Chapter 1 Sak

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SAK 2001CHAPTER 1

INTRODUCTION



Chapter 1 Objectives

Define the term, computer

Identify the components

of a computer

Discuss the advantages anddisadvantages of using computers

Distinguish between system softwareand application software

Describe the categories of computers

The History of computer

Describe the various typesof computer users

Discuss various computerapplications in society



How is a computer defined?

What Is a Computer?

p. 6

Produces and stores results

Electronic device operating under the control of instructions stored in its own memory

Processes data into informationinformationData that is organized,meaningful, and useful

Accepts datadataRaw facts, text,number, figures, andsymbolsCollection of

unprocessed item



What Is a Computer?

What is the information processing cycle ?

p. 6 Fig. 1-2

InputProcessOutput

StorageCommunication



FIRST GENERATION (1946-1957)Powered by vacuum tubes

They were bulky and largeGenerated excessive heatHad to be physically wired and reset to run

programs

The input was primarily on punch cardMachine language and assembly languagewere used to program these computers



COMPUTER HISTORY TIMELINE



CONTINUE



SECOND GENERATION (1958-1963)

Used transistor physically smaller, more powerful, morereliable and faster

input on punch card and magnetic tapemagnetic tape and disks used as storagehigh level programming language were used





1964



THIRD GENERATION (1964-1970)evolved when integrated circuits (IC) –

computer chip began being used instead of transistors.

Computer became even smaller and reliableKeyboard and monitor were introduced

Magnetic disks as storageEmergence of operating system meant thatoperators no longer had to manually resetrelays and wiring



1967 1969





FOURTH GENERATION (1971-present)began with large-scale integration (LSI),

resulted in chips that contain thousand of transistor

Very large-scale integration (VLSI) resultedin microprocessor.

The keyboard and mouse are predominantinput devices, monitors, printers, storage withmagnetic disk, optical disk and memory chips









The Components of aComputer

What is an input device ? Hardware used

to enter dataand instructions




What is an output device ?Hardware thatconveys

informationto one or morepeople



What is the system unit ?

p. 8 Fig. 1-3

Casecontainingelectroniccomponentsused to process data




What is storage?

p. 8

Storage mediaStorage mediaPhysical material on which data, instructions,and information are stored

Storage deviceStorage deviceRecords and retrieves items to and fromstorage media

Holds data, instructions, and informationfor future use




What is a communications device ?

Hardware component thatenables a computer tosend and receive data, instructions,

and information

Occurs over cables, telephonelines, cellular radio networks,

satellites, and othertransmission media

d d d



Advantages and Disadvantagesof Using Computers

p. 10

What are the advantages of using computers?

Next



Advantages and Disadvantagesof Using Computers

p. 10 - 11

What are the disadvantages of usingcomputers?

Next

Violation of Privacy

Confidential recordPrivacy violated

identity stolen

Impact onLabor Force

Improved productivityReplaced with computer

Health RisksImproper use can lead

to injuries

Impact onEnvironment

Release toxic materialDangerous level of mercury



Consists of a seriesof instructions thattells the computer

what to do

Computer SoftwareWhat is software ?

p. 15

Also called aprogram



Computer SoftwareWhat is system software ?

p. 15-16

Operating System (OS)Operating System (OS)is a set of programsthat coordinates allactivities amongcomputer hardware

devices and allowsusers to runapplication software

Utility ProgramsUtility Programs allow the user to perform maintenance-type tasksusually related to managing acomputer, its devices or its programs

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



Computer SoftwareWhat is a graphical user interface (GUI) ?

p. 15 Fig. 1-10

Allows you tointeract with thesoftware usinggraphics and iconsControls how youenter data and howthe screen displaysinformation



Computer Software

What is applicationsoftware ?

PresentationGraphics

Spreadsheet

Database

WordProcessing

Programs that perform

specific tasks for users



Categories of Computers

p. 19

What are the categories of computers?

Personal Computers(desktop)

Mobile Computers andMobile Devices

Servers

Mainframes

Supercomputers



Personal ComputersWhat are the two most popular series of

personal computers ?

PC and compatiblesuse the Windowsoperating system

Apple Macintoshuses the Macintosh

operating system(Mac OS)



Personal ComputersWhat is a desktop computer ?

p. 19-20 Fig. 1-15

Designed so all of the components fit entirelyon or under a desk or table



Mobile Computers and MobileDevices

What is a notebookcomputer ?

Portable, small enough

to fit on your lapAlso called a laptopcomputer Generally moreexpensive than adesktop computer



ServersWhat types of servers are there?

Mainframe Very powerful,expensive computer that supportsthousands of computers

Supercomputer The fastest, mostpowerful, most expensivecomputer. Used for applicationsrequiring complex mathematicalcalculations

A server controls access to network resources and provides centralizedstorage



Mobile Computers and MobileDevicesWhat is a Tablet PC ?

p. 21 Fig. 1-18 Next

Especially useful for taking

notes

Resembles a letter-sizedslate

Allows you to write on thescreen using a digital pen



Examples of Computer Usage

What are the needs of a power user ?

p. 29 Fig. 1-32

Speed and large amounts of storageTypes of power users

EngineersScientistsArchitectsDesktop publishersGraphic artists



TYPE OF COMPUTER USER

Home User Small Office/Home Office (SOHO)

Mobile User Power User Large Business User



Computer Applications inSociety

What are some examplesof computer applicationsin society?

p. 32-36 Figs. 1-36–1-43

Next

EducationFinanceGovernmentHealthcareSciencePublishingTravelManufacturing



Numbering System & DataRepresentation

Human speech – Analog , because it uses continuous (waveform) signals that very strength and quality.Computer – Digital , recognize only two states; ON and OFF.The digit 0 represent the electronic state of OFF. The digit 1represent the electronic state of ONHuman use digits in Decimal System (0-9)Computer uses Binary System , number system that just twounique digits, 0 and 1.

Bit (binary digit), is the smallest unit of data computer canprocess.When 8 bits are grouped as unit, it forms as BYTE .



Byte (character), includes alphabet, punctuation marks,others. It is the basic storage unit in memoryCombinations of 0 and 1 defined by patterns called codingscheme. 2 most popular are ASCII and EBCDIC (used inmainframe and high-end server) and also Unicode

Contoh,8 bit for number 4 = 001101008 bit for number 6 = 001101108 bit for alphabet N = 010011108 bit for symbol $ = 00100100

ASCII—American Standard Code for Information InterchangeEBCDIC—Extended Binary

Coded Decimal Interchange CodeUnicode—coding scheme capableof representing all languages



Data RepresentationHow is a letter converted to binary form and

back?

p. 196 Fig. 4-14

Step 2.An electronic signal for thecapital letter T is sent to thesystem unit.

Step 3.The signal for the capital letter T is converted to its ASCII binarycode (01010100) and is stored inmemory for processing.

Step 1.The user pressesthe capital letter T (shift+T key) onthe keyboard.

Step 4.After processing, the binarycode for the capital letter T isconverted to an image, anddisplayed on the output device.



U it P P t (UPP / CPU) ( b )



Unit Pemprosesan Pusat (UPP / CPU) – (samb…)

Saiz storan -

Kilobyte : 1024 (210) bytes

- Kapasiti utk personal komputer.

Megabyte : roughly 1 million (220) bytes

- Personal computer memory.

- Portable storage devices (disket, CD-ROM). Gigabyte : roughly 1 billion (230) bytes

- Storage devices (hard drives).

- Mainframe & network server memory.

Terabyte : roughly 1 trillion (240) bytes

- Storage devices on very large systems.



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Chapter 1 Sak