COMPUTER
CHARACTERISTICS OF
COMPUTER
1) Speed: - speed is
the most important characteristics of computer system. Fast speed of
calculations and storing of information, all is done by computer without
loosing their accuracy. They can be made to work without giving any rest. It is
measured in terms of instructions per second (IPS).
2) Storage: - we can
store information in our brain for future use. In the same way computer can also
store data for future use.
3) Accuracy: -
computers are accurate; it acts as per our instructions on the data supplied by
us. Most of the mistakes or errors are because of the feeding wrong data or
instruction.
4) Diligence: - unlike
humans, computers never get tiered or bored. It can do repetitive work any
number of times.
5) Automatic: - a
computer works automatically once program are stored and data is given to it.
It does not require constant supervision from the operator
6) Versatile: -
Computers seem capable of doing almost any task that can be reduced to a series
of logical steps. Compute is versatile tool. It can change over to various
types of jobs within a very short span of time. One moment, it is preparing the
results of particular examination, the next moment it is busy preparing
electricity bills and in between it may be helping an office secretary to trace
an important letter in seconds.
7) Database: - The use of
computer in business organization facilitates establishment of database, which
reduces data redundancy
LIMITATIONS OF COMPUTER
1) It needs
electricity to work.
2) It has limited
memory.
3) It needs operator
or human being to control or work on it.
4) Virus can affect
and crash the system
5) Without software
computer can not work
COMPUTER
CATEGORIZATION
1) According
to size
2) According
to configuration
ACCORDING TO SIZE
a) Mini computer: The hardware of a minicomputer is not as standard of
PC’s . It is medium sized computer
running a multitasking operating system capable of managing more than one
hundred users simultaneously. Some
distinguished features are:
·
suitable for used in small companies/ govt.
departments
·
Mainly uses 16/32 bit microprocessor
·
1 mb ram which can be increased to 5-6 MB
·
e.g.:- laptop,
palm top
b) Mainframe
computer: Mainframes are generally
more powerful than a typical mini computer. It is a
large, fast, multi-user operating system, often utilizing multiple processors,
designed to manage large amount of data and complex computing tasks. Main
frames are normal installed in large corporation, universities or military
installation. Some distinguished features are:
·
all brain at one central
location
·
32/64 bit addressing
·
large amount of RAM and storage
capacity
·
large no. of users
·
e.g.:- used for weather
forecasting
c) Micro
computer: A Micro computer is a single
processor computer, which is of von Neumann architecture. It has one input and
one output unit directly connected to C.P.U (with single CU, single ALU, and
limited base memory). It is the smallest and least expensive class o f
computers.
e.g.:- desktop computers, laptop, palm top
ACCORDING TO
CONFIGURATION
a)
Analog computer :- Analog
computer is a data device that operates data in the form of continuously
variable , physical quantities such as voltage, current, temperature etc. these
are generally used for process control application in space and industry.
b)
Digital computers: - a Digital
computer is a device that manipulates discrete data and performs arithmetic and
logic operations on data. Digital computers use binary digits that Is 0’s and
1’s for their operation
c)
Hybrid computer: - It is a
combination of analog and digital computer, where the analog signal is
converted into digital means 0, 1 language. For e.g.: when we use access the
internet by telephone. in telephone data is converted
APPLICATIONS OF
COMPUTER
1) Telecommunication: - use of computer in
telecommunication has changed the world, and made it as small for the people as
every one can contact each other.
2) Railway: - in railway, computerization has made the
reservation procedure easier.
3) Banking: - computerization has made the procedure
fast and secure.
4) Computers are
also used in weather forecasting purpose.
5) Internet: - it has become a gift for
the people, as through this we can contact to the other person anywhere world
wide.
6) Computers are
widely used in the field of education, training and research and development.
7) Doctors use
computer technology for the diagnosis purpose.
Computers are widely used in
space and research purpose.
Computers are widely used in
space and research purpose.
8) Architects use
the computers to draw layers and design of the building.
HARDWARE AND
SOFTWARE
HARDWARE: - A Computer is an electronic device which
performs arithmetic and logical operation on the input data to produce an
output. Each of these functions requires some physical devices which constitute
the hardware of the computer.In addition to the physical device the computer
also requires a set of instruction that specify how the input is to be
processed called the software.
FUNDAMENTAL FUNCTIONS OF COMPUTER
These functions of a computer are to accept input,
process the data and give the output.
SOFTWARE:
- For the computer to perform any task, it needs to be given a set of command
to perform the task; these command or instructions are called as SOFTWARE. Or
It is the set of programs designed and developed to
make the computer an intelligent computing device. Without the software the
computer system is a dumb machine
1. Input Unit: The data is entered
using an input device such as a Keyboard or a Mouse.
2. Brain Unit: The computer
processes the data according to a set of instructions called Program.
3. Output: The computer returns the
processed information in the form of output that can either be printed or
displayed on the output devices like Printer or Monitor.
4. Memory: The computer saves the
data and the instructions in the memory for further retrieval.
INPUT DEVICES
An
input device presents data to the brain unit in a machine-readable form.
Key
board
The
keyboard is very much like a standard typewriter keyboard with a few additional
keys. The additional keys are included to perform certain special functions
such as loading a program, edition a text, etc. These are known as function
keys that vary in number from system to system.
Mouse
Mouse is a
device that controls the movement of the cursor or pointer on a display screen.
As you move the mouse, the pointer on the display screen moves in the same
direction. Mouse contains at least one button and sometimes as many as three,
which have different functions depending on what program is running.
OUTPUT DEVICES
Output
devices receive information from the CPU and present it to the user in the
desired form. Output devices include
display screen, loudspeakers, printers, plotters, etc.
1. Visual
Display Screen: It
is the standard output device which is similar to a television screen. It
displays the characters. The user can
read the program line by line and make corrections before it is stored or
printed on a printer. The cursor on the
screen is controlled by the cursor keys on the keyboard. It has following
different types:
v
CRT (Cathode Ray Tube) Monitor: Monochrome
i.e., two Color only and the color monitor
v
LCD (Liquid Crystal
Display) Monitor
v
TFT (Thin Film Transistor) Monitor
v
LED (Light Emitting
Diode) Monitor
Printer
It is an
output device which is used to see the results on a paper and prints text or
illustrations on paper and in many cases on transparencies and other media.
When the printer receives the electrical signal it converts each string in the
code into the corresponding letter or number and types the character. The
result is called HARD COPY. Wide range of printers varying in quality and speed
are available. Some of the popular types are dot matrix, daisy wheel, line,
laser printer. A printer is either Impact or Non-Impact.
Impact Printer:
Any printer which produces lot of noise pollution, use
mechanical components like wheels and pins etc is called Impact Printer. It
also consumes more electricity.
Non-Impact Printer: Any
printer which produces no noise pollution, use electro-mechanical components
like electronic-circuits and Microprocessor etc is called Non-Impact Printer.
It consumes negligible amount of electricity. In terms of the technology
utilized, printers fall into the following categories.
TYPES OF SOFTWARE
System software:
It is also the set of program,
which are necessary for the computer system itself. The system software helps
the user to actually operate the computer system. It is responsible to make the
computer system operational and to control, operate and to manage the
peripheral devices.
Categories of system software
are:
1.
Operating system: - ms-dos, window, Linux, Unix
2.
Language translator: - compiler and interpreter
3.
Device driver: - mouse, keyboard, monitor, printer,
web camera
4.
Tools and utilities: - virus scanner
5.
Communication Protocols: TCP/IP, SMTP, Telnet
Application software
It is also the set of programs designed
and developed to solve one specific problem in our day-to-day life. Such as
word brain software, graphics or spreadsheet analysis.
Categories
of Application software are:
1.
Pre-written
application software: - It is generally the integrated software suit, which is
available in market as the readymade or already designed application software.
e.g. - Ms-dos, e-mail program, web browser, and 2d/3d drawing program.
2. Customized application software: - When the user designed and
developed the software for him for the specific problem. It is called
customized or tailored application software. e.g., payroll system, library
information system, banking transaction system, hospital information system,
examination and result brain system.
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