2. What is System Software? System software consists of the programs that control or maintain the operations of the computer and its devices. Two types of system software . Operating systems Utility programs. An operating system (OS)is a set of programs containing instructions that work together to coordinate all the activities among computer hardware resources .
3. Operating systems Operating systems are divided in to three basic categories : 1.Stand-alone OS: is a complete operating system that works on a desktop computer ,notebook computer, or mobile computing device. Names of Stand-alone operating systems: DOS /Early Windows Versions (Windows 3.x,Windows 95, Windows NT Workstation, Windows 98, Windows 2000 professional, Windows Millennium Edition, Windows XP)/Windows Vista/ Mac OS X/UNIX/Linux. 2.Server OS: is an operating system that is designed specifically to support a network. Names of Server operating systems: Early Windows server versions(Windows NT Server, Windows 2000 server, Windows Server 2003)//Windows Server 2008 /UNIX /Linux /Solaris/ Netware.
4. -Embedded OS :The operating system on mobile devices and many consumer electronics. -Names of embedded OS :Windows Embedded CE/Windows Mobile/ Palm OS / i Phones OS /BlackBerry/ Embedded Linux /Symbian OS. ~The Boot Process~ -Is the process of starting or restarting a computer is called booting. -When turning on a computer that has been powered off completely, you are performing a cold boot. A warm boot is the process of using the operating system to restart a computer. -Steps of the boot process:- 1-The power supply sends a signal to the components in the system unit. 2-The processor finds the ROM chips(s) that contains the BIOS (basic input/output system.
5. 3-The BIOS performs the POST (power on self test) ,which checks components ,such as the mouse , keyboard &adapter cards. 4-The results of the POST are compared with data in a CMOS (Complementary metal-oxide semiconductor) chip. 5-The BIOS may look for the system files on a USB flash drive or on an optical disc drive or may look directly on drive C (hard disk). 6-The system files and the kernel of the operating system load into memory (RAM) from storage (i.e., hard disk). 7-The operating system loads configuration information , may request user information , starts several background processes , and displays the desktop on the screen