UNIT 1 1 Introduction to Computer System COM

UNIT 1. 1 Introduction to Computer System COM E 211: Basic Computer Programming

UNIT 1. 1 Introduction to Computer System l Number System l Computer Concepts l Operating System – DOS l Operating System – WINDOWS COM E 211: Basic Computer Programming

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

l Categories of Software ¡ Application l Includes programs written to accomplish as specific task (or application) such as word processor, spreadsheet or database program. ¡ System l 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 Classes of Memory devices: l Primary Storage (main memory) ¡ Is a fast memory capable of operating at electronic speed, where programs & data are stores during execution. ¡ Examples: l RAM (random access memory) l ROM (read-only memory) • • l l Input Unit ¡ ¡ l Memory Unit ¡ ¡ l 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) ¡ Sole function is to store programs and data. Is non-volatile memory Secondary Storage ¡ Computer accept coded information by means of input units, which is consists of devices capable of reading such data. Example: keyboard, mouse, scanner Used to store volatile programs & data Execution of most operation with in the computer. COM E 211: Basic Computer Programming

l CU (Control Unit) ¡ Sends control signals to other units of the computer system. ¡ Coordinates the operation of the computer system to maintain its properation. l 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 l Number System l Computer Concepts l Operating System – DOS l Operating System – WINDOWS COM E 211: Basic Computer Programming

Operating System l. 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) l Four parts of DOS: ¡ ¡ l External Commands ¡ ¡ ¡ System Files ¡ ¡ ¡ l l System files Internal Commands / Programs External Commends / Programs DOS Utility Programs command. com IBMBIO. com (IO. sys) IBMDOS. com (MSDOS. sys) l 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. Internal DOS Commands ¡ ¡ Reside in the memory as part of command. com Two parts of command. com l l Resident part Transient part COM E 211: Basic Computer Programming

BOOTING THE COMPUTER l l Booting, starting the computer Perform to program that reside the ROM l POST (Power On Self Test) ¡ l Check the existence of necessary peripheral devices of the computer Bootstrap Loader ¡ Short routine that loads necessary programs to boot DOS. l DOS is the first program your computer run each time it starts. l Bootable disk ¡ l 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 l Clearing the screen ¡ l Changing drive ¡ l Syntax: TIME or TIME hh: mm: ss Modifies the DOS prompt ¡ l Syntax: DATE or DATE mm-dd-yy Display current time ¡ l Syntax: VER Display the current date ¡ l Syntax: target_drive: Display the version of DOS ¡ l Syntax: CLS 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 l Change the filename of the existing file ¡ l Copies file’s content to another file / disk ¡ ¡ l Syntax: TYPE target_file Delete file(s) from the disk ¡ l Syntax: COPYCON target_file Display content of a text file ¡ l Syntax: COPY source_file target_file Syntax: A: > COPY C: filename B: Creating a file ¡ l Syntax: REN old_name new_name Syntax: DEL target_file Help on DOS command options, syntax format ¡ ¡ Synatax: DOS_command/? Example: DIR/? , COPY/? COM E 211: Basic Computer Programming

l 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 (*) l ¡ The Question Mark Wildcard (? ) l l l Directs DOS to ignore the character in the position containing the wildcard. Represent only one character position. Redirection (>) ¡ ¡ ¡ l Perform file operation s on a group of files by specifying “don’t care” character positions within the filename or extension 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 l l ¡ Is a file that contains the name of one or more DOS commands. Uses BAT extension Autoexec. bat l l 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 l Prepares a disk for use by DOS ¡ Creates File Allocation Table (FAT) l ¡ ¡ l ¡ External file: unformat. com Syntax: UNFORMAT disk_drive: Used to make copies of a disk ¡ ¡ l External file: format. com Syntax: FORMAT disk_drive: Recover the data of the newly formatted disk ¡ l Contains info to keep track of the used, unused and bad sector 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 l Copies system ile from one disk to another ¡ ¡ l Creates or change the volume label of disk ¡ ¡ l ¡ External file: attribute. exe Syntax: ATTRIB option target_file Collects a previous DOS commands ¡ ¡ l External file: label. exe Syntax: LABEL target_drive: volume_name Modifies the attribute of a file ¡ l External file: sys. com Syntax: SYS target_drive: 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 () l Internal commands in working with directories: l ¡ ¡ MD – make directory CD – change directory l l ¡ CD – returns to root directory CD. . – returns the user to parent RD – remove directory l 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 l Number System l Computer Concepts l Operating System – DOS l Operating System – WINDOWS COM E 211: Basic Computer Programming

INTRODUCTION TO WINDOWS l Windows is a graphical operating system. Users communicate with the computer by choosing items or menu options & small graphical images instead of typing hard-torecall 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 l l l 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 l a pointer on the screen that represents the mouse is called MOUSE POINTER l COMMON MOUSE TERM Point moves the pointer on the screen until it is over the desired location or object. Click quickly press & release the left mouse button Double-click quick press the left mouse button twice Drag hold 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

l Icon ¡ a picture representing a program, disk, drive, file, folder or other items COMMON Desktop Setup Desktop the entire background area of your screen; represents your working environment when you are operating your PC START button as a starting point for day-to-day activities such as running programs, opening & editing document & finding files Taskbar helps you monitor & switch between the various activities you’ll perform Sound Volume Control for multimedia computing, provides a quick way of changing the sound volume Time Box you’ll see the current time displayed at the right end of the Taskbar; double-clicking, easily reset time when wrong My Computer allows you to browse the disk drives on your PC Recycle Bin represents 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 e-mail 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 l COM E 211: Basic Computer Programming

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

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

l 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 l 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 Tools contain tools for managing & maintaining your hard & floppy disk Scandisk check 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 Player play audio CD in your CD-ROM drive Media player play 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 Calculator helps perform calculations Hyper. Terminal 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 Map to insert special characters into documents Note Pad very basic word processing program COM E 211: Basic Computer Programming

l Organizing Files & Folders ¡ l Windows Explorer ¡ l to create some new folders, move existing files into those folders & perhaps rename & delete some files 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) COM E 211: Basic Computer Programming