Foundation year Lec.3: Computer SoftwareLec.3: Computer Software Lecturer: Dalia Mirghani Year: 2014/2015

Software

1. OPERATING SYSTEMS The operating system or`OS is the foundation software of a computer, that which schedules tasks, allocates storage, and presents a default interface to the user between applications. 3

Some Functions of an Operating System: 1.Boot-up the computer. 2.Control the hard drives. (This includes such features as formatting and defragmenting disks ). 3.Control input devices such as keyboards, mice and scanners. 4.Control output devices such as the video display and printer. 5.Control the external ports. (Ports are the external connections that enable peripheral devices to be connected to a computer. The important types of ports are USB ports). 6. Provide the functionality for computers to be linked in a network. 7. Provide the foundation for application software to be launched. 8. Enable application software to access and use the hardware. 4

User / Programmer Operating System Human Understandable Language (High Level Language) Machine Language (Low Level Language) Computer Machine How the Operating System work? 5

Operating systems can be classified as follows: 1.Multi-user A multi-user operating system allows for multiple users to use the same computer at the same time and different times, examples : Linux, Unix, and Windows 2000 (Server) 6

Operating systems can be classified as follows: 2. Single-user, single task This operating system is designed to manage the handheld computers so that one user can effectively do one thing at a time, example: The Palm OS for Palm handheld computers. 7

Operating systems ( Cont….) 3. Single-user, multi-tasking Most people uses this operating system on their desktop and laptop computers today, Microsoft's Windows, Apple's Mac OS 8 Windows Linux Mac Android

Operating systems ( Cont….) 4. Real-time operating system (RTOS) Is a computer operating system designed to handle events as they occur. It commonly found and used in robotics, cameras, and Medical devices (medical imaging, nuclear medicine, medical diagnostics and several medical applications). 9

Popular Medical Operating Systems: 1. LynxOS: GENIE Acquisition system Nuclear Medicine Imaging System 10

Medical Reference Design QNX Neutrino RTOS Popular Medical Operating Systems:

Graphical User Interface (GUI) 12

Old Operating System Microsoft Disk operating system, MS-DOS 13

Graphical user interface Graphical user interface (GUI), is a type of user interface that allows users to interact with electronic devices through graphical icons. The most widely used type of graphical user interfaces are WIMP systems. WIMP stands for Windows Icons Menu Pointer. 14

GUI basic components: 1)Pointer : A symbol that appears on the display screen and that you move to select objects and commands. 2) Pointing device : A device, such as a mouse, light pen that enables you to select objects on the display screen. 15

GUI basic components: 3) Icons : Small pictures that represent commands, files, or windows. 4) Desktop : The area on the screen that displays the icons, gadgets, and taskbar. 16

GUI basic components (Cont…) 5) Windows: You can divide the screen into different areas. In each window, you can run a different program or display a different file. 6) Menus : Most graphical user interfaces let you execute commands by selecting a choice from a menu. 17

Advantages and Disadvantages of GUI’s: Advantages:  This type of interface is easy to use, especially for a beginner.  Easy to explore and find your way around the system using a WIMP/GUI interface.  Let you exchange data between different software application. Disadvantage:  Require a lot of memory (RAM) to run.  Take up a much amount of hard disc space.  They use more processing power. 18

2. Languages  Language software present a simplified means to execute a series of instructions. It consists of a vocabulary and an accompanying set of rules that tell the computer how to work.  Popular languages include: - C++. - COBOL (Common Business Oriented Language). - Java. - Visual Basic. 19

Language Generations 1- Machine languages are the lowest level and consist of numbers only. 2- Assembly languages are the next generation of languages, that give the programmer the ability to use names instead of numbers when telling the computer what to do. 3- High level languages enables programmers to develop software applications using ordinary words and symbols rather than binary numbers. 20

3. Applications Software  Applications software (Also known as 'apps') are designed to allow the user of the system complete a specific task or set of tasks. Major types of applications or programs include the following: 1) General – purpose software such as: Word processor, communications programs,

3. Applications Software 2) Educational programs such as: Training software, Computer – assisted learning (Internet). 3) Utility programs are a group of software programs that help with the management or maintenance of the computer and protection of the computer from the unwanted intrusion such as: Virus scanners, personal firewalls,

4) Personal programs help people manage their personal lives such as: Calculators, calendars. 5) Entertainment programs The class of software programs that the industry has designed for fun such as: Games an, simulations Applications Software

Queries??? 24