ICT 141 Computing Skills Fundamentals I Lecture 8 - Computer Software PDF

ICT 141 COMPUTING SKILLS FUNDAMENTALS I FACULTY OF SCIENCE Lecture 8: Computer Software Computing Skills Fundamentals 1 Lecture Outline  Types of Software (re-cap)  System Software  Application Software  Categories o...

ICT 141 COMPUTING SKILLS FUNDAMENTALS I FACULTY OF SCIENCE Lecture 8: Computer Software Computing Skills Fundamentals 1 Lecture Outline  Types of Software (re-cap)  System Software  Application Software  Categories of application software 2 Computer Software Application software is software that has been developed to solve a particular problem for users—to perform useful work on specific tasks or to provide entertainment. System software runs at the most basic level of your computer and enables the application software to interact with the computer and helps the computer to manage its internal and external resources, as well as manage the hardware. 3 SystemSoftware  Collection of programs that manage the computer  Provides foundation for the running of application software  Such as printing a document, saving a file, etc.  Examples of system software:  Operating system  Utility programs  Device drivers  Program translation software 4 1.Operating systems: An operating system is the principal component of system software in any computing system. 2. Device drivers: Device drivers help the computer control peripheral devices. 3. Utility programs: Utility programs are generally used to support, enhance, or expand existing programs in a computer system.  The operating system manages the entire computer system. The operating system (OS) consists of the low-level, master system of programs that manage the basic operations of the computer. – Every general-purpose computer must have OS to run other programs. – OS allows users to concentrate on applications rather than on complexities of the computer. – Each application program is written to run on top of a particular OS. The OS manages (Functions of OS): – Booting – CPU management – File management 6 – Task management – Security management Booting The process of loading an OS into the computer’s main memory Booting involves four steps: 1.Turn the computer on. 2.Diagnostic routines test main memory, CPU, and other hardware. 3.Basic Input/Output System (BIOS) programs are copied to main memory. – BIOS contains instructions for operating the hardware. – The computer needs those instructions to operate the hardware and find a copy of the OS. 4.Boot program obtains the OS and loads it into computer’s main memory. 7 8 Some useful OS programs  Bootstrap program ◦ Stored in ROM ◦ Program loaded at machine start-up / reboot ◦ Loads the Kernel & starts its execution  Kernel ◦ A program that runs on a computer at all times 9  CPU Management – CPU is the central processing unit. – Supervisor (kernel) is the software that manages CPU Remains in memory while the computer runs Directs other programs not in memory to perform tasks that support application programs Memory Management OS keeps track of memory locations to prevent programs and data from overlapping each other Swaps portions of programs and data into the same memory but at different times Keeps track of virtual memory 10  File Management – A file is either a Data File: a named collection of data Program File: a program that exists in a computer’s secondary storage – Files are located in many places on secondary storage devices; OS locates files and facilitates access to them – The file system arranges files in a hierarchical manner Top level is directories (folders) Subdirectories come below folders – Find files using their pathname. Example: 11 C:/MyDocuments/Termpaper/section1.doc  Task Management – Computers are required to perform many different tasks at once—to do task management. – Task: An operation such as storing, printing, or calculating – Multitasking: Handling more than one program concurrently Example: You do word processing while playing music on your computer. OS directs processor to alternate time on each program until processing is complete. 12  Security Management – Operating Systems permit users to control access to their computers. – Users gain access using an ID and password. – You set the password the first time you boot up a new computer. – After that, when you boot up, you’ll be prepared to type in your username and password. 13 Other functions of the OS  Resource allocation and management ◦ Processes ◦ Storage ◦ Memory ◦ Devices  Control program execution and other Computer activities 14 OS Examples i. Desktop OS Windows Mac Linux ii. Mobile OS 15 Windows 11 is out 16 Classification of OS  2 broad groups a) Single-user OS ◦ Only one person can use the computer at a time b) Multi-user OS ◦ Allow more than one person to use the computer simultaneously ◦ Originally common in mainframes 17 Types of OS i. Single user/single tasking OS ◦ One user at a time  Performing one task a time ◦ E.g.:  MS-DOS, Palm OS 18 ii. Single user/ multitasking OS ◦ Multitasking  timesharing/multiprogramming ◦ One user at a time BUT more than one task at a time  Type a letter, listen to music & watch a video concurrently ◦ Common in PCs ◦ E.g.: Windows, Linux & Mac OS X 19 iii. Multi user/Multitasking OS ◦ Many users can connect to the computer simultaneously  Each can run multiple applications ◦ Most common in mainframe or supercomputers ◦ Eg: UNIX, Linux, VMS 20 iv. Multi-processing OS ◦ 2 or more CPUs (processors) can be used ◦ CPUs simultaneously execute several programs ◦ E.g.: Linux, Unix, Windows 2000, Windows XP & Mac OS X 19 v. Network OS ◦ Allow many PCs to share resources ◦ Aware of network resources (PCs, peripherals) ◦ E.g.: Windows 2008 Server, Netware 20 v. Real-time OS ◦ For executing real-time applications  E.g. ATMs, flight control, MP3 player, medical devices, vehicle control system, etc ◦ Built into devices ◦ Quick response to user input/request ◦ E.g.: Symbian OS, PalmOS, Windows CE, etc 23  Graphical User Interface (GUI) – Allows you to use a mouse or keystrokes to select icons and commands from menus. – Three main features of GUI are desktop, icons, and menus. Desktop: The system’s main interface screen. Icons: Small pictorial figures that represent programs, data files, or procedures. Rollover: A small text box that explains the icon when you roll your mouse over it. Menus: Lists of built-in commands and/or options from which to choose pull-down, cascading, pull-up, pop-up. 24  Command-Line Interface ◦ Data and commands entered by typing and pressing command string & special keys via keyboard ◦ User need to know these commands (creating directories, copying & move files, etc) 25 b) Device Drivers – Specialized software programs that allow input and output devices to communicate with the rest of the computer system. – When you buy a computer, many device drivers come with the system software. – Device drivers also come with new hardware (on CDs/DVDs) or can be downloaded from the manufacturer’s website. 26 c) Utilities  Developed to help configure, analyse, optimise or perform computer maintenance ◦ For a specific maintenance-related task that is related to managing the computer  Examples ◦ File Manager ◦ Uninstaller ◦ Antivirus Software ◦ File compression tools ◦ Pop-up blocker ◦ Backup utility ◦ Firewall 27 d) ProgramTranslators  Programs written using programming language ◦ Relatively close to English in syntax. ◦ E.g.:  C++, Java  A translator ◦ convert a program written in a human understandable language (source code) into computer understandable language (machine code) 28 Example: Java Program  Source code  Machine code ICT121 – 2015/16 29 Application software  Application Software: applied to real-world user tasks  created for a specific user task  AKA application packages Type Uses Examples Document Word processing, Ms Word, WordPerfect, production desktop publishing, FrontPage, Apache etc OpenOffice Writer, etc. Numerical Numerical data Ms Excel, Lotus-1-2-3, SPSS, Analysis processing etc Presentation Presentations Ms Powerpoint, OpenOffice Impress, Corel Presentations Databases computer databases Ms Access, Oracle, DB2, etc processing Graphics Drawing, photo Paint, CorelDraw, AutoCAD, editing, CAD, etc. etc 30 Categories of application software  Generic/packages ◦ For general-purpose functions needed by many people ◦ Ready made ◦ AKA off-the-shelf software, or pre-packaged ◦ E.g. word processing applications  Custom ◦ Software specifically created/customised for some company ◦ AKA tailor-made software or bespoke software ◦ E.g. BTC billing system, UB student management system, etc. 31 Other classes of application software  Open source software  Freely available from the internet  Anyone can modify & even distribute to others  Examples: Moodle, Linux, FrontlineSMS, WordPress  Web application software  Software that runs on a remote internet server rather than on a person’s own personal computer.  For applications that uses a web-browser  Examples: Dropbox & Google Docs 32  In-house  Application developed using the user company’s resources  IT department  Proprietary software  Licenced software under exclusive rights of the owner/developer  May not be copied/distributed with their approval  Rentalware  Online software that users lease for a fee and download whenever they want it. 33  Freeware ◦ Freely available for use ◦ Users NOT allowed to sell it to others  Developer has copyright ◦ E.g. some anti-virus applications  Shareware ◦ Copyrighted software that is distributed free for a trial period, but users must then pay the software developer to continue using it. ◦ Available for free ◦ BUT developer may request users to register and pay a small fee for future upgrades 34  Integrated software packages (software suites)  A collection of software applications  Have common features  Examples:  Microsoft Office 2010  Corel WordPerfect Office X7  Apache OpenOffice ICT121 – 2015/16 35