Unit 1 part 1 introduction BCE

INTRODUCTION
 Use of computer in daily life
 Calculation (time saving, accuracy, reduce complexity)
 Entertainment
 Medical Diagnosis
 Weather forecasting
 Payment of bills
 Banking
 Manufacturing products like automobiles, shoes etc.
 Animation
 Space research
 Creation of blueprints for houses

DEFINITIONS OF COMPUTER
 A computer is electronic device that can accept
store and process information to produce the
required result.
 Computer is a device that can solve any
mathematical operation and it operates on
information or data.
 Computer can be defined in terms of its functions. It
can
 Accept data
 Store data
 Process data as desired
 Retrieve the stored data as and when required
 Print the result in desired format

FEATURES OF COMPUTER
 Speed
 Accuracy
 Storage
 Diligence
 Versatility
 Power of Remembering

CAPABILITIES OF COMPUTER
 Processes information very fast
 Accurate results
 Stores large amount of data and information
 Restore or bring back any works
 Automatics
 More then one things at the same time
 Improved and upgraded

LIMITATIONS OF COMPUTER
 Intelligence
 Feelings
 Can not remove error itself
 Can not work without human intervention
 GIGO (Garbage in Garbage out)

GENERATION OF COMPUTER
 First Generation (1942-1955)
 Second Generation (1955-1964)
 Third Generation (1964-1975)
 Fourth Generation (1975-1990)
 Fifth Generation (1990 – till date)

MAIN FEATURES
 Major Innovation -Vacuum tubes
 Main Memory- Punched cards
 Input Output devices- punched cards and papers
 Languages- Low level machine language
 Operating system- No operating system, human
operates to set switches
 Size- Main frame for example ENIAC, EDVAC,
UNIVAC

ADVANTAGES
 Vacuum tube were the only electronic components
available during those days.
 Vacuum tube technology made possible the advent
of electronic digital computers.
 These computers were the fastest calculating
devices of their time.
 They could perform computations in milliseconds.

DISADVANTAGE
 Too heavy in size
 Unreliable
 They produced large amount of heat
 Air conditioning required
 Possibility to frequent hardware failures
 Constant maintenance required
 Not portable
 Commercial production was difficult and costly

MAIN FEATURES
 Major Innovation – Transistors as main component
 Main Memory- RAM and ROM
 External storage- Magnetic tapes and Magnetic
Disk
 Input output Devices- Magnetic tapes and Magnetic
Disk.
 Languages- Assembly language, some high level
languages for Example BASIC, COBOL, FORTRAN
 Operating System- Human handles punched card
 Size- Main frame for example IBM-1401, NCR-300,
IBM-600 etc

ADVANTAGE
 Smaller in size as compared to first generation
computer
 More reliable
 Less heat generated
 These computer were able to reduce computational
times from milliseconds to microseconds
 Less possibility to hardware failure
 Better portability
 Wider commercial use

DISADVANTAGE
 Air conditioning still required
 Frequent maintenance required
 Manual assembly of individual components into a
functioning unit was required
 Commercial production was difficult and costly.

THIRD GENERATION (1964-1975)
 Based on integrated circuits.

MAIN FEATURES
 Major Innovation Integrated circuit (ICs) as basic
electronic component
 Main Memory – PROM and DRAM
 External Storage- Improve disk (Floppy disk)
 Input and output Devices- Keyboard for input,
Monitor for output
 Languages- More high level languages
 Operating System- Complete operating system
were introduced
 Size- Mini, for example: IBM SYSTEM/360, ICH-
360, HONEY WELL-316 etc.

ADVANTAGE
 Smaller in size as compared to previous generation
computers
 Even more reliable than second- generation computers
 Lower heat generated than second generation
computers
 Able to reduce computational times from microseconds
to nanoseconds
 Maintenance cost is low because hardware failures are
rare.
 Easily portable
 Widely used for various commercial applications all over
the world
 Less power requirements than previous generation
computers.

DISADVANTAGE
 Air conditioning required in many cases.
 Highly sophisticated technology required for the
manufacture of IC chips

MAIN FEATURES
 Major Innovation – LSIC and VLSIC (Micro
Processor)
 Main Memory-EPROM and SRAM
 External Storage- Floppy Disk and Hard Disk
 Input and output Devices- Monitor for output
 Languages- High Level languages and Application
software
 Operating system-MS DOS and PC-DOS
 Size- Micro computer e.g. IBM-PC, Apple
Macintosh etc.

ADVANTAGE
 Low cost
 High Speed
 Large memory
 Small size
 Less power consumption
 Floppy disk is used as storage device. Semi
conductor internal memory
 Improve in software
 Hardware failure is negligible
 Heat generated is negligible
 Cheapest among all generation

DISADVANTAGE
 Highly sophisticated technology is required for the
manufacture of chip.

FIFTH GENERATION (1990 - TILL DATE)
 ULSIC

MAIN FEATURES
 Major Innovations- ULSIC (Ultra Large scale
Integrated circuit)
 Main Memory-EEPROM, SIMM and DIMM
 External Storage- Modified magnetic, Optical disks
and flesh drive.
 Input/ Output Devices- Keyboard, Pointing Device,
Scanner as input and monitor as main output.
 Language- AI expert systems.
 Operating system- GUI based like Windows XP,
Windows 7 etc.
 Size- Very small

ADVANTAGE
 Very large storage capacity
 Long bit processor builds
 Artificial Intelligence Language developed
DISADVANTAGE
 Complex technology required to developed.

CLASSIFICATION OF COMPUTER
 Classification based on Application/ computational
method
 Classification based on purpose
 Classification based on size and capability

CLASSIFICATION BASED ON APPLICATION
 Analog computer
 Digital computer
 Hybrid computers

ANALOG COMPUTER
 This type of computer is worked on quantity like in
petrol pump, Weather forecasting , temperature etc.
 Process data input in a continuous form.
 Data such as voltage, resistance or temperature is
represented in the computer.
 Analog signals are used for working.

ADVANTAGE
 Analog computers carried out measurement by a
few single purpose devices. So they are offers low
cost.
DISADVANTAGE
 Accuracy factor- Result of analog computer is not
accurate.
 Limited storage capacity
 Not suitable for processing business data.

DIGITAL COMPUTER
 General computer works on 1 and 0.
 It gives accurate result because this computer uses
digital signals for working.
 They can count, and accept numbers and letters
through various input devices.
 The input devices convert data into electronic
pulses and perform arithmetical operations.

ADVANTAGE
 Digital computers give result any desired level of
accuracy.
 Most suitable for business application
DISADVANTAGE
 High cost of digital computer
 Digital computers have complexity in programming.

HYBRID COMPUTER
 It is a combination of analog and digital computer.
 Computer works on both analog and digital signals.
 It can convert analog signals to digital and digital to
analog.
 Example MODEM

CLASSIFICATION BASED ON PURPOSE
 General Purpose computer
 Is a normal computer that is used everywhere.
 This type of computer can do programming, calculation,
accounting work or painting work.
 Generally used in homes, schools and colleges.
 Example - Digital computer
 Special Purpose computer
 This computer is designed according to special tasks
like for weather forecasting, research or to make a film
in photo studio.

CLASSIFICATION BASED ON SIZE AND
CAPABILITY
 Micro Computer
 Mini Computer
 Mainframe Computer
 Super Computer

TYPES OF PERSONAL COMPUTER
 Desktop
 Laptop
 Notebook
 Palmtop
 Handheld computer
 Tablet PCs
 Workstation

HANDHELD COMPUTER (PDA PERSONAL
DIGITAL COMPUTER)

COMPUTER OPERATION
 Input
 Storage
 Processing
 Control
 Output

INPUT UNIT
 The input unit takes data from us to the computer in
an organized manner for processing.
OUTPUT UNIT
 Output unit of computer display the result.
 Visual Display such as monitor
 In printed form by printer
 In graphic form by plotters
 In the form of sound by speaker
 Other output devices such as projector or LCD

STORAGE UNIT
 Storage unit provides space for storing data and
instructions in computer.
 All the data and instructions are stored here before
and after processing.
 Intermediate results of processing are also stored
here.

CENTRAL PROCESSING UNIT
 A central processing unit controls the execution of
programs and performs the calculations.
 Manipulating the data like word processing letter.
 Writing, sorting, editing, makes catalog of data.
 Converting data of one form into another
 Communicating data to far off distances.
 Storing the data temporarily and retrieving it as and
when required.
 CPU does every thing in the form of binary language

ARITHMETIC AND LOGICAL UNIT (ALU)
 Is used to perform arithmetic and logical operation.
 ALU takes data from memory unit and returns
information to memory unit.
 ALU used a number of registers and accumulators
for short term storage of characters while doing
calculations or computations.

CONTROL UNIT (CU)
 Determines the sequence in which computer
programs and instructions are executed.

REGISTERS
 Registers are temporary storage units within the CPU.
 Memory Address Register (MAR)
 Memory Buffer Register (MBR)
 Program Counter (PC)
 Instruction Register (IR)
 Accumulator

BUS ARCHITECTURE
 A set of parallel conductors which allow the flow of
instructions and data between devices.
 Data bus
 Address bus
 Control bus

SECONDARY MEMORY
 Magnetic tape
 Hard Disk
 Floppy Disk
 3.5 Inch (1.44 MB) and 5.25 Inch (1.2 MB)
 Optical Disk
 CD-ROM (Compact Disk Read Only Memory)
 Write Once Read Many (WORM)
 Erasable optical disk
 Digital Video Disk (DVD)
 Zip drive
 USB Flash Drive

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65
HARD DRIVE
Interface
Controller
Power
Connector
HDA

Storage System Environment
PHYSICAL DISK STRUCTURE
Sector
Track
Platter
Sector
Track
Cylinder
Spindle

LOGICAL BLOCK ADDRESSING
Physical Address= CHS
Cylinder 2
Head 0
Sector 10
Block 48
Block 16
Block 32
Logical Block Address= Block#
Block 0
Block 8
(Upper Surface)
(Lower Surface)

PLATTER GEOMETRY AND ZONED-BIT RECORDING
Platter Without Zones
Sector
Track
Platter With Zones

DISK DRIVE PERFORMANCE: SEEK TIME
 Time taken to position the
read/write head
 Lower the seek time, the faster
the I/O operation
 Seek time specifications
include:
 Full stroke
 Average
 Track-to-track

DISK DRIVE PERFORMANCE: ROTATIONAL SPEED/LATENCY
 The time taken by platter to
rotate and position the data
under the R/W head
 Depends on the rotation speed
of the spindle
 Average rotational latency
 One-half of the time taken for a
full rotation
 Appx. 5.5 ms for 5400-rpm
drive
 Appx. 2.0 ms for 15000-rpm
drive

FLOPPY DISK
 3.5 inch – 1.44 MB
 5.25 inch – 1.2 MB

OPTICAL DISK
 CD-ROM
 WORM
 Erasable optical disk
 DVD
 Zip drive (100 MB)

USB FLUSH DRIVE
 Universal Serial Bus

Unit 1 part 1 introduction BCE

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Unit 1 part 1 introduction BCE