First Lecture:Essential

Introduction to Computers

Norazila Mat

A World of Computers

What is computer literacy (digital literacy)? Current knowledge and understanding

of computers and their uses Computers are everywhere

What Is a Computer?

An electronic device, operating under the control of instructions stored in its own memory,

What Does a Computer Do?

Four basic operations compromise the information processing cycle

1. Accept data (input)

2. Process the data according to specified rules (process)

3. Produce results (output)

4. Store the results for future use (storage)

5. Communication

Data Vs Information

Processes data into Information:

Conveys meaning and isuseful to people

Data:Collection of unprocessed items

What are the Components of a Computer?The six primary components of a computer are:1) input devices

2) the processor (control unit and arithmetic/logic unit),

3) memory,

4) output devices,

5) storage devices

6) communications devicesThe processor, memory, and storage devices are housed in a box-like case called the system unit - CPU

InputDevices

StorageDevices

OutputDevicesMemoryData Information

InstructionsData

Information

InstructionsData

Information

2Processor

Control Unit

Arithmetic Logic Unit (ALU)

Arithmetic Logic Unit (ALU)

Control Unit

INPUT: What Is Input and Input Device?What is input?

Input device is any hardware component that allows users to enter data and instructions

Data or instructions entered into memory of computer Data = Unprocessed text, numbers, images, audio, and video Instructions = Programs, Commands, User responses

INPUT: Types of input device? (1) Keyboards Pointing device

Mouse– Trackball– Touchpad– Pointing stick

Light pen Touch screen Digital pen Game controllers

Audio videos device Voice recognition MIDI (musical instrument digital interface)

Digital camera Digital video (DV) camera Web cam

INPUT: Types of input device? (2)

Scanners Reading Devices

Bar code reader Optical reader Optical character recognition

(OCR) reads characters in OCR font

Optical mark recognition (OMR) reads hand-drawn pencil marks, such as small circles

Magnetic stripe card reader

Magnetic-ink character recognition (MICR) reader

Data collection device (POS) terminal Automated teller

machine (ATM) Biometric Input

Fingerprint reader Voice verification

system Signature

verification system Iris recognition

system

The System Unit

What is the system unit? Case that contains

electronic components of the computer used to process data Sometimes called

the chassis

The System Unit

What are common components inside the system unit?

p. 185 Fig. 4-2

Memory Adapter cards

Sound card Video card

Drive bays Power supply

Processor

Processor

What is the central processing unit (CPU)?Interprets and carries

out basic instructions that operate a computer Control unit directs and

coordinates operations in computer

Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations

Also called the processor

Memory

How is memory measured? By number of bytes available for

storage

What is memory? Electronic components that store

instructions, data, and results Consists of one or

more chips on motherboard orother circuit board

Each byte stored in unique location called an address

Term Abbreviation Approximate Size

Kilobyte KB or K 1 thousand bytes

Megabyte MB 1 million bytes

Gigabyte GB 1 billion bytes

Terabyte TB 1 trillion bytes

OUTPUT: What is Output?

What is output? Data that has been processed into a useful form

Output device is any hardware component that can convey information to one or more people

OUTPUT: Display Devices Output device that visually

conveys text, graphics, and video information Information on display device

sometimes called soft copy Monitor houses display device

that is packaged as separate peripheral LCD (liquid crystal display)

monitor Plasma monitor CRT (cathode-ray tube) monitor

Printer Impact printer –dot matrix printer Nonimpact printers

Ink-jet printer photo printer laser printer thermal printer Plotter

print cartridge

print head

firing chamber

nozzlebubble resistor ink

ink dot

OUTPUT: Audio output device

Computer component that produces music, speech, or other sounds

Speakers and headsets are common devices

OUTPUT: Other Output Devices

facsimile (fax) machine multifunction peripheral data projector interactive whiteboard

Storage

What is storage? Holds data, instructions, and information for future use Storage medium is physical material used for storage

Also called secondary storage

Storage

What is capacity?

Kilobyte (KB) 1 thousand

Megabyte (MB) 1 million

Gigabyte (GB) 1 billion

Terabyte (TB) 1 trillion

Petabyte (PB) 1 quadrillion

Number of bytes (characters) a storage medium can hold

Exabyte (EB) 1 quintillion

Zettabyte (ZB) 1 sextillion

Yottabyte (YB) 1 septillion

Storage Medium(hard disks, CDs, DVDs,USB flash drives, etc.)

Storage

How does volatility compare?

No

nvo

lati

le

Storage medium is nonvolatile—contents retained when power is off

Contents retained

Contents available to user

Memory(most RAM)

(chips on motherboard)

Screen Display

ON OFF

Vo

lati

le Display disappears

Data andinstructions

available to user

Display appears

Data and instructions erased

Memory is volatile—holds data and instructions temporarily

read/writehead

plattersides

cylinder

tracksector

Storage device: Hard- Disc

High-capacity storage, most are housed inside the system unit

Consists of several inflexible, circular platters that magnetically store data, instructions and information electronically

External hard disk—freestandinghard disk that connects to system unit

Removable hard disk—hard diskthat you insert and removefrom hard disk drive

Magnetic disc use magnetic particles to store items on a

disk’s surface. Magnetic Tape

is a magnetically coated ribbon of plastic housed in a tape cartridge

Other Storage device: Floppy disc

Is an inexpensive portable storage medium Optical Disc

is a portable storage medium that consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser

CD-ROM (Compact disc read-only memory)

CD-RWs (Compact disc-rewritable) erasable disc you can write on

multiple times CD-R (compact disc-recordable)

disc you can write on once DVD-ROM (digital versatile disc-ROM or

digital video disc-ROM) Online storage microfilm and microfiche

Miniature Mobile Storage Media

What is miniature mobile storage media? Storage for small mobile devices

• flash memory cards• USB Flash Drive• smart card

Consists of a seriesof instructions thattells the computer

what to do and how to do it

Consists of a seriesof instructions thattells the computer

what to do and how to do it

Computer Software

What is software?

Also called aprogram

Also called aprogram

Two types of software: system software and application software

Computer Software

What is system software?

Operating System (OS)is a set of programs that coordinates all activities among computer hardware devices

Operating System (OS)is a set of programs that coordinates all activities among computer hardware devices

Utility Programs allow the user to perform maintenance-type tasks usually related to managing a computer, its devices or its programs

Utility Programs allow the user to perform maintenance-type tasks usually related to managing a computer, its devices or its programs

Programs that control or maintain the operations of the computer and its devices

Operating Systems

What are the functions of an operating system?

Operating Systems

Operating system Microsoft Windows Vista Microsoft Windows XP Apple Mac OS X Linux

Booting Process of starting or restarting a computer

Spooling Sending print jobs to buffer instead of directly to printer

Graphical user interface (GUI)– User interacts with menus and visual images such as buttons and other graphical

objects Program management features of operating systems

Multitasking, multiprocessing, multiuser and fault-tolerant

Operating System Utility ProgramsWhat is a utility program? System software that performs

maintenance-type tasks Also called

utility

Application Software

What is application software? Programs designed to make users more productive

and/or assist them with personal tasks

Application Software

How is software distributed? Packaged software, mass-produced Custom software, performs functions specific to a

business or industry Web-based software, hosted by a Web site Open source software, provided for use, modification,

and redistribution Shareware, copyrighted software that is distributed

free for trial period Freeware, copyrighted software provided at no cost Public-domain software, freeware with no copyright

restrictions

Communications Devices

is a hardware component that enables a computer to send and receive data, instructions, and information to and from one or more computers Transmission media Network through wire or wireless

– Telephone lines, cables, cellular radio networks & satellites

Used to shareUsed to share

ResourcesResources

Hardware devices

Hardware devices

Software programs

Software programs

DataDataSaves time and

money

Saves time and

moneyInformationInformation

Networks and the Internet

A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media Local area network (LAN) Wide area network(WAN)

1 2

Networks and the Internet

The world’s largest network is the Internet, which is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals Internet service provider (ISP) Online service provider (OSP) Wireless Internet service provider (WISP)

Networks and the Internet

The World Wide Web contains billions of documents called Web pages

Web page Web site Web browser Uniform Resource Locator (URL) Hypertext transfer protocol

Networks and the Internet

Why do users access the Internet?

2. Research and Information

3. Shopping

4. Banking and Investing

5. Classes

6. Entertainment

1. Communications

7. Download Music

8. Share Information

Networks and the Internet

• When you conduct business activities online, you are participating in electronic commerce, also known as e-commerce

– Business to consumer (B2C)– Consumer to consumer (C2C)– Business to business (B2B)

Storage Communications

Advantages and Disadvantages of Using Computers

What are the advantages of using computers?

Speed Reliability

Next

Consistency

Impact onLabor Force

Advantages and Disadvantages of Using Computers

What are the disadvantages of using computers?

Violation ofPrivacy

Health Risks

Public Safety

Impact onEnvironment

Categories of Computers

What are the categories of computers?Personal Computers

(desktop)

Mobile Computers andMobile Devices

Game Consoles

Servers

Mainframes

Supercomputers

Embedded Computers

Servers

What types of servers are there?

Mainframe Very powerful, expensive computer that supports thousands of connected users

Supercomputer The fastest, most powerful, most expensive computer. Used for applications requiring complex mathematical calculations

A server controls access to network resources and provides centralized storage

Elements of an Information SystemWhat are information system elements? Hardware Software Data People Procedures

Examples of Computer Usage

What software is available for a home user? Personal finance

management Web access Communications Entertainment

Examples of Computer Usage

Productivity software

Specialty software

Web usage E-mail

What software is available for a small office/home office (SOHO) user?

Hardware Notebook computers Tablet PCs Internet-enabled PDAs Smart phones

Examples of Computer Usage

What is available for a mobile user?

Software Word processing Spreadsheet Presentation graphics

software

Examples of Computer Usage

What are the needs of a power user? Speed and large amounts of storage Types of power users

Engineers Scientists Architects Desktop publishers Graphic artists

Examples of Computer Usage

What are the needs of the large business user? Payroll Inventory E-commerce Desktop

publishing

Computer Applications in SocietyWhat are some examples of computer applications in society?

Education Finance Government Health Care Science Publishing Travel Manufacturing