unit 1.1 introduction to computer system. com e 211: basic computer programming unit 1.1...

UNIT 1.1 Introduction to Computer System

COM E 211: Basic Computer Programming


Number SystemComputer ConceptsOperating System – DOSOperating System – WINDOWS


Computer Concepts

COMPUTER Is an electronic device that can perform prescribed

operation given to it.

Computer System Hardware

Is the computer’s 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.


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.


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.


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


Operating System

A collection of programs that supervises all the activities that take place within a computer.


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.


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


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


DOS Common Internal Commands Change the filename of the existing file

Syntax: REN old_name new_name

Copies file’s 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/?


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 “don’t 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.


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


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


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


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.


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 TERMPoint moves the pointer on the screen until it is over the desired location or object.Click quickly press & release the left mouse buttonDouble-click quick press the left mouse button twiceDrag hold down the left mouse button while moving the mouseDrag & Drop hold down the left mouse button while moving the mouse; release the mouse button when the pointer is over the desired location


Icon a picture representing a program, disk, drive, file, folder or other items

COMMON Desktop SetupDesktop the entire background area of your screen; represents your

working environment when you are operating your PCSTART button as a starting point for day-to-day activities such as running

programs, opening & editing document & finding filesTaskbar helps you monitor & switch between the various activities you’ll

performSound Volume Control for multimedia computing, provides a quick way of changing

the sound volumeTime Box you’ll see the current time displayed at the right end of the Taskbar;

double-clicking, easily reset time when wrongMy Computer allows you to browse the disk drives on your PCRecycle 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


FEATURES OF WINDOWSControl 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/ switches the window between its maximum size & the smaller sizeRestore Button 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


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 program’s icon in the folder where it’s located

& double-clicking on icon Using the RUN command

from the Start menu


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


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

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 Map to insert special characters into documents

Note Pad very basic word processing program


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)

unit 1.1 introduction to computer system. com e 211: basic computer programming unit 1.1...

Documents

computer programs

computer memory

computer input unit

computer system slide

computer booting

computer system hardware

dos utility programs

system software