COMPUTER OVERVIEW

COMPUTER OVERVIEW

Upon completion of this course students should

•      Understand basic computer terminologies and history of computers

•      Understand computer hardware and software fundamentals

•      Become proficient in the use windows and Linux environment

•      Create word processing documents and understand word processing fundamentals

•      Use electronic spread sheet to solve problem

•      Use the internet and world wide web in accessing/search information and sending and receiving messages

•      Installing and configure programs in the computer system

OVERVIEW

•      Information technology concept

•      Data and Information

•      What is computer?

•      Parts of computer

•      What does computer do?

•      Why Is A Computer So Powerful?

•      Computer software

INFORMATION TECHNOLOGY CONCEPTS

•      Information technology (IT) is the application of computers and telecommunications equipment to store, retrieve, transmit and manipulate data, often in the context of a business or other enterprise.

OR

•      Information technology (IT) is a technology which uses computers to gather, process, store, protect, and transfer information.

•      Today, it is common to use the term Information and communications technology (ICT) because it is unimaginable to work on a computer which is not connected to the network.

•      Information technology is the hardware and software that make information systems possible.

•      An information system is a system that uses information technology to capture, transmit, store, retrieve, manipulate, or display information used in one or more business processes

DATA, INFORMATION, AND SYSTEMS

Computer-based Information System takes data as raw material, process it, and produce information as output.

What Is A Computer?

A computer is an electronic device, operating under the control of instructions (software) stored in its own memory unit, that can accept data (input), manipulate data (process), and produce information (output) from the processing.

Generally, the term is used to describe a collection of devices that function together as a system.

The computer consists of:

•      Hardware – physical computer parts, tangible and visible

•      Software – set of commands that are "understandable" to the computer; instructions to its tangible parts, giving orders what to do

Devices that comprise a computer system

 

What Does A Computer Do?

Computers can perform four general operations, which comprise the information processing cycle.

n   Input

n   Process

n   Output

n   Storage

When you connect them (Computers), Communication will be included in the cycle

DATA AND INFORMATION

•      All computer processing requires data, which is a collection of raw facts, figures and symbols, such as numbers, words, images, video and sound, given to the computer during the input phase.

•      Computers manipulate data to create information. Information is data that is organized, meaningful, and useful.

•      During the output Phase, the information that has been created is put into some form, such as a printed report.

•      The information can also be put in computer storage for future use.

Why Is A Computer So Powerful?

•      The ability to perform the information processing cycle with amazing speed.

•      Reliability (low failure rate).

•      Accuracy.

•      Ability to store huge amounts of data and information.

•      Ability to communicate with other computers.

How Does a Computer know what to do?

•      It must be given a detailed list of instructions, called a compute program or software that tells it exactly what to do.

•      Before processing a specific job, the computer program corresponding to that job must be stored in memory.

•      Once the program is stored in memory the compute can start the operation by executing the program instructions one after the other.

What Are The Primary Components Of A Computer?

•      Input devices.

•      Central Processing Unit (containing the control unit and the arithmetic/logic unit).

•      Memory.

•      Output devices.

•      Storage devices.

INPUT DEVICES

•      Keyboard

•      Scanner

•      Touchpad

•      Mouse

•      Trackball

•      Joystick

•      Microphone

•      Camera (Web, Digital)     

THE KEYBOARD

•      The most commonly used input device is the keyboard on which data is entered by manually keying in or typing certain keys. A keyboard typically has 101 or 105 keys.

The Mouse

 

•      Is a pointing device which is used to control the movement of a mouse pointer on the screen to make selections from the screen. A mouse has one to five buttons. The bottom of the mouse is flat and contains a mechanism that detects movement of the mouse.

THE CENTRAL PROCESSING UNIT

 

•      The central processing unit (CPU) contains electronic circuits that cause processing to occur. The CPU interprets instructions to the computer, performs the logical and arithmetic processing operations, and causes the input and output operations to occur. It is considered the “brain” of the computer.

Memory

•      Memory also called Random Access Memory or RAM (temporary memory) is the main memory of the computer. It consists of electronic components that store data including numbers, letters of the alphabet, graphics and sound. Any information stored in RAM is lost when the computer is turned off.

•      Read Only Memory or ROM is memory that is etched on a chip that has start-up directions for your computer. It is permanent memory.

AMOUNT OF RAM IN COMPUTERS

•      The amount of memory in computers is typically measured in kilobytes, megabytes sor gigabyte. One kilobyte (K or KB) equals approximately 1,000 memory locations and one megabyte (M or MB) equals approximately one million locations.

•      A memory location, or byte, usually stores one character.

•      Therefore, a computer with 8 MB of memory can store approximately 8 million characters. One megabyte can hold approximately 500 pages of text information.

DATA REPRESENTATION

 

•      Binary digits (bits)

•      A series of eight bits is called a byte

•      ASCII

–     American Standard Code for Information Interchange

OUTPUT DEVICES

 

•      Output devices make the information resulting from the processing available for use. The two output devices more commonly used are the printer and the computer screen.

•      The printer produces a hard copy of your output, and the computer screen produces a soft copy of your output.

Output Devices

•      Projector

•      Plotter

•      Speakers

•      Earphones   

Storage Devices

•      Secondary storage devices are used to store data when they are not being used in memory. The most common types of auxiliary storage used on personal computers are floppy disks, hard disks and CD-ROM drives.

•      Others:

§  Flash disk

§  Memory card and

§  others

FLOPPY DISKS

 

•      A floppy disk is a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shell.

 

 

HARD DISKS

 

•      Another form of secondary storage is a hard disk. A hard disk consists of one or more rigid metal plates coated with a metal oxide material that allows data to be magnetically recorded on the surface of the platters.

•      The hard disk platters spin at a high rate of speed, typically 5400 to 7200 revolutions per minute (RPM).

•      Storage capacities of hard disks for personal computers range from 10 GB to 120 GB (one billion bytes are called a gigabyte).

 

 

COMPACT DISCS

 

•      A compact disk (CD), also called an optical disc, is a flat round, portable storage medium that is usually 4.75 inch in diameter.

•      A CD-ROM (read only memory), is a compact disc that used the same laser technology as audio CDs for recording music. In addition it can contain other types of data such as text, graphics, and video.

•      The capacity of a CD-ROM is 650 MB of data.

FLASH DISK

 

COMPUTER SOFTWHERE

•      Computer software, or just software, is any set of machine-readable instructions that directs a computer's processor to perform specific operations

•      A computer program, or just a program, is a sequence of instructions, written to perform a specified task with a computer.

•      Computer software is the key to productive use of computers.

•      Software - a computer program which, as opposed to hardware, is an intangible part of the computer, written to perform a single or multiple tasks on computer using the built-in hardware. 

•      Software can be categorized into two types:

n   System software: Manage all computer resources

n   Application software: perform special task for user

OPERATING SYSTEM SOFTWARE

•      Operating system software tells the computer how to perform the functions of loading, storing and executing an application and how to transfer data.

•      Today, many computers use an operating system that has a graphical user interface (GUI) that provides visual clues such as icon symbols to help the user. Microsoft Windows 2007, 2008 are widely used graphical operating system. DOS (Disk Operating System) is an older but still widely used operating system that is text-based.

•      Unix-based Operating systems are also very common nowadays, there are of different types

•      Red Hat Linux

•      Fedora

•      CentOS

•      Ubuntu

•      Others

•      MAC OS

•      Sun Solaris

•      Android etc.

APPLICATION SOFTWARE

•      Application Software consists of programs that tell a computer how to produce information. Some of the more commonly used packages are:

•       

n   Word processing

n   Electronic spreadsheet

n   Database

n  Internet explorer

WORD PROCESSING

 

•      Word Processing software is used to create and print documents. A key advantage of word processing software is that users easily can make changes in documents.

ELECTRONIC SPREADSHEETS

•      Electronic spreadsheet software allows the user to add, subtract, and perform user-defined calculations on rows and columns of numbers. These numbers can be changed and the spreadsheet quickly recalculates the new results.

Electronic Spreadsheets

 

DATABASE SOFTWARE

•      Allows the user to enter, retrieve, and update data in an organized and efficient manner, with flexible inquiry and reporting capabilities.

 

INTERNET EXPLORER

•      A browser lets you access the World Wide Web and “browse” the Internet for information