ssd2 unit1 computer systems

8/6/2019 Ssd2 Unit1 Computer Systems

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SSD2: Introduction to ComputerSSD2: Introduction to Computer

SystemsSystems

Version 4.0 Fall 2003


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Unit 1. Computer SystemsUnit 1. Computer Systems

1.1 Overview of Computer Systems1.2 Evolution of Computer Systems

1.3 Data Representation in a Computer System


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Subsystems of a ComputerSubsystems of a Computer

Software System

Operating System (Unix, Mac OS, Microsoft

Windows)

Web browser (Netscape, Internet Explorer)

Office productivity applications (Microsoft

Office, Star Office)

Hardware System

Keyboard

MonitorSystem unit

Network System

Internet services (email)

Network connections (modems, network cards)

Internet


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Hardware SystemHardware System

Speakers

Printer

Mouse

Keyboard

Monitor

System unit


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Hardware Components: PeripheralHardware Components: Peripheral

DevicesDevices

Equipment added to computer to enhance its functionalityModify and expand the basic computer system

Examples of peripheral devices:

Keyboard

Monitor

Mouse

Printer

Scanner

Digital Video Camera

Graphic Tablet

Joy Stick


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Hardware Components:Hardware Components: Storage DevicesStorage Devices

Optical Disks CD-ROM

CD-RW

DVD-ROM

Magnetic Disks

Floppy disk

Hard disk (removable & fixed)


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What is Software?What is Software?

Software is a set of computer instructions or data.Software receives input from the user and

processes this input through the computer to

produce output.

Software directs how the computer interacts with the

user.

Software specifies how to process the user's data


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Software SystemSoftware System

Two categories: operating system (OS)software and application software.Operating system software, also calledsystem software, is the master controllerfor all activities that take place within acomputer Examples of OS software:

Microsoft Windows Unix

Mac OS

Application software is a set of one ormore computer programs that helps apersoncarry out a task

Examples of application software: Microsoft Word

Internet Explorer

Macromedia Dreamweaver

Adobe Acrobat Reader

Hardware System

Application Software

Operating System Software

Users


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Network SystemNetwork System

A network provides connections among computers to enable computers on a

network to share data (e.g. documents), hardware (e.g. printers), and software

resources (e.g. application programs).

Network users can also send messages to each other.

A network must be secured to protect data from unauthorized usage (e.g. using

login name and password to gain access to a network).

Network connection

components:

Network Interface Card

(NIC)

Modem

Phone line or cable

Internet Service

Provider (ISP)

Internet


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Basic Computer ModelBasic Computer Model

All computers perform four basic operations Input Data

Process Data

Store Data

Output Data


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Basic OperationsBasic Operations

Input data is to feed information which can be supplied byany person, environment or other computer.

Processing data is manipulating data by performing

calculations, sorting lists of words or numbers, drawing

pictures.Storing data is for future retrieval and processing. Memory

holds data that is waiting to be processed, and storage areas

hold data permanently until the data is deleted.

Output data is the result produced by a computer, whichincludes reports, documents, music, graphs and pictures.


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Categories of ComputersCategories of Computers

Computers are classified based on their technology,function, physical size, performance and cost. The

categories of computers include:

Personal computers

Handheld computers

Mainframes

Supercomputers


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Personal Computer (PC)Personal Computer (PC)

Designed to meet the computing needs of anindividual

Desktop computers

Notebook computers


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Handheld ComputerHandheld Computer

Designed to fit into a pocket,run on batteries, and be used

while you are holding it

Also called a PDA (Personal

Digital Assistant)

Send and receive e-mail

Use maps and global

positioning

Maintain expense account,

contacts, to-do lists, memos,

etc.

Make voice calls using cellular

serviceA personal digital

assistant (PDA)

accepts info

on a touch-sensitive

screen


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Mainframe ComputerMainframe Computer

It is a large and expensive computer that is capable ofhandling requests and passing data simultaneously to

many users.

Used by governments and large corporations to provide

centralized storage and controlProcesses billions of data per second and includes many

units where one directs overall operations, a second one

handles communication between users, and third

searches for requests given by user.


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SupercomputerSupercomputer

It is the fastest type of computer.Supercomputers are very expensive and are employed for

specialized applications that require immense amounts of

mathematical calculations.

It is often used for:

Breaking codes

Modeling weather systems

Simulating nuclear explosions

Research simulations

Capable of performing over 600 billion floating-point

operations per second.

Examples: Deep Blue, PARAM 1000, Hitachi's SR2201


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Evolution of ComputersEvolution of Computers

Needed calculation devices to keep track of accounting forcommerce

1200sManual Calculating Devices: the abacus


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Evolution of Computers (continued)Evolution of Computers (continued)

1600sMechanical Calculators Used wheels, gears, and counters

To work a mechanical calculator, the operator enters

the numbers for a calculation, and then pulls a lever

or turns a wheel to carry out the calculation

Example: the Pascaline invented by Blaise Pascal. It

used some principles of the abacus, but used wheels

to move counters.


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1800sPunched Cards

Used holes following a specific pattern to represent the instructions

given to the machine or stored data

Different program instructions can be stored on separate punched

cards, which can be fed through the computing machine

repeatedly.

Once punched, the cards were fed into a card reader that used an

array of metal rods to electronically read the data from the cards

and tabulate the results. This is called the Hollerith Tabulating

Machine

Hollerith incorporated The Tabulating Machine better known today

as IBM.


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Charles Babbage designed a new general-purpose calculatingdevice, theAnalytical Engine, which is the ancestor of modern

computers.

It included the essential components of present-day computers,

which are input, process, storage, and output of data.


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1940sVacuum Tubes

Used to control the flow of electrons. Since vacuum tubes responded faster

than mechanical components, faster computations were possible. But, the

tubes consumed a lot of power and burned out quickly.

The first computer prototype using vacuum tubes was ENIAC (ElectronicNumerical Integrator and Computer). It was designed to calculate

trajectory tables for the U.S. Army during World War II, but it was not

completed until three months after the war.


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1950sTransistors

Smaller, cheaper, more reliable, and consumed less power

than vacuum tubes.

Could perform 200,000 to 250,000 calculations per

second.


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1960sIntegrated Circuits Thin slice of silicon packed with microscopic circuit

elements such as wire, transistors, capacitors, and

resistors.

Enabled the equivalent of thousands of vacuum tubes

or transistors to be packed onto a single miniature

chip about the size of your fingernail

Reduces the physical size, weight, and powerrequirements for devices such as computers


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1970s to PresentMicroprocessor

Combined components of a computer on a microchip

Can be manufactured and then programmed for various

purposes


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Pace of Processor Advancement


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Applications of Computer SystemsApplications of Computer Systems

In Education Multimedia-Facilitated Learning

Simulation-Based Education

Intelligent Machine-Based Training

Interactive LearningIn Business

Supply Chain Management

Project Management

Customer Relationship Management Sales and Marketing Using Electronic Commerce

Manufacturing Research


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Applications of Computer SystemsApplications of Computer Systems

In Entertainment Movies

Video Games

Music

Digital Photography Travel

Wearable Computer Systems

Developing new applications of computer systems:

Research at Carnegie Mellon Universityhttp://www.cs.cmu.edu/research/projects/

Research at Massachusetts Institute of Technology Media Lab

http://www.media.mit.edu/


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Computer IndustryComputer Industry

Computer industry encompasses those companies thatmanufacture handheld computers, personal computers, high-

end workstations, servers, mainframes, and supercomputers

Information technology industry(or IT industry), is typically

used to refer to the companies that develop, produce, sell, orsupport computers, software, and computer-related products

IT companies include:

Equipment manufacturers

Chipmakers Software publishers

Service companies

Retailers


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Computer Industry (continued)Computer Industry (continued)

The 1990s spawned a group of Internet-basedcompanies that came to be called dot coms, from

the companies domain names, which inevitably

ended with .com and many of the companies even

incorporated .com into their official company

names

Amazon.com was one of the first Internet-based

companies


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Computer Industry (continued)Computer Industry (continued)

Governments and private businesses havediscovered that they can become much more

efficient with a liberal application of computers and

other information technologies

As businesses globalize, they encounter new

competitors with technological advantages

Bottom line: if your business competitors turn to

technology, so must you


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Careers in ComputingCareers in Computing

A systems analystinvestigates the requirements of a

business or organization, its employees, and its customers in

order to plan and implement new or improved computer

services

A security specialistanalyzes a computer systems

vulnerability to threats from viruses, worms, unauthorizedaccess, and physical damage

A computer programmerdesigns, codes, and tests

computer programs

A quality assurance specialistparticipates in alpha andbeta test cycles of software

A database administratoranalyzes a companys data to

determine the most effective way to collect and store it


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Careers in Computing (continued)Careers in Computing (continued)

A network specialist/administratorplans, installs,and maintains one or more local area networks

A computer operatortypically works with

minicomputers, mainframes, and supercomputers

A computer engineerdesigns and tests new

hardware products, such as computer chips, circuit

boards, computers, and peripheral devices

A technical support specialistprovides phone or

online help to customers of computer companies

and software publishers


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A technical writercreates documentation for largeprogramming projects, and writes the online or

printed user manuals that accompany computers,

peripheral devices, and software

A computer salesperson, or sales rep, sellscomputers

A Web site designercreates, tests, posts, and

modifies Web pages

A manufacturing technician participates in the

fabrication of computer chips, circuit boards, system

units, or peripheral devices


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The U.S. Bureau of Labor Statistics (BLS) projectsthat the number of jobs in the computer industry will

substantially increase between now and 2008

According to the BLS, the largest increases in

available jobs will be for database administrators,computer support specialists, and computer

engineers

Over the next few years, economic trends may

cause significant changes in the job market

A daily look at in-demand tech skills can be viewed

at: http://mshiltonj.com/sm/


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IT Salaries in the U.S.IT Salaries in the U.S.

Source: http://www.bls.gov


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Data Representation: Bits andBytesData Representation: Bits andBytes

Recall computers are made up of electrical components

Data can be represented electronically with electrical

components being on or off.

On and off states can be represented using digits 0s and 1s.

For example: 0: Off state

1: On state

Thus, data can be represented digitally using digits 0 and 1.

0 and 1 are called binary digits.

Each binary digit is called a bit.

Eight Bits equal to one byte.


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Number SystemsNumber Systems

Decimal: base10 (digits 0-

9)

Binary: base 2 (digits 0-1)

Hexadecimal: base16 (digits 0-9 and A-F)

Each hexadecimal digit represents four binary places.

Hex digit can be used as shorthand for binary

notation

One Hex digit four bits

One byte = 8 bits two Hex digits


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END ofUnit 1END ofUnit 1

ssd2 unit1 computer systems

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