BASIC COMPONENTS OF COMPUTER
There are three basic Functional
Unit / Elements of a computer.
- Input Unit.
- Processing Unit.
- Output Unit.
Input Unit
The devices through which we enter
data and instruction (Programs) into computer is called input devices. e.g.
Keyboard, Mouse, Scanner, Digital Camera etc.
Central Processing Unit
Central processing unit (CPU) of a
computer admin section. It is the brain of computer. CPU is located on
motherboard. Data passes through CPU continually. Data come from RAM and other
unit such as keyboard and drivers. The CPU processes the data and sends it back
to RAM and other units. CPU all the input, output and storage devices connected
to and controls all functions of these devices. CPU receives data from input
devices perform data processing and output devices sends the result of the
count data. The CPU is a combination of two units.
- Control Unit :- Control
Unit is the nerve center of the computer. It controls all activities of
computer system. The control unit direct and coordinate the entire
Computer System in carrying out program instruction. It accepts data from
input device and sends it to the memory. Memories data are then send the
result to the output unit ALU.
- Arithmetic and Logic Unit (ALU) :- This is the calculation section Computer. All arithmetic
operation like addition subtraction, multiplication, and division as well
as some logical operation are performed in this section. It consists of
two units a- Arithmetic Unit b- Logic Unit.
- Arithmetic Unit :- Arithmetic Unit of the ALU performs basic
arithmetic function as addition such as addition, subtraction,
multiplication and division.
- Logic Unit :- Logic Unit of the ALU performs logical operation like comparing two data items to find which data item is greater than, equal to or less than the other.
STORAGE UNIT (Primary Memory
The memory is stored in the
processing space where computer programs and data. It is a temporary storage
unit for memory information, instructions and information. The storage unit is
often called main storage or internal storage or primary storage. Usually there
are two types of primary storage.
- RAM :-
It stands for Random Access Memory or read / write Memory because information can either be read from or written to RAM. RAM is called volatile or semiconductor memory. This is the memory whose or semiconductor memory. It is memory which can be erased or changed. It is temporary memory. Anything stored in RAM is lost when Computer is switched off. - ROM :-
It stands for Read Only Memory. Information ROM can be read but can not write the information. It is memory that cannot be changed information. If we turn off the computer, the information stored in it cannot be lost. ROM is used to store permanent program. This informatics’ available on small pieces of the memory called chips. If we turn off the computer, the information stored in it cannot be lost.
OUTPUT UNIT
The user is called production unit
output device used to display information. An output device can be used to
store, display or print the information. e.g. monitor, printer, speaker etc.
Input Device :-
We called the device through which data and instructions in a computer input
device. There are many devices for input. These devices of a digital Computer
are responsible for accepting programs and data from the outside world, feeding
it to the computer memory. These devices work in micro-processor control. Below
are some of the popular input devices, keyboard, mouse scanner, microphone,
video camera, touch screen, and optical scanning.
Key Board :-
This key is a very common input tool
that helps in the necessary information in the computer. The keyboard can be
used effectively to communicate with the computer input device, but it is very
slow. The keyboard is just like a typewriter in shape but enhance than that. It
consists of normal Alphabetic, numeric, functions & other special
characters or control keys, which are not available in a typewriter.
1.
Pointing
Devices :-
Used to control a pointer on the screen is called using an input device
indicating devices. A pointer is a small icon that appears on the screen in the
graphical user interface. Some example of pointing devices is Mouse. Track
ball, joy stick etc.
o
MOUSE :-
A mouse is a quick input device and is very small in size. The mouse is moved
on a flat surface to control the movement of a cursor on a screen (pointer). A
mouse usually has two buttons & one scroll ball. These buttons are used to
perform various functions.
o
THE
TRACKBALL :-
The track ball is often used in place the mouse pointing devices. A trackball
(inverted) device related to the mouse. It's a ball over and you can spin with
your hand directly to the ball. The trackball is used in laptop computer. No
need of mouse pad for track ball.
2.
TOUCH SENSITIVE SCREENS
:-
Touch screen finger touch is a video display screen that get their input. The
screen is covered with a layer of plastic. Behind the scenes there are
invisible beam of infrared light. The user enters data by touching icons. or menus
on the screen. Most touch screen computer use sensors to detect a finger touch.
3.
PEN -
BASED COMPUTING (LIGHT PEN) :-
Do not enter data into the computer via a video screen pen-based devices use
the optical circuit. A user on a display, light-sensitive pen can write the
user sends specially designed pen touch screen parts information to the
computer. Light pens are commonly used by engineers, graphic designers, and
illustrators.
4.
VOICE
RECOGNITION :-
The voice recognition device is used to convert spoken data directly into
electronic from a computer system. Voice recognition and voice response is the
easiest way for data entry and conversational. The microphone is connected to
the computer with voice support. The capability of a computer to distinguish
spoken works is called voice recognition or speech recognition. Voice input is
a fast way of entering data. Much word processing application. Provide the
facility of voice input. The user speaks in microphone and the application
software writes the spoken words as a text. Speech microprocessors toys,
calculators, tools, automobiles, and other users can find, commercial, and
industrial product type.
5.
SCANNER :-
Scanner is Optical character recognition equipment that can read special - purpose
characters and codes. The scanner provides a way to insert data directly from
source documents into a computer system. There are many types of optical
readers, but they all use photoelectric devices to scan the readable
characters. Data light patterns electronic impulses, which are then reflect the
change to be accepted as input into the computer system. OCR-based optical
scanning systems are widely used in credit card billing operations of credit
card companies, banks and oil companies.
6.
MICROPHONE
:-
This is an input device that is used for keyboard and voice input instead of
using the mouse. Special software place of using the keyboard and mouse.
Special software is used to convert voice into test. This fast processing and a
lot of memory and will become more common as technology improved. The
microphone converts the digital audio signal
7.
VIDEO
CAMERAS :-
The video camera is an input device that is capable of capturing any kind of
data images. Most scanners incorporate a special type of camera that is made up
of a charge-coupled device (CCD). Each CCD receives light from the image and
the light generates an electric charge. This means that the image dots represent
light areas and dark areas of the charged cells of the non-charged cells.
8.
DIGITAL
CAMERA :- Digital Camera is used to take
and store picture in digital form. It does not use traditional camera film. It
save money and the photos can be customizing using different application
software. Digital cameras store pictures using different techniques like floppy
disks. Super disk, PC card. Compact flash card, memory stick and micro drive. Through
the digital camera's USB port can be easily connected to a computer.
OUTPUT DEVICES
Device information is a process by
which output devices to the outside world. To print to an output device or
information can be used. (e.g. monitor, printer, plotter, speaker).
MONITOR:-
A TV like device that is used by the Computer for displaying the information to
the outside sued is known as CRT or VDU or more simply a Computer Screen. The
monitor is basically glass cone, the cone back and which contains special
electron guns to hit the screen with different colors to create text or graph.
Monitors / Screens can be selected on the basis of user requirements. The
following are the different types of monitors.
MONOCHROME MONITOR:-
Monochrome means one color. Monochrome displays images in a single color,
usually white or blue display. Normally Monochrome is any monitor that cannot
display colors. They can be black and white type but they are often available
in green colors because green color is easier to eyes. A Monochrome monitor
usually cannot display graphics. But then monitors the technique was developed
to have graphics capability.
COLOR MONITOR:-
Color monitor display output in different color. Graphics, picture4 and
colorful images are best viewed in colorful images are best viewed in color
monitor.
FLAT PANEL OR LCD MONITORS :-
Laptop PCs use flat-panel monitors. These monitors take less space. Use a
variety of flat panel monitor technology. The most common is LCD (Liquid
Crystal Display), LCD monitor use much less power than manual monitor. The LCD
monitor is generally transparent but produces images with a special type of
liquid crystal that becomes solid when charged electrically.
PRINTERS :-
Role of printer paper, logos, and graphics output device that prints. Hard copy
is the printed output. Generally inch print resolution (DPI) is measured in
dots per. Many types of printers vary in speed and quality. Different types of
printers as follow
1.
Impact Printers.
2.
Non-Impact Printers.
IMPACT PRINTER :-
Impact printer works like a typewriter. It can kill a print hammer or wheel
against an inked ribbon or images in print. Impact printers are the following
- DOT-MATRIX PRINTER :- Dot Matrix printer produce prenticed images when
tiny pins on a print head strikes an inked ribbon. Press the ribbon
against the paper, it creates dots that form characters and graphics. The
dot matrix printer head contain 9 to 24 pins. It depends on the printer
model number and manufacture of pins. A number of pins that have more dots
print high-quality output. 150 DPI affordable dot matrix printer uses 100.
His speed is 200 to 300 characters per minute. 300 DPI printers are
expensive and speed from 1000 to 3000 characters per minute.
- DAISY-WHEEL PRINTERS :- Daisy wheel is similar to type writer. As dot
matrix printer rather than create excellent letter quality printout. They
work just like a typewriter and using a hammer and a wheel to print
anything on paper. But they are very noisy and therefore are not so
popular. Impact Printers other so-called non-impact printers.
NON-IMPACT PRINTER
Non-Impact Printer Paper produces
character without striking devices. They are much quieter than impact printer.
The following are the non-impact printer.
- LASER PRINTERS :- The most expensive and quality bearer printers are the
laser printers, which produce high quality printout and are used for
desktop publishing and graphics. A laser printer works on the principles
of a photocopy. Only the toner is loaded with a special metal drum, and
thus the printed ink splashed on paper only. They use multiple fonts for
text and graphics as well as fast in work. Apart from these there are now
color printers available in dot matrix as well as laser printers and all
the others as well.
- INK JET :- It
prints character and graphics by spraying tiny drops of liquid in on
paper. It can create both text and graphics in black and white and color
printers. Inkjet printer is slower than laser printer. They can print from
1 to 6 pages per minute. The higher print quality dot matrix printer. And
the use of a black ink Color: Most inkjet printers usually have two print
cartridges.
PLOTTERS
In a variety of color plotter is an output device that is used to create
photo-quality graphics. Plotter works by drawing lines on paper using a
mechanical arm holding pen. They are mostly used for engineering drawings and
Maps purposes.
SPEAKER 7 HEADSET
The speaker is an output device for producing audio. These devices are music,
speech, or beep speaker and headset etc. The two commonly used audio output
devices such as a second voice. It produces soft copy output. We use the speaker
to listen to any sound.
STORAGE DEVICE
The device in which we store the data and information is called storage
devices. there are two types of storage device.
- Main / Primary Storage Devices.
Rom - Secondary Storage Devices.
Hard Disk, Floppy Disk, Flash Drive, USB etc.
Main / Primary Memory or Internal Memory :-
The Main memory (Primary Memory) of CPU is they place where the
computer program and data are stored during processing. This storage unit is
often called either central storage or internal storage or primary storage.
- RAM :- It stands
for Random Access Memory or write/read memory because information can
either be read from or written to the RAM. It is memory which can be
erased or changed. It is temporary memory. Stored in RAM is lost when the
computer is off anything.
- ROM :- It stands
for Read Only Memory. Information can be read from ROM but we cannot write
or change information to it. It is memory that cannot be changed
information. We cannot lose the information stored in the computer, then
turn off. ROM is used to store permanent program. This information is
available on small pieces of memory chips called.
Secondary / Auxiliary / External
Memory (Storage) :-
A computer device such as software
and data store information that is permanently called secondary storage. Disk
can store a large amount of data can be obtained and where it is, where it is a
secondary storage device. It has different types e.g. H.DD., CD-ROM, Removable Disk,
Magnetic Tape etc.
Following are the Secondary Storage Devices:
- Magnetic Disk:-
The Magnetic Disk is made up of one or more rotating platters, on which data is stored magnetically. It is made from coated on both sides with a magnetic object that iron oxide plastic. We have two main types of Magnetic Disk, which is used in computer, i.e. Floppy Disk and Hard Disk. - Hard Disk:-
It made up of one or more rotating platter, which is enclosed with magnetically object that is iron oxide. This circular object that metallic ally iron oxide. It is a circular metal plate is completely sealed off as relatively thick in size and permanently. Date is recorded on magnetic plates. - Floppy Disk: -
It is a removable Plastic Disk. It is not fixed in the computer. The object of the magnetically encoded with the iron oxide. Hard disk storage capacity is less. You must have a floppy disk drive to use a floppy disk. You must have a floppy disk drive to use a floppy disk. Floppy disk drives are used for A & B.
- OPTICAL DISK STORAGE :-
Optical Disk is the fast growing storage medium. CD-ROM is Optical disk. Compact Disk Read Only Memory is known as CD-ROM. CD-ROM technology uses 12 centimetre (4.7 Inches) compact disk similar to those used in stereo music system. It is the latest invention. It is so called CED-ROM because the information may be just read from it but not written down. A CD-ROM can store up to 840 megabytes of data. We run CD through CD Rom. You must use the CD-ROM to a CD. Other optical disk technology produces WORM (Write Once Read Many) and CD-R (CD Record able) disk. CD-ROM, CD-R, and the worm drive is important that the recorded data cannot be erased. However erasable optical disk system is also available (CD-RW). CD-RW provides full re-writable capabilities. This technology record and erases data by using a laser to heat a microscopic point of the disk surface. In some version, a magnetic coil changes the spot reflective property from one direction to another, thus recording a binary one or zero (1 or 0), a laser device can then read the binary code on the disk by sensing the direction of reflected light. The newest optical disk is digital video disk (DVD) or digital versatile disk provide to large amount of data and transferring data on higher speed (up to 12MBps). Digital Video Disks are designed to work with a video player and television. - MAGNETIC TAPE: -
Magnetic Tape is a flexible plastic tape, coated on one side with magnetic iron oxide material. It is used when large amounts of data are to be processed sequentially. An advantage of magnetic tape is that is very cheap and economical storage medium but very slow in processing. - MAGNETIC DRUM: -
It is therefore a rotatable cylinder whose surface is coated with a magnetically sensitive iron oxide compound. A number of the tracks, each track is divided into one or more of the reading and recording heads it. Magnetic drums are commonly used when very fast access and transfer speeds are required. There is one disadvantage is that they cannot be removed from the unit. - FLASH MEMORY: -
Now a day the latest and modem storage device is flash memory or USB is used as a secondary storage device. It is semiconductor memory. This RAM is the same as ROM in circuitry. It is used as secondary storage for moving data.