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8/18/2019 BBA-II-Intro To Computers.pptx
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BASIC CONCEPTS OF
COMPUTERS
Unit I
8/18/2019 BBA-II-Intro To Computers.pptx
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WHAT IS A COMPUTER?
A computer:
Is an electronic device
Operating under the control of instructions
(software) stored in its own memory unit,That can accept data (input),
Manipulate data (process), and
Produce information (output)
Generally, the term is used to describe acollection of devices that function together as a
system.
8/18/2019 BBA-II-Intro To Computers.pptx
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DEVICES THAT COMPRISE A
COMPUTER SYSTEM
Printer
(output)
Monitor
(output)Speaker
(output)
Scanner
(input)
Mouse
(input)
Keyboard
(input)
System unit
(processor, memory…)
Storage devices
(CD-RW, Floppy,Hard disk, zip,…)
8/18/2019 BBA-II-Intro To Computers.pptx
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CHARACTERISTICS OF COMPUTERS
Speed:Computer is very fast and accurate device.It can process millions and millions of instructionswithin seconds.
Accuracy:Computer results are highly accurate.
Memory:Computers have a large amount of memory to hold avery large amount of data or information.
Programmed Intelligence:Computer themselves as such are dumb terminals.But they are programmed in such a way that they canperform those operations which have been fed intothem in the form of executable programs.
8/18/2019 BBA-II-Intro To Computers.pptx
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CHARACTERISTICS OF COMPUTERS
Diligence:Computer is free from problems like lack of
concentration, and confusions etc.
Computer may never be confused like humans.
Versatility:We can perform many different types of tasks on
computer.
One moment it might be busy in calculating the
statistical data for annual performance evaluation of a
business organization and next moment it might beworking on playing movies.
Power of Remembrance:Unlike humans, computer can store things for unlimited
period of time.
8/18/2019 BBA-II-Intro To Computers.pptx
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WHAT DOES A COMPUTER DO?
Computers can perform five general operations,
which comprise the information processing cycle.
Input
Process Output
Storage
Control
8/18/2019 BBA-II-Intro To Computers.pptx
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DATA AND INFORMATION
All computer processing requiresdata, which is a
collection of raw facts, figures and symbols, such as
numbers, words, images, video and sound, given to
the computer during the input phase.
Computers manipulate data to create information.
Information is data that is organized,
meaningful, and useful.
During theoutput Phase, the information that
has been created is put into some form, such as a
printed report.
The information can also be put in computer
storage for future use.
8/18/2019 BBA-II-Intro To Computers.pptx
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HOW DOES A COMPUTER KNOW
WHAT TO DO?
It must be given a detailed list of instructions,
called acomputer program orsoftware, that
tells it exactly what to do.
Before processing a specific job, the computer
program corresponding to that job must be stored
inmemory.
Once the program is stored in memory the
computer can start the operation byexecuting
the program instructions one after the other.
8/18/2019 BBA-II-Intro To Computers.pptx
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WHAT ARE THE PRIMARY
COMPONENTS OF A COMPUTER ?
Input devices.
Central Processing
Unit (containing the
control unit and the
arithmetic/logic unit).
Memory.
Output devices.
Storage devices.
These are also known as theFunctional
Componentsof a Computer!
8/18/2019 BBA-II-Intro To Computers.pptx
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BLOCK DIAGRAM OF COMPUTER
SYSTEM
SecondaryMemory
PrimaryMemory
Control Unit
Arithmetic LogicUnit
InputUnit
OutputUnit
Program &Data
Resul
ts
Storage Unit
Central
Flo o!
ControlFlo o!Data
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF INPUT UNIT
Links the external environment with the computer
system.
Accepts or reads the instructions and data from
the outside world.
Converts these instructions and data into
computer acceptable form (Binary Codes).This transformation is accomplished by units called
input interfaces.
Supplies the converted instructions and data to the
computer system for further processing.
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF OUTPUT UNIT
Links the computer system with the external
environment
Accepts the result produced by the computer (in
binary codes).
Converts these results into human readable form.This transformation is accomplished by units called
output interfaces.
Supplies the converted results to the outside world.
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF STORAGE UNIT
Provides space for storing:Data and instructions required for processing, and
received from input devices.
Intermediate results of processing.
Final results of processing, before they are released toan output device.
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF ARITHMETIC/LOGIC
UNIT
It is the place where actual execution of instructions
takes place, during the processing operation.
Calculations are performed and all comparisons are
made in the ALU.
The data and instructions stored in the primary
memory, are transferred as and when needed to the
ALU.
Intermediate results generated by the ALU are
temporarily transferred back to the primary memory.Hence, data may move from primary memory to
ALU, and back again to memory, many times before
processing is over.
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF CONTROL UNIT
It does not perform any actual processing of data.
But it acts as a central nervous system for other
components of the computer system.
It manages and coordinates the entire computersystem.
It obtains instructions from the program stored in
main memory, interprets the instructions, and
issues signals.
These signals cause other units of the system to
execute the instructions.
8/18/2019 BBA-II-Intro To Computers.pptx
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FUNCTIONS OF CENTRAL
PROCESSING UNIT
The Control Unit and Arithmetic Logic Unit are
jointly known as the Central Processing Unit of the
system.
The CPU is the brain of a computer system.
In a computer system, all major calculations are
performed inside the CPU.
The CPU is responsible for activating and
controlling the operations of other units of the
computer system.