of a single program to run at the same time.
• Real-Time: Its responds to input immediately.  

• The outermost layer of OS is called user interface and innermost layer is hardware. v  OS is a master control program.
• UNIX is one of the time sharing operating systems.
• An OS (Operating System) developed by Tim Peterson of Seattle Computers was refined for the first version of MS-DOS.
• The first version of UNIX was written by Ten Thompson, later joined by Dennis Ritchie.
• The latest version of MS-DOS available in market is 7.x.