Computer Fundamentals: Preep K. Sinha & Priti Sinha

Computer Fundamentals: Preep K. Sinha & Priti Sinha

Slide 1/17Chapter 1: Introduction to ComputersRef Page

/17Chapter 1: Introduction to Computers

Computer Fundamentals: Pradeep K. Sinha & Priti Sinha

Learning Objectives

In this chapter you will learn about:

Computer

Data processing

Characteristic features of computers

Computers’ evolution to their present form

Computer generations

Characteristic features of each computer generation

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Computer

The word computer comes from the word “compute”,which means, “to calculate”

Thereby, a computer is an electronic device that canperform arithmetic operations at high speed

A computer is also called a data processor because it canstore, process, and retrieve data whenever desired

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Data Processing

The activity of processing data using a computer is calleddata processing

Data

Capture Data

Manipulate Data

Output Results

Information

Data is raw material used as input and information isprocessed data obtained as output of data processing

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Characteristics of Computers

1) Automatic: Given a job, computer can work on itautomatically without human interventions

2) Speed: Computer can perform data processing jobsvery fast, usually measured in microseconds (10-6),nanoseconds (10-9), and picoseconds (10-12)

3) Accuracy: Accuracy of a computer is consistently highand the degree of its accuracy depends upon its design.Computer errors caused due to incorrect input data orunreliable programs are often referred to as Garbage-In-Garbage-Out (GIGO)

(Continued on next slide)

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Characteristics of Computers(Continued from previous slide..)

4) Diligence: Computer is free from monotony, tiredness,and lack of concentration. It can continuously work forhours without creating any error and without grumbling

5) Versatility: Computer is capable of performing almostany task, if the task can be reduced to a finite series oflogical steps

6) Power of Remembering: Computer can store andrecall any amount of information because of itssecondary storage capability. It forgets or looses certaininformation only when it is asked to do so


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Characteristics of Computers(Continued from previous slide..)

7) No I.Q.: A computer does only what it is programmedto do. It cannot take its own decision in this regard

8) No Feelings: Computers are devoid of emotions. Theirjudgement is based on the instructions given to them inthe form of programs that are written by us (humanbeings)


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Evolution of Computers

Blaise Pascal invented the first mechanical addingmachine in 1642

Baron Gottfried Wilhelm von Leibniz invented the firstcalculator for multiplication in 1671

Keyboard machines originated in the United Statesaround 1880

Around 1880, Herman Hollerith came up with the conceptof punched cards that were extensively used as inputmedia until late 1970s

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He designed “Difference Engine” in 1822

He designed a fully automatic analytical engine in1842 for performing basic arithmetic functions

His efforts established a number of principles thatare fundamental to the design of any digitalcomputer



Evolution of Computers(Continued from previous slide..)

Charles Babbage is considered to be the father ofmodern digital computers

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Some Well Known Early Computers

The Mark I Computer (1937-44)

The Atanasoff-Berry Computer (1939-42)

The ENIAC (1943-46)

The EDVAC (1946-52)

The EDSAC (1947-49)

Manchester Mark I (1948)

The UNIVAC I (1951)

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Computer Generations

“Generation” in computer talk is a step in technology. Itprovides a framework for the growth of computer industry

Originally it was used to distinguish between varioushardware technologies, but now it has been extended toinclude both hardware and software

Till today, there are five computer generations


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Generation(Period)

Keyhardwaretechnologies

Keysoftwaretechnologies

Keycharacteristics

Somerepresentative

systems

First(1942-1955)

VacuumtubesElectromagneticrelaymemoryPunchedcardssecondarystorage

MachineandassemblylanguagesStoredprogramconceptMostlyscientificapplications

BulkyinsizeHighlyunreliableLimitedcommercialuseandcostlyDifficultcommercialproductionDifficulttouse

ENIACEDVACEDSACUNIVACIIBM701

Second(1955-1964)

TransistorsMagneticcoresmemoryMagnetictapesDisksforsecondarystorage

BatchoperatingsystemHigh-level

programminglanguagesScientificandcommercialapplications

Faster,smaller,morereliableandeasiertoprogramthanpreviousgenerationsystemsCommercialproductionwasstilldifficultandcostly

Honeywell400IBM7030CDC1604UNIVACLARC

Slide 12/17Chapter 1: Introduction to Computers


Computer Generations(Continued from previous slide..)


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Generation(Period)



Keycharacteristics

Somerep.systems

Third(1964-1975) ICswithSSIand

MSItechnologiesLargermagneticcoresmemoryLargercapacitydisksandmagnetictapessecondarystorageMinicomputers;upwardcompatiblefamilyofcomputers

TimesharingoperatingsystemStandardizationofhigh-level

programminglanguagesUnbundlingofsoftwarefromhardware

Faster,smaller,morereliable,easierandcheapertoproduceCommercially,easiertouse,andeasiertoupgradethanpreviousgenerationsystemsScientific,commercialandinteractiveon-lineapplications

IBM360/370PDP-8PDP-11CDC6600





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Generation(Period)

KeyhardwareTechnologies


Keycharacteristics

Somerep.systems

Fourth(1975-1989) ICswithVLSI

technologyMicroprocessors;semiconductormemoryLargercapacityharddisksasin-builtsecondarystorageMagnetictapesandfloppydisksasportablestoragemediaPersonalcomputersSupercomputersbasedonparallelvectorprocessingandsymmetricmultiprocessingtechnologiesSpreadofhigh-speedcomputernetworks

OperatingsystemsforPCswithGUIandmultiplewindowsonasingleterminalscreenMultiprocessingOSwithconcurrentprogramminglanguagesUNIXoperatingsystemwithCprogramminglanguageObject-orienteddesignandprogrammingPC,Network-based,andsupercomputingapplications

Small,affordable,reliable,andeasytousePCsMorepowerfulandreliablemainframesystemsand

supercomputersTotallygeneralpurposemachinesEasiertoproducecommerciallyEasiertoupgradeRapidsoftwaredevelopmentpossible

IBMPCanditsclonesAppleIITRS-80VAX9000CRAY-1CRAY-2CRAY-X/MP





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Generation(Period)



Keycharacteristics

Somerep.systems

Fifth(1989-Present) ICswithULSI

technologyLargercapacitymainmemory,harddiskswithRAIDsupportOpticaldisksasportableread-onlystoragemediaNotebooks,powerfuldesktopPCsandworkstationsPowerfulservers,

supercomputersInternetClustercomputing

Micro-kernelbased,multithreading,

distributedOSParallelprogramminglibrarieslikeMPI&PVMJAVAWorldWideWebMultimedia,InternetapplicationsMorecomplex

supercomputingapplications

PortablecomputersPowerful,cheaper,reliable,andeasiertousedesktopmachinesPowerful

supercomputersHighuptimeduetohot-pluggablecomponentsTotallygeneralpurposemachinesEasiertoproducecommercially,easiertoupgradeRapidsoftwaredevelopmentpossible

IBMnotebooksPentiumPCsSUNWorkstationsIBMSP/2SGIOrigin2000PARAM10000




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Slide 1/16Chapter 2: Basic Computer OrganizationRef. Page

/16Chapter 2: Basic Computer Organization


Learning Objectives

In this chapter you will learn about:

Basic operations performed by all types of computersystems

Basic organization of a computer system

Input unit and its functions

Output unit and its functions

Storage unit and its functions

Types of storage used in a computer system


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Learning Objectives(Continued from previous slide..)

Arithmetic Logic Unit (ALU)

Control Unit (CU)

Central Processing Unit (CPU)

Computer as a system

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The Five Basic Operations of a Computer System

Inputting. The process of entering data and instructionsinto the computer system

Storing. Saving data and instructions to make themreadily available for initial or additional processingwhenever required

Processing. Performing arithmetic operations (add,subtract, multiply, divide, etc.) or logical operations(comparisons like equal to, less than, greater than, etc.)on data to convert them into useful information


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The Five Basic Operations of a Computer System

Outputting. The process of producing useful informationor results for the user such as a printed report or visualdisplay

Controlling. Directing the manner and sequence in whichall of the above operations are performed

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PrimaryStorage

ArithmeticLogic Unit


InputUnit

OutputUnit

ProgramandData

Information(Results)

ControlUnit

Indicates flow ofinstructions and data

Indicates the controlexercised by thecontrol unit


Basic Organization of a Computer System

Storage Unit

SecondaryStorage

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Input Unit

An input unit of a computer system performs the

following functions:

1. It accepts (or reads) instructions and data from outsideworld

2. It converts these instructions and data in computeracceptable form

3. It supplies the converted instructions and data to thecomputer system for further processing

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Output Unit

An output unit of a computer system performs the


1. It accepts the results produced by the computer, whichare in coded form and hence, cannot be easilyunderstood by us

2. It converts these coded results to human acceptable(readable) form

3. It supplies the converted results to outside world

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Storage Unit

The storage unit of a computer system holds (or stores)

the following :

1. Data and instructions required for processing (receivedfrom input devices)

2. Intermediate results of processing

3. Final results of processing, before they are released toan output device

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Two Types of Storage

Primary storage

Used to hold running program instructions

Used to hold data, intermediate results, andresults of ongoing processing of job(s)

Fast in operation

Small Capacity

Expensive

Volatile (looses data on power dissipation)


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PrimaryStorage



InputUnit

OutputUnit

ProgramandData

Information(Results)

ControlUnit

Indicates flow ofinstructions and data

Indicates the controlexercised by thecontrol unit


Basic Organization of a Computer System

Storage Unit

SecondaryStorage

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Input Unit

An input unit of a computer system performs the


1. It accepts (or reads) instructions and data from outsideworld

2. It converts these instructions and data in computeracceptable form

3. It supplies the converted instructions and data to thecomputer system for further processing

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Output Unit

An output unit of a computer system performs the


1. It accepts the results produced by the computer, whichare in coded form and hence, cannot be easilyunderstood by us

2. It converts these coded results to human acceptable(readable) form

3. It supplies the converted results to outside world

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Storage Unit

The storage unit of a computer system holds (or stores)

the following :

1. Data and instructions required for processing (receivedfrom input devices)

2. Intermediate results of processing

3. Final results of processing, before they are released toan output device

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Two Types of Storage

Primary storage

Used to hold running program instructions

Used to hold data, intermediate results, andresults of ongoing processing of job(s)

Fast in operation

Small Capacity

Expensive

Volatile (looses data on power dissipation)


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Two Types of Storage(Continued from previous slide..)

Secondary storage

Used to hold stored program instructions

Used to hold data and information of stored jobs

Slower than primary storage

Large Capacity

Lot cheaper that primary storage

Retains data even without power

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Arithmetic Logic Unit (ALU)

Arithmetic Logic Unit of a computer system is the placewhere the actual executions of instructions takes place duringprocessing operation

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Control Unit (CU)

Control Unit of a computer system manages and coordinatesthe operations of all other components of the computersystem

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(ALU)

Control Unit(CU)

=

CentralProcessingUnit (CPU)

It is the brain of a computer system

It is responsible for controlling the operations ofall other units of a computer system

+



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The System Concept

A system has following three characteristics:

1. A system has more than one element

2. All elements of a system are logically related

3. All elements of a system are controlled in a manner toachieve the system goal

A computer is a system as it comprises of integratedcomponents (input unit, output unit, storage unit, and CPU)that work together to perform the steps called for in theexecuting program

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Computer Fundamentals: Preep K. Sinha & Priti Sinha

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