Computer Fundamental with all input output devices with image

1. What is Computer?
Definition of Computer : Computer is an electronic device that is designed to work with
Information. The term ‘computer is derived from the Latin term ‘computer’, this means to
calculate. Computer can not do anything without a Program. it represents the decimal
numbers through a string of binary digits. The Word 'Computer‘ usually refers to the Center
Processor Unit plus Internal memory.
Charles Babbage is called the "Grand Father" of the computer. The First mechanical
computer designed by charles Babbage was called Analytical Engine. It uses read-only
memory in the form of punch cards.
Four Functions about computer are:
accepts data  Input
processes data  Processing
produces output  Output
stores results  Storage
Input:- Input is the raw information entered into a computer from the input devices. It is the
collection of letters, numbers, images etc.
Process:- Process is the operation of data as per given instruction. It is totally internal
process of the computer system.
Output:- Output is the processed data given by computer after data processing. Output is
also called as Result. We can save these results in the storage devices for the future use.
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2. Input devices enable a user to input
data and commands to the computer
to be processed.
Keyboard :- a keyboard is a typewriter-style keyboard, which uses an
arrangement of buttons or keys, to act as mechanical levers or electronic
switches. Following the decline of punch cards and paper tape, interaction via
teleprinter-style keyboards became the main input device for computers.
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3. The mouse is a pointing device that rolls around on a flat surface and
controls the location of the pointer on the screen.
The mouse performs the following functions:
Pointing: Placing the on-screen pointer at a specific place
Clicking: Pressing and releasing the mouse button
Dragging: Holding down the mouse button and dragging an object
to a new location by dragging the mouse
Double-clicking: Pressing and releasing the mouse button twice
very quickly
Right-clicking: Pressing the right mouse button
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4. Trackball: This is like a mouse turned upside
down. You roll a ball around with your fingers to
control the location of the pointer.
Biometric input: Uses fingerprint, face,
handwriting, and voice for identification.
Scanner:- Devices that can convert a graphical image into a digital
image and input it to the computer.
BCR
HAND HELD
Retina Scanner By

5. Digital cameras: Used to take pictures
and store them on a magnetic disk
instead of on film
Their images can be input directly
into the computer.
Video input: Input from a camcorder
or VCR using video capture cards
WEBCAMERA:- A video camera that
inputs to a computer connected to the
Internet, so that its images can be seen
by Internet users.
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6. Closed-circuit Television (CCTV):- Cameras can
produce images or recordings for surveillance
purposes, and can be either video cameras, or
digital stills cameras. Marie Van Brittan Brown was
the inventor of the CCTV camera.
Touch Screen:- A touch screen is an electronic visual display that
can detect the presence and location of a touch within the
display area. The term generally refers to touching the display of
the device with a finger or hand.
LIGHT PEN :- A Light Pen is a pointing device shaped like a pen
and is connected to a VDU.
The tip of the light pen contains a light-sensitive element
which, when placed against the screen, detects the light from the
screen enabling the computer to identify the location of the pen on
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7. Joystick:- A joystick is an input device consisting of a stick that
pivots on a base and reports its angle or direction to the device it is
controlling. Joysticks, also known as 'control columns', are the
principal control in the cockpit of many civilian and military aircraft,
either as a center stick or side-stick. They often have supplementary
switches on them to control other aspects of the aircraft's flight.
Micro Phone:- A microphone is an example of a transducer, a device
that changes information from one form to another. Sound
information exists as patterns of air pressure; the microphone
changes this information into patterns of electric current. The
recording engineer is interested in the accuracy of this
transformation, a concept he thinks of as fidelity.
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8. Monitor:- Alternatively referred to as a video display terminal (VDT) and video
display unit (VDU), a monitor is a video display screen and the hard shell that
holds it. In its most common usage, monitor refers only to devices that contain no
electronic equipment other than what is essentially needed to display and adjust
the characteristics of an image
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9. What is a printer?
A printer is an output device that produces text and graphics on
paper.
Type of Printer
1. Dot Matrix:- The term DOT matrix refers to the process of placing dots
to form an image; the quality of the image being determined by the dots
per inch.
Dot matrix printers were first introduced by Centronics in 1970
and is a printer that uses print heads to shoot ink or strike an ink ribbon to
place hundreds to thousands of little dots to form text or images. Today
dot matrix printers are rarely used or found because of the low quality
print outs when compared to ink jet printers or other later printer
technologies
1. Inkjet Printer:- The most popular printer for home computer
users that prints by spraying streams of quick-drying ink on paper.
The ink is stored in disposable ink cartridges, often a separate
cartridge is used for each of the major colors. These colors are
usually Black, Red/Magenta, Green/Cyan, and Yellow (CYMK). In
the picture to the right, is an example of a computer inkjet printer.
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10. 3. Ledger Printer:- First developed at Xerox PARC by Gary Starkweather
and released in 1971, a laser printer is a printer that utilizes laser
technology to print images on the paper. Laser printers are often used in
corporate, school, and other environments that require print jobs to be
completed quickly and in large quantities. In the picture to the right, is an
example of what a laser printer may look like. This picture is of the
Lexmark C782n laser printer and as can be seen much larger than an ink
jet printer found in most homes. Finally, below is a chart of the steps a
laser printer takes to print.
4. Thermal Printer:- Traditional thermal printers use direct thermal
method by pushing electrically heated pins against heat-sensitive paper
(thermal paper). The coating on the thermal paper turns black in the
areas where it is heated, producing characters or images. Direct
thermal printers have no ink, toner or ribbon. These printers are
durable, easy to use and cost less to print than other
printers. However, the thermal paper is sensitive to heat, light, water,
and abrasion and the text and images may fade over time.
Line Printers:- Line Printer can Print One Line at a Time. The line
printer is a form of high speed impact printer. They can Print 300 to
3000 Lines per Minute. So that they are very fast. Large Computer
system typically use Line Printer. The Line Printers are of two Types.
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11. Chain Printers:- These are also Line Printers, which Prints one Line at a
Time. All the Characters are printed on the Chain and the Set of
Characters are placed on the Chain. There are 48 and 64 and 96
Characters set Printers are Available. There are also Some Hammers,
those are Placed in Front of the Chain, and Paper is Placed between
the Hammer and the Inked Ribbon. The Total Number of Hammers will
be Equals to the Total Number of Print Positions.
plotter Printer:- The plotter is a computer printer for
printing vector graphics. In the past, plotters were
used in applications such as computer-aided design,
though they have generally been replaced with wide-
format conventional printers. It is now commonplace
to refer to such wide-format printers as "plotters,"
even though they technically are not.
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12. Type of Computer
Analog Computers:-
An analog computer (spelt analogue in British English) is a form
of computer that uses continuous physical phenomena such as
electrical, mechanical, or hydraulic quantities to model the
problem being solved.
Digital Computer:-
A computer that performs calculations and logical operations
with quantities represented as digits, usually in the binary
number system.
Hybrid Computer (Analog + Digital) :-
A combination of computers those are capable of inputting and
outputting in both digital and analog signals. A hybrid computer
system setup offers a cost effective method of performing
complex simulations.
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13. On the basis of Size
Micro Computers:-
The invention of microprocessor (single chip CPU) gave birth to the much
cheaper micro computers. They are further classified into
•Desktop Computers Laptop Computers Handheld
Computers(PDAs)
Desktop Computers:-
Today the Desktop computers are the most popular computer systems.
These desktop computers are also known as personal computers or simply
PCs. They are usually easier to use and more affordable. They are
normally intended for individual users for their word processing and other
small application requirements.
Laptop Computers:-
Laptop computers are portable computers. They are lightweight
computers with a thin screen. They are also called as notebook computers
because of their small size. They can operate on batteries and hence are
very popular with travelers. The screen folds down onto the keyboard
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14. Handheld Computers:-
Handheld computers or Personal Digital Assistants (PDAs) are pen-based and also
battery-powered. They are small and can be carried anywhere. They use a pen like
stylus and accept handwritten input directly on the screen. They are not as
powerful as desktops or laptops but they are used for scheduling appointments,
storing addresses and playing games. They have touch screens which we use with a
finger or a stylus.
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15. Generation of Computer:-
Each generation of computer is characterized by a major technological
development that fundamentally changed the way computers operate,
resulting in increasingly smaller, cheaper, more powerful and more efficient
and reliable devices.
The various generations of computers an listed below :-
(i) First Generation (1946-1954) : In 1946 there was no 'best' way of storing
instructions and data in a computer memory. There were four competing
technologies for providing computer memory: electrostatic storage tubes,
acoustic delay lines (mercury or nickel), magnetic drums (and disks?), and
magnetic core storage.
Example: ENIAC, UNIVAC, IBM 650 etc
(ii) Second Generation (1955-1964) : The second-generation computer used
transistors for CPU components & ferrite cores for main memory &
magnetic disks for secondary memory. They used high-level languages such
as FORTRAN (1956), ALGOL (1960) & COBOL (1960 - 1961). I/O processor
was included to control I/O operations.
1. IBM 1620: Its size was smaller as compared to First Generation computers
and mostly used for scientific purpose.
2. IBM 1401: Its size was small to medium and used for business
applications.
3. CDC 3600: Its size was large and is used for scientific purposes.
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16. (iii) Third Generation (1964-1977) : By the development of a small chip
consisting of the capacity of the 300 transistors. These ICs are popularly known as
Chips. A single IC has many transistors, registers and capacitors built on a single
thin slice of silicon. So it is quite obvious that the size of the computer got further
reduced. Some of the computers developed during this period were IBM-360, ICL-
1900, IBM-370, and VAX-750. Higher level language such as BASIC (Beginners All
purpose Symbolic Instruction Code) was developed during this period. Computers
of this generation were small in size, low cost, large memory and processing speed
is very high. Very soon ICs Were replaced by LSI (Large Scale Integration), which
consisted about 100 components. An IC containing about 100 components is called
LSI.
(iv) Fourth Generation : An IC containing about 100 components is called LSI
(Large Scale Integration) and the one, which has more than 1000 such components,
is called as VLSI (Very Large Scale Integration). It uses large scale Integrated
Circuits (LSIC) built on a single silicon chip called microprocessors. Due to the
development of microprocessor it is possible to place computer’s central
processing unit (CPU) on single chip. These computers are called microcomputers.
Later very large scale Integrated Circuits (VLSIC) replaced LSICs. Thus the computer
which was occupying a very large room in earlier days can now be placed on a
table. The personal computer (PC) that you see in your school is a Fourth
Generation Computer Main memory used fast semiconductors chips up to 4 M bits
size. Hard disks were used as secondary memory. Keyboards, dot matrix printers
etc. were developed. OS-such as MS-DOS, UNIX, Apple’s Macintosh were available.
Object oriented language, C++ etc were developed.
Example: IBM PC, Apple-Macintosh etc.
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17. (v) Fifth Generation (1991- continued) : 5th generation computers use
ULSI (Ultra-Large Scale Integration) chips. Millions of transistors are placed
in a single IC in ULSI chips. 64 bit microprocessors have been developed
during this period. Data flow & EPIC architecture of these processors have
been developed. RISC & CISC, both types of designs are used in modern
processors. Memory chips and flash memory up to 1 GB, hard disks up to
600 GB & optical disks up to 50 GB have been developed. fifth generation
digital computer will be Artificial intelligence.
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18. Memory:- This is very fast storage used to hold data. It has to be fast
because it connects directly to the microprocessor. There are several
specific types of memory in a computer.
Type of Memory
1. Cash Memory:- The cache is a smaller, faster memory which stores
copies of the data from the most frequently used main memory
locations.
2. Primary Memory:- Primary storage (or main memory or internal
memory), often referred to simply as memory, is the only one directly
accessible to the CPU. The CPU continuously reads instructions stored
there and executes them as required. Any data actively operated on is
also stored there in uniform manner.
RAM & ROM
RAM (Random Access Memory): It is used to temporarily store
information that the computer is currently working with.
Type of RAM:-
SRAM: Static random access memory uses multiple transistors,
typically four to six, for each memory cell but doesn't have a capacitor in
each cell. It is used primarily for cache.
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19. DRAM: Dynamic random access memory has memory cells with a
paired transistor and capacitor requiring constant refreshing.
EDO DRAM: Extended data-out dynamic random access memory does
not wait for all of the processing of the first bit before continuing to the
next one. As soon as the address of the first bit is located, EDO DRAM
begins looking for the next bit. It is about five percent faster than FPM.
Maximum transfer rate to L2 cache is approximately 264 MBps.
SDRAM: Synchronous dynamic random access memory takes
advantage of the burst mode concept to greatly improve performance. It
does this by staying on the row containing the requested bit and moving
rapidly through the columns, reading each bit as it goes. The idea is that
most of the time the data needed by the CPU will be in sequence. SDRAM
is about five percent faster than EDO RAM and is the most common form
in desktops today. Maximum transfer rate to L2 cache is approximately
528 MBps
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20. ROM (Read Only Memory) ROM is a class of storage medium used in
computers and other electronic devices. Data stored in ROM cannot be
modified, or can be modified only slowly or with difficulty, so it is mainly used
to distribute firmware (software that is very closely tied to specific hardware,
and unlikely to need frequent updates).
Type of Read only Memory (ROM)
Programmable read-only memory (PROM), or one-time programmable
ROM (OTP), can be written to or programmed via a special device called a
PROM programmer. Typically, this device uses high voltages to permanently
destroy or create internal links within the chip. Consequently, a PROM can
only be programmed once.
Erasable programmable read-only memory (EPROM) can be erased by
exposure to strong ultraviolet light (typically for 10 minutes or longer), then
rewritten with a process that again needs higher than usual voltage applied.
Repeated exposure to UV light will eventually wear out an EPROM, but the
endurance of most EPROM chips exceeds 1000 cycles of erasing and
reprogramming. EPROM chip packages can often be identified by the
prominent quartz "window" which allows UV light to enter. After
programming, the window is typically covered with a label to prevent
accidental erasure. Some EPROM chips are factory-erased before they are
packaged, and include no window; these are effectively PROM.
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21. Electrically erasable programmable read-only memory (EEPROM) is based
on a similar semiconductor structure to EPROM, but allows its entire contents
(or selected banks) to be electrically erased, then rewritten electrically, so
that they need not be removed from the computer (or camera, MP3 player,
etc.). Writing or flashing an EEPROM is much slower (milliseconds per bit)
than reading from a ROM or writing to a RAM (nanoseconds in both cases).
Type of Electrically Erasable Programmable Read only memory
Electrically alterable read-only memory (EAROM) is a type of EEPROM that
can be modified one bit at a time. Writing is a very slow process and again
needs higher voltage (usually around 12 V) than is used for read access.
EAROMs are intended for applications that require infrequent and only partial
rewriting. EAROM may be used as non-volatile storage for critical system
setup information; in many applications, EAROM has been supplanted by
CMOS RAM supplied by mains power and backed-up with a lithium battery.
Flash memory (or simply flash) is a modern type of EEPROM invented in
1984. Flash memory can be erased and rewritten faster than ordinary
EEPROM, and newer designs feature very high endurance (exceeding
1,000,000 cycles). Modern NAND flash makes efficient use of silicon chip
area, resulting in individual ICs with a capacity as high as 32 GB as of 2007;
this feature, along with its endurance and physical durability, has allowed
NAND flash to replace magnetic in some applications (such as USB flash
drives). Flash memory is sometimes called flash ROM or flash EEPROM when
used as a replacement for older ROM types, but not in applications that take
advantage of its ability to be modified quickly and frequently.
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22. Secondary Memory:- Secondary storage (also known as external memory
or auxiliary storage), differs from primary storage in that it is not directly
accessible by the CPU. The computer usually uses its input/output
channels to access secondary storage and transfers the desired data using
intermediate area in primary storage. Secondary storage does not lose the
data when the device is powered down—it is non-volatile. Per unit, it is
typically also two orders of magnitude less expensive than primary
storage. Consequently, modern computer systems typically have two
orders of magnitude more secondary storage than primary storage and
data are kept for a longer time there.
Type of Secondary Memory
A) A hard disk drive (HDD; also hard drive, hard disk, or disk drive) is a
device for storing and retrieving digital information, primarily
computer data. It consists of one or more rigid (hence "hard") rapidly
rotating discs (platters) coated with magnetic material, and with
magnetic heads arranged to write data to the surfaces and read it
from them.
B) A floppy disk is a disk storage medium composed of a disk of thin and
flexible magnetic storage medium, sealed in a rectangular plastic
carrier lined with fabric that removes dust particles. They are read and
written by a floppy disk drive (FDD)
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23. C) CD-ROMs are popularly used to distribute computer software, including
video games and multimedia applications, though any data can be stored
(up to the capacity limit of a disc). Some CDs hold both computer data
and audio with the latter capable of being played on a CD player, while
data (such as software or digital video) is only usable on a computer (such
as ISO 9660 format PC CD-ROMs). These are called enhanced CDs.
D) DVD is an optical disc storage format, invented and developed by
Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage
capacity than Compact Discs while having the same dimensions.
E) Magnetic tape data storage uses digital recording on to magnetic tape
to store digital information. Modern magnetic tape is most commonly
packaged in cartridges and cassettes. The device that performs actual
writing or reading of data is a tape drive. Autoloaders and tape libraries
are frequently used to automate cartridge handling.
BIOS(Basic input/output system): A type of ROM that is used by the
computer to establish basic communications when the computer is first
turned on caching-The storing of frequently used data in extremely fast
RAM that connects directly to the CPU.
Virtual Memory: space on hard disk used to temporarily store data and
swap it in and out of RAM as needed.
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24. What is Networking?
In the world of computers, networking is the practice of linking two or more
computing devices together for the purpose of sharing data. Networks are built
with a mix of computer hardware and computer software.
TYPE OF NETWORKING
LAN - Local Area Network
A LAN connects network devices over a relatively short distance. A
networked office building, school, or home usually contains a single LAN,
though sometimes one building will contain a few small LANs (perhaps one per
room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP
networking, a LAN is often but not always implemented as a single IP subnet.
WLAN - Wireless Local Area Network
As the term implies, a WAN spans a large physical distance. The Internet is the
largest WAN, spanning the Earth. A WAN is a geographically-dispersed
collection of LANs. A network device called a router connects LANs to a WAN. In
IP networking, the router maintains both a LAN address and a WAN address
WAN - Wide Area Network
A WAN spans a large geographic area, such as a state, province or country.
WANs often connect multiple smaller networks, such as local area networks
(LANs) or metro area networks (MANs).
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25. MAN - Metropolitan Area Network
Metropolitan Area Network - A network spanning a physical area
larger than a LAN but smaller than a WAN, such as a city. A MAN is
typically owned an operated by a single entity such as a
government body or large corporation.
SAN - Storage Area Network, System Area Network, Server Area
Network, or sometimes Small Area Network
Connects servers to data storage devices through a
technology like Fibre Channel.
CAN - Campus Area Network, Controller Area Network, or
sometimes Cluster Area Network
A network spanning multiple LANs but smaller than a
MAN, such as on a university or local business campus.
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26. What is a window?
A window is an area on your desktop within which all Windows-based programs run.
What is a desktop?
When you start your computer, the first thing you see is the desktop. The desktop is your
work area.
How do I shut down my computer?
Click the Start button. The Start menu will appear.
Click Turn Off Computer. The Turn Off Computer dialog box will appear.
Click the Turn Off icon. Your computer will shut down.
How do I restart my computer?
You may need to shut down and restart your computer after installing a new program or if
your system becomes unstable. To shut down and immediately restart your computer:
1. Click the Start button. The Start menu will appear.
2. Click Turn Off Computer. The Turn Off Computer dialog box will appear.
3. Click the Restart icon. Your computer will restart.
What is Standby mode?
When your computer is in the Standby mode, your computer consumes less electricity,
but is ready for immediate use. However, if the computer loses electrical power while in
the standby mode, any information you have not saved will be lost
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27. What is Windows Explorer?
Windows Explorer is a place where you can view the drives on your computer and
manipulate the folders and files. Using Windows Explorer, you can cut, copy, paste,
rename, and delete folders and files.
What is the Most Recently Used Document list?
As you work, Windows XP tracks the last 15 files you used. It lists these files on the Most
Recently Used Document list. To view the Most Recently Used Document list:
1. Click the Start button.
2. Highlight Documents. The most recently used documents will display.
3. To open a file listed on the Most Recently Used Document list, click the file name.
How do I clear my Most Recently Used Document list?
1. Click the Start button. The Start menu will appear.
2. Highlight Settings.
3. Click Taskbar and Start menu. A dialog box will appear.
4. Click the Start Menu tab.
5. Click Customize.
6. Click Clear.
7. Click OK.
8. Click OK again.
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