introduction (ch 2)

8/2/2019 Introduction (Ch 2)

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Chp03_Introduction toComputers ICMAP/FI/ZAQ 2

Computer Systems

ComputerSystem - A collection of elements thatincludes the computer and components thatcontribute to making it a useful tool.

Keep track of bank transactions and credit card

purchases

Are cornerstone of airlines massive reservationssystems Control direct production in factories Provide business executives with up to date

information Create illusion of a real situation Are embedded in watches, television sets, phones,

fax machines, kitchen appliances etc.


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Computers in the Workplace

Multipurpose workstation

Design

The Internet Home Based Business

Music

Wireless Communications


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Whats a Computer & What Does it Do?

The operation of a Computer System is defined in fourwords

Input- What is supplied to a computer process

Processing - The conversion of input to output)

Output- The results of a computer process)

Storage - An area that holds materials going to or comingfrom the computer


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Data and Information

Data are essentially raw, unorganized facts.

Fourtypes ofdata

textgraphics

audio

video


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Data and Information

Information, in the language of computers,refers to data that have processed into ameaningful form

Information is a relativeterm

Conversion of data into information is called

informationprocessing

Data + meaning = Information


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Data Versus Information

Data are Information is

Stored facts Presented facts

Inactive (they exist)Active (it enablesdoing)

Technology based Business based

Gathered fromvarious sources

Transformed fromdata


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Desirable Qualities of

InformationQuality Description

Availability Is accessible to those who need

itComprehensibility Is understandable to those who

need itRelevance Has bearing on matters

pertaining to the performance ofthe organization

Usefulness Is in a form that makes itcapable of being used


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Desirable Qualities of

Information

Quality Description

Timeliness Is available at the right time

Reliability Can be counted on to betrustworthy

Accuracy Is correct

Consistency Is not self - contracdictory


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Programs

Program - A set of instructions that causes thecomputer system to perform specific actions.

ProgrammingLanguage - A set of rules used towrite computer programs.

The ability to program makes computer generalpurposedevice.


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Computer Storage

There are two types of storage

Primary (Internal) Also known as memory

This section of the computer system temporarily holds data andprogram instructions awaiting processing, intermediate results, andprocessed output

Secondary (external) Storage on media such as disk and tape that supplements memory


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Hardware

Physical equipment in a computingenvironment, such as the computer and its

peripheraldevices.

For e.g. monitor, printer, speakers, mouse, hard- disk drive, diskettes, diskette drive, CD-ROMdrive, CD-ROM disks


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Application Software

A combination of programs which enables abusiness application (e.g. a purchase ledger) tobe processed by a computer.

Application software written for one particular

purpose is termed bespokesoftware.


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computing bank account interest preparing bills creating letters and book manuscripts

preparing and analyzing budgets managing files and databases playing games

scheduling airline flights diagnosing patients illnesses


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Productivitysoftware is the class of applicationssoftware designed to make workers moreproductive at their jobs.

For e.g., word processors, spreadsheets,presentation graphics, database management,desktop publishing, web browser


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System Software

Background programs, such as the operating

system, that enable application programs to run

on a computer systems hardware. For e.g. operating system, compilers, interpreters

and assemblers.


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Software Package

Software package consist of one or more

programdisks, aprintedusersguide, and a

printeduserslicense inside a shrinkwrapped

box orplasticcase.

Each revision is referred to as a version or

release.


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Organizing Data and Programs

Document-Any single piece of work thatscreated with software and, then, given a name bywhich it may be accessed.

Folder- A container for documents.

A folder can contain a mixture ofsubfoldersand documents.


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Organizing Data and Programs

Field- A collection of related characters.

Record- A collection of related fields.

File - A collection of related records.

Database - A collection of related files.

Be aware, a word processed file and aword processed document generally

refer to the same thing.


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Users and the Experts

User(end users) - A person(s) who needs the

results that a computer produces.

Programmer- A person who writes computer

programs.


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Computer Networks

Networks allow workers in an organization tocommunicate with each other, share expensivedevices like printers, and send and receive materials

to and from the outside world. To access a computer network, you need two kinds

of resources

hardware (network adapter) e.g. modem

communicationsoftware


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Computer Networks

Online - A state that allows a device to send

data to or receive data from other devices.

Offline - A state that does not allow a device to

send data to or receive data from other devices.


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Types of Computer System

Small orMicro computers

Medium sized orMidrange computers

Large orMainframe computers

Superlarge or Supercomputers


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Microcomputers

A computer system driven by a microprocessor

chip. Also known as microcomputer, or micro.

A microcomputer system designed to be used byone person at a time. Also known as apersonal

computersystem (PC).


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Sizes of Microcomputer Systems

Desktop Units

Desktop model

Tower model

Portable Units

Laptop (8 - 15 pounds)

Notebook (6 - 8 pounds)

Subnotebook (2 - 6 pounds) Palmtop / Handheld / Personal Digital Assistants

(PDAs)


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Desktop Units

Desktop model the system unit case is designed to rest on a desk

Towermodel

the system unit case stands upright on either a desktop orfloor

more room to fix secondary storage units

leave more work space on the desktop

the system unit case often sit at a distance may notprovide as convenient way to mount and dismount disksfrom drives.


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Platform

Platform is a foundation technology bewhich a computer system operates.

Two major platforms are

PCcompatibles (IBM design, Intelmicroprocessor & Microsoft Windowsapplications)

Macintoshcompatibles (Apple design,Motorola, Umax, Power Computingmicroprocessor & Macintosh applications)


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Network Computers

Networkcomputers (NCs) are disklessmicrocomputers with features that optimize themfor use on the Internet and intracompany networks.

Network computers offer lower purchase and support costs

better control over employee computing activities

central control prevent users from storing material ontheir own system which prevents corruption of thesystem.


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Midrange Computers

Also called minicomputers or minis

An intermediate sized and medium pricedcomputer

More expensive than microcomputers.

Can interact with hundreds of users.

Useful a small company or department of acompany


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Mainframes

A large computer that performs extensive businesstransaction processing.

Operates 24 hours a day

Serves thousands of users

Used for tracking customer purchases andpayments, sending out bills and reminder notices &

paying employees e.g. IBS ES/9000


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Supercomputers

The fastest and most expensive type ofcomputer.

Sending astronauts into space, testing safety &aerodynamics features on cars and aircraft andweather forecasting.

MassivelyParallelProcessors (MPPs)


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Supercomputers

At the high end of supercomputing are computers likeIBM's "Blue Pacific," announced on October 29, 1998.

Built in partnership with Lawrence Livermore NationalLaboratory in California., Blue Pacific is reported tooperated at 3.9 teraflop (trillion operations per second),15,000 times faster than the average personal computer.

It consists of 5,800 processors containing a total of 2.6

trilllion bytes of memory and interconnected with fivemiles of cable.
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