2. 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
3. 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
4. FEATURES OF COMPUTER
Speed
Accuracy
Storage
Diligence
Versatility
Power of Remembering
5. 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
6. LIMITATIONS OF COMPUTER
Intelligence
Feelings
Can not remove error itself
Can not work without human intervention
GIGO (Garbage in Garbage out)
7. GENERATION OF COMPUTER
First Generation (1942-1955)
Second Generation (1955-1964)
Third Generation (1964-1975)
Fourth Generation (1975-1990)
Fifth Generation (1990 – till date)
9. 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
10. 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.
11. 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
13. 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
14. 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
15. 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.
17. 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.
18. 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.
19. DISADVANTAGE
Air conditioning required in many cases.
Highly sophisticated technology required for the
manufacture of IC chips
21. 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.
22. 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
25. 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
26. ADVANTAGE
Very large storage capacity
Long bit processor builds
Artificial Intelligence Language developed
DISADVANTAGE
Complex technology required to developed.
27. CLASSIFICATION OF COMPUTER
Classification based on Application/ computational
method
Classification based on purpose
Classification based on size and capability
29. 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.
30. 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.
31. 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.
32. 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.
33. 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
34. 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.
35. CLASSIFICATION BASED ON SIZE AND
CAPABILITY
Micro Computer
Mini Computer
Mainframe Computer
Super Computer
49. 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
50. 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.
51. 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
52. 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.
53. CONTROL UNIT (CU)
Determines the sequence in which computer
programs and instructions are executed.
54. REGISTERS
Registers are temporary storage units within the CPU.
Memory Address Register (MAR)
Memory Buffer Register (MBR)
Program Counter (PC)
Instruction Register (IR)
Accumulator
55. BUS ARCHITECTURE
A set of parallel conductors which allow the flow of
instructions and data between devices.
Data bus
Address bus
Control bus
63. 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
69. Storage System Environment
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
70. Storage System Environment
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
