UNIT 1.1 Introduction to Computer System

COM E 211: Basic Computer Programming UNIT 1.1 Introduction to Computer System Number System Computer Concepts Operating System – DOS Operating System – WINDOWS

COM E 211: Basic Computer Programming Computer Concepts COMPUTER Is an electronic device that can perform prescribed operation given to it. Computer System Hardware Is the computers physical components such as the keyboard, screen and printer Software Is the computer programs containing a set of instructions that tell the hardware what to do.

COM E 211: Basic Computer Programming Categories of Software Application software Includes programs written to accomplish as specific task (or application) such as word processor, spreadsheet or database program. System software Includes programs that are necessary for your computer to run. These are programs that direct hardware related tasks. For instance, operating systems.

COM E 211: Basic Computer Programming Basic Parts of a Computer Input Unit Computer accept coded information by means of input units, which is consists of devices capable of reading such data. Example: keyboard, mouse, scanner Memory Unit Sole function is to store programs and data. Classes of Memory devices: Primary Storage (main memory) Is a fast memory capable of operating at electronic speed, where programs & data are stores during execution. Examples: RAM (random access memory) Used to store volatile programs & data ROM (read-only memory) Is non-volatile memory Secondary Storage Used when a large amount of information have to be stores particularly if some of these data need not be accessed frequently. Example: disk ALU (Arithmetic Logic Unit) Execution of most operation with in the computer.

COM E 211: Basic Computer Programming CU (Control Unit) Sends control signals to other units of the computer system. Coordinates the operation of the computer system to maintain its proper operation. Output Unit Is to return the processed result to the outside world. Examples: monitor, printer

COM E 211: Basic Computer Programming UNIT 1.1 Introduction to Computer System Number System Computer Concepts Operating System – DOS Operating System – WINDOWS

COM E 211: Basic Computer Programming Operating System A collection of programs that supervises all the activities that take place within a computer.

COM E 211: Basic Computer Programming Disk Operating System (DOS) Four parts of DOS: System files Internal Commands / Programs External Commends / Programs DOS Utility Programs System Files command.com IBMBIO.com (IO.sys) IBMDOS.com (MSDOS.sys) Internal DOS Commands Reside in the memory as part of command.com Two parts of command.com Resident part Transient part External Commands Commands which need an external files to be loaded to memory for its execution. DOS must locate the command on disk and then loaded into computer memory. Precede the command name with directory path to the program file. DOS Utility Programs Programs used for specialized purpose.

COM E 211: Basic Computer Programming BOOTING THE COMPUTER Booting, starting the computer Perform to program that reside the ROM POST (Power On Self Test) Check the existence of necessary peripheral devices of the computer Bootstrap Loader Short routine that loads necessary programs to boot DOS. DOS is the first program your computer run each time it starts. Bootable disk Is a system disk capable of starting DOS Ways computer can be reset/restart: Turn OFF the power switch then turn it ON again Press reset button Press Ctrl+Alt+Del keys at the same time

COM E 211: Basic Computer Programming DOS Common Internal Commands Clearing the screen Syntax: CLS Changing drive Syntax: target_drive: Display the version of DOS Syntax: VER Display the current date Syntax: DATE or DATE mm-dd-yy Display current time Syntax: TIME or TIME hh:mm:ss Modifies the DOS prompt Syntax: A:> PROMPT desired_prompt Displays files inside the disk Syntax: DIR or DIR/option

COM E 211: Basic Computer Programming DOS Common Internal Commands Change the filename of the existing file Syntax: REN old_name new_name Copies files content to another file / disk Syntax: COPY source_file target_file Syntax: A:> COPY C: filename B: Creating a file Syntax: COPYCON target_file Display content of a text file Syntax: TYPE target_file Delete file(s) from the disk Syntax: DEL target_file Help on DOS command options, syntax format Synatax: DOS_command/? Example: DIR/?, COPY/?

COM E 211: Basic Computer Programming Working with group of files WILDCARD characters (* and ?), help select a group of files Replaces the character with the name of all matching files The Asterisk Wildcard (*) Perform file operation s on a group of files by specifying dont care character positions within the filename or extension The Question Mark Wildcard (?) Directs DOS to ignore the character in the position containing the wildcard. Represent only one character position. Redirection (>) To redirect the output from the terminal screen to a file or to a printer. Example: A:> DIR > files.dat A:> TYPE files.dat > prn Creating Batch Files Batch File Is a file that contains the name of one or more DOS commands. Uses BAT extension Autoexec.bat Most useful batch file Unique from all other batch files because each time the computer starts, DOS automatically locates and executes the command in this special file.

COM E 211: Basic Computer Programming DOS Common External Commands Prepares a disk for use by DOS Creates File Allocation Table (FAT) Contains info to keep track of the used, unused and bad sector External file: format.com Syntax: FORMAT disk_drive: Recover the data of the newly formatted disk External file: unformat.com Syntax: UNFORMAT disk_drive: Used to make copies of a disk External file: diskcopy.com Syntax: DISKCOPY source_drive: target_drive: Copies files, advance form of COPY command External file: xcopy.com Syntax: XCOPY source_drive: target_drive: /option

COM E 211: Basic Computer Programming DOS Common External Commands Copies system ile from one disk to another External file: sys.com Syntax: SYS target_drive: Creates or change the volume label of disk External file: label.exe Syntax: LABEL target_drive: volume_name Modifies the attribute of a file External file: attribute.exe Syntax: ATTRIB option target_file Collects a previous DOS commands External file: doskey.com Syntax: DOSKEY Displays all directories present on your disk External file: tree.com Syntax: TREE

COM E 211: Basic Computer Programming DOS Directories Root directory (\) Internal commands in working with directories: MD – make directory CD – change directory CD\ – returns to root directory CD.. – returns the user to parent RD – remove directory Before using RD command: Erase all content of the directory (files & subdirectories) Remove all directory & its parent or at a much higher directory

COM E 211: Basic Computer Programming UNIT 1.1 Introduction to Computer System Number System Computer Concepts Operating System – DOS Operating System – WINDOWS

COM E 211: Basic Computer Programming INTRODUCTION TO WINDOWS Windows is a graphical operating system. Users communicate with the computer by choosing items or menu options & small graphical images instead of typing hard-to- recall text commands such as were found in older operating system such as DOS. It is greatly made easy for users to use different software without having to learn new commands in a new environment or application.

COM E 211: Basic Computer Programming MOUSE an input device which is cable connected to the PC through a serial port or special mouse port it has a mouse ball that senses the movement of the mouse it is implemented in Windows through: select menu commands move icons size windows start programs choose options a pointer on the screen that represents the mouse is called MOUSE POINTER COMMON MOUSE TERM Pointmoves the pointer on the screen until it is over the desired location or object. Clickquickly press & release the left mouse button Double-clickquick press the left mouse button twice Draghold down the left mouse button while moving the mouse Drag & Drop hold down the left mouse button while moving the mouse; release the mouse button when the pointer is over the desired location

COM E 211: Basic Computer Programming Icon a picture representing a program, disk, drive, file, folder or other items COMMON Desktop Setup Desktopthe entire background area of your screen; represents your working environment when you are operating your PC START buttonas a starting point for day-to-day activities such as running programs, opening & editing document & finding files Taskbarhelps you monitor & switch between the various activities youll perform Sound Volume Control for multimedia computing, provides a quick way of changing the sound volume Time Boxyoull see the current time displayed at the right end of the Taskbar; double-clicking, easily reset time when wrong My Computerallows you to browse the disk drives on your PC Recycle Binrepresents a temporary storage are on your hard disk for files you no longer need; retrieve file that is in the Recycle Bin; once emptied, file is irretrievable Microsoft Exchange Inbox provides access to Microsoft exchange, a feature that allows you to send & receive messages and fax message & to view & organize all your message in one place Network Neighborhood provides a gateway to any other computers connected to your PC as part of a network

COM E 211: Basic Computer Programming FEATURES OF WINDOWS Control Icon menu of commands for moving, resizing & closing the window Title Barcontains the windows name Menu Bar causes a drop-down menu to appear Minimize Buttonshrinks the window so that it appear only as a button on the Taskbar Maximize/switches the window between its maximum size & the smaller size Restore Buttonto which it was previously set Close Buttoncloses the window Status Barcontains information or messages relevant to the contents or activity in the window Window Bordersdragging, resizing the window

COM E 211: Basic Computer Programming Shutdown & Reset to use Shut Down menu, which prepares the computer to be turned off or restarted LAUNCHING PROGRAMS Using the Programs Menu programs groups on the Programs menu depend on what software has been installed on the PC Launching from the Folder window by finding a programs icon in the folder where its located & double-clicking on icon Using the RUN command from the Start menu

COM E 211: Basic Computer Programming Control Panel provides you with a number of utilities that allow you to set up Windows & your computer hardware in a way that suits you Help System consists of step by step instructions on hundreds of Windows tasks; there is specific Help System for each Windows accessory

COM E 211: Basic Computer Programming Accessories a group of programs consists of various utilities that can help you get the most out of your PC. System Toolscontain tools for managing & maintaining your hard & floppy disk Scandiskcheck your disk surface, files & folders for errors & to repair damaged area Disk Defragmenter rearranges files & folders on your hard disk so that program can run faster Multimedia to use these accessories in this program group one must have a sound card installed; any combination of text, pictures, sound & video CD Playerplay audio CD in your CD-ROM drive Media playerplay audio, video or animation files & to control settings for multimedia hardware devices Sound Recorder to record, play & edit sound files; microphone for live recording Games Word Pad mini word processing program Calculatorhelps perform calculations HyperTerminal Connections exchange files with a remote computer via modem or connect to computer bulletin boards Phone Dialer automatically dial a telephone number from any PC w/ modem attached Character Mapto insert special characters into documents Note Pad very basic word processing program

COM E 211: Basic Computer Programming Organizing Files & Folders to create some new folders, move existing files into those folders & perhaps rename & delete some files Windows Explorer a feature you can use to view the contents of your computer & network drives in a hierarchical structure Find, Shortcuts & Timesavers, Running MS-DOS find from the Start menu creating / removing shortcut onto desktop; Shortcut is an icon that links to a file or folder running MS-DOS (opening; using & customize the prompt window; properties)