E- Learning and Writing Skills IGGU 1101 Operating System Windows Dr. Sana’a Wafa Al-Sayegh

System Software System software is software that: –Controls and supports the computer system’s activities –Supports application software by directing the computer’s basic functions –Facilitates program development, testing, and debugging –Is independent of any specific type of application

Systems Software (continued) System Control Programs –Control use of all system resources (hardware, software, data); operating system System Support Programs –Specialized support capabilities Systems Software System Control Programs Systems Support Programs

System Control Programs Operating System - main system control program –supervises the overall operation of the computer –allocates CPU time and main memory to programs running on the computer –provides an interface between the user and the hardware

Operating System Services Process management – manage program(s) running on processor –Multitasking or Multiprogramming - managing two or more tasks, or programs, running on the computer system at the same time –Multithreading – type of multitasking; run two or more tasks from the same application simultaneously –Timesharing - many users share same CPU, each using a different input/output terminal –Multiprocessing – simultaneous processing with multiple CPUs

Operating System Services (continued) Virtual memory - simulates more main memory than actually exists in the computer system File management and security - managing the arrangement of, and access to, files held in secondary storage Fault tolerance - system can produce correct results and continue to operate even in the presence of faults or errors User interface - allows users to have direct control of visible objects (icons) and actions that replace complex command syntax

Major Desktop Operating Systems Types of Operating Systems MS-DOS Windows 95 Windows 98 Windows NTWindows 2000 Microsoft Products: Windows XP Windows ME Macintosh Operating System UNIX Java Operating System (JavaOS) Other Products: Linux IBM O/S 2

Departmental Server Operating Systems –Support hundreds of concurrent users –UNIX, Linux, Windows 2000, Windows XP, Novell NetWare Enterprise Operating Systems –Support thousands of concurrent users; millions of transactions per day –IBM’s OS/390, IBM’s VM (Virtual Machine), IBM’s VSE (Virtual Storage Extended), and IBM’s OS/400 Types of Operating Systems (continued)

A family of operating systems for personal computers. Windows dominates the personal computer world, running, by some estimates, on 90% of all personal computers. The remaining 10% are mostly Macintosh computers. Like the Macintosh operating environment, Windows provides a graphical user interface (GUI), virtual memory management, multitasking, and support for many peripheral devices.operating systemspersonal computersWindowsrunningMacintosh computersoperating environmentgraphical user interface (GUI)virtual memorymultitaskingsupportperipheral devices Windows Definition