bis 03 hardware

7/30/2019 BIS 03 Hardware

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Slide 3.1

Bocij, Chaffey, Greasley, Hickie, Business Information Systems, 3rd Edition Pearson Education Limited 2006

Chapter 3

Hardware


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Slide 3.2


Learning objectives

After this lecture, you will be able to:

categorise the type of computer system that a

business uses;

recognise the different components of a computer; specify the components needed for the purchase of

a personal computer;

define the criteria for selection of hardware.


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Slide 3.3


Management issues

From a managerial perspective, this chapteraddresses the following areas:

Learning the characteristics of input, output and storagedevices will allow managers to select the correct

equipment for a given application. An understanding of selection criteria will allow

managers to specify equipment in terms of requiredquality and functionality.

An increased understanding of computers will helpmanagers see how technology can be used to improveexisting business processes and identify potentialapplications.


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Slide 3.4


Key concepts

Computer system: Interrelated components

including hardware and software that work

together with the aim of converting data into

information. Hardware: The physical components of a

computer system: input devices, memory, central

processing unit, output devices and storage

devices.


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Slide 3.5


Figure 3.1 Basic hardware components of a computer system


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Slide 3.6


Figure 3.2 A personal computer labelled with the typical components


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Slide 3.7


Hardware components

Input device: Hardware used to enter data, information orinstructions into a computer-based information system.

Central processing unit (CPU): The processor found in acomputer system that controls all of the computers main functionsand enables users to execute programs or process data.

Memory: A temporary means of storing data awaiting processing,instructions used to process data or control the computer system,and data or information that has been processed.

Storage devices: A permanent means of storing data andprograms until they are required.

Output devices: Translate the results of processing output intoa human readable form.


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Slide 3.8


Figure 3.3 Different forms of computer system


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Slide 3.9


The client/server concept

Client/server: The client/server architecture

consists of client computers such as PCs sharing

resources such as a database stored on a more

powerful server computer. Give examples:

In the office or university

Within a company with multiple sites

In the context of the Internet


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Slide 3.10


Cost-efficient forms of PC

Net PC: A hybrid between a traditional PC and an NC,it will usually feature no floppy or hard drive andlimited memory and processor since it will use thepower of the server to provide applications.

Thin client: In a network system, this describes anarchitecture where the bulk of the processing iscarried out by a central server.

Total cost of ownership (TCO): TCO refers to the

total cost for a company operating a computer. Thisincludes not only the purchase or leasing cost butalso the cost of all the services needed to support theend-user.


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Slide 3.11


Figure 3.4 Input devices in context


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Slide 3.12


Input devices 1

Natural keyboard: Keys are arranged so that users can locatethem more quickly and easily in a way that makes prolonged usemore comfortable.

Graphical user interface (GUI): Allows the user to control theoperation of a computer program or item of computer hardware

using a pointing device, such as a mouse by selecting optionsfrom icons and menu options.

Mouse: A pointing device found on most modern personalcomputers.

Pointing device: An input device that allows the user to control

the movement of a small pointer displayed on the screen that isused to select options.


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Slide 3.13


Input devices 2

Lightpen: A pointing device used to control

applications by pointing to items on the screen.

Trackball: A trackball is a pointing device that is

controlled by rotating a small ball with thefingertips or palm of the hand.

Optical scanner: An input device used to

capture graphics and text from printeddocuments.


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Slide 3.14


Input devices 3

Optical character recognition (OCR): Software that attempts torecognise individual characters.

Optical mark recognition (OMR): Detection and recognition ofsimple marks made on a document.

Bar code: A means of displaying a unique identification number

as a series of thick and thin lines. Universal product code: A standard for defining bar codes used

frequently in retailing.

Bar code reader: Measures the intensity of a light beam reflectedfrom a printed bar code to identify the digits making up a unique

identification number. Touch screen: A transparent, pressure-sensitive covering that is

attached to the screen of the monitor. Users make selections andcontrol programs by pressing onto the screen.


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Slide 3.15


Input devices 4

Interactive kiosk: A typical application for touch screen systems, aninteractive kiosk allows a user to purchase items or browse through a listof products by pressing buttons or other controls shown on the screen.

Graphics tablet: Used in the same way as a writing pad; a stylus is usedto draw images on a rigid pad located near to the computer.

Video capture card: The video capture card records and stores video

sequences (motion video). Sound card: A sound card allows a personal computer to play speech,

music and other sounds. A sound card can also be used to capturesound, music and speech from a variety of sources.

Voice recognition: The facility to control a computer program or carryout data entry through spoken commands via a microphone connected to

a sound card. Multimedia: A combination of several media under the control of an

interactive computer program including text, graphics, sound, video andanimation.


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Slide 3.16


Selecting input devices key issues

Volume

Speed

Accuracy

Cost

Data complexity

Frequency of data entry


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Slide 3.17


Figure 3.7 Output devices in context


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Slide 3.18

Bocij, Chaffey, Greasley, Hickie, Business Information Systems, 3rd

Edition Pearson Education Limited 2006

Output devices 1

Visual display unit (VDU): A monitor connected to a computersystem, traditionally used to describe character-basedterminals.

Resolution: The fineness of the image that can be displayed,expressed as number of pixels (picture elements) theindividual dots that make up an image on the screen.

Dot pitch: A method of gauging the quality of a monitorsdisplay that involves measuring the distance between thepixels on the screen.

Refresh rate: A method of gauging the quality of a monitorsdisplay that involves measuring the number of times the imageis drawn upon the screen each second.


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Slide 3.19



Output devices 2

Interlaced display: Each complete image shown on amonitors display is drawn in two steps.

Non-interlaced display: The monitor refreshes the display ina single pass.

Video projector: A computer system can be connecteddirectly to a projector so that output is directed to a projectionscreen.

Plotter: A plotter uses a number of different coloured pens todraw lines upon the paper as it moves through the machine.

MIDI (musical instrument digital interface): MIDIconnections allow users to control musical instruments orsynthesise any sounds or effects required in order to play themusic.


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Slide 3.20



Output devices 3

Computer output to microfilm (COM):Information is processed via a computer and sentdirectly to a device that produces microfilmnegatives.

Response time: The time it takes to respond toan action. For instance, the delay betweenpressing a key on the keyboard and a letterappearing on the screen. Response time canalso refer to the time it takes for a maintenanceprovider to fix a problem.


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Slide 3.21



Selecting output devices key issues

Appropriateness

Permanence

Response time

Speed

Cost

Data complexity

Frequency of data entry


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Slide 3.22



Printers

Laser printer: A laser is used to charge sectionsof a rotating drum which is then used to printusing toner powder, achieving a combination ofspeed with high print quality.

Inkjet printer: An inkjet printer uses a print-headcontaining 50 or more small nozzles that squirtink onto paper by varying electrostatic chargesproduced by the printer.

Dot-matrix printer: A character is transferred tothe paper by striking pins against an ink ribbon.


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Slide 3.23



Selecting printers key issues

Purchase cost

Printing cost

Print quality

Paper handling

Volume

Speed


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Slide 3.24



Figure 3.8 Storage devices in context


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Slide 3.25



Storage devices

Primary storage: Data and instructions are

loaded into memory such as random access

memory. Such storage is temporary.

Secondary storage: Floppy disks and harddisks are secondary storage which provides

permanent storage.


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Slide 3.26



Measuring storage capacity

Bit: A single binary digit representing a (0) zero or a 1.

Byte: Made up of eight bits and represents the

amount of space required to hold a single character.

Kilobyte (kb): Approximately 1000 bytes, or theequivalent of 1000 characters.

Megabyte (Mb): Approximately 1000 kb, or the

equivalent of one million characters.

Gigabyte (Gb): Approximately 1000 Mb, or theequivalent of one billion characters.


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Slide 3.27



Secondary storage

Floppy disk: Consists of a plastic disk, coated

with a magnetic covering and enclosed within a

rigid plastic case.

Hard disk: A magnetic medium that stores dataupon a number of rigid platters that are rotated at

very high speeds.


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Slide 3.28



Figure 3.9 Different views of the platters and sectors on hard disk drives


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Slide 3.29



Other forms of secondary storage

Personal video recorder (PVR): A PVR is asophisticated video recorder that uses a harddisk drive to store programs. The use of a harddisk drive allows a PVR to offer a range of

sophisticated features, such as the ability topause live broadcasts.

Flash drive: A flash drive is a portable storagedevice that connects to a computer via astandard USB port. Flash drives have no movingparts, so are reliable and robust.


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Slide 3.30



Optical secondary storage

CD-ROM: A computer storage device offering a relatively highcapacity. The acronym CD-ROM stands for Compact DiscRead Only Memory, denoting the fact that CD-ROM discs areread-only devices.

Compact disc (CD): The media used by CD-ROM players. The

data on a compact disc is encoded as a series of dips and raisedareas.

CD-R (CD-recordable): Can both read conventional compactdiscs and also write data to special gold discs.

CDRW: In addition to providing the functionality of the CDR

drive, the CDRW drive also allows the use of special compactdisc media that can be written and erased many times.

Digital versatile disc (DVD): Similar to CD-ROM but with higherstorage capacities, typically between 4 Gb and 7 Gb and whichis accessed at higher speeds.


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Slide 3.31



Primary storage memory

Volatile memory: Anything held in memory is lost once the powerto the computer system is switched off.

Non-volatile memory: Non-volatile memory retains its contentsuntil altered or erased.

Random access memory (RAM): RAM is used as volatile,

working storage by a computer, holding instructions and data thatare waiting to be processed.

Read-only memory (ROM): The contents of ROM are fixed andcannot be altered. ROM is non-volatile.

EPROM (erasable programmable read-only memory): This is aform of ROM memory that retains its contents until changed using

a special device known as a burner. Cache memory: Used to improve performance by anticipating the

data and instructions needed by the processor. The required datais retrieved and held in the cache, ready to be transferred directlyto the processor when required.


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Slide 3.32



Figure 3.10 Relationship between primary and secondary storage on a PC


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Slide 3.33



Storage-type summary of

selection criteria

Storage medium Speed Cost Capacity Permanent

Magnetic tape Very slow Very low Very high No

Floppy disk Slow Low Very low No

Hard disk drive Fast Low Very high No

CD-ROM Slow Low Very high Yes

Memory Very fast High Low No/yes


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Slide 3.34



Figure 3.11 The processor in context


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Slide 3.35



Processors

Processor: Uses instructions from software to control thedifferent components of a PC.

Clock speed: Measured in MHz (megahertz, or millions ofpulses per second). The clock speed is governed by aquartz-crystal circuit.

Bus width: Describes how many pieces of data can betransmitted or received at one time by the bus connecting theprocessor to other components of the PC.

VGA (video graphics array): A common standard for graphicscards. All graphics cards support the VGA standard whichspecifies a maximum image size of 640 by 320 pixels,displayed in 16 colours.


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Slide 3.36



Activity 3.9 Selecting processors

What are the current specifications for:

an entry-level cheap and cheerful basic PC;

a high-end PC for a graphics designer;

a web server.


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Slide 3.37



Graphics cards

VGA (video graphics array): A common

standard for graphics cards. All graphics cards

support the VGA (video graphics array) standard

which specifies a maximum image size of 640 by320 pixels, displayed in 16 colours.


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Slide 3.38



Graphics card standards

Standard Highest resolution Maximum colours

MDA Text only 2

Hercules 720 by 348 2

CGA 640 by 200 2

EGA 640 by 350 16

VGA 640 by 480 16

XGA 1024 by 768 65000SVGA 1600 by 1200 16 million


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Slide 3.39



Figure 3.13 A typical expansion card for use with a personal computer


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Slide 3.40



Summary activity match the following

Hardware descriptions

1. Store programs and data in a PC when it is powered down.

2. Store data for fast access when the computer is running.

3. Access 25000 clipart samples for incorporating into presentations.

4. Backing up company financial data.

5. Automatically reading the ISBN of a book.6. Performing calculations of company profit and loss.

7. Obtaining hard copy of a spreadsheet to discuss with your accountant.

8. Connecting to the Internet.

9. Taking data home to analyse on your PC.

10. Joining five PCs together.

11. Storing data to share between users on five networked PCs.Hardware types

(a) RAM; (b) laser printer; (c) floppy disk; (d) fax-modem; (e) CD-ROM;(f) bar-code reader; (g) Intel Pentium processor; (h) CDRW or tapestreamer; (i) local area network (LAN); (j) server; (k) hard disk drive


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Slide 3.41

Bocij, Chaffey, Greasley, Hickie, Business Information Systems, 3

rd


Managing technological change

Reported quotations from conservative technologyadopters

This telephone has too many shortcomings to beseriously considered as a means of communication. The

device is inherently of no value to us. Western Unioninternal memo, 1876.

Who the hell wants to hear actors talk?H.M. Warner,Warner Brothers, 1927.

I think there is a world market for maybe five computers.Thomas Watson, chairman of IBM, 1943.

There is no reason anyone would want a computer intheir home.Ken Olson, Founder of DEC, 1977.


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Slide 3.42

Bocij, Chaffey, Greasley, Hickie, Business Information Systems, 3

rd


Moores law

Gordon Moore, co-founder of Intel, predicted in

1965 that the transistor density of semiconductor

chips would double roughly every 18 months.


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Slide 3.43

rd

Figure 3.14 Typical diffusion of innovation curve

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