System Software
- It consists of the programs that control or maintain the operations of the computer and its devices
- Eg: Operating system (OS), utility programs
Operating System (OS)
- It is a set of programs containing instructions that work together to coordinate all the activities among computer hardware resources
- Activities such as:
Start and shut down a computer
Provide a user interface
Manage programs
Manage memory
Coordinate tasks
Configure devices
Establish an internet connection
Monitor performance
Provide utilities
Automatically update
Control a network
Administer security
OS Functions
- Booting is the process of starting or restarting a computer
- 2 types of booting:
Cold boot - Turning on a computer that has been powered off completely
Warm boot - Using the operating system to restart a computer
- A boot device is the drive from which your computer starts.
- A computer can start from a boot disk
- Boot disk is a removable digital data storage medium (CD-ROMs, USB flash drives, hard disks ) from which a computer can load and run an OS or utility program
- A recovery disc contains a few system files that will start the computer
- Recovery disc contains a backup of the original factory condition a computer as configured by an original equipment manufacturer (OEM)
- Recovery disk can also be created by an end-user which contains a favored condition of a computer
- An OS includes various shut down options:
Sleep - This mode saves any open documents and programs to RAM, turns off all unneeded functions and then places the computer in a low-power state
Hibernate - This mode saves any open documents and programs to a hard disk before removing power from the computer
- User interface controls how you enter data and instructions and how information is displayed on the screen
- With graphical user interface (GUI), a user interacts with menus and visual images
- With command-line interface, a user uses the keyboard to enter data and instructions
- Ways an OS handles programs directly affects its productivity:
Single use and multiuser
Single tasking and multitasking
Foreground and background
Preemptive multitasking - It works on a time sharing feature, where each process may be allocated equal shares of computing resources
Multiprocessing
- Memory management optimizes the use of RAM
- Virtual memory is a portion of a storage medium functioning as additional RAM
- OS determines the order in which task are processed
- Driver is a small program that tells the OS how to communicate with a specific device
- Plug & Play automatically configures new devices as you install them
- OS typically provide a means to establish internet connections
- Performance monitor is a program that assesses and reports information about various computer resources and devices
- OS often provide users with the capability of:
Manage files
Search for files
View images
Secure a computer
Uninstall programs
Clean up disks
Defragment disks
Diagnose problems
Backup files and disks
Setting up screen savers
- Automatic update automatically provides updates to the program
- Some OS are designed to work with server on a network
- Server OS organizes and coordinates how multiple users access and share resources on a network
- A network administrator uses the server operating system to:
Add and remove users, computers and other devices
Install software and administer network security
- Each user has a user account
User ID identifies a specific user
Password is a private combination of characters associated with the user name
Store
Cortana
Microsoft Edge
- Macintosh OS has set the standard for OS ease of use
- Mac OS X is the latest version
- UNIX is a multitasking OS developed in the early 1970s
- Linux is an open-source, popular, multitasking UNIX-type OS
Server OS
Windows Server 2008
Linux
Solaris
Netware
- Windows Server 2008 is an upgrade to Windows Server 2003. Has multiple editions. Most editions include Hyper-V, a virtualization technology
- Virtualization is the practice of sharing or pooling computing resources
Embedded OS
- It resides on a ROM chip on a mobile device or consumer electronic device
- Eg: Windows Embedded CE, Windows Phone, Palm OS, iOS, BlackBerry OS, Android, Embedded Linux, Symbian OS
Utility Programs
- It is a type of system software that allows a user to perform maintenance-type tasks
- File manager is a utility that performs functions related to file management. It:
Display a list of files
Organise files in folders
Copy, rename, delete, move and sort files & folders
Create shortcuts
- Search utility is a program that attempts to locate a file on your computer based on criteria user specify
- Image viewer allows users to display, copy & print the contents of a graphics file
- Uninstaller removes a program, as well as any associated entries in the system files
- Disk cleanup utility searches for and removes unnecessary files, such as:
Downloaded program files
Temporary internet files
deleted files
Unused program files
- Disk defragmenter reorganizes the files and unused space an a computer's hard disk so that the OS accesses data more quickly and programs run faster
- Backup utility allows users to copy files to another storage medium
- Restore utility reverses the process and returns backed up files to their original form
- Screen saver causes a display device's screen to show a moving image or blank screen if no activity occurs for a specified time
- Personal firewall detects and protects a personal computer from unauthorized intrusions
- Virus describes a potentially damaging computer program that affects a computer negatively
- Worm copies itself repeatedly in memory or over a network
- Torjan horse hides within or looks like a legitimate program
- Antivirus program protects a computer against viruses
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