UNIT – I
INTRODUCTION TO
COMPUTERS
In troduction – Characteristics of Computers – Evolution of C
omputers –Computer Generations – Classification of Computers Basic Computer organization –Number Systems.
2 MARKS
1. Define computers?
A computer is a programmable machine or device that performs pre-defined or programmed
computations or controls operations that are expressible in
numerical or logical terms at high
speed and with great accuracy.
(Or)
Computer is a fast
operating electronic device, which automatically accepts and store input data,
processes them and produces results under the direction of step by step
program.
2. What is Data and Inf ormation?
Data - Data is the fact or raw material for the information processing.
Information – The processed data is called information.
4. What are the basic operations of Computer?
1) It accepts data or instructions by way of input.
2) It stores data.
3) It can process data as required by the user.
4) It gives results in the form of output.
5) It controls all operations inside a computer.
5. Give the applications computer?
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Word Processing
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Internet
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Desktop publishing
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· Digital
video or audio composition
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Mathematical Calculations
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Robotics
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Weather analysis
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6. What are the characteristics of computers?
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(JAN 2009)
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· Speed
· Accuracy.
· Automation.
· Endurance.
· Versatility.
· Storage.
· Cost Reduction.
7. How will you classify computer systems?
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(JAN2009)
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Based on physical size,
performance and application areas, we can generally divide computers into four
major categories:
1. Micro computer
2. Mini Computer
3. Mainframe computer and
4. Super Computer
8. Specify the Electronic components used for
different computer generations.
Generations Electronic Components
I Generation Vacuum tubes
II Generation Transistors
III Generation Integrated Circuits
IV Generation Microprocessors
V Generation Artificial Intelligence
9. Compare Computer with calculator
SNO
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Characteristic
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Calculator
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Computer
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1
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Speed
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Fast
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Much Fast
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2
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Performance
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Simple Calculation and
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Complex problem and
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numeric processing.
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non-numeric processing also.
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3
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Memory
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Less internal memory, no
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Large internal memory and large
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permanent storage, temporary
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permanent storage available.
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storage only.
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4
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Machine
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Electronic Device.
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Electronic Device.
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5
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Operation
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Arithmetic.
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Arithmetic and logical.
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10. What are the languages used in computer
generations.
Generations Languages used
I Generation Machine Language.
II Generation Assemble Language, Mnemonics
III Generation High Level Language, BASIC,
PASCAL, COBOL, FORTRON.
IV Generation 4GL
V Generation Artificial Intelligence.
11.
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Expand ENIVAC, ABC, EDVAC, EDSAC and UNIVAC.
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(JAN2010)
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ENIAC – Electronic
Numerical Integrator and Calculator.
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ABC – Atanasoff
and Berry Computer.
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EDVAC – Electronic
Discrete Variable Automatic Calculator.
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EDSAC – Electronic
Delay Storage Automatic Calculator.
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UNIVAC – UNIversal
Automatic Computer.
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12.
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Who is the father of computer? Why?
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Charles Babbage is the
father of computer, because the parts and working principle of the Analytical
Engine, which is invented by Charles Babbage is similar to today‘s computer.
13. Expand COBOL, BASIC, FORTRON and IBM.
COBOL – Common Business Oriented Language.
BASIC - Beginner‘s All Purpose Symbolic Instruction
Code.
FORTRON – FORmula TRANslation.
IBM – International Business Machine.
14. Expand IC, SSI, MSI, LSI, and VLSI.
IC – Integrated Circuit.
SSI - Small Scale Integration. MSI - Medium Scale
Integration. LSI
- Large Scale Integration.
VLSI - Very Large Scale Integration.
15. What are the components of the computer systems?
Basic components of the
computer system are Input Unit, Central Processing Unit, Secondary Storage Unit
and Output Unit.
16. What are the functions in the input unit?
An input device is a
device that is used to input data or information into a computer. Some examples
of input devices include:
· Keyboards.
· Computer mice.
· Light Pen.
· Digitizer.
· Touchpad.
· Trackball.
· Image scanner.
· Webcam.
· Video capture / tuner cards.
· Microphones.
· MIDI instruments.
17. What are the functions in the output unit?
In computers, a unit
which delivers information from the computer to an external device or from
internal storage to external storage.
· Speakers.
· Printer.
· Headphone.
· Monitor (or) V isual Display Unit (VDU).
· Plotter.
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20. What is a CPU?
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The
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CPU
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(central
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processing
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unit)
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is
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the
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part
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of a computer
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controls
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the interpretation
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and execution of instructions. Generally, the CPU is a
single microchip.
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(Or)
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The
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computing part of
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the
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computer.
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Also
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called the
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"processor,"
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it is
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made
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up
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of
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the
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control unit and ALU. Today,
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the CPUs
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of
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almost
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all
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computers are contained
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on
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a
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single
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chip.
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The
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CPU,
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clock
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and main
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memory
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make
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up
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a computer.
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A
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complete
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computer
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system
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requires
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the addition
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of
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control
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units,
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input,
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output
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and
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storage
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devices
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and
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an
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operating
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system.
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21. What is meant by generation in computer
terminology?
Generation is the period of years in which the
computers are enhanced as previous.
22. Define personal computers?
A small, relatively inexpensive computer
designed for an individual user.
In price, personal
computers range anywhere from a few hundred dollars to thousands of dollars.
All are based on the
microprocessor technology that enables manufacturers to put an entire CPU on
one chip.
Example:
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· Businesses use personal computers for word
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processing, accounting,
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desktop
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publishing, and for running spreadsheet and database
management applications.
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· At home,
the most popular use for personal computers is for playing games.
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23.
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Define Mainframe computer?
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Mainframes are computers used mainly by large organizations for
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critical
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applications,
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typically bulk data processing such as census, industry
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and consumer
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statistics,
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enterprise
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resource planning, and financial processing.
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The term probably had originated from the early mainframes, as
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they were
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housed in
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enormous, room-sized metal boxes or frames.
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24.
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Define Mini computers?
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A mini computer is a
multi-user or time -sharing system. It is used for medium scale data processing
such as Bank account processing, Payroll processing etc., Mini computer process
greater storage capacity and larger memories as compared to micro computer.
25. Define super computer?
The fastest type of
computer. Supercomputers are very expensive and are employed for specialized
applications that require immense amounts of mathematical calculations.
For example, weather forecasting requires
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a supercomputer. Other uses of
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supercomputers include
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animated graphics,
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fluid dynamic calculations, nuclear energy
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research, and petroleum
exploration.
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26. Define Software?
Computer instructions or
data, anything that can be stored electronically is software. (Or)
Computer software or
just software is a general term used to describe the role that computer
programs, procedures and documentation in a computer system.
The term includes:
27.
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Define hardware?
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Computer hardware - (computer science) the mechanical, magnetic, electronic, and
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electrical components making up a computer system
hardware.
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Hardware
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includes not
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only
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the
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computer
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proper
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but also the
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cables,
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connectors,
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power
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supply
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units,
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and
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peripheral
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devices
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such
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as
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the
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keyboard,
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mouse,
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audio
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speakers,
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and
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printers.
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28.
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What is an instruction?
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An instruction is a basic command. The
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term instruction is often used to
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describe
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the
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most
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rudimentary
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programming
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commands. For
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example, a
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computer's
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instruction
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set
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is the
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list of all the basic commands in the computer's machine
language.
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29.
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Define memory?
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Computer
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memory refers to
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devices
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that
are
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used
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to
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store
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data
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or programs
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(sequences
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of instructions) on a temporary or permanent basis for use
in an electronic digital computer.
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30.
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What is a volatile and non-volatile memory?
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Volatile
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memory: also
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known
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as
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volatile
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storage is computer memory that
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requires
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power to maintain the stored information, unlike
non-volatile memory which does not require
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a maintained power supply. It has been less popularly
known as temporary me mory.
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Non-volatile memory:nonvolatile
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memory, NVM
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or
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non-volatile
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storage, is computer
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memory that can retain the stored information
even when not powered.
Examples of non-volatile memory
· read-only memory
· flash memory
· most types of magnetic
computer storage devices (e.g.hard / floppy disks & magnetic tape)
· optical discs
· Early computer storage methods such as paper
tape and punch cards.
Non-volatile
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memory
is
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for long-term persistent storage. The
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most widely
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used
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form of
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primary
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storage
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today is
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a volatile form of random access memory
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(RAM),
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meaning
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that
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when the computer is shut down, anything contained in RAM
is lost.
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31. What is a primary memory?
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The
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primary
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memory
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or the
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main
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memory is
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part of
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the
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main
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computer
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system.
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The
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processor
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or
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the
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CPU
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directly
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stores
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and retrieves
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information
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from
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it.
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This
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memory
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is
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accessed
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by
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CPU,
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in random
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fashion.
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That means
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any location of
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this
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memory can
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be
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accessed by the CPU to either read information
from it, or to store information in it.
Types of Primary Memory:
· RAM is RWM (Read Write Memory), the CPU can
write and read information from
any
primary memory location implemented using RAM.
· ROM stands for Read Only Memory.
32. What is a secondary memory?
The secondary memory is much slower and also
less costly. It stores the da permanently unless it is erased.
Memory chips etc.,
33. What is a microprocessor?
A microprocessor incorporates most or all of the functions of a central processing unit
(CPU) on a single integrated circuit (IC).
The first microprocessors emerged in the early 1970s and were used for electronic
calculators, using binary-coded decimal (BCD)
arithmetic on 4-bit words.
34. What is transistor?
A device composed of semiconductor material that
amplifies a signal or opens or closes a
circuit. Invented in 1947 at Bell Labs, transistors have become the key ingredient of all
digital circuits, including computers. Microprocessors contain tens of millions of
microscopic transistors.
35. What is an IC? How does it help in re ducing the
size of Computers?
IC is an Integrated Circuit; it integrates large number of circuit elements into very small
surface (less than 5mm square) of silicon known
as Chip‘s.
36. What are the components of the computer systems?
· Input Unit
· Central Processing Unit.
· Secondary Storage Unit.
· Output Unit.
37. Define number system.
The
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term
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computer
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numbering
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formats
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refers
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to
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the
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schemes
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implemented
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in
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digital
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computer and calculator hardware
and software to represent numbers.
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For example,
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if
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one multiplies:
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one
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might perhaps
expect
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to
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get
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a
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result
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of exactly
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1,
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which
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is
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the correct answer when
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applying
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an exact rational
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number or
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algebraic
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model.
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In
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practice,
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however,
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the
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result on a
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digital computer
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or
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calculator
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ma y
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prove to
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be
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something
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such
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as
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precisely
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0.9999999999999999
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(as
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one might
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find
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when
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doing the
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calculation
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on
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paper) or, in certain cases, perhaps
0.99999999923475.
38. What are the types of Number System?
· Positional Number System.
· Non-Positional Number System.
39. What are the positional number systems and what
is their base?
Number System Base
Decimal Number System 10
Binary Number System 2
Octal Number System 8
Hexa Decimal Number System 16
40. Define (1) Nibble (2) Bit (3) Byte?
(1) In computers and digital technology, a nibble (pronounced NIHB-uhl; sometimes
spelled
nybble) is four binary digits or half of an
eight-bit byte. A nibble can be conveniently
represented by one hexadecimal digit.
(2) A bit (short for binary digit) is the smallest unit of data in a computer. A bit has a
single
binary value,
either 0 or 1. Although computers usually provide instructions
that can test
and manipulate bits, they generally are designed to store data and execute instructions in
bit multiples called bytes.
(3) In most computer systems, a byte is a unit of data that is eight
binary digits long. A byte
is
the unit most computers use to represent a character such as a letter, number, or
typographic symbol (for example, "g",
"5", or "?"). A byte can also hold a string of bits
that need to be used in some larger unit for
application purposes.
41. What is a Base?
A base is the total number of bits in the number
system.
42. What is meant by conversion in number system?
Conversion is the
process of converting from one number system to another number system.
Example:
· Decimal to Octal.
· Hexadecimal to Decimal
43. Define (1) MSB (2) LSB?
(1)
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In computing,
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the most
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significant
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bit (MSB)
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is the bit position in a binary number
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having the greatest value. The
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MSB
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is
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sometimes
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referred to as
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the left-most bit on
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big-endian architectures, due to
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the
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convention
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in
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positional notation of writing more
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significant digits further to the
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left.
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The
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MSB
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can
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also correspond
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to the
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sign of a signed
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binary number in one
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or two's complement
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notation. "1" meaning negative
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and "0"
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meaning
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positive.
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(2) In computing, the least significant bit (LSB) is
the bit position in a binary integer giving
the units value, that is, determining whether the number is even
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or
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odd. The
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LSB is
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sometimes referred to
as the right-most bit, due to the convention
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in
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positional
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notation
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of
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writing less significant digit
further to the right.
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44. Specify the method to convert decimal number
system.
1. Remainder method.
2. Power method.
45. What is a binary number system?
The binary
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numeral
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system
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or base-2 number system represents numeric values using
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two symbols,
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0 and 1.
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More
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specifically, the usual base-2 system is a positional notation
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with a radix of 2.
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46. What is a decimal number system?
The decimal numeral
system (also called base ten or occasionally denary) has ten as its base. It is
the most widely used numeral base.
Examples are
· Roman numerals.
· Brahmi numerals.
· Chinese numerals.
· Hindu-Arabic numerals.
· Roman numerals have symbols for the decimal
powers (1, 10, 100, and 1000).
47. What is an octal number system?
The octal
numeral system, or oct for short, is the base-8 number system, and uses the
digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary
digits into groups of three (starting from the
right).
For example:
112 in octal is equal to 64+8+2 = 74 in decimal. Octal is sometimes used in
computing
instead of hexadecimal.
48. What is a hexadecimal number system?
In mathematics and computer science, hexadecimal (also base-16, hexa, or hex) is a
numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the
symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F (or a through f) to
represent values ten to fifteen.
Its primary use is as a human-friendly representation of binary coded values, so it is often
used
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in
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digital
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electronics
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and
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computer
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engineering.
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Since
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each
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hexadecimal
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digit
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represents
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four
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binary
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digits
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(bits)—also called a
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nibble—it
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is a
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compact
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and
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easily
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translated shorthand to express values in base two.
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49. Write short notes on primary storage.
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Stores
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and provides very fast. This
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memory is
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generally
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used
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to
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hold
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the
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program
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being
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currently
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executed in the computer, the data
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being
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received
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from
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the
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input
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unit,
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the
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intermediate and final results of the program.
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The
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primary me mory
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is temporary
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in nature.
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The data
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is lost,
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when
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the computer
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is
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switched
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off. In order to store the data permanently, the data has to
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be
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transferred
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to
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the
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secondary memory.
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50. Write short notes on secondary storage.
Secondary storage is used like
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an archive.
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It stores several programs, documents,
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data
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bases etc. the programs that we
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run on the
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computer are first transferred to the
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primary
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memory before it is actually run.
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Whenever the results are saved, again they
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get stored in the secondary memory.
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The
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secondary memory is slower and
cheaper than the primary memory. Some of 1 the commonly
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used secondary me mory devices are
Hard disk, CD, etc.,
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51. List out the types of computers based on size,
memory capacity.
1. Micro computers
2. Mini computers
3. Mainframe computers
4. Super computers
53. What are the major
operations of computers?
A computer performs basically 5 major operations or functions
irrespective of their size they
are
· It accepts data or instructions by way of input.
· It stores data.
· It can process data as required by the user.
· It gives results in the form of output.
· It controls all operations inside a computer.
54. Write short notes on cache
memory.
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The speed of CPU is extremely high compared to the
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access time of main memory.
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Therefore, the performance of CPU decreases due to the
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slow speed of main memory. To
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decrease
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the mismatch
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in
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operating
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speed,
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a small memory
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chip
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is attached between CPU
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and main
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memory
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whose
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access
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time
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is
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very
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close to
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the processing speed of CPU. It is
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called CACHE
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me
mory.
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CACHE
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memories are accessed
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much
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faster than conventional
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RAM. It is used to
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store programs
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or
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data
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currently
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being executed or temporary data
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frequently
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used
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by
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the
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CPU.
So each
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memory
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makes main
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memory to be faster and larger
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than it really is. It is
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also
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very expensive to have bigger size of
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cache memory and its size is
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normally kept small.
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55.
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Write the binary and octal equivalent of hexadecimal number 7BD?
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(APR2009)
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Binary Equivalent of 7BD
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= (0111 1011 1101)2
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Octal Equivalent of 7BD
|
= (011 110 111 101) = (3675)8
|
|
56.
|
Give any tw o tasks, which humans perform better
than computers?
|
(JAN2009)
|
• Humans can communicate better than computers.
• Humans are much reliable than computers.
57. What is the use of computer in
medicine and healthcare?
|
(JAN2009)
|
· Study of biological vision system.
· Medical Imaging.
· Mobile healthcare technology.
· Nano technology.
· Bioinformatics.
58.
|
Convert binary number 100110 into its octal equivalent?
|
|
|
(JAN2009)
|
|
|
|
Octal equivalent of 100110 = (100 110) = (46)8
|
|
|
|
|
|
59.
|
What are registers?
|
|
|
|
|
|
|
(J
|
|
A special, high-speed storage area
|
within the
|
CPU. All
|
data
|
must
|
be
|
represented
|
in a
|
register before it can be
processed.
|
|
|
|
|
|
|
|
For example,if two numbers are to be
|
multiplied,
|
both numbers
|
must
|
be
|
in
|
registers, and
|
the
|
result is also placed in a
register.
|
|
|
|
|
|
|
|
60.
|
Differentiate analog and digital computers?
|
|
|
|
|
(JAN2010)
|
|
S
No
|
Analog Computer
|
|
Digital Computer
|
|
|
|
|
1
|
Process measured data
|
Process discrete data
|
|
|
|
|
|
|
2
|
Analog computers are not precise
|
Digital computers are more precise
|
|
|
|
3
|
Processing speed is low.
|
Processing speed is high.
|
|
|
|
|
|
4
|
Less accuracy.
|
More accuracy.
|
|
|
|
|
|
61. Find the decimal equivalent of
hexadecimal number 4D.C8
|
|
|
|
(JAN2010)
|
4D.C8 = 4 X 161 + 13 X 162 + 12 X 16-1 + 8 X 16-2
= 64 + 13 +0.75 + 0.03125
= (77.78)2
62. Convert hexadecimal number
into binary equivalent of EBC
|
(JAN2010)
|
Binary equivalent of EBC = (1110 1011 1100)2
