tmx1022 lu2 computer systems

8/18/2019 TMX1022 LU2 Computer Systems

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TMX1022 ICT Competency

Learning Unit 2: Computer Systems

Semester 2, 2015/2016


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Learning Outcomes

By the end of this unit, students will be able to:

• Explain the computer system

• Distinguish between hardware and software

• Identify the function of each fundamental computerhardware component

• Explain the Input-Process-Output (IPO) Cycle

• Discuss recent developments in hardware and

software technologies


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What is a Computer?

• A computer is amultipurpose electronic devicethat

accepts input, processes data, stores data, and

produces output, all according to a series of stored

instructions

Image: Shelly et al. (2012)


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IPOS Model

• A computer accepts input, then processes the input

using a set of instructions to produce output. – Input: whatever that is typed, submitted or transmitted into a

computer

– Output: the results produced by a computer after being processed;can be stored for future use.


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IPOS Model

• Input →Process (may involveStorage) →Output

• IPOS model describes how a computer works in

general – the most basic structure of an information processing entity

• All computer systems operate based on the

information processing cycle


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IPOS Model

Image: Parsons & Oja (2013)


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IPOS Model

• Data is a collection of unprocessed (raw) items.

• Information is the message/meaning being conveyed,

derived from data.

Image: Vermaat, Sebok & re!n" (201#)


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Computer Hardware & Software

• A computer consists of 2 basic parts: hardware and

software



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Computer Hardware

• Any part of the computer that has a physical structure

(tangible parts) is considered a hardware. – Example: Keyboard, monitor, CPU.

• Computer hardware components:

Input devices Output devices

System unit

Storage media& devices

Communications devices

Ports &Connections


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Hardware – Input Devices

• An input device is any hardware device that sends

data to a computer, allowing user to interact with and

control the computer

• Common input devices: – Keyboards: contain keys that user can press to key in data

– Pointing devices:allow user to control a small symbol on

the screen, the pointer

– Voice & video input:let user give instructions by speaking

or capturing live full-motion images – Scanners:light-sensing input devices that convert printed

texts and images into a format the computer can process


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Hardware – Input Devices


Scanner


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Hardware – Output Devices

• An output device functions to convey information from

the computer to the user

• Usually for display, projection, or physical

reproduction

• Common output devices: – Displays: consists of a screen that visually conveys text,

graphics, image and video information

– Printers: produces text, graphics and image information on a

physical medium (e.g. paper) – Speakers: allow users to hear audio (music, voice, sounds)


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Hardware – Output Devices

Printer

Headphones/earbuds

Speakers



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Hardware – Storage Media & Devices

• Storage media are used to keep data, information and

instructions

• Storage devices record and/or retrieve items to and from

storage media – Capable of holding information either temporarily or

permanently

– Storage devices can function as input and output devices as

they transfer items from storage to memory and vice versa

– Examples: CD/DVD drives

– The process of recording items to a storage media is called

writing.

– The process of retrieving items from a storage media is called

reading.


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• Common storage media examples: – Hard disks: contains one or more inflexible, circular platters

that use magnetic particles to store data, information and

instructions; can be fixed (internal) or external (portable)

– USB flash drive: portable flash memory storage device thatis small and lightweight enough to be carried on a keychain or

in a pocket

– Solid-state drives: durable and shock-resistant media that

typically uses flash memory to store data, information and

instructions

Image: Vermaat, Sebok & re!n" (201#)Hard disks USB flash drive Solid-state drive


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• Common storage media examples: – Optical discs: consists of a flat, round, portable metal disc

made of plastic, metal and lacquer; optical discs are read and

written using laser

– Memory cards: removable flash memory that can beinserted and removed from a lot in a computer/mobile device,

card reader; usually no bigger than 1.5 inches

– Cloud storage: an Internet service that provides storage to

computer users, as opposed to storing on locally (on the

computer itself)

Optical discs Memory cards Cloud storageImage: Vermaat, Sebok & re!n" (201#)


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Hardware – System Unit

• The system unit consists of electronic components that

are used to process data.

• The system unit’s circuitry is connected to the

motherboard (a circuit board), which consists of two

main components: the processor and memory. – Processor: interprets and carries out the basic instructions

that operate the computer; also known as Central Processing

Unit (CPU)

– Memory: stores instructions waiting to be executed and dataneeded by those instructions


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Hardware – System Unit


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Hardware – Communications Devices

• Communications devices allows a computer to transmit (send)

and receive data, information and instructions to and from one or

more computers.

• Communications take place over cables, telephone lines, cellular

radio networks, satellites and other transmission media.

• Some transmission media are wireless, so there are no physical

structures, lines or wires involved.

• Examples: – Modem: short for MOdulator-DEModulator; converts digital and analog data

for computer-to-computer communication

– Router: connects multiple networks together so data can be transmitter

between computers on the networks


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Hardware – Ports & Connections

• A peripheral device attaches to or communicates with

a computer via ports

• Peripheral devices include keyboard, printer, monitor,

speakers, etc.



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Hardware – Ports & Connections

• A connector joins a cable to a port



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Software

• Software is a series of related instructions that tells

the computer what to do. – Example: word processors (MS Word), web browsers (Mozilla

Firefox), games (Defense of the Ancients)

• Software is also referred to as computer program• Software is not available physically, users interact with

software by using a graphical user interface (GUI)

• There are 2 categories of software:

– System software: programs that control and maintain theoperations of the computers and its devices

– Application software: programs designed to make users

more productive and/or assist them with personal tasks


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Software – System Software

• System software types

Utility program$llo%s !ser to er'orm

mantenane*tye tasks!s!ally relate" to managng aom!ter, ts "e+es an"rograms.-amle: $ rogram totrans'er "gtal hotos to anotal "s

Operating system$ set o' rograms that

oor"nates all the at+tesamong om!ter har"%are"e+es-amle: roso't /n"o%s,$ OS, n!-, $n"ro"


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Software – Application Software

• Application software types

Productivityapplications• /or" roessng•

Presentaton• Srea"sheet• ote takng• $o!ntng• Personal nane

Personal interestapplications• 'estyle•

"!aton• ntertanment• e"al• on+enene

Graphics & Mediasoftware• om!ter*a"e"

"esgn ($4)

• 4eskto !blshng• Image e"tng• V"eo5a!"o e"tng• /ebste5m!ltme"

a a!thorng

Communicationsapplications• 6loggng• 6ro%sng• hat room• Instant messagng• mal• VoIP

Security tools• Personal re%all• $nt+r!s rogram• al%are remo+er• Internet5hshng

lters• Po*! blokers

File & dismanagement tools• le manager• Searh tool• Image +e%er• 7nnstaller• 4sk lean! tool• Sreen sa+er


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Software

• Software types:1)Free:- permission for anyone to use/copy/distribute both binary and source

code, either verbatim or with modifications (free here refers to “freedom”).

2)Open Source:- similar to (1.), but accept more restrictive licenses, for

example, not for commercial uses, outside the European Union, et cetera.

3)Public domain:- non/no longer copyrighted, usually the binary is releasedin public domain but not the source code.

4)Non Free:- use, redistribution or modification is prohibited, requires you to

ask for permission.

5)Proprietary:- Similar to (4.), but user have to pay to get that permission

6)Freeware:- permits redistribution of the binary but not modification, and

source code is not available.7)Shareware :- allows for redistribution, but anyone who continues to use a

copy is required to pay a license fee.


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Operating Systems

• An operating system is atype of system softwarethat

acts as the master controller for all activities that take

place within a computer system


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Operating Systems



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Operating Systems

• The tasks of an operating system: – Manage processor resources to handle simultaneous input,

output and processing tasks

– Manage memory by allocating space for all the programs and

data that are in use during a computing session – Keep track of storage resources so that files and programs can

be found and manipulated

– Ensure that input and output proceed in an orderly manner

by communicating with peripheral devices

– Establish basic elements of the user interface such as theappearance of the desktop, menus, and toolbars


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Operating Systems



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Operating Systems

• Available operating systems today: – Microsoft Windows

– Mac OS

– Linux

– UNIX – iOS

– Android


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File Management

Methods used to ensure computer files are stored in

an orderly manner

A computer’s file location is defined by a file

specification, or path

An operating system maintains a directory for each

storage disk, CD, DVD, BD, or USB flash drive Root directory

Subdirectory

Depicted as folders



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File Management

• Why is file management needed?


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File Management

• Applications generally provide a way to open files and

save them in a specific folder on a designated storage

device



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File Management



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File Management

• File management utilities show you the files stored on

your disks and help you work with them



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File Management

• Windows Explorer



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File Management

• Consider the following tips/best practices for managing files on

computer – Naming conventions – use descriptive names for files and folders, avoid

cryptic abbreviations

– Maintain file extensions – keep the original file extension so that it can

be opened with the correct software – Group similar files – separate files into folders based on subject matter

– Organize folders from top down – use folders and subfolders

– Delete or archive files no longer needed – avoid from taking up spaces

– Be aware of storage location – specify the correct storage device and

location, for easy retrieval – Back up – have copies of your files in case the original has problems

– Use secondary/external storage – do not keep everything in only one

computer


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Digital Media

• Audio (sound), video, and graphics (images) that exist

in a computer-readable format – Traditional media, in digitized format

• The digitized form allows new ways for storing,

distributing, and “playing” the media

• Can be combined, hence the term “multimedia”


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Digital Media – Audio

• Digital audio is music, speech, and other sounds

represented in binary format for use in digital devices

• Computers can record, store and play sounds – Music, sound effects, recordings, narrations



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Digital Media – Audio

• Examples of digital audio file formats: – MP3, AAC, WAV, WMA

• Audio or media player software is needed to play

digital audio files

• Examples: Windows Media Player, QuickAudio, Audacity,iTunes

• The HTML5 tag can be used to embed digital

audio files into a Web page

• Streaming audio is played as its file is downloaded• Avoid lengthy delays while the entire audio file is downloaded

• Music is stored on CDs in the CDDA format


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Digital Media – Graphics

• A bitmap graphic is composed of a grid of dots – The grid divides a picture into cells called pixels

– Pixel = picture element

– The colour of each pixel is stored as a binary number

• Bitmap graphics are used to create realistic images, such asphotographs

• Bitmap graphic is also known as raster graphic



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• Types of bitmap graphics – Different types of bitmap

formats available

– The best type of format

depend on what the imageis intended for

– JPEG, PNG and GIF are

formats supported by most

Web browsers



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• A vector graphic consists of a set of instructions for

creating a picture – Instructions to create the shape, size, position and colour for

each object in an image

– Does not store each pixel’s colour value• Vector graphics can have flat, cartoon-like quality but

others can look fairly realistic

• Vector graphics have file extensions such as .wmf,

.ai, .dxf, .eps, .swf, and .svg• Vector graphics are suitable for most line art, logos,

simple illustrations and diagrams that may be

displayed and printed at various sizes


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• Vector graphics vs. bitmap graphics: – Vector graphics resize better

• The objects in vector graphics change proportionally and maintain their edges

when resized; bitmap graphics may appear to have jagged edges when

enlarged

– Bitmap images are more realistic• The cartoon-like characteristic of vector images results from the use of objects

filled with blocks of colour

• Bitmap graphics can be created using graphics software,

scanner or digital camera

– Adobe Photoshop, Corel Painter, Microsoft Paint• Vector graphics can be created using vector graphics

software (drawing software) – Adobe Illustrator, Corel DESIGNER, LibreOffice Draw, Inkscape


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• A vector graphic can be converted into bitmap graphic

through a process called rasterization – Rasterization: superimpose a grid over the vector image and

determine the colour for each pixel

– Can be carried out using graphics software – specify theoutput size for the final bitmap image

• A bitmap graphic can be converted into vector graphic

using tracing software – The tracing software locates the edges of objects in bitmap

image and converts the resulting shapes into vector graphic

objects


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• Scalable Vector Graphics (SVG) and Flash graphic are

widely used on the Web today



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• Advantages of using vector graphics on the Web: – Consistent quality

• Appear with the same consistent quality on Web pages across all

computer screens

• Browsers can adjust the image size on the fly to fit correctly on a screen,

regardless of its size or resolution

– Searchable• Text in vector graphics is stored as actual text, not series of coloured dots

• Search engines can index this text to be included in keyword searches

– Compact file size

• A fairly complex vector graphics can be stored under 30 kilobytes• This require little storage space and can be transmitted quickly from Web

server to browser


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• 3D (three dimensional) graphics are also stored ad a

set of instructions

• The instructions also contain locations and lengths of

lines that form a wireframe for a 3D object



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• The process of covering a wireframe with surface colour

and texture is called rendering – The output is a bitmap image

• The technique for adding light and shadows to a 3D

image for further realism is called ray tracing• 3D graphics software is used to created 3D images

– Autodesk AutoCAD, Caligari Truespace, Autodesk Maya, 3ds

Max

• 3D graphics can be animated to produce special effectsfor movies or create interactive, animated characters

and environments – Toy Story, Avatar, Happy Feet


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Digital Media – Video

• A video is a series of still frames, projected

at a rate fast enough to fool the human eye

into perceiving continuous motion

• Digital video uses bits to store colour and

brightness data for each video frame – Similar to storing the data in bitmap images – The colour for each pixel is represented by a

binary number

• Footage for digital videos can be supplied

from a digital source, or from an analogsource that requires conversion



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Digital Media



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Digital Media

• There are many digital video formats available: – AVI, MOV, MPEG, WebM, ASF, Flash video, VOB, Blu-ray Disc

Movie

• The format should be compatible with the devices on which

it is played and its browser/video player software

• Digital video formats are also known as container formats – Hold both audio and compressed video data streams

• Transcoding is the process used to convert from one digital

video format to another format

– May cause loss of quality• Examples of video editing software: Adobe Premiere, Apple

Final Cut Pro, Windows Live Movie Maker, Corel

VideoStudio


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Digital Media

• Web-based videos are stored in files on Web server

• There are two ways of transferring digital video from

the Web to a computer: – The computer waits until it downloads the entire video file

before starting to play it – Streaming video: the computer continuously play segments of

the video file as it is received, until the video ends

• YouTube is a video sharing site that allows videos to

be uploaded, viewed, and rated


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Category of Computers

Personal

computers

Categories

of

Computer

Embedded

computers

Supercomputers

Servers

Terminals

Game devices

Mobile

computers &

devices


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Personal Computers• A personal computercan perform all of its

input, processing,

output and storage by

itself

• It is intended to be used

by one person at a time



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Personal Computers• A desktop computer is designed to be in fixedlocation (stationary)

– On top of a desk/table

– Under a desk/table

• Two popular architectures of personal computers are

the PC and the Apple computer



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Mobile Computers & Devices

• A laptop computer has a screen in its lid, and akeyboard in its base

• It is a mobile personal computer designed for easy

portability

• A laptop computer is also known as a notebook

computer



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• A tablet is a mobile computer that is thin and

lightweight

• It has a touch screen, which functions as both input

and output device

• It is smaller than a laptop, but larger than a

smartphone



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• A smartphone is an Internet-capable phone

• It has advanced computing and connectivity

capabilities compared to basic phones

• Smartphones have a variety of screens and

keyboards



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• A phablet is a device that is a combination of a

smartphone and a tablet

• It is larger than a typical smartphone, but smaller

than full-sized tablets


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• An electronic book

reader, or e-reader, is a

mobile device that is

used for reading e-books

and publications in

digital format



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• Other mobile devices include digital cameras and

portable media players



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Game Devices• A game console is a mobile

computing device designed

for single or multi player

computer/video games

• A handheld game device is

a small mobile device that

contains a screen,

speakers, controls and a

game console all in one

unit that can fit into the

hands



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Game Devices• Game controllers include gamepads, joysticks and

wheels, dance pads, and a variety of motion-sensing

controllers



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Supercomputers• Supercomputers are the fastest and most powerful

computers available

• It is capable of processing trillions of instructions in

a second, up to 20,000 times that of an average

computer

• Because of its computing powers, supercomputersare the most expensive computers



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Embedded Computers• An embedded computer is a special-purpose

computer that is included as a component in a larger

product

• Examples of embedded computers:

Consumer electronics: mobile phones, digital televisions, cameras,

answering machines, DVD players and recorders

Home automation devices: sprinkling systems, thermostats, security

systems, appliances, lighting systems

Automobiles: engine control modules, electronic stability control, airbag

controller, cruise control, navigation systems

Computer devices & office machines: keyboards, printers, copy

machines, fax

Process controllers & robotics: remote monitoring systems, power

monitors, machine controllers, medical devices


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Embedded Computers• Embedded computers in automobiles:



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Servers• A server is a computer

that functions to provide

services to other

computers connected to

it via a network

• Servers can support

between two to several

thousands of computers

simultaneously

• The mainframe is a

large, powerful and

expensive server



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Terminals• A terminal is a computer that allows user to send

and receive information from a server or host

computer

• It usually has limited components and processing

capabilities

•Widely-used terminal examples:Point-Of-Sale (POS) terminals: record purchases, process credit/debit

cards, and update inventories in retail stores

Automated Teller Machine (ATM): banking terminals for customers

to access their banking accounts and money easily

Self-service kiosks: freestanding terminals for a variety of purposes –

pay bills, print photos, buy food/drink, tickets, track visitors etc.

i l


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!erminals

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