Computer funadamentals

COMPUTERFUNDAMENTALS
1. INTRODUCTION TO COMPUTER SYSTEM
 1.0.Founderof Computer
 1.1.Generations Of Computers
 1.2. First Generation Computers
 1.3. Second Generation Computers
 1.4.Third Generation Computers
 1.6.Fifth Generation Computers
2. DEFINITION OF COMPUTER AND ITS CONCEPTS.
 2.0computer Definition
 2.1computer Block Diagram
 2.2. Input Devices
 2.2.1. Keyboard
 2.2.1.2 Keyboard Shortcuts
 2.2.2 Mouse
 2.2.3 Joystick
 2.2.4 Light Pen
 2.2.5Track Ball
 2.2.6 Scanner
 2.2.7 Digitizer [Graphic Tablet]
 2.2.8 Microphone
 2.2.9.MagneticInk Card Reader(MICR)
 2.3. Optical Character Reader (OCR)
 2.4 Bar Code Reader
 2.5 Webcam
 2.6 Biometrics [Thumb Impression / Face Detection]
 2.7. Output Devices
 2.7.1.Monitors
 2.7.2. Cathode-Ray Tube (CRT) Monitor
 2.7.3. Flat-Panel Display Monitor
 2.8.Printers
 2.8.1.ImpactPrinters

 2.8.2. Character Printers
 2.8.3. Dot Matrix Printer
 2.8.4. Daisy Wheel
 2.8.5line Printers
 2.8.6drum Printer
 2.8.7chain Printer
 2.8.9.Non-ImpactPrinters
 2.9.CharacteristicsofNon-ImpactPrinters
 2.9.1laser Printers
 2.9.2. Inkjet Printers
3. FUNDAMENTALS OF COMPUTER ARCHITECTURE
 3.1. CPU Block Diagram
 3.2. CPU Phases
 3.3. Memory Unit
 3.4. Memory Classification
 3.4.1. Random Access Memory [Ram]
 3.4.2. SRAM
 3.4.3 .DRAM
 3.5. Rom Classification
 3.5. 1.PROM
 3.5.2. EPROM
 3.5.3. EEPROM
 3.6 Cache Memory
 3.7. Control Unit
 3.8. Arithmetic Logic Unit [ALU]
 3.9. Buses In CPU
 3.9.1. Instruction Cycle
 3.9.2. Measure of CPU Performance.

4. MOTHERBOARD [INTERNAL COMPONENTS]
 4.1Features ofMotherboard
 4.2PopularManufacturers
 4.3The Important Components of Motherboard
 4.4complete Mother Board View
5. COMPUTER –SOFTWARE
 5.1.System Software
 5.1.1. Operating System
 5.1.2. System Development Software
 5.1.3. Utility Programs
 5.2. Application Software
5.2.2. Custom Software
 5.3. Assembler
 5.4. Compiler
 5.5. Interpreter
6. OPERATING SYSTEM
 6.1Basics of operating system
 6.2 Types Of Operating System
 6.3Process management
 6.31Process
 6.3.2Process scheduling
7. INTER PROCESSOR COMMUNICATION
 7.1introduction
 7.1.1. Race Conditions
 7.1.2Semaphores
 7.1.3Message Passing
 7.1.4scheduling Algorithms

8. DEADLOCKS
 8.1.1 Definition Of Deadlock
 8.1.2 Characteristics
 8.1.3deadlock’s Prevention
 8.1.4 Banker’s Algorithm
9. MEMORY MANAGEMENT
 9.1.1basic Memory Management
 9.1 .2definition
 9.1.3 Logical &Physical Address Map
 9.1.4continuous Memory Allocation
 9.1.5fixed And Variable Portion
 9.1.6 Internal And External Fragmentation And
Compaction
 9.1.7paging: Principle Of Operation
 9.1.8 Page Allocation
 9.1.9hardware Support For Paging
 9.1.10protection And Sharing
 9.1.11disadvantages Of Paging
9.2 Virtual Memory
 9.2. Basics Of Virtual Memory
 9.2.1demand Paging
 9.2.2.Pagereplacement Algorithm
 9.2.3.Reference String
 9.2.4.First In First Out Algorithm[FIFO]
 9.2.5.Leastrecently Used Algorithm[LRU]
 9.2.7 Least Frequently Used Algorithm[LFU]
 9.2.8.Most Frequently Used Algorithm[MFU]

10. I/O MANAGEMENT
 10.1 I/O Devices,
 10.2 Device Controllers
 10.3direct Memory Access Principles Of I/O Software:
 10.4 Goals of Interrupt Handlers
 10.5 Device Drivers
 10.6secondary-Storage Structure:
 10.7 Disk Structure
 10.8 Disk Scheduling Algorithm
 10.9. Raid [RedundantArray Of IndependentDisks]
 10.10. Disk Attachment
11. FILEMANAGEMENT
 11.1 Access Methods
 11.2file Types
 11.3file Operations
 11.4 Directory Structure

1. INTRODUCTION TOCOMPUTER SYSTEM
CHARLES BABBAGE
[DEC-16-1791toOCT-18-1871]

1. 0.FOUNDER OF COMPUTER
1.0. First-GenerationComputerfromCharlesBabbage
CHARLES BABBAGE, [26 December 1791 –18 October 1871] Was A Mathematician,
Philosopher, Inventor And Mechanical Engineer, Babbage Is Best Remembered For
Originating The Concept Of A Programmable Computer.
Parts Of Babbage's Uncompleted Mechanisms Are On Display In The London Science
Museum.
In 1991, A Perfectly Functioning Difference Was Constructed From Babbage's
Original Plans.
Built To Tolerances Achievable In The 19th Century, The Success Of The Finished
Engine Indicated That Babbage's Machine Would Have Worked.
1. A. First Programmable Computer 1.B.Babbage Engine

1.1.GENERATIONS OF COMPUTERS
1.1.A. Generation Of Computers

1.2. FIRST GENERATION COMPUTERS [1946-1959].
The Computers Of First Generation Used Vacuum Tubes As The Basic Components
For Memory And Circuitry For CPU (Central Processing Unit).
These Tubes, Like Electric Bulbs, Produced A Lot Of Heat And Were Prone To
Frequent Fusing Of The Installations, Therefore, Were Very Expensive And Could Be
Afforded Only By Very Large Organizations.
In This Generation Mainly Batch Processing Operating System Were Used. Punched
Cards, Paper Tape, And Magnetic Tape Were Used As Input And Output Devices. The
Computers In This Generation Used Machine Code As Programming Language.
1.2. A. First -Generationcomputer1 1.2.B.First-Generationcomputer2
1.2. C. Top View of First-Generation Computer

1.2.1FIRST GENERATION COMPUTERS FEATURES
The main features of first generation are:
 Vacuum Tube Technology
 Unreliable
 Supported Machine Language Only
 Very Costly
 Generated Lot Of Heat
 Slow Input And Output Devices
 Huge Size
 Need of A.C.
 Non-Portable
 Consumed Lot Of Electricity
Some computers of this generation were:
 ENIAC
 EDVAC
 UNIVAC
 IBM-701
 IBM-650
1.2.1. A. John Von Neumann with IAS Computer 1.2.1.B Vacuum Tubes.

1.3. SECOND GENERATION COMPUTERS [1959-1965]
In This Generation Transistors Were Used That Were Cheaper, Consumed Less
Power, More Compact In Size, More Reliable And Faster Than The First Generation
Machines Made Of Vacuum Tubes
In This Generation, Magnetic Cores Were Used As Primary Memory And Magnetic
Tape And Magnetic Disks As Secondary Storage Devices
. In This Generation Assembly Language And High-Level Programming Languages
Like FORTRAN, COBOL Was Used. The Computers Used Batch Processing And
Multiprogramming Operating System.
1.3.A.Secondgeneration Ibm Computer 1.3.B.Secon Generation Computer
1.3.C Secongeneration Pc 1.3.D.Secondgeneration Pc 1.3.E.Ibmpc
[Tranistors Replaced By Vaccumetubes]

1.3.1. SECOND GENERATION COMPUTERS FEATURES
The main features of second generation are:
 Use Of Transistors
 Reliable In Comparison To First Generation Computers
 Smaller Size As Compared To First Generation Computers
 Generated Less Heat As Compared To First Generation Computers
 Consumed Less Electricity As Compared To First Generation Computers
 Faster Than First Generation Computers
 Still Very Costly
 A.C. Needed
 Supported Machine And Assembly Languages
Some computers of this generation were:
 IBM 1620
 IBM 7094
 CDC 1604
 CDC 3600
 UNIVAC 1108
1.3.1.A.Ibm7090pc 1.3.1.B.Secondgeneration Pc

1.4.THIRD GENERATION COMPUTERS[1965-1971]
The Computers Of Third Generation Used Integrated Circuits (IC's) In Place Of
Transistors.
A Single IC Has Many Transistors, Resistors And Capacitors Along With The
Associated Circuitry. The IC Was Invented By Jack Kilby.
This Development Made Computers Smaller In Size, Reliable And Efficient.
In This Generation Remote Processing, Time-Sharing, Multi-Programming Operating
System Were Used.
High-Level Languages (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68
Etc.) Were Used During This Generation.
The Main Features Of Third Generation Are:
 IC Used
 More Reliable In Comparison To Previous Two Generations
 Smaller Size
 Generated Less Heat
 Faster
 Lesser Maintenance
 Still Costly
 A.C Needed
 Consumed Lesser Electricity
 Supported High-Level Language
Some Computers Of This Generation Were:
 Ibm-360 Series
 Honeywell-6000 Series
 PDP(Personal Data Processor)
 Ibm-370/168
 Tdc-316

1.4.1THIRD GENERATION COMPUTERS
1.4.1.A. Third Generation Computer1
[ It Is Developed By High Levelonguage Like C] 1.4.1.B Third Generation
Computer
[Having Ups Separate Cpu]
1.4.1.C.Corei7based Embedded Computer 1.4.1.D.Third Generation Pc

1.5.FOURTH GENERATION COMPUTERS[1971-1980]
The Computers of Fourth Generation Used Very Large Scale Integrated (VLSI)
Circuits.
VLSI Circuits Having About 5000 Transistors And Other Circuit Elements And Their
Associated Circuits On A Single Chip Made It Possible To Have Microcomputers Of
Fourth Generation.
Fourth Generation Computers Became More Powerful, Compact, Reliable, and
Affordable. As A Result, It Gave Rise To Personal Computer (Pc) Revolution.
In This Generation Time Sharing, Real Time, Networks, Distributed Operating
System Were Used.
All The High-Level Languages Like C, C++, Dbase Etc., Were Used In This Generation.
1.5.1.FOURTH GENERATION COMPUTERS FEATURES :
The Main Features Of Fourth Generation Are:
 VLSI Technology Used
 Very Cheap
 Portable And Reliable
 Use Of PC's
 Very Small Size
 Pipeline Processing
 No A.C. Needed
 Concept Of Internet Was Introduced
 Great Developments In The Fields Of Networks
 Computers Became Easily Available
Some Computers Of This Generation Were:
 DEC 10
 STAR 1000
 PDP 11
 CRAY-1(Super Computer)

 CRAY-X-MP(Super Computer)
1.5.2.FOURTH GENERATION COMPUTERS
1.5.2.A. Fourth Generation Pc 1.5.2.B.Apple Laptop
1.5.2.Apple Pc

1.6.FIFTH GENERATION COMPUTERS[1980-Till Date]
In The Fifth Generation, The VLSI Technology Became ULSI (Ultra Large Scale
Integration) Technology, Resulting In The Production Of Microprocessor Chips
Having Ten Million Electronic Components.
This Generation Is Based On Parallel Processing Hardware And AI (Artificial
Intelligence) Software.
AI Is An Emerging Branch In Computer Science, Which Interprets Means And
Method Of Making Computers Think Like Human Beings
.All the High-Level Languages like C and C++, Java, .Net Etc., Are Used in This
Generation.
Fifth Generation Computers Includes:
 Robotics
 Neural Networks
 Game Playing
 Development of Expert Systems To Make Decisions In Real Life Situations.
 Natural Language Understanding and Generation.
1.6.A. Fifth Generation Computers Based On Artificial Intelligence [Robots].

1.6.B.Samsung Galaxy Tab S10.5
1.6.C.Apple I Phone6 1.6D.Samsumng S6

QUESTIONS ON COMPUTER I/O DEVICES
1. What Are The Disadvantages Of First Generation Of Computers?
A) Portable
B) Huge Size
C) Simple
D) Reliable
Answer: B
2. Which Programming Was Used In The First Generation Of Computers?
A) Machine Code
B) High Level
C) Assembly Language
D) Java
Answer: A
3. In First Generation Of Computers Which Type Of OS (Operating System) Was Used?
A) Batch Processing
B) Windows-95
C) Multiprogramming
D) Time Sharing
Answer: A
4. ULSI Microprocessor Was Used In Which Generation Of Computers?
A) 1st
B) 2nd
C) 4th
D) 5th
Answer: D
5. When The Fifth Generations Of Computers Were Used?
A) 1980-2000
B) 1965-1980
C) 1980-Onwards
D) No Fifth Generations Of Computer Exist
Answer: C
6. VLSI Microprocessor Was Used In Which Generation Of Computers?
A) 1st
B) 2nd
C) 3rd
D) 4th
Answer: D
7. When The Fourth Generations Of Computers Were Used?

A) 1946-1959
B) 1975-1995
C) 1971-1980
D) 1980-1995
Answer: C
8. Integrated circuit (IC) was used in which generation of computers?
a) First
b) Second
c) Third
d) Fourth
Answer: C
9. When the Third generations of computers were used?
a) 1946-1965
b) 1965-1971
c) 1956-1965
d) 1971-1980
Answer: B
10. Transistors were used in which generation of computers?
a) First
b) Second
c) Third
Answer: B
11.Microprocessor Introduced In Which Generation
A) First Generartion
B) Second Generation
C) Third Generation
D) Fouth Generation
Answer: D
12. GUI Stands For
A) Graphical User Interface
B) Graph User Interface
C) Graph Universal Interface
Answer: A

2. DEFINITION OFCOMPUTER ANDITS CONCEPTS.
2.0. COMPUTER DEFINITION
“An Electronic Device Which Is Capable Of Receiving Information
(Data) In A Particular Form And Of Performing A Sequence Of Operations In Accordance
With A Predetermined But Variable Set Of Procedural Instructions (Program) To Produce A
Result In The Form Of Information Or Signals”.
2.1COMPUTER BLOCK DIAGRAM
2.1. A. Computer Block Diagram.

2.2. INPUT DEVICES
An Input Device Is Any Hardware Device That Sends Data To A Computer,
Allowing You To Interact With And Control The Computer.
The Most Commonly Used Input Devices On A Computer Are The Keyboard And Mouse.
However, There Are Dozens Of Other Devices That Can Also Be Used To Input Data Into The
Computer. Below Is A List Of Computer Input Devices That Can Be Used With A Computer
Or A Computing Device.
Keyboard
Mouse
Joy Stick
Light Pen
Track Ball
Scanner
Graphic Tablet
Microphone
Magnetic Ink Card Reader(MICR)
Optical Character Reader(OCR)
Bar Code Reader
Webcam
Biometrics (Thumb Impression / Face Detection)

2.2. A. Input and Output Devices of Computer
2.2. Input/output devices

2.2.1. KEYBOARD
Keyboard Is The Most Common And Very Popular Input Device Which Helps In
Inputting Data To The Computer.
The Layout Of The Keyboard Is Like That Of Traditional Typewriter, Although
There Are Some Additional Keys Provided For Performing Additional Functions.
Keyboards Are Of Two Sizes 84 Keys or 101/102 Keys, But Now Keyboards With
104 Keys Or 108 Keys Are Also Available For Windows And Internet.
2.2.1. A. Gaming Type Keyboard 2.2.1.B.Sumsung Wired Keyboard
2.2.1. Apple Wireless Keyboard

The Keys On The Keyboard Are As Follows:
SR.NO KEYS DESCRIPTION
1 Typing Keys These Keys Include The Letter Keys (A-Z) And Digit
Keys (0-9) Which Generally Give Same Layout As
That Of Typewriters.
2 Numeric Keypad It Is Used To Enter Numeric Data Or Cursor
Movement. Generally, It Consists Of A Set Of 17 Keys
That Are Laid Out In The Same Configuration Used By
Most Adding Machines And Calculators.
3 Function Keys The Twelve Function Keys Are Present On The
Keyboard Which Is Arranged In A Row At The Top Of
The Keyboard. Each Function Key Has Unique
Meaning And Is Used For Some Specific Purpose.
4 Control Keys These Keys Provide Cursor And Screen Control. It
Includes Four Directional Arrow Keys. Control Keys
Also Include Home, End, Insert, Delete, Page Up, Page
Down, Control(Ctrl), Alternate(Alt), Escape(Esc).
5 Special Purpose Keys Keyboard Also Contains Some Special Purpose Keys
Such As Enter, Shift, Caps Lock, NUM Lock, Space Bar,
Tab, And Print Screen.
2.2.1. A. List of Keyboard Keys Table

2.2.1.2 KEYBOARD SHORTCUTS
2.2.1. Keyboard Shortcut Keys Figure

2.2.2 MOUSE
Mouse Is Most Popular Pointing Device.
It Is A Very Famous Cursor-Control Device Having A Small Palm Size Box With A
Round Ball At Its Base Which Senses The Movement Of Mouse And Sends
Corresponding Signals To CPU When The Mouse Buttons Are Pressed.
Generally It Has Two Buttons Called Left And Right Button And A Wheel Is Present
Between The Buttons.
Mouse Can Be Used To Control The Position Of Cursor On Screen, But It Cannot Be
Used To Enter Text Into The Computer.
Advantages
Easy To Use
Not Very Expensive
Moves The Cursor Faster Than The Arrow Keys Of Keyboard.
2.2.2. A.USB type mouse 2.2.2.B.gaming type wireless mouse
2.2.2.c.wireless mouse

2.2.3 JOYSTICK
Joystick Is Also A Pointing Device Which Is Used To Move Cursor Position On A
Monitor Screen.
It Is A Stick Having A Spherical Ball At Its Both Lower And Upper Ends.
The Lower Spherical Ball Moves In A Socket. The Joystick Can Be Moved In All Four
Directions.
The Function Of Joystick Is Similar To That Of A Mouse. It Is Mainly Used In
Computer Aided Designing (Cad) And Playing Computer Games.
2.2.3. A. PCJOY Stick 2.2.3.B.Logitech G27racing Wheel.
2.2.3. C. Advanced Joystick

2.2.4 LIGHT PEN
Light Pen Is A Pointing Device Which Is Similar To A Pen.
It Is Used To Select A Displayed Menu Item Or Draw Pictures On The Monitor
Screen.
It Consists Of A Photocell And An Optical System Placed In A Small Tube.
When The Tip Of A Light Pen Is Moved Over The Monitor Screen And Pen Button Is
Pressed.
Its Photocell Sensing Element Detects The Screen Location And Sends The
Corresponding Signal To The CPU.
2.2.4. A. Win touch Tool 2.2.4.B.Computer Lighten
2.2.4. C. Asus Digitalized Tablet Using Lighten

2.2.5TRACK BALL
Track Ball Is An Input Device That Is Mostly Used In Notebook Or Laptop Computer,
Instead Of A Mouse.
This Is A Ball Which Is Half Inserted And By Moving Fingers On Ball, Pointer Can Be
Moved.
Since The Whole Device Is Not Moved, A Track Ball Requires Less Space Than A
Mouse.
A Track Ball Comes In Various Shapes Like A Ball, A Button And A Square.
2.2.5. A. Different Types of Trackball Mousses 2.2.5.B.Logitechmouse
2.2.5. Kingston Mouse with Orbit Ball

2.2.6 SCANNER
Scanner Is An Input Device Which Works More Like A Photocopy Machine.
It Is Used When Some Information Is Available On A Paper And It Is To Be
Transferred To The Hard Disc Of The Computer For Further Manipulation.
Scanner Captures Images From The Source Which Are Then Converted Into The
Digital Form That Can Be Stored On The Disc.
These Images Can Be Edited Before They Are Printed.
2.2.6. A. Epson Scanner 2.2.6.B .Cannon Scanner
2.2.6. C .Cool Computer Scanner

2.2.7 DIGITIZER[GRAPHIC TABLET]
Digitizer Is An Input Device Which Converts Analog Information Into Digital Form.
Digitizer Can Convert A Signal From The Television Or Camera Into A Series Of
Numbers That Could Be Stored In A Computer.
They Can Be Used By The Computer To Create A Picture Of Whatever The Camera
Had Been Pointed At.
Digitizer Is Also Known As Tablet Or Graphics Tablet Because It Converts Graphics
And Pictorial Data Into Binary Inputs.
A Graphic Tablet As Digitizer Is Used For Doing Fine Works Of Drawing And Image
Manipulation Applications.
2.2.7. A. Dizitilizer 2.2.7.B.Apple Tab
2.2.7. C.Painting on tablet

2.2.8 MICROPHONE
Microphones Are A Type Of Transducer “A Device Which Converts
Energy From One Form To Another. Microphones Convert Acoustical Energy (Sound
Waves) Into Electrical Energy (The Audio Signal)”.
Different Types Of Microphone Have Different Ways Of Converting Energy But They
All Share One Thing In Common
The Diaphragm. This Is A Thin Piece Of Material (Such As Paper, Plastic Or
Aluminum) Which Vibrates When It Is Struck By Sound Waves
. In A Typical Hand-Held MIC Like The One Below, The Diaphragm Is Located In The
Head Of The Microphone.
Microphone Usage In Our Real Time Computer System Example.
http://www.onlinemictest.com/microphone-settings/windows-8
2.2.8. A. microphone block diagram 2.2.8.B.wireless microphone
2.2.8. C.35mm Jack W Flexible Neck Microphone

2.2.9.MAGNETICINKCARDREADER(MICR)
MICR Input Device Is Generally Used In Banks Because Of A Large Number Of
CHEQUES To Be Processed Every Day.
The Bank's Code Number And CHEQUE Number Are Printed On The CHEQUES With
A Special Type Of Ink That Contains Particles Of Magnetic Material That Are
Machine Readable.
This Reading Process Is Called Magnetic Ink Character Recognition (MICR). The
Main Advantages Of MICR Is That It Is Fast And Less Error Prone.
For better understanding of MCR watch this video
https://www.youtube.com/watch?v=LX-FyRcdUmM
2.2.9. A.MICR character recognizer 2.2.9.B.MICR reading code.
2.2.9. C. Epson MICR for multitasking

2.3. OPTICAL CHARACTER READER (OCR)
Optical Character Recognition Refers To The Branch Of Computer Science That
Involves Reading Text From Paper And Translating The Images Into A Form That
The Computer Can Manipulate (For Example, Into ASCII Codes).
An OCR System enables you to take a Book or a Magazine Article, Feed It Directly
Into An Electronic Computer File, And Then Edit the File Using a Word Processor.
All OCR Systems Include An Optical Scanner For Reading Text, And
Sophisticated Software For Analyzing Images.
Most OCR Systems Use A Combination Of Hardware (Specialized Circuit Boards)
And Software To Recognize Characters, Although Some Inexpensive Systems Do It
Entirely Through Software.
Advanced OCR Systems Can Read Text In Large Variety Of Fonts, But They Still Have
Difficulty With Handwritten Text.
The Potential Of OCR Systems Is Enormous Because They Enable Users To Harness
The Power Of Computers to access Printed Documents.
OCR Is Already Being Used Widely In The Legal Profession, Where Searches That
Once Required Hours Or Days Can Now Be Accomplished In A Few Seconds.
2.3. A.OCR 2.3.B.Nuscan501ocr
2.3. C. IRIPSEN Optical Character Recognizer

2.4 BAR CODE READER
Bar Code Reader Is A Device Used For Reading Bar Coded Data (Data In Form Of
Light And Dark Lines).
Bar Coded Data Is Generally Used In Labeling Goods, Numbering The Books Etc.
It May Be A Hand Held Scanner Or May Be Embedded In A Stationary Scanner.
Bar Code Reader Scans A Bar Code Image, Converts It Into An Alphanumeric Value
Which Is Then Fed To The Computer To Which Bar Code Reader Is Connected.
2.4. A.Barcode Reader 2.4.B.Datalogic Barcode Reader
2.4. C. Operation of Barcode Reader

2.5 WEBCAME
A WEBCAM Is A Video Camera That Feeds Or Streams It’s Image In Real Time To Or
Through A Computer To Computer Network.
When "Captured" By The Computer, The Video Stream May Be Saved, Viewed Or
Sent On To Other Networks Via Systems Such As The Internet, And Email As An
Attachment.
When Sent To A Remote Location, The Video Stream May Be Saved, Viewed Or On
Sent There.
Unlike An IP Camera (Which Connects Using Ethernet Or Wi-Fi), A Webcam Is
Generally Connected By A USB Cable, Or Similar Cable, Or Built Into Computer
Hardware, Such As Laptops.
2.5. A Webcam 2.5.B.Circle Type Webcam
2.5. C. Apple Latest Webcam

2.6 BIOMETRICS [THUMB IMPRESSION / FACE DETECTION]
One Of The Widely Used Access Control Biometric Machines In Any
Technology Oriented Organization Is Thumb Impression Attendance System. Nowadays, To
Avoid Proxy Attendance Or Duplicate Voting Most Employers Use Thumb Impression
Attendance System, Which Collects The Thumb Impression Through A Finger Print
Scanning Device.
A Thumb Impression Attendance System Device Contains Hardware That Scans The
Thumb Impression Of A Person And A Software Application That Verifies The Scanned
Impression Against The Previously Collected Impression That Is Stored In The Built-In
Biometric Database During The Time Of Enrollment. Thumb Impression Attendance
System Is Hassle-Free and A Very Convenient Device For Any Security Oriented Business
Face Recognition Biometric Attendance Machines Can Help You In Cost Saving
Because These Machines Are Available In Very Low Prices.
These Devices Help In Bringing Punctuality In The Organization Because They Keep
Records Of Employees In And Out Timings.
These Machines Come With Different Features Like Card Reader, Face Recognition
System, and Thumb Impression Facility
. There Is Software For These Machines Which Is Capable Of Generating 150+
Industry Standard Reports.
These Machines Comes With A Free Software For Payroll Management Of Your
Employees.
2.6. A. Biometric Time Attendance System 2.6.B. Thumb Impression System
2.6.8. C. Face Reorganization System

2.7. OUTPUT DEVICES
Following Are Few Of The Important Output Devices Which Are Used In A
Computer.
 Monitors
 Graphic Plotter
 Printer
2.7.1.MONITORS
Monitors, Commonly Called As Visual Display Unit (VDU), Are The
Main Output Device Of A Computer. It Forms Images From Tiny Dots, Called Pixels That
Are Arranged In A Rectangular Form. The Sharpness Of The Image Depends Upon The
Number Of Pixels.
There Are Two Kinds Of Viewing Screen Used For Monitors.
 Cathode-Ray Tube (CRT)
 Flat- Panel Display
2.7.2. CATHODE-RAY TUBE (CRT) MONITOR
The CRT Display Is Made Up Of Small Picture Elements Called Pixels. The Smaller
the Pixels,
The Better the Image Clarity, Or Resolution. It Takes More Than One Illuminated
Pixel To Form Whole Character, Such As The Letter ‘E’ In The Word Help.
A Finite Number Of Characters Can Be Displayed On A Screen At Once.
The Screen Can Be Divided Into A Series Of Character Boxes - Fixed Location On
The Screen Where A Standard Character Can Be Placed.
Most Screens Are Capable Of Displaying 80 Characters Of Data Horizontally And 25
Lines Vertically.
There Are Some Disadvantages Of CRT:
 Large In Size
 High Power Consumption

2.7.2. A.CRT Deflection System. 2.7.2. B. Samsung CRT Monitor.
2.7.3. FLAT-PANEL DISPLAY MONITOR
The Flat-Panel Display Refers To A Class Of Video Devices That
Have Reduced Volume, Weight And Power Requirement In Comparison To The CRT. You
Can Hang Them On Walls Or Wear Them On Your Wrists. Current Uses Of Flat-Panel
Displays Include Calculators, Video Games, Monitors, Laptop Computer, and Graphics
Display.
The Flat-Panel Display Is Divided Into Two Categories:
 Emissive Displays - The Emissive Displays Are Devices That Convert Electrical
Energy Into Light. Example Are Plasma Panel And LED (Light-Emitting Diodes).
 Non-Emissive Displays - The Non-Emissive Displays Use Optical Effects To
Convert Sunlight Or Light From Some Other Source Into Graphics Patterns. Example
Is LCD(Liquid-Crystal Device)

2.7.3. B. NEC 43-Inch Curved LCD
2.7.3. A. AOC LED
2.8.PRINTERS
Printer Is An Output Device, Which Is Used To Print Information On Paper.
There Are Two Types Of Printers:
1. Impact Printers
2. Non-Impact Printers
2.8.1.IMPACTPRINTERS
The Impact Printers Print The Characters By Striking Them On The Ribbon Which Is Then
Pressed On The Paper.
Characteristics Of Impact Printers Are The Following:
 Very Low Consumable Costs
 Very Noisy
 Useful For Bulk Printing Due To Low Cost
 There Is Physical Contact With The Paper To Produce An Image
2.8.1. A.Impact Printer 2.8.1.B.Impact Printer (2)

IMPACT PRINTERS Are Of Two Types
1. Character Printers
2. Line Printers
2.8.2. CHARACTER PRINTERS
Character Printers Are The Printers Which Print One Character At A Time.
These Are Further Divided Into Two Types:
1. Dot Matrix Printer(DMP)
2. Daisy Wheel
2.8.3. DOT MATRIX PRINTER
In The Market One Of The Most Popular Printers Is Dot Matrix Printer.
These Printers Are Popular Because Of Their Ease Of Printing And Economical
Price.
Each Character Printed Is In Form Of Pattern Of Dots And Head Consists Of A Matrix
Of Pins Of Size (5*7, 7*9, 9*7 Or 9*9) Which Come Out To Form A Character That Is
Why It Is Called Dot Matrix Printer.
2.8.3. A. Dot-matrix Printer
Advantages
 Inexpensive
 Widely Used
 Other Language Characters Can Be Printed
Disadvantages
 Slow Speed
 Poor Quality

2.8.4. DAISY WHEEL
Head Is Lying On A Wheel And Pins Corresponding To Characters Are Like Petals Of Daisy
(Flower Name) That Is Why It Is Called Daisy Wheel Printer. These Printers Are Generally
Used For Word-Processing In Offices Which Require A Few Letters To Be Sent Here And
There With Very Nice Quality.
Advantages
 More Reliable Than DMP
 Better Quality
 The Fonts Of Character Can Be Easily Changed
Disadvantages
 Slower Than DMP
 Noisy
 More Expensive Than DMP
2.8.4. A. Daisy Wheel 2.8.4.B Daisy Wheel Keyboard
2.8.5LINE PRINTERS
Line Printers Are The Printers Which Print One Line At A Time.
These Are Of Further Two Types
1. Drum Printer
2. Chain Printer

2.8.6DRUM PRINTER
This Printer Is Like A Drum In Shape So It Is Called Drum Printer. The Surface Of Drum Is
Divided Into Number Of Tracks. Total Tracks Are Equal To Size Of Paper I.E. For A Paper
Width Of 132 Characters, Drum Will Have 132 Tracks. A Character Set Is Embossed On
Track. The Different Character Sets Available In The Market Are 48 Character Set, 64 And
96 Characters Set. One Rotation Of Drum Prints One Line. Drum Printers Are Fast In Speed
And Can Print 300 To 2000 Lines Per Minute.
2.8.6. A. Drum Type Printer 2.8.6. B .Drum Or Toner Cartridge
Advantages
 Very High Speed
Disadvantages
 Very Expensive
 Characters Fonts Cannot Be Changed
2.8.7CHAIN PRINTER
In This Printer, Chain Of Character Sets Are Used So It Is Called Chain Printer. A Standard
Character Set May Have 48, 64, Or 96 Characters.

2.8.7.A.Chain Type Printer
Advantages
 Character Fonts Can Easily Be Changed.
 Different Languages Can Be Used With The Same Printer.
Disadvantages
 Noisy
2.8.9.NON-IMPACTPRINTERS
Non-Impact Printers Print The Characters Without Using Ribbon. These Printers Print A
Complete Page At A Time So They Are Also Called As Page Printers.
These Printers Are Of Two Types
1. Laser Printers
2. Inkjet Printers
2.9.CHARACTERISTICSOFNON-IMPACTPRINTERS
1. Faster than impact printers.
2. They are not noisy.
3. High quality.
4. Support many fonts and different character size.

2.9.1LASER PRINTERS
These are non-impact page printers. They use laser lights to produce the dots needed to
form the characters to be printed on a page.
3.9.1. A. HP Laser Printer
Advantages
1. Very high speed
2. Very high quality output
3. Give good graphics quality
4. Support many fonts and different character size
Disadvantages
1. Expensive.
2. Cannot be used to produce multiple copies of a document in a single printing.
2.9.2. INKJET PRINTERS
Inkjet Printers Are Non-Impact Character Printers Based On A Relatively New
Technology.
They Print Characters By Spraying Small Drops Of Ink Onto Paper.
Inkjet Printers Produce High Quality Output With Presentable Features.

They Make Less Noise Because No Hammering Is Done And These Have Many
Styles Of Printing Modes Available.
Color Printing Is Also Possible. Some Models Of Inkjet Printers Can Produce
Multiple Copies Of Printing Also.
2.9.2. A. Inject Printer 2.9.2. B. A Canon Inkjet with CMYK Cartridges
Advantages
1. High Quality Printing.
2. More Reliable.
Disadvantages
1. Expensive As Cost Per Page Is High.
2. Slow As Compared To Laser Printer.

QUESTIONS ON COMPUTER I/O DEVICES
1. Which Is An Important Data Transfer Technique:
A. CPU
B. DMA
C. CAD
D. None of These
ANS: B
2. Which Device Can Be Thought Of As Transducers Which Can Sense Physical Effects And
Convert Them Into Machine-Tractable Data:
A. Storage Devices
B. Peripheral Devices
C. Both
D. None
ANS: B
3. Which Devices Are Usually Designed On The Complex Electromechanical Principle?
A. Storage Devices
B. Peripheral Devices
C. Input Devices
D. All of These
ANS: C
4. Which disk is one of the important I/O devices and its most commonly used as permanent
storage devices in any processor:
A. Hard Disk
B. Optical Disk
C. Magneto Disk
D. Magneto Optical Disk
ANS: A

5. In storage devices PC have hard disk having capacities in the range of _____:
A. 12GB to 15GB
B. 15GB to 20GB
C. 20GB to 80GB
D. 80GB to 85GB
ANS: C
6. Which disk is a 3.5-inch diskette with a capacity of 1.44MB?
A. Soft Disk
B. Floppy Disk
C. Both
D. None
ANS: C
7. Which has a large storage capacity of 2 to8GB?
A. Magnetic Tape
B. Magnetic Disk
C. Soft Disk
D. Floppy Disk
ANS: A
8. Which disk read the data by reflecting pulses of laser beams on the surface?
a. Magnetic disk
b. Soft disk
c. Floppy disk
d. Optical disk
ANS: D
9. Data access time of optical disk varies from 200 to 350minutes with transfer rate of
________:
A. 130kb/S to 400kb/S
B. 130kb/S to 500kb/S
C. 150kb/S to 600kb/S
D. 150kb/S to 800kb/S
ANS: D

10. NAND type flash memory data storage devices integrated with a _______ interface:
A. ATM
B. LAN
C. USB
D. DBMS
ANS: C
11. Which disk is based on the same principle as the optical disk:
A. Optical Disk
B. Magnetic Disk
C. Magneto-Optical Disk
D. All Of These
ANS: C
12. WAN stands for:
A. Wide Area Network
B. Word Area Network
C. World Area Network
D. Window Area Network
ANS: A
13. The human-interactive I/O devices can be further categorized as____:
a. Direct
b. Indirect
c. Both
d. None
ANS: C
14. I/O devices are categorized in 2 parts are:
A. Character Devices
B. Block Devices
C. Numeral Devices
D. Both A & B
ANS: D

15. UART stands for:
A. Universal Asynchronization Receiver/Transmitter
B. Universal Asynchronous Receiver/Transmitter
C. United Asynchronous Receiver/Transmitter
D. Universal Automatic Receiver/Transmitter
ANS: B
16. Which are following pointing devices
A. Light Pen
B. Joystick
C. Mouse
D. All of These
ANS: D
17. Full form of LED:
A. Light Emitting Diode
B. Light Encounter Destination
C. Live Emitting Diode
D. None Of These
ANS: A
18. In_______ mouse we use pair of LED:
A. Optical
B. Digital
C. Analog
D. All of These
ANS: A
19. ______is device that is designed for gaming purposes and based on principle of electricity:
a. Joy
b. Stick
c. Joystick
d. None of these
ANS: C

20. Joystick uses shaft potentiometers for:
A. X-Y Direction
B. Only X Direction
C. Only Y Direction
D. All of These
ANS: A
21. Full form of ADC:
a. Analog to digital converter
b. Digital to analog converter
c. Accumulator digital converter
d. All of these
ANS: A
22. A system that enables computer to recognize human voice called:
A. Voice System
B. Voice Input System
C. Input System
D. None of These
ANS: B
23. 2 commonly used voice input systems are:
A. Micro
B. Microphone
C. Voice Recognition Software
D. Both B & C
ANS: D
24. Optical Scanner Devices Are:
A. MICR
B. OMR
C. OCR
D. All Of These
ANS: D

25. MICR Stands For:
A. Magnetic Ink Character Recognition
B. Magnetic Initiate Character Recognition
C. Both A & B
D. None Of These
ANS: A
26. _______Technique Is Used In Evaluating Objective Answer Sheets:
A. Optical Mark Reader
B. Optical Marker Reader
C. Optical Marker Reading
D. All Of These
ANS: A
27. _______Technique Help In Banking Sector:
A. OCR
B. OMR
C. MICR
D. None of These
ANS: C

3. FUNDAMENTALS OF COMPUTER ARCHITECTURE
CPU Consists Of The Following Features:
CPU Is Considered As The Brain Of The Computer.
CPU Performs All Types Of Data Processing Operations.
It Stores Data, Intermediate Results and Instructions (Program).
It Controls The Operation Of All Parts Of Computer.
3.1. CPU BLOCK DIAGRAM
3.1. A. CPU Block Diagram 3.1.B.Appple CPU

3.2.CPU PHASES
 Memory Unit
 Control Unit
 ALU Unit
3.3. MEMORY UNIT
This Unit Can Store Instructions, Data and Intermediate Results.
This Unit Supplies Information to the Other Units of the Computer When Needed.
It Is Also Known As Internal Storage Unit Or Main Memory Or Primary Storage Or
Random Access Memory (RAM).
Its Size Affects Speed, Power and Capability. Primary Memory And Secondary
Memory Are Two Types Of Memories In The Computer.
Functions Of Memory Unit Are:
It Stores All The Data And The Instructions Required For Processing.
It Stores Intermediate Results Of Processing.
It Stores Final Results Of Processing Before These Results Are Released To An
Output Device.
All Inputs And Outputs Are Transmitted Through Main Memory
3.3. A Semiconductor Ram. 3.3. B.Hard Disk

3.4. MEMORY CLASSIFICATION
3.4. A. Memory Classification Diagram

3.4.1. RANDOM ACCESS MEMORY [RAM]
Ram Is A Memory Scheme Within The Computer System Responsible For Storing
Data On A Temporary Basis, So That It Can Be Promptly Accessed By The Processor
As And When Needed.
It Is Volatile In Nature, Which Means That Data Will Be Erased Once Supply To The
Storage Device Is Turned Off.
Ram Stores Data Randomly and the Processor Accesses These Data Randomly From
the Ram Storage.
The Information Stored In The Ram Is Typically Loaded From The Computer's Hard
Disk, And Includes Data Related To The Operating System And Certain Applications.
When The System Is Switched Off, The Ram Loses All Stored Information
. The Data Remains Stored On Secondary Storage Though, And Can Be Retained
When The System Is Running Again.
Some Of The Earliest Computers Used Delay-Line Format Of Computer Storage.
Most Modern Computers Use An Embedded Ram Circuitry On The Motherboard
Which Reads Data In Bursts.
So, Modern Ram Devices Are Not Random Memory Devices As Such; They Are Burst
Memory Access Devices, But the Term Ram Has Stuck In Everyday Usage.
There Are Primarily Two Forms Of Ram: STATIC RAM (SRAM) And DYNAMIC RAM
(DRAM).
3.4.1. A.RAM1 3.4.1.B.RAM2

3.4.2. SRAM [STATIC RANDOM ASSESSABLE MEMORY]
Where The Word Static Indicates That It, Does Not Need To Be Periodically
Refreshed, As SRAM Uses Bi stable Latching Circuitry (I.E., Flip-Flops) To Store Each
Bit. Each Bit Is Stored As A Voltage
Each Memory Cell Requires Six Transistors, Thus Giving Chip Low Density But High
Speed.
However, SRAM is still volatile in the (Conventional) Sense That Data Is Lost When
Power down.
Disadvantages Are More Expensive And Also Consumes More Power Than Dram.
In High Speed Processors (Such As Pentium), SRAM Is Known as Cache
Memory and Is Included On The Processor Chip.
However High-Speed Cache Memory Is Also Included External To The Processor To
Improve Total Performance.
3.4.2. A.SRAM Chip 3.4.2.B.SRAM Port

3.4.3 .DRAM [DYNAMIC RANDOM ASSESSABLE MEMORY]
Its Advantage Over SRAM Is Its Structural Simplicity: Only One Transistor (MOSFET
Gates) And A Capacitor (To Store A Bit As A Charge) Are Required Per Bit, Compared
To Six Transistors In SRAM.
This Allows DRAM To Reach Very High Density.
Also It Consumes Less Power And Is Even Cheaper Than SRAM (Except When The
System Size Is Less Than 8 K).
But The Disadvantage Is That Since It Stores Bit Information As Charge Which
Leaks;
Therefore Information Needs To Be Read And Written Again Every Few
Milliseconds.
This Is Known As Refreshing The Memory And It Requires Extra Circuitry, Adding
To The Cost Of System.
3.4.3. A.DRAM Views

3.4.4. READ-ONLY MEMORY [ROM]
Read Only Memory (ROM) Is An Example Of Nonvolatile Memory.
ROM Is A Class Of Storage Medium Used In Computers And Other Electronic Devices.
Read Only Memory (ROM), Also Known As Firmware, Is An Integrated Circuit
Programmed With Specific Data When It Is Manufactured.
The Instructions For Starting The Computer Are Housed On Read Only Memory
Chip.
ROM Chips Are Used Not Only In Computers, But In Most Other Electronic Items As
Well
Because Data Is Fully Incorporated At The ROM Chip's Manufacture, Data Stored Can
Neither Be Erased Nor Replaced. This Means Permanent And Secure Data Storage
However, If A Mistake Is Made In Manufacture, A ROM Chip Becomes Unusable. The
Most Expensive Stage Of ROM Manufacture, Therefore, Is Creating The Template.
If A Template Is Readily Available, Duplicating The ROM Chip Is Very Easy And
Affordable.
A ROM Chip Is Also Non Volatile So Data Stored In It Is Not Lost When Power Is
Turned Off.
ROM Is A Semiconductor Memory That Is Capable Of Operating At Electronics
Speed.

3.5. ROM CLASSIFICATION
3.5. A. ROM Classification Diagram
3.5. 1.PROM [PROGRAMMABLE READ ONLY MEMORY]
PROM Stands For Programmable Read-Only Memory,
A Memory Chip On Which Data Can Be Written Only Once.
Once A Program Has Been Written Onto A PROM, It Remains There Forever. Unlike
RAM, Proms Retain Their Contents When The Computer Is Turned Off.
The Difference Between A PROM And A ROM (Read-Only Memory) Is That A PROM
Is Manufactured As Blank Memory, Whereas A ROM Is Programmed During The
Manufacturing Process.
To Write Data Onto A PROM Chip, You Need A Special Device Called A PROM
Programmer Or PROM Burner.
The Process Of Programming A PROM Is Sometimes Called Burning The PROM.
3.5.1.A.Prom Programmer 3.5.1.B. Romchip

3.5.2. EPROM [ERASABLE AND PROGRAMMABLE READ ONLY MEMORY]
Acronym For Erasable Programmable Read-Only Memory, And Pronounced Ee-
Prom, EPROM Is A Special Type Of Memory That Retains Its Contents Until It Is
Exposed To Ultraviolet Light.
The Ultraviolet Light Clears Its Contents, Making It Possible To Reprogram The
Memory.
To Write To And Erase An EPROM, You Need A Special Device Called A PROM
Programmer Or PROM Burner.
3.5.2.A.Kinstonprndrive 3.5.2.B.EEPROM Chip
3.5.3. EEPROM
Short Form of Electrically Erasable Programmable Read-Only Memory is EEPROM
EEPROM Is A Special Type Of PROM That Can Be Erased By Exposing It To An
Electrical Charge. Like Other Types Of PROM, EEPROM Retains Its Contents Even
When The Power Is Turned Off.
Also Like Other Types Of ROM, EEPROM Is Not As Fast As RAM.
3.5.3. A. EEPROM Chip 3.5.3.B.EEPROM as NBTV Signal Generator

3.6 CACHE MEMORY
Cache Memory, Also Called CPU Memory, Is Random Access Memory
(RAM) That A Computer Microprocessor Can Access More Quickly Than It Can Access
Regular RAM. This memory is Typically Integrated Directly With The CPU Chip Or Placed
On A Separate Chip that Has A Separate Bus Interconnect With The CPU.
Cache Memory Operations
The Basic Purpose of Cache Memory Is to Store program Instructions That Are
Frequently Re-Referenced By Software During Operation.
Fast access To These Instructions Increases the Overall Speed of the Software
Program.
As The Microprocessor Processes Data, It Looks First In The Cache Memory; If It
Finds The Instructions There (From A Previous Reading Of Data), It Does Not Have
To Do A More Time-Consuming Reading Of Data From Larger Memory Or Other
Data Storage Devices.
Most Programs Use Very Few Resources Once They Have Been Opened And
Operated For A Time, Mainly Because Frequently Re-Referenced Instructions Tend
To Be Cached.
This Explains Why Measurements Of System Performance In Computers With
Slower processors But Larger Caches Tend To Be Faster Than Measurements Of
System Performance In Computers With Faster Processors But More Limited Cache
Space.
Multi-Tier Or Multilevel Caching Has Become Popular
In Server And Desktop Architectures, With Different Levels Providing Greater
Efficiency Through Managed tiring.

Simply Put, The Less Frequently Access Is Made To Certain Data Or Instructions, The
Lower Down The Cache Level The Data Or Instructions Are Written.
3.6. A. Cache Memory
3.6. B. Cache Memory Organization

3.7. CONTROL UNIT
This Unit Controls The Operations Of All Parts Of Computer But Does Not Carry Out Any
Actual Data Processing Operations.
Functions Of This Unit Are:
It Is Responsible For Controlling The Transfer Of Data And Instructions Among
Other Units Of A Computer.
It Manages and Coordinates All the Units Of The Computer.
It Obtains The Instructions From The Memory, Interprets Them, And Directs The
Operation Of The Computer.
It Communicates With Input/output Devices for Transfer of Data or Results from
Storage.
It Does Not Process or Store Data.
3.7. A. Control unit functioning

3.8. ARITHMETIC LOGIC UNIT [ALU]
ALU Stands For "Arithmetic Logic Unit." An ALU Is An Integrated Circuit Within
A CPU Or GPU That Performs Arithmetic And Logic Operations. Arithmetic Instructions
Include Addition, Subtraction, And Shifting Operations, While Logic Instructions
Include Boolean comparisons, Such As AND, OR, XOR, And NOT Operations.
ALUS Are Designed to Perform Integer calculations.
Therefore, Besides Adding And Subtracting Numbers, ALUS Often Handle The
Multiplication Of Two Integers, Since The Result Is Also An Integer.
However, ALUS Typically Do Not Perform Division Operations, Since The Result May
Be A Fraction, Or A "Floating Point" Number.
Instead, Division Operations Are Usually Handled By The Floating-Point Unit (FPU),
Which Also Performs Other Non-Integer Calculations.
While The ALU Is A Fundamental Component Of All Processors.
The Design And Function Of An ALU May Vary Between Different Processor Models.
For Example, Some ALUS Only Perform Integer Calculations, While Others Are
Designed To Handle Floating Point Operations As Well.
Some Processors Contain A Single ALU, While Others Include Several Arithmetic
Logic Units That Work Together To Perform Calculations.

3.8 A.ALU operation figure
3.8. B.ALU basic operation figure

3.9. BUSES IN CPU
3.9. A .bus computing fig
Address Bus
Is Used To Specify A Physical Memory Address.
This Can Include Primary Memory (E.G. RAM And ROM) Secondary Memory (E.G.
Hard Disk Drives) And Any Other Connected Devices.
Monitors, Printers, Scanners, And Keyboards Will All Be Mapped To Memory.
The Width Of The Address Bus Determines The Amount Of Memory That Can Be
Addressed. A 32-Bit Bus Can Address 4,294,967,296 (2 ^ 32) Bytes Of Memory.
This Explains The 4 GB Memory Restriction On 32-Bit Operating Systems.
Data Bus
Connects The Microprocessor (CPU) With Other Devices Mapped Onto The System.
This Is Often Described Pictorially Using A Memory Map. Unlike The Address Bus,
The Data Bus Is Two-Way (It Supports Read And Write Operations).
The Data Bus Is Not Limited To Transferring Data;
It Is Also Used To Transfer Program Instructions.
Control Bus
Carries Commands From And Returns Status Signals To The Microprocessor.
The Control Unit Inside A CPU Manages The Internal Control Bus — Internal To The
CPU — And The External Control Bus.

3.9.1.INSTRUCTION CYCLE
An Instruction Cycle (Sometimes Called Fetch-And-Execute Cycle, Fetch-Decode-Execute Cycle,
Or FDX) Is The Basic Operation Cycle Of A Computer.
It Is The Process By Which A Computer Retrieves A Program Instruction From Its Memory,
Determines What Actions The Instruction Requires, And Carries Out Those Actions.
This Cycle Is Repeated Continuously By The Central Processing Unit (CPU), From Boot up to
When the Computer Is Shut Down.
In Simpler CPUS, The Instruction Cycle Is Executed Sequentially:
Each Instruction Is Completely Processed Before The Next One Is Started.
In Most Modern CPUS, The Instruction Cycle Is Instead Executed Concurrently In Parallel, As
An Instruction Pipeline:
The Next Instruction Starts Being Processed Before The Previous Instruction Is Finished, Which
Is Possible Because The Cycle Is Broken Up Into Separate Steps.
o Program Counter (PC) - An Incrementing Counter That Keeps Track Of The Memory Address Of
The Instruction That Is To Be Executed Next Or In Other Words, Holds The Address Of The
Instruction To Be Executed Next.
o Memory Address Register (MAR) - Holds The Address Of A Memory Block To Be Read From Or
Written To.
o Memory Data Register (MDR) - A Two-Way Register That Holds Data Fetched From Memory
(And Ready for the CPU to Process) or Data Waiting To Be Stored In Memory. (This Is Also
Known As the Memory Buffer Register (MBR).
o Instruction Register (IR) - A Temporary Holding Ground for the Instruction That Has Just Been
Fetched From Memory.
o Control Unit (CU) - Decodes The Program Instruction In The Ir, Selecting Machine Resources
Such As A Data Source Register And A Particular Arithmetic Operation, And Coordinates
Activation Of Those Resources.

o Arithmetic Logic Unit (ALU) - Performs Mathematical And Logical Operations.
Each Computer's CPU Can Have Different Cycles Based On Different Instruction Sets, But Will Be Similar
To The Following Cycle:
1. Fetching The Instruction: The Next Instruction Is Fetched From The Memory Address That Is
Currently Stored In The Program Counter (Pc), And Stored In The Instruction Register (IR). At
The End Of The Fetch Operation, The Pc Points To The Next Instruction That Will Be Read At
The Next Cycle.
2. Decode the Instruction: During This Cycle the Encoded Instruction Present In The IR
(Instruction Register) Is Interpreted By The Decoder.
3. Read The Effective Address: In Case Of A Memory Instruction (Direct Or Indirect) The
Execution Phase Will Be In The Next Clock Pulse. If The Instruction Has An Indirect Address, The
Effective Address Is Read From Main Memory, And Any Required Data Is Fetched From Main
Memory To Be Processed And Then Placed Into Data Registers (Clock Pulse: T3). If The
Instruction Is Direct, Nothing Is Done At This Clock Pulse. If This Is An I/O Instruction Or A
Register Instruction, The Operation Is Performed (Executed) At Clock Pulse.
4. Execute The Instruction: The Control Unit Of The CPU Passes The Decoded Information As A
Sequence Of Control Signals To The Relevant Function Units Of The CPU To Perform The Actions
Required By The Instruction Such As Reading Values From Registers, Passing Them To The ALU
To Perform Mathematical Or Logic Functions On Them, And Writing The Result Back To A
Register. If The ALU Is Involved, It Sends A Condition Signal Back To The Cu. The Result
Generated By The Operation Is Stored In The Main Memory, Or Sent To An Output Device. Based
On The Condition Of Any Feedback From The ALU, Program Counter May Be Updated To A
Different Address From Which The Next Instruction Will Be Fetched.
The Cycle Is Then Repeated.
3.9.1.A.Instruction Cycle

3.9.1.B.Fectch Cycle 3.6.1.C.Exicution Cycle
3.6.2.D.Insruction Cycle

3.9.2. Measure Of CPU Performance.
Computer Performance Is Characterized By The Amount Of Useful Work Accomplished By A Computer
System Or Computer Network Compared To The Time And Resources Used. Depending On The Context,
High Computer Performance May Involve One Or More Of The Following:
1) Short Response Time For A Given Piece Of Work
2) High Throughput (Rate Of Processing Work)
3) Low Utilization Of Computing Resource(S)
4) High Availability Of The Computing System Or Application
5) Fast (Or Highly Compact) Data Compression And Decompression
6) High Bandwidth
7) Short Data Transmission Time
3.9.2.A.Measure Of Computer Performance

Questions On Computer Fundamentals Of Computer Architecture
Q1] The Brain Of Any Computer System Is?
A.ALU
Memory
C.CPU
D. Control Unit None Of These
ANS: A
Q2] A Computer Assisted Method For The Recording And Analyzing Of Existing Or Hypothetical
Systems Is?
A. Data transmission
B. Dataflow
C. Data Processing
D. Data Capture
ANS.:B
Q3] what are the main parts in central processing unit?
A. ALU, Controlunit,Memoryunit
B. Axulary devices
C. Control unit ,Hard Disk
D. Memory
ANS: A
Q4] The Section Of The CPU That Selects, Interprets And Sees To The Execution Of Program
Instructions?
A. Memory Unit
B. Control Unit
C. ALU
D. None Of The Above
ANS: B

Q5]. CPU Fetches The Instruction From Memory According To The Value Of……..
A) Program Counter
B) Status Register
C) Instruction Register
D) Program Status Word
ANS: C
Q6] A Memory Buffer Used To Accommodate A Speed Differential Is Called………
A) Stack Pointer
B) Cache
C) Accumulator
D) Disk Buffer
ANS: B
Q7]. Which One Of The Following Is The Address Generated By CPU?
A) Physical Address
B) Absolute Address
C) Logical Address
D) None Of The Mentioned
ANS: C
Q8] Run Time Mapping From Virtual To Physical Address Is Done By……..
A) Memory Management Unit
B) CPU
C) PCI
D) None of the Mentioned
ANS: A

Q9] Which Of The Following Computer Implemented Binary Numbers, Perform
Calculations Using Electronics And Implemented Separate Computation And Memory
For The First Time?
A) Mark I
B) ABC
C) Z3
D) None Of Above
ANS: B
Q10] FORTRAN Is A Programming Language. What Does FORTRAN Stand For?
A) File Translation
B) Format Translation
C) Formula Translation
D) Floppy Translation
ANS: C
Q11] Which Of The Following Memories Needs Refreshing?
A) SRAM
B) DRAM
C) ROM
D) All Of Above
ANS: B
Q12] Can You Tell What Passes Into And Out From The Computer Via Its Ports?
A) Data
B) Bytes
C) Graphics
D) Pictures
ANS: A

Q13] An Output Device That Uses Words Or Messages Recorded On A Magnetic
Medium To Produce Audio Response Is
A) Magnetic Tape
B) Voice Response Unit
C) Voice Recognition Unit
D) Voice Band
ANS: B
Q14] Which of the Items Below Are Considered Removable Storage Media?
A) Removable Hard Disk Cartridges
B) (Magneto-Optical) Disk
C) Flexible Disks Cartridges
D) All of The Above
ANS: D
Q15] Which Of The Following Is Not Purely Output Device?
A) Screen
B) Printer
C) Speaker
D) Plotter
ANS: A
Q16] Who Developed A Mechanical Device In The 17th Century That Could Add,
Subtract, Multiple, Divide And Find Square Roots?
A) Napier
B) Babbage
C) Pascal
D) Leibniz
ANS: D

Q17] The First Macintosh Computer Was From
A) First Generation
B) Second Generation
C) Third Generation
D) Fourth Generation
ANS: D
Q18] Which of The Following Is Not A Form Of Data?
A) Numbers and Characters
B) Images
C) Sound
D) None Of Above
ANS: D
Q19] Which Is Not A Computer Classification?
A) Mainframe
B) Max frame
C) Mini
D) Notebook
ANS: B
Q20] The Control Unit Of A Microprocessor
A) Stores Data In The Memory
B) Accepts Input Data From Keyboard
C) Performs Arithmetic/Logic Function
D) None Of Above
ANS: D

Q21] Which Of The Following Is Internal Memory?
A) Disks
B) Pen Drives
C) RAM
D) CDS
ANS: C
Q22] Which Operation Is Not Performed By Computer?
A) Inputting
B) Processing
C) Controlling
D) Understanding
ANS: D
Q23] Floppy Disks Which Are Made From Flexible Plastic Material Are Also Called?
A) Hard Disks
B) High-Density Disks
C) Diskettes
D) Templates
ANS: C
Q24]The Magnetic Storage Chip Used To Provide Non-Volatile Direct Access
Storage Of Data And That Have No Moving Parts Are Known As
A) Magnetic Core Memory
B) Magnetic Tape Memory
C) Magnetic Disk Memory
D) Magnetic Bubble Memory
ANS: B

Q25]A Collection Of Related Instructions Organized For A Common Purpose Is
Referred To As
A) File
B) Database
C) Program
D) None Of Above
ANS: C
Q26]Plotter Accuracy Is Measured In Terms Of Repeatability And
A) Buffer Size
B) Resolution
C) Vertical Dimensions
D) Intelligence
ANS: B
Q27] Computer Instructions Written With The Use Of English Words Instead Of
Binary Machine Code Is Called
A) Mnemonics
B) Symbolic Code
C) Gray Codes
D) OPCODE
ANS: B
Q28] Which Language Is Directly Understood By The Computer Without Translation
Program?
A) Machine Language
B) Assembly Language
C) High Level Language
D) None Of Above
ANS: A

Q29] On Which Aspect The Analog Computers Are Better Than Digital?
A) Speed
B) Accuracy
C) Reliability
D) Automatic
ANS: B
Q30] Which Of The Following Processors Use RISC Technology?
A) 486dx
B) Power PC
C) 486sx
D) 6340
ANS: B
Q31] Which of The Following Machine Was Not Invented By Charles Babbage?
A) Tabulating Machine
B) Analytical Engine
C) Difference Engine
D) Both C And D
ANS: A
Q32]. How Many Numbers Could ENIAC Store In Its Internal Memory
A) 100
B) 20
C) 80
D) 40
ANS: B

Q34] The Subject Of Cybernetics Deals With The Science Of
A) Genetics
B) Control And Communication
C) Molecular Biology
D) Biochemistry
ANS: B
Q33] Why ABC Is Considered Electro-Mechanical Computer?
A) Because It Was Invented Before Electronic Computers Were Developed
B) Because There Are Wheels, Drums, Bars To Rotate And Move To Produce Result
C) Because They Use The Flow Of Electrons In Different Component
D) None Of Above
ANS: B
Q24]Binary Circuit Elements Have
A) One Stable State
B) Two Stable State
C) Three Stable State
D) None Of Above
ANS: B
Q35]Which Of The Following Is Used For Manufacturing Chips?
A) Control Bus
B) Control Unit
C) Parity Unit
D) Semiconductor
ANS: B

Q36] Which Of The Following Is Not A Micro Computer?
A) Laptop Pcs
B) Tablet Pcs
C) Desktop Pcs
D) None Of Above
ANS: D
Q37] The Value Of Each Bead In Earth Is
A) 1
B) 3
C) 5
D) 7
ANS: D
Q38] When Did John Napier Develop Logarithm?
A) 1416
B) 1614
C) 1641
D) 1804
ANS: B
Q39] Which Of The Following Terms Is The Most Closely Related To Main Memory?
A) Non Volatile
B) Permanent
C) Control Unit
D) Temporary
ANS: D

Q40] Which Was the World’s First Minicomputer And When Was It Introduced?
A) PDP-I, 1958
B) IBM System/36, 1960
C) PDP-II, 1961
D) VAX 11/780, 1962
ANS: A
Q41]A Group Of Magnetic Tapes, Videos Or Terminals Usually Under The Control Of
One Master Is
A) Cylinder
B) Surface
C) Track
D) Cluster
ANS: D
Q42]The Word Length Of A Computer Is Measured In
A) Bytes
B) Millimeters
C) Meters
D) Bits
ANS: D
Q43] What Type Of Memory Is Not Directly Addressable By The CPU And Requires
Special Softw3are Called EMS (Expanded Memory Specification)?
A) Extended
B) Expanded
C) Base
D) Conventional
ANS: D

Q44] Which Unit Holds Data Permanently?
A) Input Unit
B) Secondary Storage Unit
C) Output Unit
D) Primary Memory Unit
ANS: B
Q45] Before A Disk Can Be Used To Store Data. It Must Be_______
A) Formatted
B) Reformatted
C) Addressed
D) None Of The Above
ANS: B
Q46]Computer System Comprises Of Major Units
A) Input Unit, Output Unit, Control Unit
B) Input Unit, Output Unit, Control Unit And Storage
C) Input Unit, Output Unit, Central Processing Unit And Storage Unit
D) Input, Output And Storage Units
ANS: C
Q47]The First General Purpose Electronic Digital Computer In The World Was
A) UNIVAC
B) EDVAC
C) ENIAC
D) All Of Above
ANS; A

Q48]. Signals Can Be Analog Or Digital And A Computer That Processes The Both
Type Of Signals Is Known As
A) Analog Computer
B) Digital Computer
C) Hybrid Computer
D) Mainframe Computer
ANS: C
Q49]. High Level Language Is Also Called
A) Problem Oriented Language
B) Business Oriented Language
C) Mathematically Oriented Language
D) All Of The Above
ANS: D
Q50]. Human Beings Are Referred To As Homo- sapiens, Which Device Is Called
Silicon Sapiens?
A) Monitor
B) Hardware
C) Robot
D) Computer
ANS: D

4. MOTHERBOARD[INTERNALCOMPONENTS]
The motherboard serves as a single platform to connect all of the parts of a
computer together.
A motherboard connects CPU, memory, hard drives, optical drives, video card,
sound card, and other ports and expansion cards directly or via cables.
It can be considered as the backbone of a computer.
4.A.Mother Board Top View

4.1FEATURES OFMOTHERBOARD
A Motherboard Comes With Following Features:
Motherboard Varies Greatly In Supporting Various Types Of Components.
Normally A Motherboard Supports A Single Type Of CPU And Few Types Of
Memories.
Video Cards, Hard Disks, Sound Cards Have To Be Compatible With Motherboard To
Function Properly
Motherboards, Cases And Power Supplies Must Be Compatible To Work Properly
Together.
4.2POPULARMANUFACTURERS
Intel
ASUS
An Open
ABIT
Bio star
Gigabyte
MSI

4.3. The ImportantConstituentComponentsOfAn ATXMotherboard AreGivenBelow:
1. Mouse & keyboard
2. USB
3. Parallel port
4. CPU Chip
5. RAM slots
6. Floppy controller
7. IDE controller
8. PCI slot
9. ISA slot
10. CMOS Battery
11. AGP slot
12. CPU slot
13. Power supply plug in
1. MOUSE
A Computer Mouse Enables Its User To Move A Cursor Smoothly And Intuitively
Across A Two-Dimensional Plane.
It's Therefore An Essential Input Device For Selecting, Dragging, Hovering, And
Clicking.
The Mouse Allows Users To Switch Between Applications, Select Options And
Buttons, And Move Around The Screen With A Great Degree Of Accuracy And
Fluidity.
It Is Used To Move Between And Select Links On A Website, Buttons On An
Options Screen, Entries On A Menu, And Many More Tasks That Would Be Far
More Difficult Using A Keyboard Alone.
2. KEBOARD
A Computer Keyboard Is An Input Device Used To Enter Characters
And Functions Into The Computer System By Pressing Buttons, Or Keys.
It Is The Primary Device Used To Enter Text. A Keyboard Typically Contains
Keys For Individual Letters, Numbers And Special Characters, As Well As
Keys For Specific Functions
4.3.A.Applekeyboard and Mouse

2. USB
I/O Ports- This Is Located In The Rear Panel Of The CPU, This Use To Connect The Outside
Hardware Or Peripherals Of The Computer.
• PS/2 Ports- These Are Used To Connect The Mouse (Green Color) And The Keyboard
(Purple Color)
• DB 25 Female Connector (Printer Port)-This Is Use To Connect The Impact
Printer, One Of That The DOT MATRIX Printer, Ex. The Epson LX 300 +
• DB 9 Male Connector (Serial Or Com1 Port)-This Use To Connect A Serial Device
Of The Computer, Such As The Serial Mouse And External Modem.
• VGA Port (Built-In)- This Is Use To Interface The DB Cord Of The Monitor Screen Or
To Connect The Monitor Screen Of The Computer. The Fastest Video Card Versions Are
Based On The Standard Of The VGA Slots, Ex: The AGP And PCI’e Card.
• USB 2.0 × 2 Ports- These Are The Ports Of The USB Devices Of The Computer.
Attached Externally Of The System Unit, One Of That Are The USB Flash Drives. As Of Now
The Versions Or Speed Of The USB Are The 1.0 And 2.0 Compatible.
• LAN Port- This Called As Local Area Network Of The Computer. This Is Use To
Connect The Numbers Of Node Or Workstations (PC) To Form A Local Area Network Of The
Computer With In Their Area. Using Type Of Communication Media Such As The Network
Switch And Router.
• Audio Port- This Is Use To Connect The Speaker, Mike, And MIDI (Musical
Instrument Digital Interface) Device Of The Computer.
2. ATX Power Connector(4 Pin)- This Is Use To Connect The 4 Pin Of The Power Supply
Unit(PSU) .This Is Separate Of The 20 Or 24 Pin Of ATX Power Supply To Provide DC
Voltage Of Computer Processor.
4.3. B.I/O Ports

3. PARALLEL PORT
A Parallel Port Is A Type Of Interface Found On Computers (Personal And
Otherwise) For Connecting Peripherals.
In Computing, A Parallel Port Is A Parallel Communication Physical Interface.
It Is Also Known As A Printer Port.
It Was An Industry De Facto Standard For Many Years, And Was Finally
Standardized As IEEE 1284 In The Late 1990s, Which Defined The Enhanced
Parallel Port (EPP) And Extended Capability Port (ECP) Bi-Directional Versions.
Today, The Parallel Port Interface Is Seeing Decreasing Use Because Of The Rise
Of Universal Serial Bus (USB) Devices, Along With Network Printing Using
4.3.C.Parallel Port 4.3.D.Parlleport Cable

4. CPU CHIP
The Central Processing Unit, Or CPU, Is The Brain Of A Computer.
Without This Vital Component, The Computer Wouldn’t Be Able Perform Any Of
The Functions Related To Moving And Processing Data.
Each New Processor Release From Manufacturers (Primarily AMD And Intel,)
CPU Become Faster And More Powerful. Speed And Reliability Is The Name Of The
Game When Consumers Compare CPU Chips In New Pcs.
For Some, The Brand Of CPU Is A Major Selling Point When Buying A New
Computer. For Others, Raw Speed Is More Important.
4.3. E.CPU Chip 4.3.F.Intel Processor

5. RAM SLOTS
Located in the Upper-Right Part of the Motherboard,
The Memory Slots Are Used to House the Computer’s Memory Modules.
The Number Of Slots Can Vary, Depending On Motherboard, From 2, In
Low-End Motherboards,
All The Way Up To 8 Memory Slots, On High-End And Gaming
Motherboards.
It Is Important To Pay Close Attention To The Type Of Memory A
Motherboard Supports, In Order To Buy The Appropriate Memory Modules.
Newer Motherboards Support DDR3 Memory, The Current Industry
Standard Memory Architecture, But Motherboards With DDR2 Memory
Slots And Even DDR1 Memory Slots Are Still Present On The Market. An
Interesting Aspect Is That There Are Some Older Motherboard Models That
Supported Different Types Of Memory, And Usually Come With Two DDR1
Memory Slots And 2 DDR2 Memory Slots, Or Two DDR2 Slots And Two
DDR3 Slots.
These Motherboards Were Great Options For People That Wanted To
Upgrade A Motherboard Without Having To Upgrade All The Other
Components As Well.
4.3. G. Memory Slots on Mother Board

4.3. I. Memory Slots Arrangement
6. FLOPPY CONTROLLER
Definition - What Does Floppy Disk Drive (FDD) Mean?
A Floppy Disk Drive (FDD), Or Floppy Drive, Is A Hardware Device That Reads Data
Storage Information.
It Was Invented In 1967 By A Team At IBM And Was One Of The First Types Of
Hardware Storage That Could Read/Write A Portable Device.
FDDS Are Used For Reading And Writing On Removable Floppy Discs.
Floppy Disks Are Now Outdated, And Have Been Replaced By Other Storage Devices
Such As USB And Network File Transfer.
4.3.J. Sony Floppydisk Drive

Explanation of Floppy Disk Drive (FDD)
A Floppy Disk Commonly Came In Three Sizes, 8 Inches, 5.5 Inches And 3.5
Inches, Becoming Smaller As The Technology Advanced.
The Newer, 3.5-Inch Version Used More Cutting-Edge Technology And Held More
Data Than Previous Models, While The Original 8-Inch Floppy Drive Was Developed To
Load Hardware-Level Instructions And/or Data Structures Called Microcode Into The Ibm
System/370 Mainframe. The 8-Inch Flexible Diskette Was Read-Only, Held 80 Kilobytes Of
Memory And Was Referred To As A Memory Disk. Eight-Inch Floppy Drives Did Not
Connect To The Motherboard, But Rotated On A Turntable That Was Run By An Idler
Wheel.
As Technology Advanced, Floppy Disks Were Finally Able To Read And Write. By This
Point, FDDS Had Four Basic Components:
1. Magnetic Read/Write Heads (One Or Two)
2. A Spindle Clamping Device That Held The Disk In Place As It Was Spinning 300 To
360 Rotations Per Minute
3. A Frame With Levers That Opened And Closed The Device
4. A Circuit Board That Contained All Of The Electronics.
4.3. K.Different Types Of Floppy Disks 4.3.L. Dell Floppy Disk

7. IDE CONTROLLER
IDE (Integrated Drive Electronics) Is A Standard Electronic Interface Used Between
A Computer Motherboard's Data Paths Or Bus And The Computer's
Disk Storage Devices.
The IDE Interface Is Based On The IBM PC Industry Standard Architecture (ISA) 16-
Bit Bus Standard, But It Is Also Used In Computers That Use Other Bus Standards.
IDE Was Adopted As A Standard By The American National Standards Institute
(ANSI) In November 1990.
The ANSI Name For IDE Is Advanced Technology Attachment (ATA), And The ATA
Standard Is One Of Several Related Standards Maintained By The T10 Committee.
In Today's Computers, The IDE Controller Is Often Built Into The Motherboard.
Prior To The IDE Drive, Controllers Were Separate External Devices So IDE
Reduced Problems Associated With Storage Devices And Integrated Controllers.
4.3. M. IDE Controller Chip.
4.3.N. Conneting Ide To Harddisk

8. PCI SLOT [Peripheral Component Interconnect]
Since The First Pc, Launched In 1981,
The Computer Has Had Expansion Slots Where You Can Install Additional Cards To
Add Capabilities Not Available On The Motherboard Of The Computer.
Currently, The Most Common Type Of Expansion Slot Available Is Called Pci Express.
In This Tutorial, You Will Learn Everything You Need To Know About This Kind Of
Connection: How It Works, Versions, Slots, And More.
Before Talking About The PCI Express, We Must Talk A Little Bit About The History
Of Pc Expansion Slots And Their Main Challenges, So You Can Understand What
Makes The PCI Express Different.
Below We List The Most Common Types Of Expansion Slots That Were Launched For The
Pc Throughout Its History:
 ISA (Industry Standard Architecture)
 MCA (Micro Channel Architecture)
 EISA (Extended Industry Standard Architecture)
 VLB (VESA Local Bus)
 PCI (Peripheral Component Interconnect)
 PCI-X (Peripheral Component Interconnect Extended)
 AGP (Accelerated Graphics Port)
 PCI Express (Peripheral Component Interconnect Express)
4.3.O.Pci ,Agp&Isa Slots On Mother Bord 4.3.P.Pci Slots

9. ISA SLOTS
Stands For "Industry Standard Architecture." Isa Is A Type Of Bus Used In Pcs For
Adding Expansion Cards.
For Example, An Isa Slot May Be Used To Add A Video Card, A Network Card, Or An
Extra Serial Port.
The Original 8-Bit Version Of PCI Uses A 62 Pin Connection And Supports Clock
Speeds Of 8 And 33 Mhz. 16-Bit PCI Uses 98 Pins And Supports The Same Clock
Speeds.
The Original 8-Bit Version Of Isa Was Introduced In 1981 But The Technology Did
Not Become Widely Used Until 1984, When The 16-Bit Version Was Released.
Two Competing Technologies -- MCA and VLB -- Were Also Used By Some
Manufacturers, But Isa Remained the Most Common Expansion Bus for Most Of The
1980s And 1990s.
However, By The End Of The Twentieth Century, Isa Ports Were Beginning To Be
Replaced By Faster PCI And AGP Slots. Today, Most Computers Only Support PCI
and AGP Expansion Cards.
4.3.P.Isa.Pci And Ramslots In Mother Board

1O.CMOS BATTERY
The CMOS Is A Physical Part Of The Motherboard
It Is A Memory Chip That Houses Setting Configurations And Is Powered By The
Onboard Battery.
The CMOS Is Reset And Loses All Custom Settings In Case The Battery Runs Out Of
Energy, Additionally, The System Clock Resets When The CMOS Loses Power
The CMOS Is Also A Computer Chip On The Motherboard, But More Specifically, It Is
A RAM Chip.
This Is A Type Of Memory Chip Which Stores Information About The Computer
Components, As Well As Settings For Those Components.
However, Normal RAM Chips Lose The Information Stored In Them When Power Is
No Longer Supplied To Them.
To Retain The Information In The CMOS Chip, A CMOS Battery On The Motherboard
Supplies Constant Power To That CMOS Chip.
4.3.Q.Cmos Battery 4.3.R.CMOS Battery On Mother Board

11. ACCELERATED GRAPHICS PORT [AGP SLOT]
Stands For "ACCELERATED GRAPHICS PORT." AGP Is A Type Of Expansion Slot
Designed Specifically For Graphics Cards.
It Was Developed In 1996 As An Alternative To The PCI Standard. Since The AGP
Interface Provides A Dedicated Bus for Graphics Data, AGP Cards Are Able To
Render Graphics Faster Than Comparable PCI Graphics Cards.
Like PCI Slots, AGP Slots Are Built Into A Computer's Motherboard.
They Have A Similar Form Factor To PCI Slots, But Can Only Be Used For Graphics
Cards.
Additionally, Several AGP Specifications Exist, Including AGP 1.0, 2.0, and 3.0, Which
Each Use A Different Voltage.
Therefore, AGP Cards Must Be Compatible With The Specification Of The AGP Slot
They Are Installed In.
Since AGP Cards Require An Expansion Slot, They Can Only Be Used In Desktop
Computers.
4.3.S.AGP Slot On Mother Board

12.CPU SLOT
Since The Very First CPU, Both Intel And AMD Have Been Creating Several Different
Sockets To Be Used By Their Processors.
In The Beginning, A CPU Socket Was Compatible With Just One Kind Of Processor.
This Scenario Changed With The Launching Of The 486 Processor And The Massive
Use Of ZIF (Zero Insertion Force) Sockets, Also Known As LIF (Low Insertion Force).
The First Pentium Processors (60 MHZ And 66 MHZ) Used A Pin out Standard Called
Socket 4,
Which Was Fed With 5 V. Pentium Processors From 75 MHz On Were Fed With 3.3
V, Requiring A New Socket, Called Socket 5, Which Was Incompatible With Socket 4.
(For Example, A Pentium-60 Couldn’t Be Installed On Socket 5 And A Pentium-100
Couldn’t Be Installed On Socket 4.).
Socket 7 Uses The Same Pin out As Socket 5 With The Addition Of One Key Pin,
Accepting The Same Processors Accepted By Socket 5 Plus New CPUS, Especially
CPUS Designed By Competing Companies.
4.3.T. Processor Slot 4.3.U.Procesor In Cpu Slot

13. POWER SUPPLY PLUG IN
A Power Supply Unit (PSU) Converts Mains Ac To Low-Voltage Regulated Dc
Power For The Internal Components Of A Computer.
Modern Personal Computers Universally Use A Switched-Mode Power Supply.
Some Power Supplies Have A Manual Selector For Input Voltage, While Others
Automatically Adapt To The Supply Voltage.
Most Modern Desktop Personal Computer Power Supplies Conform To The Atx
Specification, Which Includes Form Factor And Voltage Tolerances.
While An Atx Power Supply Is Connected To The Mains Supply, It Always Provides A
5 V Standby (5vsb) Voltage So That The Standby Functions On The Computer And
Certain Peripherals Are Powered.
Atx Power Supplies Are Turned On And Off By A Signal From The Motherboard.
They Also Provide A Signal To The Motherboard To Indicate When The Dc Voltages
Are In Spec, So That The Computer Is Able To Safely Power Up And Boot. The Most
Recent Atx PSU Standard Is Version 2.31 Of Mid-2008.
4.3. V.SMPS 4.3.W.SMPS Connection to Mother Board

4.3.X. Power Cables 4.3.Y. Power Connection To Cpu
4.4COMPLETE MOTHER BOARD VIEW
4.4.A.Connecting Devices To Mother Board

4.4. Complete Mother Board Description

Questions on Computer Mother Board
Q1 ] UNIVAC IS
A. Universal Automatic Computer
B. Universal Array Computer
C. Unique Automatic Computer
D. Unvalued Automatic Computer
Correct Answer: A. Universal Automatic Computer
Explanation: There Are No Computers With The Name As In Other Options. UNIVAC Was
The First General Purpose Electronic Digital Computer Designed For Commercial Use,
Produced By Universal Accounting Company Of John M And JP Eckert In 1951.
Q2] CD-ROM Stands For
A. Compactable Read Only Memory
B. Compact Data Read Only Memory
C. Compactable Disk Read Only Memory
D. Compact Disk Read Only Memory
Correct Answer: D. Compact Disk Read Only Memory
Explanation: There Are No Objects With The Name As In Other Options. CD-ROM Is A Non-
Volatile Optical Data Storage Medium Using The Same Physical Format As Audio Compact
Disk, Readable By A Computer With A CD-ROM Drive. The Standard 12 Cm Diameter CD-
ROM Store About 660 Megabytes.
Q3] ALU Means
A. Arithmetic Logic Unit
B. Array Logic Unit
C. Application Logic Unit
D. None Of Above
Correct Answer: A. Arithmetic Logic Unit
Explanation: ALU Is A Unit In Central Processing Unit In A Computer System That Is

Responsible For Arithmetic Calculations And Logical Operations. Apart From ALU, The CPU
Contains MU (Memory Unit) And CU (Control Unit).
Q4] VGA Is
A. Video Graphics Array
B. Visual Graphics Array
C. Volatile Graphics Array
D. Video Graphics Adapter
Correct Answer: A. Video Graphics Array
Explanation: VGA Is A Type Of Graphics Adapter. Graphic Adapter Is An Electronic board
That Controls The Display Of A Monitor. This Device Helps the Motherboard to Work with
the Monitor and In VGA and SVGA the Last Letter ‘A’ Stands For ‘Array’ Whereas In MDA,
CGA, MCGA the Last Letter ‘A’ Stands For ‘Adapter
Q5] I BM 1401 Is
A. First Generation Computer
B. Second Generation Computer
C. Third Generation Computer
D. Fourth Generation Computer
Correct Answer: B. Second Generation Computer
Explanation: IBM 1401 Is A Second Generation Computer And Is The First Computer To
Enter Nepal In 2028 BS For Census. Government Of Nepal Had Brought This Computer On
Rent And Later Purchased For Data Processing In Bureau Of Statistics. After This Computer,
Another ICL 2950/10, A British Computer, Was Purchased By The Fund Of UNDP And
UNFPA For The Census Of 2038 BS Is Second Computer In NEPAL.
Q6] MSI Stands For
A. Medium Scale Integrated Circuits
B. Medium System Integrated Circuits

C. Medium Scale Intelligent Circuit
D. Medium System Intelligent Circuit
Correct Answer: A. Medium Scale Integrated Circuits
Explanation: After The Invention Of IC Chips The Development Of Computers Plunged Into
Next Phase. Small Scale Integration And Medium Scale Integration (SSI And MSI) Were
Used In Third Generation Of Computers And Large Scale Integration And Very Large Scale
Integration (LSI And VLSI) Are Being Used In Fourth Generation Of Computers. People Are
Now Expecting ULSI (Ultra Large Scale Integration) Circuits To Be Used For Fifth
Generation Computers.
Q7] The Capacity Of 3.5 Inch Floppy Disk Is
A. 1.40 MB
B. 1.44 GB
C. 1.40 GB
D. 1.44 MB
Correct Answer: D. 1.44 MB
Explanation: Microfloppy Disks (3.5 Inch) If It Is High Density (MF2HD) Can Store 1.44 MB
And If It Is Low Density (MF2DD), It Can Store 720 KB. Mini Floppy Disks (5.25 Inch) If It Is
High Density (MD2HD) Can Store 1.2 MB And Low Density (MD2DD) Stores 360 KB Of
Data.
Q8.]The First Computer Introduced In Nepal Was
A. IBM 1400
B. IBM 1401
C. IBM 1402
D. IBM1402
Correct Answer: B. IBM 1401
Explanation: IBM 1401, A Second Generation Computer Was Brought In Nepal By The
government Of Nepal Paying One Lakh And Twenty Five Thousands Per Month To Use In
The Census In 2028 B.S. Before This Computer, Nepal Was Using A Calculating Device
Called Facet For Statistical Tasks.

Correct Answer: B. Wide Area Network
Explanation: There Are Three Different Classes Of Computer Network 1. LAN – Local Area
Net Work 2. MAN: Metropolitan Net Work 3. WAN: Wide Area Network
Q9] WAN Stands For
A. WAP Area Network
B. Wide Area Network
C. Wide Array Net
D. Wireless Area Network
Q10] MICR Stands For
A. Magnetic Ink Character Reader
B. Magnetic Ink Code Reader
C. Magnetic Ink Cases Reader
D. None
Correct Answer: A. Magnetic Ink Character Reader
Explanation: MICR (Magnetic Ink Character Reader) Is Kind Of Scanner That Can Scan And
Identify The Writing Of Magnetic Ink. This Device Is Used In Banks To Verify Signatures In
Checks.
Q11] Which of the Following Is Not Real Security and Privacy Risk?
A. Hackers B. Spam C. Viruses D. Identity Theft
Correct Answer: B
Q12] Who Is Known As Father of Computers
A. Lord Wellington B. Charles Babbage C. Jack Kilby D. Bill Gates
Correct Answer: B
Q13 ] ROM Stands For ?

A. Random Only Memory B. Readable Only Memory C. Read Only Memory D. Random
Other Memory
Correct Answer: C
Q14] N -TH First Generation Computers Built Between (1945 -1956) What Was Used For
Calculations
A. Transistors B. Integrated Circuits C. Very Large Scale Integration D. Vacuum Tubes
Correct Answer: D
Q15] UPS Stands For?
A United Power Solutions B. Uninterrupted Power Supply C. Uninterrupted Power Solution
D. Untied Power Supply
Correct Answer: D
Q16] The Number System Based On "0" And "1" Only Is Known As
A. Binary System B Barter System C. Number System D. HEXA Decimal System
Q19 Which of the Following Is an Advantage Of Using A Local Area Network (LAN)?
A. Protects Against Virus Infection B. Shared Resources C. Data Security D. Prevents
Computer Misuse
Correct Answer: B
Q17] Server Is A?
A. Multimedia CD B. Personal Computer C. Multi – User Computer D. Integrated
Data Management
Correct Answer: B

Q18] What Is Internet?
A. Network of All Computers in a Company Not Connected To Web
B. Network of All Computers in a Company Not Connected To Web
C. Global Network of Computers
Correct Answer: C
Q19] Which of the Following Is Not an Integral Part of Computer
A. CPU B. Mouse C. Monitor D. UPS
Correct Answer: A
Q20] RAM Stands For?
A. Revolutionary Access Memory B. Relational Access Memory C. Random Access Memory
D. Rotational Access Memory
Correct Answer: C

5. COMPUTER –SOFTWARE
Software Is A Set Of Programs, Which Is Designed To Perform A Well-
Defined Function. A Program Is A Sequence Of Instructions Written To Solve A Particular
Problem.
There Are Two Types of Software
1) System Software
2) Application Software
5. A.Software Classification

5.1] SYSTEM SOFTWARE
The system software is collection of programs designed to operate, control, and
extend the processing capabilities of the computer itself.
System software is generally prepared by computer manufactures.
These software products comprise of programs written in low-level languages
which interact with the hardware at a very basic level.
System software serves as the interface between hardware and the end users.
Some examples of system software are Operating System, Compilers, Interpreter,
and Assemblers etc.
5. 1.A.Examples Of System Software
Features Of System Software Are As Follows:
 Close To System
 Fast In Speed
 Difficult To Design
 Difficult To Understand
 Less Interactive
 Smaller In Size
 Difficult To Manipulate
 Generally Written In Low-Level Language

System Software Can be classified into Following Types
1] Operating system
2] System development software
3] Utility programs
5.1.1. OPERATING SYSTEM
Operating System is Software That Communicates With The Hardware And Allows
Other Programs To Run.
It is comprised of system/The Fundamental Files Your Computer Needs To Boot
up And Function.
Every Desktop Computer, Tablet, And Smartphone Includes An Operating System
That Provides Basic Functionality For The Device.
Common Desktop Operating Systems Include windows, Mac OS X, And Linux. While
Each OS Is Different, They All Provide A Graphical User Interface, Or GUI, That
Includes A Desktop And The Ability To Manage Files And Folders.
They Also Allow You To Install And Run Programs Written For The Operating
System.
While Windows And Linux Can Be Installed On Standard PC Hardware, Mac OS X
Can Only Run On Macintosh Computers.
Therefore, The Hardware You Choose Affects What Operating System(S) You Can
Run.
5.1.1. A.Examples of Operating System

5.1.2. SYSTEM DEVELOPMENT SOFTWARE
Software Development Is The Computer Programming, Documenting, Testing,
And Bug Fixing Involved In Creating And Maintaining
Applications And Frameworks Involved In A Software Release Life Cycle And
Resulting In A Software Product.
The Term Refers To A Process Of Writing And Maintaining The Source Code, But In
A Broader Sense Of The Term.
It Includes All That Is Involved Between The Conception Of The Desired Software
Through To The Final Manifestation Of The Software, Ideally In A Planned
Therefore, Software Development May Include Research, New Development,
Prototyping, Modification, Reuse, Re-Engineering, Maintenance, Or Any Other
Activities That Result In Software Products.[2]
5.1.2. A.Software Development Cycle

5.1.3. UTILITY PROGRAMS
Utility Software Helps To Manage, Maintain And Control Computer Resources.
Operating Systems Typically Contain The Necessary Tools For This, But Separate
Utility Programs Can Provide Improved Functionality.
Utility Software Is Often Somewhat Technical And Targeted At Users With A Solid
Knowledge Of Computers.
If You Use A Computer Mostly For E-Mail, Some Internet Browsing And Typing Up A
Report, You May Not Have Much Need For These Utilities.
However, If You Are An Avid Computer User, These Utilities Can Help Make Sure
Your Computer Stays In Tip-Top Shape.
Examples Of Utility Programs Are Antivirus Software, Backup Software And Disk
Tools. Let's Look At Each Of These In A Bit More Detail.
Antivirus Software, As The Name Suggests, Helps To Protect A Computer System
From Viruses And Other Harmful Programs.
5.1.3. A.Utility Software Example

5.2. APPLICATION SOFTWARE
Application Software, Or Simply Applications, Are Often Called Productivity
Programs Or End-User Programs
Because They Enable The User To Complete Tasks Such As Creating Documents,
Spreadsheets, Databases, And Publications, Doing Online Research, Sending Email,
Designing Graphics, Running Businesses, And Even Playing Games! Application
Software Is Specific To The Task It Is Designed For And Can Be As Simple As A
Calculator Application Or As Complex As A Word Processing Application.
When You Begin Creating A Document, The Word Processing Software Has Already
Set The Margins, Font Style And Size, And The Line Spacing For You.
But You Can Change These Settings, And You Have Many More Formatting Options
Available.
For Example, The Word Processor Application Makes It Easy To Add Color,
Headings, And Pictures Or Delete, Copy, Move, And Change The Document's
Appearance To Suit Your Needs.
Microsoft Word Is A Popular Word-Processing Application That Is Included In
The Software Suite Of Applications Called Microsoft Office.
A Software Suite Is A Group Of Software Applications With Related Functionality.
For Example, Office Software Suites Might Include Word Processing, Spreadsheet,
Database, Presentation, And Email Applications.

Graphics Suites Such As Adobe Creative Suite Include Applications For Creating And
Editing Images, While Sony Audio Master Suite Is Used For Audio Production.
5.2. A.Application Software Examples

5.2.1. USER DEVELOPED PROGRAMS
End-user development (EUD) or end-user programming (EUP) refers to activities
and tools that allow end-users – people who are not professional software
developers – to program computers.
People who are not professional developers can use EUD tools to create or
modify software artifacts (descriptions of automated behavior) and complex data
objects without significant knowledge of programming.
Various approaches exist, and it is an active research topic within the field
of computer science and human-computer interaction.
Examples include spreadsheets, scripting languages (particularly in an office suite
or art application), and programming by example.
The most popular EUD tool is the spreadsheet. Due to their unrestricted nature,
spreadsheets allow relatively un-sophisticated computer users to write programs
that represent complex data models, while shielding them from the need to learn
lower-level programming languages.
Because of their common use in business, spreadsheet skills are among the most
beneficial skills for a graduate employee to have, and are therefore the most
commonly sought after In the United States of America alone, there are an estimated
13 million end user developers programming with spreadsheets.
5.2.1A.Software Description

5.2.2. CUSTOM SOFTWARE
Custom software (also known as bespoke software or tailor-made software)
is software that is specially developed for some specific organization or other user.
As such, it can be contrasted with the use of software packages developed for
the mass market, such as commercial off-the-shelf (COTS) software, or existing free
software.
Since custom software is developed for a single customer it can accommodate that
customer's particular preferences and expectations.
Custom software may be designed in stage by stage processes, allowing all nuances
and possible hidden dangers to be taken into account, including issues which were
not mentioned in the specifications.
Especially the first phase in the software development process may involve many
departments, including marketing, engineering, research and development and
general management.
Large companies commonly use custom software for critical functions,
including content management, inventory management, customer
management, human resource management, or otherwise to fill the gaps present in
the existing software packages.
Often such software is legacy software, developed before COTS software packages
offering the required functionality became available.
5.2.2. B.Custom Software Development Cycle

5.3. ASSEMBLER
An Assembler Is Not Equivalent To An Interpreter, Or Compiler, Assembly
Language Is A Low Level Language.
An Assembler Is One Form Of Program Translation. This Is One Relationship
Between Assembler, Compiler And Interpreter. Each Assembly Language
Statement Directly Corresponds To One Machine Instruction.
The Assembler Changes Assembly Instructions Into Machine Language,
Whereas A Compiler Runs A Higher Level Programming Language
Instructions Into Assembly Instructions And Then Those Are Converted Into
Executable Machine Language.
Accumulated Programming Languages Normally Generate Lots Of Lines Of
Assembly Instructions For Each Program Report.
An Assemblercreatesobject Code by Changing Symbols Or Substitute Names
Into machine Code. One Could Conclude That Assembly Language Is Not A
Programming Language At All, Just Guilty By Association. Assembly Language
Is Nothing More Than A "Shorthand" System Of Writing, Machine Language,
Programs Using Symbols That "Friendless Personality Lacking, Knuckle
Dragging WOW Players", Otherwise Known As Programmers, Can
Understand
5.3. A.AssemblerFig

5.4. COMPILER
A Compiler Converts An Entire Program Written In Source Code And
Translates It Into Object Code.
A Second Relationship Is That The Compiler And Interpreter Both Process
Source Code.
A Compiler Translates Source Code From A high-Level Programming
Language to Assembly Language/ Machine Code. Acompilerworks with What
Is Called Higher-Levellanguages3rd Generation languages, Such As Java And
C. Typically A Person Writes Source Code Using An Editor In A Language Such
As C, Pascal Or C++. The Programmer Then Selects The Appropriate Compiler
For The Source Code.
5.4. A.Compiler Phases
5.4. B. General Compilation

5.5. INTERPRETER
Another relationship is that the interpreter is the step by step version of a
compiler. Obviously this takes a lot of time and resources compared to
previously compiled program.
An interpreter doesn't have to examine the entire program before it can
begin executing code.
An interpreter is a computer program that takes source code and processes
one line at a time. Interpreters translate code one line at time, executing each
line as it is "translated," Interpreters do generate binary code, but that code
is never compiled into one program. Instead, the binary code is interpreted
every time the program executes.
5.5.A.Interpreter
5.5.B.Compilervs Interpreter

QUESITONS ON COMPUTER SOFTWARE
1. If There Are Multiple Recycle Bin For A Hard Disk
A. You Can Set Different Size For Each Recycle Bin
B. You Can Choose Which Recycle Bin To Use To Store Your Deleted Files
C. You Can Make Any One Of Them Default Recycle Bin
D. None Of Above
ANS: A
2. Identify False Statement
A. You Can Find Deleted Files In Recycle Bin
B. You Can Restore Any Files In Recycle Bin If You Ever Need
C. You Can Increase Free Space Of Disk By Sending Files In Recycle Bin
D. You Can Right Click And Choose Empty Recycle Bin To Clean It At Once
ANS: C
3. If the Displayed System Time And Date Is Wrong, You Can Reset It Using
A. Write
B. Calendar
C. Write File
D. Control Panel
ANS: D

4. You Should Save Your Computer From?
A. Viruses
B. Time Bombs
C. Worms
D. All of The Above
ANS: D
5. World Wide Web Is Being Standard By
A. Worldwide Corporation
B. W3c
C. World Wide Consortium
D. World Wide Web Standard
ANS: B
6. A Co-Processor
A. Is Relatively Easy To Support In Software
B. Causes All Processor To Function Equally
C. Works With Any Application
D. Is Quite Common In Modern Computer
ANS: A
7. A Microsoft Windows Is …..
A. Operating System
B. Graphic Program
C. Word Processing
D. Database Program
ANS: A

8. Which Of The Following Is Program Group?
A. Accessories
B. Paint
C. Word
D. All Of Above
ANS: A
9. Which Is Not Application Software?
A. Windows.NET
B. Page Maker
C. Windows XP
D. Photoshop
ANS: A
10. The ….. Program Compresses Large Files Into A Smaller File
A. WinZip
B. Win shrinks
C. Win style
D. None Of Above
ANS: A
11. Which Of The Following Is An Example Of A Real Time Operating System?
A. Lynx
B. MS Dos
C. Windows XP
D. Process Control
ANS: D

12. Which Of The Following Operating System Does Not Implement The Multitasking Truly?
A. Windows 98
B. Windows Net
C. Windows XP
D. MS Dos
ANS: D
13. Which Of The Following Windows Version Support 64 Bit Processor?
A. Windows 98
B. Windows 2000
C. Windows XP
D. Windows 95
ANS: A
14. Which Of The Following Operating System Does Not Implement Multitasking Truly?
A. Windows 98
B. Windows Net
C. Windows XP
D. MS Dos
ANS: D
15. What Program Runs First After Computer Is Booted And Loading GUI?
A. Desktop Manager
B. File Manager
C. Windows Explorer
D. Authentication
ANS: D

16. Which Of The Following Operating System Do You Choose To Implement A Client
Server Network?
A. MS Dos
B. Windows
C. Windows 98
D. Windows 2000
ANS: D
17. Which Of The Following Operating Systems Is Better For Implementing A Client-Server
Network
A. MS Dos
B. Windows 95
C. Windows 98
D. Windows 2000
ANS: D
18. My Computer Was Introduced From
A. Windows 3.1
B. Windows 3.11
C. Windows 95
D. Windows 98
ANS: C
19. Which Of The Following Windows Do Not Have Start Button
A. Windows Vista
B. Windows 7
C. Windows 8
D. None Of Above

ANS:C
20. Which Is The Latest Version Of MS Windows?
A. Windows 2007
B. Windows 8.1
C. Windows 2008
D. Windows 7
ANS: B
21. Which operating system doesn’t support networking between computers?
a. Windows 3.1
b. Windows 95
c. Windows 2000
d. Windows NT
ANS: A
22. Which Operating System doesn’t support networking between computers?
a. Windows 3.1
b. Windows 95
c. Windows 2000
d. Windows NT
ANS: A
23. Which of the following does not support more than one program at a time?
a. DOS
b. Linux
c. Windows
d. UNIX

ANS: A
24. Which of the following is not an operating system?
a. DOS
b. Linux
c. Windows
d. Oracle
ANS: D
25. Linux is a (n) … operating system
a. Open source
b. Microsoft
c. Windows
d. Mac
ANS: A

6. OPERATING SYSTEM
6.1BASICS OF OPERATING SYSTEM
Os-Definition
“An operating system (OS) is a collection of software that manages computer
hardware resources and provides common services for computer programs. The operating
system is a vital component of the system software in a computer system.”
In technical terms, It is a software which manages hardware. An operating System controls
the allocation of resources and services such as memory, processors, devices and
information.
An operating system is a program that acts as an interface between the user and the
computer hardware and controls the execution of all kinds of programs.
Functions of Operating System
Following Are Some Of Important Functions Of An Operating System.
Memory Management
Processor Management
Device Management
File Management
Security
Control Over System Performance
Job Accounting
Error Detecting Aids
Coordination Between Other Software And User

6.1. A.operating system with peripherals
6.1. B .Operating system architecture

6.2.TYPESOFOPERATINGSYSTEM
Following Are Few Of The Important Types Of Operating System Which Are Most
Commonly Used.
1) Batchoperatingsystem
2) Time-SharingOperatingSystems
3) DistributedOperatingSystem
4) NetworkOperatingSystem
5) RealTime OperatingSystem
1.BATCH OPERATINGSYSTEM
The Users Of Batch Operating System Do Not Interact With The Computer Directly.
Each User Prepares His Job On An Off-Line Device Like Punch Cards And Submits It
To The Computer Operator.
To Speed Up Processing, Jobs With Similar Needs Are Batched Together And Run
As A Group.
Thus, The Programmers Left Their Programs With The Operator. The Operator
Then Sorts Programs into Batches with Similar Requirements.
The Problems With Batch Systems Are Following.
 Lack of Interaction between the User and Job.
 CPU Is Often Idle, Because The Speeds Of The Mechanical I/O Devices Is Slower
Than CPU.

 Difficult To Provide The Desired Priority.
6.2.A.BatchProcessingOperatingSystem
3.TIME-SHARINGOPERATINGSYSTEMS
Time Sharing Is A Technique Which Enables Many People, Located At Various
Terminals, To Use A Particular Computer System At The Same Time
. Time-Sharing Or Multitasking Is A Logical Extension Of Multiprogramming.
Processor's Time Which Is Shared Among Multiple Users Simultaneously Is Termed
As Time-Sharing. T
He Main Difference Between Multiprogrammed Batch Systems And Time-Sharing
Systems Is That In Case Of Multiprogrammed Batch Systems, Objective Is To
Maximize Processor Use, Whereas In Time-Sharing Systems Objective Is To
Minimize Response Time.

Multiple Jobs Are Executed By The CPU By Switching Between Them, But The
Switches Occur So Frequently. Thus, The User Can Receive An Immediate
Response.
For Example, In A Transaction Processing, Processor Execute Each User Program In
A Short Burst Or Quantum Of Computation. That Is If N Users Are Present, Each
User Can Get Time Quantum. When The User Submits The Command, The Response
Time Is In Few Seconds At Most.
Advantages of Timesharing Operating Systems Are Following
 Provide Advantage Of Quick Response.
 Avoids Duplication Of Software.
 Reduces CPU Idle Time.
Disadvantages Of Timesharing Operating Systems Are Following.
 Problem Of Reliability.
 Question Of Security And Integrity Of User Programs And Data.
 Problem Of Data Communication.
6.2. B.Time Sharing Os Operation Cycle

3. DISTRIBUTEDOPERATINGSYSTEM
Distributed Systems Use Multiple Central Processors To Serve Multiple Real Time
Application And Multiple Users.
Data Processing Jobs Are Distributed Among The Processors Accordingly To Which
One Can Perform Each Job Most Efficiently.
The Processors Communicate With One Another Through Various Communication
Lines (Such As High-Speed Buses Or Telephone Lines).
These Are Referred As Loosely Coupled Systems Or Distributed Systems.
Processors In A Distributed System May Vary In Size And Function.
These Processors Are Referred As Sites, Nodes, And Computers And So On.
The Advantages Of Distributed Systems Are Following.
 With Resource Sharing Facility User At One Site May Be Able To Use The Resources
Available At Another.
 Speedup the Exchange Of Data With One Another Via Electronic Mail.
 Reduction Of The Load On The Host Computer.
 Reduction Of Delays In Data Processing.
6.2. C. Distributed type operating system

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