5.1 system concept1

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5.0 COMPUTERSYSTEM

5.1 SYSTEM CONCEPT

DC035


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LEARNING OUTCOMES

At the end of this topic, studentsshould be able to:5.1 System

Concept

5.1.1 Overview ofComputer

System

5.1.2 DataRepresentation

5.1.3 Storage Capacity

identify the process in acomputer-based information

processing.


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What Is A Computer?

An electronic device, operating under thecontrol of instructions stored in its ownmemory

3

Collectsdata

(input)Processing

Producesinformation

(output)

Information Processing Cycle

DC035 - PDT Semester 3


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Computer Definition

A computer is

an electronic device,

that accepts input,

process data, and

produces output.


Collectsdata

(input)Processing

Producesinformation

(output)


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Subsystems of aComputer

Software System

Operating System (Unix, Mac OS,MicrosoftWindows)

Web browser (Netscape, Internet

Explorer)Office productivity applications

HardwareSystem

Keyboard

MonitorSystem unit

Network SystemInternet services (email)

Network connections (modems, network cards)

Internet



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Computer SystemDefinition

A computer systemis

a complete, working

computer thatincludes

operating system,

software and

hardware which arenecessary

to make thecomputer function.



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7

Devices that comprise acomputer system

Printer(output)

Monitor(output)

Speaker(output)

Scanner(input)

Mouse(input)

Keyboard(input)

System unit

(processor, memory)

Storage devices

(CD-RW, Floppy,Hard disk, zip,)


5.1 SystemConcept

5.1.1 Overview of

ComputerSystem




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Components of ComputerSystem


Hardware

Central Processing Unit (CPU)

Input Devices

Output DevicesStorage Devices

Software

System SoftwareApplication Software


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Components of ComputerSystem

A computer contains many electric, electronic,and mechanical components known ashardware

9

Allows you to enter data and instructions into a computerInput Device

Hardware component that conveys information to one or morepeople

Output Device

Case that contains the electronic components of the computerthat are used to process data

System Unit

Records (writes) and/or retrieves (reads) items to and fromstorage media

Storage Device

Enables a computer to send and receive data, instructions, andinformation to and from one or more computers or mobiledevices

CommunicationsDevice



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Data Processing

The computing modelfor the first phase ofdigital revolution.

Based on an input-processing-outputcycle.

C


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Processes in ComputerSystem


P i C


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Information Processing Cycle

Input-process-output (IPO) Model

Input-process-output-storage (IPOS) Model

The series of input, process, output and storageactivities.


IPO Model

P i C


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All computers perform

four basic operations :-

InputProcess

Output

Storage


IPO Model

P i C


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Input datato feed informationwhich can besupplied by any

person, environmentor other computer.

Processing datamanipulating data

by performingcalculations, sortinglists of words ornumbers, drawingpictures.


IPOS Model

P i C


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Storing datafor future retrieval andprocessing.Memory holds data that

is waiting to beprocessed, and storageareas hold datapermanently until thedata is deleted.

Output datathe result produced by acomputer, whichincludes reports,documents, music,graphs and pictures.DC035 - PDT Semester 3


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Summary

Definition of

Computer

Computer System

Components of Computer System

Processes in Computer System

5.1 SystemConcept

5.1.1 Overview ofComputer

System




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LEARNING OUTCOMES


Concept

5.1.1 Overview ofComputer System



explain data representationin computer.

D t R t ti


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Data RepresentationBasics

What is data?

Symbols that represent people,events, things and ideas. or,

A collection of raw facts, figuresand symbols, such as numbers,words, images, video andsound, given to the computer

during the input phase.

Can be a number, a name, thecolors in a photograph or the

notes in a musical composition.DC035 - PDT Semester 3

D t R t ti


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What is information?

Data that is organized,meaningful, and useful. or,

Processed data thatconveys meaning and isuseful to people.


D t R t ti


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Differences between data and information


Presented

in a formatthat peoplecan

understandand use

Whengroupedbecomes

D t R t ti


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Whengroupedbecomes

Used bymachines

such ascomputers.

Used byhumans.

D t R t ti


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What is data representation?

The form in which data isstored, processed andtransmitted.

Example :- devices such asPDAs, iPod and computersstore numbers, text, music,photos and videos in formats

that can be handled byelectronic circuitry.

Can be represented using:-

Analog methodDigital method DC035 - PDT Semester 3

D t R t ti


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Difference Between Analog and DigitalMethod


Analog Digital

Represented using aninfinite scale of values.

signals are continuous andvary in strength and quality

Example :- a dimmer switch

Text, numbers, graphics,sound and video that has

been converted into discretedigits such as 0s and 1s.

signals are in one of twostates: on or off

Example :- a traditional lightswitch

Data Representation


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How does digital data work?

Most computers are digital

Digital computers: Canonly understand twostates, offand on (0 and1).

Digital datarepresentation: Theprocess of representingdata in digital form so it

can be used by acomputer. DC035 - PDT Semester 3

Ways of representing 0 and1: Binary computersrecognize only two states-offand on usuallyrepresented by 0 and 1.

Data Representation


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A computer circuitrepresents the 0 orthe 1 electronically bythe presence orabsence of anelectrical charge.

Digital Data


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Digital DataRepresentation



Bit: The smallest unit of datathat a binary computer canrecognize (a single 1 or 0)

Represents an electricalstate (on or off)

Bit 1 represents On (High)

Bit 0 represents Off (Low)

Digital Data


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Byte: Eight bits groupedtogether as a unit.

Byte = 8 bits

A byte represents a singlecharacter in the computer

Byte terminology used toexpress the size of documentsand other files, programs, etc.

Digital Data


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Differences between bits and bytes


Bits Bytes

An abbreviation forbinary digit.

Usually as a lowercaseb.

Typically used toexpress transmissionspeeds

A group of eight bits

Usually abbreviated asan uppercase B.

Typically use to expressstorage space

Digital Data


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Example :

00110100 represents 4

00110110 represents 6

01000101 represents E

H l tt i t d t


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How a letter is converted tobinary form and back

Step 1.The user

presses the

capital letterD

on the

keyboard.

Step 2.An electronic signal for

the capital letterD is

sent to the system unit.

Step 3.

The signal for the capital letterD is

converted to its binary code (01000100)

and is stored in memory for processing.

Step 4.

After processing, the binary code

for the capital letterD is

converted to an image, and

displayed on the monitor.

Digital Data


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How can bits be used to storeimages?


Must be digitized by treatingthem as a series of colored

dots.Each dot is assigned abinary number according toits color.

Example :- green dotmight be represented by0010 and red dot by1100.

Digital Data


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How can bits be used to storesound?


Characterized by the

properties of a sound wave.Represent the sound wavedigitally by sampling it atvarious points, & then

converting those points intodigital numbers.


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SummaryDefinition of :-

DataInformation


Definition of data representation

Differences between analog and digital

Differences between bits and bytes

Using bits to store :-

Image

sound

5.1 SystemConcept





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LEARNINGOUTCOMES


Concept




differentiate various size ofstorage capacity.

Typical Storage and


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Typical Storage andCapacities

Storage Capacity

Tape drive A few hundred kilobytes toseveral gigabytes

Diskette 1.44 MBCD-ROM 650 MB 1GB

Hard disksExternal hard disk

Removable hard disk

Up to 4TB or more

UP to 1TB or more

Typical Storage and


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DVD and Blu-ray Storage Capacities

Sides Layers DVD Blu-ray

1 1 4.7GB 25GB

1 2 8.5GB 50GB

2 1 9.4GB 50GB

2 2 17GB 100GB


Typical Storage and


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Typical of Flash Memory Storage

Storage Capacities

Solid State Drives(SSD) 16GB 256GB

Memory cardsCompact Flash(CF)Secure Digital(SD)SDHCXD Picture Card

512MB 100GB512MB 8GB4GB 32GB256MB 2GB

USB Flash Drive 512MB 100GB


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Storage Capacity

Each location inmemory has anaddress.

CapacityThenumber ofbytes(characters) canbe hold by storage

medium

Memory size ismeasured in

kilobytes (KB or K),me ab tes MB Discovering Computers 2012: Chapter 438


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Storage Capacity

What do the prefixes kilo-,mega-, giga- and tera- mean?

Prefixes are often used toexpress larger quantities ofbytes: kilobyte (KB),megabyte (MB), gigabyte(GB), etc



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Storage Capacity

prefixes kilo-

Abbreviated as K, means athousand.

Decimal number system thenumber 1,000 is 103.

For digital devices where base 2is the norm = 1,024 or 210.

A kilobit (Kb) = 1,024 bits.A kilobytes (KB) = 1,024 bytes

Kilobytes often used whenreferring to the size of smallcomputer files.

Also known as Kibi DC035 - PDT Semester 3


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Storage Capacity

prefixes mega-

Abbreviated as M, means amillion.Decimal number system the

number 1,000,000 is 10

6.

For digital devices where base 2is the norm = 1,048,576 or 220.A megabit (Mb) = 1,048,576 bits.A megabytes (MB) = 1,048,576bytesMegabytes often used whenreferring to the size of medium tolarge computer files or to floppydisk capacity.Also known as Mebi



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Storage Capacity

prefixes giga-

In technology lingo.

Abbreviated as G, means a

billion.Decimal number system thenumber 1,000,000,000 is 109.

For digital devices where base 2is the norm = 1,073,741,824 or

230

.A gigabit (Mb) = 1billion bits.

A gigabytes (MB) = 1billion bytes.

Gigabytes often used to refer tostorage capacity.

Also known as Gibi DC035 - PDT Semester 3


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Storage Capacity

prefixes tera-, peta-, exa-

Usually use by mainframesand supercomputer sometimes work with hugeamounts of data.

tera- (trillion).

peta- (thousand trillion).

exa- (quintilion).


The Number of Bytes in Common


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The Number of Bytes in CommonTerms

Name Number of Bytes Amount ofText

Kilobyte (KB) 210 or 1,024 page

Megabyte(MB)

220 or 104,8576 500 page or thickbook

Gigabyte(GB)

230 or 1,073,741,824 500,000 pages or1,000 thick books

Terabyte (TB) 240 or 1,099,511,627,776 1,000,000 thickbooks

Petabyte (PB) 250 or 1,125,899,906,842,624 180 Libraries ofCongress

Exabyte 260 or 1,152,292,150,460,684,6976 180 thousandLibraries ofCongress

Zettabyte 270 or 1,180,591,620,717,411,303,424 180 millionLibraries ofCongress

Yottabyte 280 or 1,208,925,819,614,629,174,706,176 180 billion Librariesof Con ress


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Data Measurement Chart


Data Measurement Size

Bit Single Binary Digit (1 or 0)

Byte 8 bits

Kilobyte (KB)Bytes 1024 Bytes

Bits 8192 Bits

Megabyte (MB)

Kilobytes 1,024 KB

Bytes 1048576 Bytes

Bits 8388608 Bits


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Gigabyte (GB)

Megabytes 1,024 MB

Kilobytes 1048576 KBBytes 1073741824 Bytes

Bits 8589934592 Bits

Terabyte (TB)

Gigabytes 1,024 GB

Megabytes 1048576 MB

Kilobytes 1073741824 KB

Bytes 1099511627776 Bytes

Bits 8796093022208 Bits


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Petabyte (PB)

Terabytes 1,024 TB

Gigabytes 1048576 GBMegabytes 1073741824 MB

Kilobytes 1099511627776 KB

Bytes 1125899906842624 Bytes

Bits 9007199254740992 Bits


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Exabyte (EB)

Petabytes 1,024 PB

Terabytes 1048576 TB

Gigabytes 1073741824 GB

Megabytes 1099511627776 MB

Kilobytes 1125899906842624 KB

Bytes 11522921504606846976Bytes

Bits 8796093022208 Bits


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Example 1 : Convert 1GB to KB


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Example 2 : Convert MB to GB

1200 MB = 1200/1024

= 1.17 GB

Example 3: Convert pixels to


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Example 3: Convert pixels toMegabytes

Using the above example, calculate the

storage requirements for the image inmegabytes.

Example 3: Convert pixels to


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Example 3: Convert pixels toMegabytes

5000 pixels x 7000 pixels =35,000,000 pixels (= 35,000,000 bits)

35,000,000 / 8 = 4,375,000 bytes

4,375,000 / 1024 = 4272.46 kilobytes

4272.46 / 1024 = 4.17 megabytes


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Summary

Memory Size

Kilo-

Mega-

Giga-Tera-

Peta-

Exa-

5.1 SystemConcept




5.1 system concept1

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