Computer Hardware and Networking - Webnet Computers

Computer

Hardware

and

Networking By Vishwaranjan Pathik.

1Made By:- VISHWARANJAN PATHIK

2

FULL FORM OF COMPUTER

C-CommonO-OperatingM-Machine P-Particularly U-used for T-Technological E-Engineering R-Research.

Made By:- VISHWARANJAN PATHIK

DEVELOPMENT OF COMPUTERActually speaking electronic data processing does not go back more than just half a centaury i.e. they are in existence merely from early 1940’s. In early days when our ancestor used to reside in cave the counting was a problem. Still it is stated becoming difficult.When they started using stone to count their animals or the possession they never knew that this day will lead to a computer of today. People today started following a set of procedure to perform calculation with these stones, which later led to creation of a digital counting device, which was the predecessor the first calculating device invented, was know as ABACUS.

THE ABACUSAbacus is known to be the first mechanical calculating device. Which was used to be performed addition and subtraction easily and speedily? This device was a first develop Ed by the Egyptians in the 10th century B.C, but it was given it final shape in the 12th century A.D. by the Chinese educationists.Abacus is made up of wooden frame in which rod where fitted across with rounds beads sliding on the rod. It id dividing into two parts called ‘Heaven’ and ‘Earth’. Heaven was the upper part and Earth was the lower one. Thus any no. can be represented by placing the beads at proper place.

3Made By:- VISHWARANJAN PATHIK

NAPIER’S BONESAs the necessity demanded, scientist started inventing better calculating device. In thus process John Napier’s of Scotland invented a calculating device, in the year 1617 called the Napier Bones.In the device, Napier’s used the bone rods of the counting purpose where some no. is printed on these rods. These rods that one can do addition, subtraction, multiplication and division easily.

PASCAL’S CALCULATORIn the year 1642, Blaise Pascal a French scientist invented an adding machine called Pascal’s calculator, which represents the position of digit with the help of gears in it.

LEIBNZ CALCULATORIn the year 1671, a German mathematics, Gottfried Leibniz modified the Pascal calculator and he developed a machine which could perform various calculation based on multiplication and division as well.

ANALYTICAL ENGINEIn the year 1833, a scientist form England knows to be Charles Babbage invented such a machine. Which could keep our data safely? This device was called Analytical engine and it deemed the first mechanical computer.It included such feature which is used in today’s computer language. For this great invention of the computer, Sir Charles Babbage is also known as the father of the computer.

4Made By:- VISHWARANJAN PATHIK

First Generation (1940-1956) Vacuum Tubes

ENIAC was the world first successful electronic computer which was develops by the two scientists namely J. P. Eckert and J. W. Mauchy. It was the beginning of first generation computer. The full form of ENIAC is “Electronic Numeric Integrated And Calculator” ENIAC was a very huge and big computer and its weight was 30 tones. It could store only limited or small amount of information. Initially in the first generation computer the concept of vacuum tubes was used. A vacuum tube was such an electronic component which had very less work efficiency and so it could not work properly and it required a large cooling system.

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, the first computers generated a lot of heat, which was often the cause of malfunctions.First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time, and it could take days or weeks to set-up a new problem. Input was based on punched cards and paper tape, and output was displayed on printouts.The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.

5Made By:- VISHWARANJAN PATHIK

FIRST GENERATION COMPUTER

• ENIAC

• UNIAC

6Made By:- VISHWARANJAN PATHIK

Second Generation (1956-1963) TransistorsTransistors replace vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.The first computers of this generation were developed for the atomic energy industry.

7Made By:- VISHWARANJAN PATHIK

Third Generation (1964-1971) Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

8Made By:- VISHWARANJAN PATHIK

9

Name Signification YearTransistors number

[47]

Logic gates number[48]

SSIsmall-scale integration

1964 1 to 10 1 to 12

MSImedium-scale

integration1968 10 to 500 13 to 99

LSIlarge-scale integration

1971 500 to 20,000 100 to 9,999

VLSIvery large-scale

integration1980 20,000 to 1,000,000 10,000 to 99,999

ULSIultra-large-scale

integration1984 1,000,000 and more 100,000 and more

Made By:- VISHWARANJAN PATHIK

Fourth Generation (1971-Present) Microprocessors

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

10Made By:- VISHWARANJAN PATHIK

Fifth Generation (Present and Beyond) Artificial Intelligence

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

11Made By:- VISHWARANJAN PATHIK

Generations of Computers

Generation of computers came into the mind, when humans were unable to perform some large calculations. So they created a calculating machine called as computers. As the needs of humans gone on increasing, there was development in the computer system.

First Generation (Mid 1940's )•Computers were using Vacuum tubes (Valves) as an electronic component.•Machine language was used.•Input was given through punch cards, paper tapes and results in the form of printouts.•Computers were as big as room in size.•Cost was very high.

Second Generation (1956)•Vacuum tubes were replaced by the transistors.•Size of transistors was much smaller than vacuum tubes.•Assembly language was used.•Consumed less power, faster and reliable.•Size of computers were came down.•Price of computers were also reduced

12Made By:- VISHWARANJAN PATHIK

Third Generation (1964)•Integrated Circuits(IC's) made up of small crystal of silicon semiconductor were used.•Structured programming language C and COBOL was used.•Speed and efficiency were increased.•Inputs were given through keyboards and output through monitors.•Size of computers, power consumption, heat generation and cost were decreased in greater extent.

Fourth Generation (1971 and present)•Microprocessor chip were used, made up of thousands of Integrated Circuits build on a single silicon chip.•Object oriented programming language and domain specific language SQL for database access.•High processing speed, high reliability and low power consumption.•Size and cost of computers were cut down.

Fifth Generation (Present and future)•Computers those are dealing with Artificial Intelligence (AI), expert systems and robotics are in 5th generation.•These computers are still in development phase.•Main goal is to respond to the natural language.•Use of Quantum, Molecular and Nano technology is going to change the face of computers in coming years.

13Made By:- VISHWARANJAN PATHIK

14

What is a Computer“A Computer is an electronic machine that can solve different problems, process data,

store & retrieve data and perform calculations faster and efficiently than

humans”.A computer is an electronic device that manipulates

information, or data. It has the ability to store, retrieve, and process data. You may already know that you can use a

computer to type documents, send email, play games, and browse the Web. You can also use it to edit or

create spreadsheets, presentations, and even videos.Made By:- VISHWARANJAN PATHIK

15

Block Diagram of Computer and its Various Components

1) It accepts data or instructions through input,2) It stores data,3) It can process required data by the user,4) It gives results as production, and5) It controls all functions inside the computer

Made By:- VISHWARANJAN PATHIK

16Made By:- VISHWARANJAN PATHIK

17

Computer is an electronic device which performs tasks given by userwith extremely fast speed and accuracy. Like any other device ormachine, a computer system has also a number of parts.A computer system can be blocked into mainly three parts:

1. Input Unit2. Central Processing Unit3. Output Unit

Made By:- VISHWARANJAN PATHIK

Four types of Computers There are many different types of computers to meet our different needs. They are of different sizes, with different capabilities, for different purposes. Some are portable for ease of travel, while others are large enough to handle great amount of data and in formation. 1.Microcomputer 2.Mini Computers 3. Mainframe Computers 4. Supercomputers .

18Made By:- VISHWARANJAN PATHIK

Analog computers•Analog computers use continuous physical magnitudes to

represent quantitative information. At first they represented quantities with mechanical components (see differential

analyzer and integrator), but after World War II voltages were

used; by the 1960s digital computers had largely replaced them.

Nonetheless, analog computers, and some hybrid digital-analog

systems, continued in use through the 1960s in tasks such as

aircraft and spaceflight simulation.

One advantage of analog computation is that it may be relatively

simple to design and build an analog computer to solve a single

problem. Another advantage is that analog computers can frequently represent and solve a problem in “real time”; that is, the

computation proceeds at the same rate as the system being

modeled by it. Their main disadvantages are that analog representations are limited in precision—typically a few decimal

places but fewer in complex mechanisms—and general-purpose

devices are expensive and not easily programmed. 19Made By:- VISHWARANJAN PATHIK

Digital computersIn contrast to analog computers, digital computers represent information in discrete form, generally

as sequences of 0s and 1s (binary digits, or bits). The modern era of digital computers began in the late 1930s and early 1940s in the United States, Britain, and Germany. The first devices used

switches operated by electromagnets (relays). Their programs were stored on punched paper tape

or cards, and they had limited internal data storage. For historical developments, see the

section Invention of the modern computer.

Mainframe computerDuring the 1950s and ’60s, Unisys (maker of the UNIVAC computer), International Business

Machines Corporation (IBM), and other companies made large, expensive computers of

increasing power. They were used by major corporations and government research laboratories,

typically as the sole computer in the organization. In 1959 the IBM 1401 computer rented for $8,000

per month (early IBM machines were almost always leased rather than sold), and in 1964 the

largest IBM S/360 computer cost several million dollars.

These computers came to be called mainframes, though the term did not become common until

smaller computers were built. Mainframe computers were characterized by having (for their time)

large storage capabilities, fast components, and powerful computational abilities. They were highly

reliable, and, because they frequently served vital needs in an organization, they were sometimes

designed with redundant components that let them survive partial failures. Because they were

complex systems, they were operated by a staff of systems programmers, who alone had access to

the computer. Other users submitted “batch jobs” to be run one at a time on the mainframe.

Such systems remain important today, though they are no longer the sole, or even primary, central

computing resource of an organization, which will typically have hundreds or thousands of personal

computers (PCs). Mainframes now provide high-capacity data storage for Internet servers, or,

through time-sharing techniques, they allow hundreds or thousands of users to run programs

simultaneously. Because of their current roles, these computers are now called servers rather than

mainframes.20Made By:- VISHWARANJAN PATHIK

SupercomputerThe most powerful computers of the day have typically been called supercomputers.

They have historically been very expensive and their use limited to high-priority

computations for government-sponsored research, such as nuclear simulations and

weather modeling. Today many of the computational techniques of early

supercomputers are in common use in PCs. On the other hand, the design of costly,

special-purpose processors for supercomputers has been supplanted by the use of large

arrays of commodity processors (from several dozen to over 8,000) operating in parallel

over a high-speed communications network.

MinicomputerAlthough minicomputers date to the early 1950s, the term was introduced in the mid-

1960s. Relatively small and inexpensive, minicomputers were typically used in a single

department of an organization and often dedicated to one task or shared by a small

group. Minicomputers generally had limited computational power, but they had excellent

compatibility with various laboratory and industrial devices for collecting and inputting

data.

One of the most important manufacturers of minicomputers was Digital Equipment

Corporation (DEC) with its Programmed Data Processor (PDP). In 1960 DEC’s PDP-1

sold for $120,000. Five years later its PDP-8 cost $18,000 and became the first widely

used minicomputer, with more than 50,000 sold. The DEC PDP-11, introduced in 1970,

came in a variety of models, small and cheap enough to control a

single manufacturing process and large enough for shared use in university computer

centres; more than 650,000 were sold. However, the microcomputer overtook this

market in the 1980s.21Made By:- VISHWARANJAN PATHIK

MicrocomputerA microcomputer is a small computer built around a microprocessor integrated circuit, or chip.

Whereas the early minicomputers replaced vacuum tubes with discrete transistors, microcomputers

(and later minicomputers as well) used microprocessors that integrated thousands or millions of

transistors on a single chip. In 1971 the Intel Corporation produced the first microprocessor,

the Intel 4004, which was powerful enough to function as a computer although it was produced for

use in a Japanese-made calculator. In 1975 the first personal computer, the Altair, used a

successor chip, the Intel 8080 microprocessor. Like minicomputers, early microcomputers had

relatively limited storage and data-handling capabilities, but these have grown as storage

technology has improved alongside processing power

Embedded processorsAnother class of computer is the embedded processor. These are small computers that use simple microprocessors to control electrical and mechanical functions. They generally do not have to do elaborate computations or be extremely fast, nor do they have to have great “input-output” capability, and so they can be inexpensive. Embedded processors help to control aircraft and industrial automation, and they are common in automobiles and in both large and small household appliances. One particular type, the digital signal processor (DSP), has become as prevalent as the microprocessor. DSPs are used in wireless telephones, digital telephone and cable modems, and some stereo equipment.

22Made By:- VISHWARANJAN PATHIK

Types of ComputersTypes of computers are based upon the purpose, functioning and

size of the computer. Accordingly they are classified into four types:

•Super computers•Mainframe computers•Mini computers•Micro computers

Super computersMost powerful computers characterized as fastest, very high processing speed and of large data storage.Specifically used for complex applications by big organization.Good example is NASA and ISRO uses supercomputers to track and control space discovery.

Mainframe computersCapable of performing high processing speed and data storage but not powerful as super computers.Wired in air-conditioned rooms.Example: ISP providers use mainframe computers to process information about millions of internet users.

23Made By:- VISHWARANJAN PATHIK

Mini computersLess processing speed than mainframe computers.Departments of large company's uses this type of computers.They can handle large database and accounting efficiently.Example: Department of computer monitoring the network traffic of whole company.

Micro computersLeast powerful type of computers but are the most widely used and growing in the fastest rate.Hardware peripherals can be attached easily.Includes Desktop computers, Laptops, tablet pc's, Personal Digital Assistants(PDA) etc.

24Made By:- VISHWARANJAN PATHIK

Computers are the electronic device which takes input from the user, processes the data and gives the exact output to the user. Computer performs three basic operations Taking the input in the form of instruction and data.Processing the instruction and data and store the results.Display the stored results or output it into the print format.Characteristics:Speed: Computer speed depends upon the type of processor and bus line architecture used. Good type of processor and bus line architecture can perform billions of operations in one second. Processor speed depends upon the clock speed and speed of computer is measured in terms of GHz (Giga Hertz).Accuracy: Computer performs millions of operations but within the given input set of instructions and data, the result obtained should be precise one without any errors.Reliability: Reliable means that they can do their task properly and consistently. Computer communication and components are very reliable and has very less failure rate.Storage: Two types of storage are used, first is primary storage and second is secondary storage. Primary storage stores the data temporarily for executing the processes i.e. RAM, while secondary storage used for permanent storage of data i.e. hard disk. Some external devices are also used to store data like portable hard disk, pen drives, memory card etc.Automation: Once a set of program is fed into the computer, then the computer can take decision automatically without interfering with the user. Example: Pen drive drivers are automatically detected and loaded called as auto play.Versatility: Computers are capable of performing various operations at same time. Like you are reading this webpage and downloading two files from the internet and also printing the documents simultaneously.Diligence: Computer can work lot of hours with same speed and accuracy on each operations, without getting tired.Limitations:Computer are not intelligent, they need to be programmed to do their task.They cannot learn from their experience. 25Made By:- VISHWARANJAN PATHIK

Functional block diagram consists of three basic units:1) Input/Output devices2) System Unit3) Storage UnitComputer hardware system consists of different types of devices. Each device is connected directly or indirectly to the motherboard. These are classified into three basic categories:Block diagram

26Made By:- VISHWARANJAN PATHIK

Input/Output Devices: User enters the commands and data through the keyboard or mouse, these data are translated into a form that computer can process. After processing the data, output devices converts it into human understandable format.Commonly used input/output devices are keyboard, mouse, monitor and printer.

System Unit : Also called as system cabinet contains the most of the electronic components that make up a computer system. Important component is processor, which controls and manipulates data to produce information. Clock is used to synchronize the whole circuitry of the system.

RAM (Random Access Memory) use to store temporarily data to read or write data onto the disk/memory. ROM (Read Only Memory) contains permanently stored programs such as monitor programs. Expansion slots are available on motherboard to enhance computer system by using graphics cards, sound cards, TV tuner card etc. Ports are connecting sockets on the system unit like monitor port, printer port, USB port, RJ45 port and audio port.

Storage Unit : Attached hard disk inside the cabinet is mainly used as storage device, as it can store more data and faster than CD drive. But still CD (Compact disc) and DVD (Digital Video Disc) are used to store and transfer data from one pc to another.

27Made By:- VISHWARANJAN PATHIK

16 Types of Computer Ports and Their Functions1 PS/22 Serial Port

2.1 DB-252.2 DE-9 or RS-232 or COM Port

3 Parallel Port or Centronics 36 Pin Port4 Audio Ports

4.1 Surround Sound Connectors or 3.5 mm TRS Connector5 S/PDIF / TOSLINK6 Video Ports

6.1 VGA Port7 Digital Video Interface (DVI)

7.1 Mini-DVI7.2 Micro-DVI

8 Display Port9 RCA Connector10 Component Video11 S-Video12 HDMI13 USB

13.1 USB Type A13.2 USB Type C

14 RJ-4515 RJ-1116 e-SATA

28Made By:- VISHWARANJAN PATHIK

Main function of a computer port is to act as a point of attachment, where the cable from the peripheral can be plugged in and allows data to flow from and to the device.

29Made By:- VISHWARANJAN PATHIK

30

SAFETY RULES FOR COMPUTER TECHNICIANSImportant Computer Repair Safety Tips

Remember to Flip the SwitchAlways, always, always remember to turn the power off before servicing anything. This should always be your first step.Do not even open the computer case unless the power is turned off. Many computers have a number of lights inside that serve certain functions so check to see that no lights are on. If any are still on then the power is probably not completely off.Many power supply units have a switch on the back, killing power to the device and ultimately the rest of your PC. If your PSU has one, be sure to turn it to the off position.If you're working on a laptop, notebook, or tablet, be sure to remove the battery, as well as disconnect the AC power, before removing or disassembling anything.

Unplug for Extra SafetyAs a second precaution, it is wise to unplug the computer from the wall or power strip. If there was any doubt as to whether the computer was off before, it's settled now.

Made By:- VISHWARANJAN PATHIK

31

Avoid Smoke and SmellsSee smoke coming from the power supply or inside the case or smell a burning or solder scent? If so:Stop what you're doing immediately.Unplug the computer from the wall.Allow the PC to cool or discharge unplugged for at least 5 minutes.Finally, if you know which device was generating the smoke or smell, remove and replace it as soon as you can. Don't try to repair a device that's been damaged to this extent, especially if it's a power supply.

Remove Hand JewelryAn easy way to get electrocuted is to work around a high voltage device like a power supply with metal rings, watches, or bracelets on.Remove anything conductive from your hands before working inside your computer, especially if you're doing something like testing your power supply.

Avoid CapacitorsCapacitors are miniature electronic components contained in many of the parts inside a PC.Capacitors can store electric charge for a short while after the power is turned off so it's a wise decision to wait a few minutes after pulling the plug before working on your PC.

Made By:- VISHWARANJAN PATHIK

32

Never Service the Non-ServiceableWhen you come across labels that say "No serviceable components inside" don't take it as a challenge or even a suggestion. This is a serious statement.Some parts of a computer are just not meant to be repaired, even by most professional computer repair persons. You will usually see this warning on power supply units but you may also see them on monitors, hard drives, optical drivesand other dangerous or highly sensitive components.

Made By:- VISHWARANJAN PATHIK

A computer port is also called as a Communication Port as it is responsible for communication between the computer and its peripheral device. Generally, the female end of the connector is referred to as a port and it usually sits on the motherboard.In Computers, communication ports can be divided into two types based on the type or protocol used for communication. They are Serial Ports and Parallel Ports.A serial port is an interface through which peripherals can be connected using a serial protocol which involves the transmission of data one bit at a time over a single communication line. The most common type of serial port is a D-Subminiature or a D-sub connector that carry RS-232 signals.A parallel port, on the other hand, is an interface through which the communication between a computer and its peripheral device is in a parallel manner i.e. data is transferred in or out in parallel using more than one communication line or wire. Printer port is an example of parallel port.The article gives a brief introduction to different types of ports along with their applications.

computer Hardware\Computer.docx

33Made By:- VISHWARANJAN PATHIK

CPU (Central Processing Unit)

•It's a microprocessor chip developed by Intel, AMD or any other company.•CPU speed depends upon the clock frequency, higher the clock frequency more number of instructions can be executed per second.•Clock frequency is measured in MHz or GHz.•CPU word size is the largest number of bits that can be handled by CPU in one clock cycle. It is either 8, 16, 32, 64 or 128 bit.•This word size value determines number of bit processor i.e. 8-bit processor, 16-bit processor, 32 bit processor etc.•CPU performance also depends upon the RAM, bus speed and cache size as well.•Called as heart of the computer.

34Made By:- VISHWARANJAN PATHIK

Working:CPU consists of three basic units: control unit, Arithmetic Logical Unit (ALU) and memory unit.Input is given through the input devices to CPU.Control unit controls communication within ALU and memory unit.Decides which circuit is to be activated.For reading instruction it uses Fetch-execute mechanism.Control unit gets instruction from memory.Control unit decides what to do of that instruction and transfers it to the ALU.ALU performs various arithmetic operations like addition, subtraction, multiplication, division and logical operations like AND, OR, NOT, NAND etc. on that instruction.Results of ALU are stored in the memory or resistor for its further operations.After completing the instruction, stored results are passed to the output devices.To synchronize all these operations CPU uses its own system clock.What it does?Executes stored instructions called as program.Tells rest of the computer system what to do.Executes arithmetic calculation and data manipulation.Holds data and instruction which are in the current use.Responsible for storing and retrieving information on disks and other media. 35Made By:- VISHWARANJAN PATHIK

MotherboardA motherboard is one of the most essential parts of a computer system. It holds together many of the crucial components of a computer, including the central processing unit (CPU), memory and connectors for input and output devices. The base of a motherboard consists of a very firm sheet of non-conductive material, typically some sort of rigid plastic. Thin layers of copper or aluminum foil, referred to as traces, are printed onto this sheet. These traces are very narrow and form the circuits between the various components. In addition to circuits, a motherboard contains a number of sockets and slots to connect the other components.

36Made By:- VISHWARANJAN PATHIK

Parts of a Motherboard

1. A CPU socket - the actual CPU is directly soldered onto the socket. Since high speed CPUs generate a lot of heat, there are heat sinks and mounting points for fans right next to the CPU socket.

2. A power connector to distribute power to the CPU and other components.

3. Slots for the system's main memory, typically in the form of DRAM chips.

4. A chip forms an interface between the CPU, the main memory and other components. On many types of motherboards, this is referred to as the Northbridge. This chip also contains a large heat sink.

37Made By:- VISHWARANJAN PATHIK

1. A second chip controls the input and output (I/O) functions. It is not connected directly to the CPU but to the Northbridge. This I/O controller is referred to as the Southbridge. The Northbridge and Southbridge combined are referred to as the chipset.

2. Several connectors, which provide the physical interface between input and output devices and the motherboard. The Southbridge handles these connections.

3. Slots for one or more hard drives to store files. The most common types of connections are Integrated Drive Electronics (IDE) and Serial Advanced Technology Attachment (SATA).

4. A read-only memory (ROM) chip, which contains the firmware, or startup instructions for the computer system. This is also called the BIOS.

5. A slot for a video or graphics card. There are a number of different types of slots, including the Accelerated Graphics Port (AGP) and Peripheral Component Interconnect Express (PCIe).

6. Additional slots to connect hardware in the form of Peripheral Component Interconnect (PCI) slots. 38Made By:- VISHWARANJAN PATHIK

39Made By:- VISHWARANJAN PATHIK

40Made By:- VISHWARANJAN PATHIK

Motherboard

•A small or large circuit board inside a cabinet containing most of the electronic components.•Everything connected to the computer is directly or indirectly plugged into motherboard. Components like CPU, BIOS, ROM, RAM, chips, and CMOS setup information.•Expansion slots for installing different cards like video, sound, graphics, and NIC.•Also contains RAM slots, system chipset, controllers and underlying circuit to tie it together.

Types of motherboardNon-integrated:•Assemblies such as I/O port connectors, hard drive connectors, CD drive connectors etc installed as expansion boards.•Takes lot of free space inside the case because of expansion slots.•If something goes wrong such as bend or broken pin or defective controller can be repaired with minor cost.•Are cheap and easy to produce.•Most of the olden motherboards were non-integrated.Integrated:•Assemblies are integrated or built right onto the board.•Serial and parallel ports, IDE, CD drive are directly connected to the motherboard.•This tends to free some space inside case and better accessibility to the components.•Cheaper to produce but are expensive to repair.•Fast, powerful, feature rich motherboard at reasonable price. 41Made By:- VISHWARANJAN PATHIK

Motherboard form factors:Determines general layout, size and feature placement on the motherboard.Form factors such as physical size, shape, component placement, power supply connectors etc.Various form factors of motherboards are AT, Baby AT, ATX, Mini-ATX, Micro-ATX, Flex ATX, LPX and Mini LPX and NLX.1) AT (Advanced Technology):Oldest and biggest form factor and popular until Baby AT.Capable of using 386 processor.12' inch size and was difficult to install, service and upgrade.2) Baby AT:Standard in computer industries and still being used in Pentium class products.CPU socket is placed in such a way that it can interfere with longer bus cards.Limitation over peripheral card installation.I/O ports are connected to pin-outs near the floppy drive which results in jumbling of ribbon cables.3) ATX (Advanced Technology Extended):Improvement done in easy to use, support for current and future I/O, and also to current and future technology.New mounting configuration for power supply.Processor relocated away from expansion slots to allow full length add-in cards.Provides air-flow through chassis and across the processor.4) Mini ATX:Commonly same as ATX.Just change in size from ATX= 12" x 9.6" to Mini ATX= 11.2" x 8.2". 42Made By:- VISHWARANJAN PATHIK

5) Micro ATX:Supports current and new processor technologies.AGP (Accelerated graphics port) to have high performance graphics.Smaller in size and less power supply.

6) Flex ATX:A subset of micro ATX.Gives chance to system developers to create new personal computer design.Enhanced flexibility to allow custom case and board design to be manufactured.Small motherboard size and supports current processor technology.

7) LPX (Low Profile Extension) and Mini LPX:Based on design by western digital.Usually found in desktop pc's.Case are slim-line, low profile case with riser card arrangement for expansion cards.Riser card arrangement means expansion boards are parallel rather than perpendicular.This make smaller case but limits number of expansion slots to two or three.High quality product at low cost but makes difficult to upgrade and repair.

8) NLX (New Low Profile Extended):Supports current and future processor technologies.Also supports new AGP and tall memory technology.Installing and upgrading the system is easy. 43Made By:- VISHWARANJAN PATHIK

Switched-Mode Power Supply

(SMPS)

44Made By:- VISHWARANJAN PATHIK

In the early days of personal computers, linear power supplies were common, which used large transformers and linear regulators, which dissipate most of the excess energy as waste heat. These had a much lower conversion efficiency from the 110 or 220V AC power than the more modern SMPS designs that can reach efficiencies of 90% or better, and in a much smaller package.

The SMPS uses an inductor to store energy in a magnetic field, and then by breaking the circuit, uses the reverse voltage spike from the collapsing magnetic field to store the energy in a capacitor at a lower voltage. A feedback circuit adjusts the switching rate to maintain the desired voltage based on load. This is called a buck converter. A slight reconfiguration results in a boost converter, which is used when the source voltage is lower than than the desired output voltage.

45Made By:- VISHWARANJAN PATHIK

46Made By:- VISHWARANJAN PATHIK

47Made By:- VISHWARANJAN PATHIK

ost modern desktop personal computer power supplies conform to the ATX specification, which includes form factor and voltage tolerances. While an ATX power supply is connected to the mains supply, it always provides a 5 Volt standby (5VSB) voltage so that the standby functions on the computer and certain peripherals are powered. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC voltages are in spec, so that the computer is able to safely power up and boot. The most recent ATX PSU standard is version 2.31 of mid-2008.

First-generation microcomputer and home computer power supply units used a heavy step-down transformer and a linear power supply. Modern computers use switched-mode power supplies (SMPS) with a ferrite-cored high frequency transformer. The switched-mode supply is much lighter and less costly, and is more efficient, than an equivalent linear power supply.

Computer power supplies may have short circuit protection, overpower (overload) protection, overvoltage protection, undervoltage protection, overcurrent protection, and over temperature protection.The first IBM PC power supply unit (PSU) supplied two main voltages: +5 V and +12 V. It supplied two other voltages, −5 V and −12 V, but with limited amounts of power. Most microchips of the time operated on 5 V power. Of the 63.5 W these PSUs could deliver, most of it was on this +5 V rail.The +12 V supply was used primarily to operate motors such as in disk drives and cooling fans. As more peripherals were added, more power was delivered on the 12 V rail. However, since most of the power is consumed by chips, the 5 V rail still delivered most of the power. The −12 V rail was used primarily to provide the negative supply voltage to the RS-232 serial ports. A −5 V rail was provided for peripherals on the ISA bus, but was not used by the motherboard.

48Made By:- VISHWARANJAN PATHIK

An early microcomputer power supply was either fully on or off, controlled by the mechanical line-voltage switch, and energy saving low-power idle modes were not a design consideration of early computer power supplies. These power supplies were generally not capable of power saving modes such as standby or "soft off", or scheduled turn-on power controls.Due to the always-on design, in the event of a short circuit, either a fuse would blow, or a switched-mode supply would repeatedly cut the power, wait a brief period of time, and attempt to restart. For some power supplies the repeated restarting is audible as a quiet rapid chirping or ticking emitted from the device.

ATX standard

When Intel developed the ATX standard power supply connector (published in 1995), microchips operating on 3.3 V were becoming more popular, beginning with the Intel 80486DX4 microprocessor in 1994, and the ATX standard supplies three positive rails: +3.3 V, +5 V, and +12 V. Earlier computers requiring 3.3 V typically derived that from a simple but inefficient linear regulator connected to the +5 V rail.The ATX connector provides multiple wires and power connections for the 3.3 V supply, because it is most sensitive to voltage drop in the supply connections. Another ATX addition was the +5 V SB (standby) rail for providing a small amount of standby power, even when the computer was nominally "off".There are two basic differences between AT and ATX power supplies: the connectors that provide power to the motherboard, and the soft switch. In ATX-style systems, the front-panel power switch provides only a control signal to the power supply and does not switch the mains AC voltage. This low-voltage control allows other hardware or software to turn the system on and off.

49Made By:- VISHWARANJAN PATHIK

50Made By:- VISHWARANJAN PATHIK

51Made By:- VISHWARANJAN PATHIK

Power supply units (PSUs)List of power supply unit (PSU) manufacturers:AdataAkasaAntecAPEVIAArcticBe quiet!BFG TechnologiesCooler MasterCorsairDeepcoolDynexEVGA CorporationFractal DesignFoxconnFSP GroupGigabyte TechnologyIn Win DevelopmentLian-LiLiteOnMaplinOCZ Technology

PC Power and CoolingRAIDMaxSeasonicSeventeamSilverStoneStarTech.comThermaltakeTrustXFXXilenceZalman

52Made By:- VISHWARANJAN PATHIK

Hard disk drive

53Made By:- VISHWARANJAN PATHIK

A hard disk drive (sometimes abbreviated as Hard drive, HD, or HDD) is a non-volatile memory hardware device that permanently stores and retrieves data on a computer. A hard drive consists of one or more platters to which data is written using a magnetic head, all inside of an air-sealed casing. Internal hard disks reside in a drive bay, connect to the motherboard using an ATA, SCSI, or SATA cable, and are powered by a connection to the PSU (power supply unit).

Tip: New users often confuse memory (RAM) with disk drive space. See our memorydefinitionfor a comparison between memory and storage. Unlike RAM a hard drive keeps all stored information even with the power is turned off.

The data on hard drives can be erased and/or overwritten, the hard drive is classed as a non-volatile storage device which means it doesn't require a constant power supply in order to retain the information stored on it (unlike RAM).

Inside every hard drive are small round disk-like objects made of either an aluminium/alloy or a glass/ceramic composite, these are called platters, each platter is coated with a special magnetic coating enabling them to store data magnetically.

Hovering above these platters are read/write heads that transfer data to and from the platters.

54Made By:- VISHWARANJAN PATHIK

55Made By:- VISHWARANJAN PATHIK

How is a hard drive connected to a computer?An internal hard drive is connected to the computer using a data cable (IDE or SATA) that connects to the motherboard and a power cable that connects to the power supply.Installing a PC IDE/EIDE hard drive.

What is stored on a hard drive?A hard drive can be used to store any data, including pictures, music, videos, text documents, and any files created or downloaded. Also, hard drives store files for the operating system and software programs that run on the computer.

Where is the hard drive found in a computer?All primary computer hard drives are found inside a computer case and are attached to the computer motherboard using an ATA, SCSI, or SATA cable, and are powered by a connection to the PSU (power supply unit).

Note: Some portable and desktop computers may have newer flash drives that connect directly to the PCIe interface or another interface and not use a cable.

56Made By:- VISHWARANJAN PATHIK

What are the sizes of hard drives?The hard drive is typically capable of storing more data than any other drive, but its size can vary depending on the type of drive and its age. Older hard drives had a storage size of several hundred megabytes (MB) to several gigabytes (GB). Newer hard drives have a storage size of several hundred gigabytes to several terabytes (TB). Each year, new and improved technology allows for increasing hard drive storage sizes.

How much is 1 byte, kilobyte, megabyte, gigabyteBelow is a list of each of the accepted disk drive space values. It is important to realize that not all manufacturers and developers list their value using binary, which is base 2. For example, a manufacturer may list a product's capacity as one gigabyte (1,000,000,000 bytes, a metric value) and not 1,073,741,824 bytes (gibibyte) that it actually is. BitA bit is a value of either a 1 or 0 (on or off).NibbleA Nibble is 4 bits.ByteToday, a Byte is 8 bits.1 character, e.g. "a", is one byte.

57Made By:- VISHWARANJAN PATHIK

Kilobyte (KB)A Kilobyte is 1,024 bytes.2 or 3 paragraphs of text.

Megabyte (MB)A Megabyte is 1,048,576 bytes or 1,024 Kilobytes873 pages of plaintext (1,200 characters)4 books (200 pages or 240,000 characters)

Gigabyte (GB)A Gigabyte is 1,073,741,824 (230) bytes. 1,024 Megabytes, or 1,048,576 Kilobytes.894,784 pages of plaintext (1,200 characters)4,473 books (200 pages or 240,000 characters)640 web pages (with 1.6 MB average file size)341 digital pictures (with 3 MB average file size)256 MP3 audio files (with 4 MB average file size)1 650 MB CD

Terabyte (TB)A Terabyte is 1,099,511,627,776 (240) bytes, 1,024 Gigabytes, or 1,048,576 Megabytes.916,259,689 pages of plaintext (1,200 characters)4,581,298 books (200 pages or 240,000 characters)655,360 web pages (with 1.6 MB average file size)349,525 digital pictures (with 3 MB average file size)262,144 MP3 audio files (with 4 MB average file size)

58Made By:- VISHWARANJAN PATHIK

How is data read and stored on a hard drive?Data sent to and read from the hard drive is interpreted by the disk controller, which tells the hard drive what to do and how to move the components in the drive. When the operating system needs to read or write information, it examines the hard drive's File Allocation Table (FAT) to determine file location and available write areas. Once they have been determined, the disk controller instructs the actuator to move the read/write arm and align the read/write head. Because files are often scattered throughout the platter, the head needs to move to different locations to access all information

59Made By:- VISHWARANJAN PATHIK

All information stored on a traditional hard drive, like the above example, is done magnetically. After completing the above steps, if the computer needs to read information from the hard drive, it would read the magnetic polarities on the platter. One side of the magnetic polarity is 0, and the other is 1. Reading this as binary data, the computer can understand what the data is on the platter. For the computer to write information to the platter, the read/write head aligns the magnetic polarities, writing 0's and 1's that can be read later.

External hard drivesAlthough most hard drives are internal, there are also stand-alone devices called external hard drives, which can backup data on computers and expand the available disk space. External drives are often stored in an enclosure that helps protect the drive and allows it to interface with the computer, usually over USB or eSATA. An excellent example of an external backup device that supports multiple hard drives is the Drobo

HDD being replaced by SSDSolid State Drives (SSDs) have started to replace hard disk drives (HDDs) because of the distinct performance advantages they have over HDD, including faster access times and lower latency. While SSDs is becoming more and more popular, HDDs continue to be used in many desktop computers largely due to the value per dollar that HDDs offer over SSDs. However, more and more laptops are beginning to utilize SSD over HDD, helping to improve the reliability and stability of laptops.

60Made By:- VISHWARANJAN PATHIK

SCSI Hard Drives:

SCSI stands for Small Computer System Interface. These drives have generally 50 to 68 pins. These drives are very high capacity and high speed than both IDE and SATA drives. 50 to 68 pin SCSI data cables are used to connect these hard drives. Generally these drives are used in servers. Capacities are 160GB, 250GB, 320GB, 500GB, 1TB, 2TB, 5TB and 10TB. 61Made By:- VISHWARANJAN PATHIK

Types of HDD :IDE : Integrated Drive Electronics. IDE drives are also known as PATA drives( Parallel advance technology attachment )SATA : Serial advance technology attachmentSCSI : Small Computer System Interface. SCSI is pronounced as scuzzy.SAS : Serial Attached SCSI

IDE / PATA (Integrated Drive Electronics Drive / Parallel Advance Technology Attachment Drive)IDE/PATA Drives have usually 40 pins.IDE/PATA Drives offer 133 MB/sec transfer rate.It sends 8 bit data at a time.PATA Cables are used to connect PATA HDD. Two drives can be connected in a single pata cable. One as master and other as slave. The configuration of master and slave is done by different combination of jumpers in the hdd.

SATA (Serial Advance Technology Attachment Drive)SATA Drives have usually 7 pins, 4 pins in pair of two for sending and receiving data and rest 3 pins are grounded.SATA Drives offers generally 300MB/sec transfer rate.It sends data bit by bit.SATA Cables are used to connect SATA HDD. Only one drive can be connected in a single sata cable.

62Made By:- VISHWARANJAN PATHIK

SCSI (Small Computer System Interface Drive)

SCSI Drives have usually 50 to 68 pins.SCSI Drive offers generally 640MB/sec transfer rate.This drives are hot swappable.SCSI cables are used to connect SCSI HDD. Maximum of 16 drives can be connected in a single scsi cable. Each hdd have a 8 bytes hexadecimal code known as WWN (worldwide name) for its identification in the cable.

SAS(Serial Attached SCSI Drive)

SAS Drives generally offers 805 MB/sec transfer rate.This drives are hot swappable.SAS Cables are used to connect SAS Drives. Maximum of 128 drives can be connected in a single sas cable.

63Made By:- VISHWARANJAN PATHIK

TYPES OF HARD DISK DRIVESHard disk drives are three types.IDE Hard drivesSATA Hard drivesSCSI Hard drives

IDE Hard Drives:

IDE Stands for Integrated Device Electronics. These drives are also called as PATA (parallel Advanced Technology Attachment) hard drives. Hard drives have 40pin data interface and 4 pin power connector and Jumper setting to change drive setting to connect motherboard. These drives have low speed and low capacity than SATA and SCSI hard drives. ATA cables are used to connect Hard drives to motherboard. These drives capacities are 10GB, 20GB, 40GB, 80GB, 120GB, 160GB, 250GB and 320GB.

64Made By:- VISHWARANJAN PATHIK

SATA Hard Drives:

SATA stands for Serial Advanced Technology Attachment. These drives have 4pin data interface and 7 pin power interface to work and no jumper pins, because no need to change drive setting. these drives have high speed and high capacity than IDE hard drives and Low speed and low capacity than SCSI hard drives. 4pin SATA cables are used to connect hard drives to motherboard. These drives capacities are 80GB, 120GB, 160GB, 250GB, 320GB, 500GB, 1TB and 2TB. 65Made By:- VISHWARANJAN PATHIK

SATA: This is the most common connector used in laptops. These come in SATA 2 and SATA 3 versions, supporting 3.0 and 6.0 Gbps respectively.

SATA drives come in two form factors. 2.5" which goes into laptops and looks like this when it is magnetic:

66Made By:- VISHWARANJAN PATHIK

SSD: Solid State Drives: You can consider these as bigger version of pen drives. They store data in memory (flash) chips, and this means they don't have any moving parts. This allows higher speeds, but also makes them expensive. Also, they don't come in the capacities HDDs come in.

67Made By:- VISHWARANJAN PATHIK

68Made By:- VISHWARANJAN PATHIK

69Made By:- VISHWARANJAN PATHIK

70Made By:- VISHWARANJAN PATHIK

71Made By:- VISHWARANJAN PATHIK

These are exclusively SSDs.

Apart from the size, you will hear about RPM rating. 5400, 7200 and 1000 RPM are the most common ones. This is the speed at which the magnetic disks inside the HDD spin in revolutions per minute A higher RPM HDD is faster, but it consumes more power and is more expensive. The extra power consumption also translates to more heat, both of which are issues in laptops, but not desktops.

Now we come to external drives.

External drives are of two main types. They are both based on SATA drives, and as a result, come in two form factors.

72Made By:- VISHWARANJAN PATHIK

73Made By:- VISHWARANJAN PATHIK

74Made By:- VISHWARANJAN PATHIK

75Made By:- VISHWARANJAN PATHIK

76Made By:- VISHWARANJAN PATHIK

77Made By:- VISHWARANJAN PATHIK

78Made By:- VISHWARANJAN PATHIK

These need external power supplies since the disks are heavier, and need more power than the port can supply. These also come in USB, Firewire and Thunderbolt versions. They are also referred to as external hard drives.

There are a few differences in the 2.5" and 3.5" external drives. 2.5" is more convenient, but 3.5" is more heavy duty and reliable. Also, 3.5" drives tend to be faster on average, thanks to the dedicated power supply.

Coming to your specific questions:

For laptops, for internal storage, you can use pretty much any 2.5" SATA drive. SSDs are obviously faster, but for a lot more money, you get a lot less storage. PCIe drives are not supported unless your laptop came with one.

For external storage, with laptops, it depends on your needs. If you need something to carry around, go for a portable USB 3.0 drive. It is fast enough, reliable and convenient to haul around. You do not need a power socket to get it to work, which is another advantage. If, however, you need something nly for backup, I would recommend an external USB 3.0 drive. They are faster, even more reliable, and you get more storage for the same money.

I personally use a 1TB Seagate Backup Plus portable drive when I'm travelling to have enough space to drain my camera's memory card, but at home, for my movies and other big data. I use a 1TB Western Digital MyBook.

79Made By:- VISHWARANJAN PATHIK

From my experiences they are MFM, RLL, ESDI, IDE, SCSI, SATA, SAS, SSD, SSHD, mSATA, PCI-e,

and lastly IDE modules. Fire external hard drives there have been many propriatory

designs since the mid 80′s, usb models, satamodels, sas models, scsi models, fiber channel models, and then with the various models they

all used some form of internal hard drive I've listed above. Sometimes a compact flash, sd

card, micro sd card, memory stick or even a tfcard for the storage medium.

80Made By:- VISHWARANJAN PATHIK

RANDOMACCESS

MEMORY(RAM)

81Made By:- VISHWARANJAN PATHIK

Random-access memory (RAM ) is a form of computer data storage which stores frequently used program instructions to increase the general speed of a system. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

RAM contains multiplexing and demultiplexing circuitry, to connect the data lines to the addressed storage for reading or writing the entry. Usually more than one bit of storage is accessed by the same address, and RAM devices often have multiple data lines and are said to be '8-bit' or '16-bit' etc. devices.

In today's technology, random-access memory takes the form of integrated circuits. RAM is normally associated with volatile types of memory (such as DRAM memory modules), where stored information is lost if power is removed, although non-volatile RAM has also been developed.[1] Other types of non-volatile memories exist that allow random access for read operations, but either do not allow write operations or have other kinds of limitations on them. These include most types of ROM and a type of flash memory called NOR-Flash. 82Made By:- VISHWARANJAN PATHIK

Integrated-circuit RAM chips came into the market in the early 1970s, with the first commercially available DRAM chip, the Intel 1103, introduced in October 1970

Types of RAMOver the evolution of the computer there have been different variations of RAM. Some of the more common examples are DIMM, RIMM, SIMM, SO-DIMM, and SOO-RIMM. Below is an example image of a 512 MB DIMM computer memory module, a typical piece of RAM found in desktop computers. This memory module would be installed into one of the memory slots on a motherboard.

Additional informationAs the computer boots, parts of the operating system and drivers are loaded into memory, which allows the CPU to process the instructions faster and speeds up the boot process. After the operating system has loaded, each program you open, such as the browser you're using to view this page, is loaded into memory while it is running. If too many programs are open the computer will swap the data in the memory between the RAM and the hard disk drive.

83Made By:- VISHWARANJAN PATHIK

DIMM

84Made By:- VISHWARANJAN PATHIK

RIMM

RIMM is not an acronym and is a trademark of Rambus incorporated for the Direct Rambus or DRAM (RDRAM) modules. RIMM is computer memory that resembles DIMMs; however, it is 184-pin and is available with built-in ECC support and Non-ECC at speeds up to 800 MHz. RIMM modules are commonly used on the IntelPentium 4 motherboards.Unlike most other computer memory, computers that support RIMM require a continuous signal. If a memory socket is left empty, the computer will not work properly. Therefore, users must utilize C-RIMM modules in any slots that do not have RIMM modules.SO-RIMM is a 160-pin module and is Rambus memory used in laptop computers.Note: RIMM is NOT short for Rambus In-line Memory Module.

85Made By:- VISHWARANJAN PATHIK

SIMM

Short for Single In-line Memory Module, SIMM is a memory module developed by Wang laboratories in 1983. The SIMM circuit board that holds six to nine memory chips per board, the ninth chip usually an error checking chip (parity or non parity). The SIMM was used with computers using a 486, early Intel Pentium, and compatible processors. However, because the Pentium is 64-bit and a SIMM is only 32-bits wide, they must be installed two at a time when used with any 64-bit processor.Below is a graphic illustration of a 4 MB SIMM as well as a diagram pointing out the important features of a SIMM. Today, the SIMM is rarely used and have been replaced by DIMMs.

DDRDDR may refer to any of the following:1. Short for Double Data Rate, DDR is memory that was first introduced in 1996 and has since been replaced by DDR2. DDR utilizes both the rising and falling edge of the system clock, potentially doubling the speed of the memory. Today, DDR technology is found on high-end video cards and computer memory such as DDR-SDRAM.

2. Short for Dial-on-Demand Routing, DDR was developed by Cisco and is a routing technique that uses existing telephone lines to help form a Wide Area Network.

3. DDR is also short for Dance Dance Revolution, a popular arcade and console game where users must move their feet on a pad in conjunction with what is being displayed on a screen.

86Made By:- VISHWARANJAN PATHIK

SDRAMSDRAM, which is short for Synchronous DRAM, is a type of memory that synchronizes itself with the computer's system clock. Being synchronized allows the memory to run at higher speeds than previous memory types and asynchronous DRAM and also supports up to 133 MHz system bus cycling. Since 1993, this has been the prevalent type of memory used in computers around the world. In the picture below is an example of a SDRAM DIMM. The original type, named SDRAM, up to the current type, DDR3, are all derivatives of the SDRAM memory type.

DDR2

Short for double data rate two, DDR2 is the second generation of DDR memory that was released in September of 2003. DDR2 is capable of operating at greater speeds than DDR, offers a greater bandwidth potential, operates on less power, and generates less heat. Due to architectural differences, DDR2 memory modules are incompatible with DDR slots.

Note: DDR2 memory was replaced by DDR3.87Made By:- VISHWARANJAN PATHIK

DDR3

88Made By:- VISHWARANJAN PATHIK

DDR4

Short for double data rate four, DDR4 is a type of system memory known as SDRAM and was released in September of 2014 as the successor to DDR3. DDR4 has bus clock speeds that range from 800 to 1600 MHz and range in storage capacity from 4 to 128 GB per DIMM. DDR4 is also more efficient at 1.2 V when compared to DDR3's 1.5 to 1.65 V range.Note: These memory chips can only be installed on a motherboard that supports DDR4 memory and are not backward compatible with DDR3 memory slots.

89Made By:- VISHWARANJAN PATHIK

RAM (Random Access Memory):

A small scale size IC's memory chip used to store and access data in any order (i.e. in random order), so the name Random Access Memory.Also called as temporary or volatile memory.Holds the program and data, which are currently processing.Data is lost as soon as computer is turned off or power failure.Data stored in this memory can be altered or changed.Types of RAMSRAM (Static RAM):Fast and has less access time.Consists of flip-flop using either transistor or MOS (Mosfet).For each bit it requires one flip-flop.Status of each bit remains as it is unless there is write operation or power is off.e.g. Cache memory.Advantages :- Refreshing circuit is not required.Disadvantages :-Costly and low package density.Requires more space.DRAM (Dynamic RAM):Slower and higher access time.Data is stored in the form of capacitors.Capacitors charges when data is 1 and doesn't charge if data is 0.Because of leakage current in capacitor, they need to be refreshed to hold the data in memory cells. Refreshing is the process in which the contents of each memory cell is read and written hundred times a second.This maintains the data of memory cells in capacitor. e.g. Main memory.AdvantagesCheaper than static RAM.DisadvantagesRequires refreshing circuit.

90Made By:- VISHWARANJAN PATHIK

ROM (Read Only Memory)

A memory storage device, whose contents can be read and accessed but cannot be modified, so the name Read Only Memory.DescriptionAlso called as non-volatile memory.Holds the permanent programs to tell system how to use circuit board.Data is not lost even the computer is switched off or power failure.Data in this memory is read only.Types of ROMMROM (Mask-programmed ROM):It is programmed at the factory.Program or data is permanently installed at the time of manufacturing.PROM (Programmable ROM):Can be custom-programmed by the user only once using special circuitry PROM programmer.This circuit uses high voltages to permanently eliminate or create inner links.EPROM (Erasable-Programmable ROM):Can be programmed by the user using strong ultraviolet light and special circuitry.EEPROM (Electrically Erasable PROM):Can be erased and reprogrammed by electrical signals.Manufacturing process is complex and expensive.Rarely used.

91Made By:- VISHWARANJAN PATHIK

What is the difference between ROM and RAM?

There is one major difference between a ROM and a RAM chip. A ROM chip is non-volatile storage and does not require a constant source of power to retain information stored on it. When power is lost or turned off, a ROM chip will keep the information stored on it. In contrast, a RAM chip is volatile and requires a constant source of power to retain information. When power is lost or turned off, a RAM chip will lose the information stored on it.Other differences between a ROM and a RAM chip include:A ROM chip is used primarily in the start up process of a computer, whereas a RAM chip is used in the normal operations of a computer after starting up and loading the operating system.Writing data to a ROM chip is a slow process, whereas writing data to a RAM chip is a faster process.A RAM chip can store multiple gigabytes (GB) of data, up to 16 GB or more per chip. A ROM chip typically stores only several megabytes (MB) of data, up to 4 MB or more per chip. 92Made By:- VISHWARANJAN PATHIK

Windows detects 2.75 GB or no more than 4 GB of memory

Often after installing more than 2 GB, users may notice not all of the memory being detected. The total memory capable of being detected by any 32-bit edition of Microsoft Windows is 4 GB.Users who want more than 4 GB of total memory support in their computer must be running a computer with a 64-bit processor and operating system. Below is a listing of 64-bit memory limitations.

93Made By:- VISHWARANJAN PATHIK

Why does BIOS detect more memory than Windows?Some users may notice when they enter the BIOS/CMOS setup that their computer is detecting more memory in it than in Windows. BIOS relies on different drivers than those loaded by Windows, so this is not uncommon.

What happens if my computer has less than 2 GB?As long as you are using an older operating system as mentioned above, you can still get away with 2 GB or less of memory. However, running an older operating system can pose a security threat because older operating systems are no longer updated. If you are running a newer computer with 2 GB or less of memory, having that low of an amount of memory can cause the computer to run slow.

WINDOWS USERSHow much ram your computer can hold depends on if you're running a 32 or 64-bit version of Windows, which depends on your CPU. The capacities are as follows, permitting you have the physical space to fit the RAM modules.32-bit systems - up to 4 GB64-bit systems - up to 128 GB

94Made By:- VISHWARANJAN PATHIK

CD-ROMShort for Compact Disc-Read Only Memory, a CD-ROM (shown right) is an optical disc which contains audio or software data whose memory is read only. A CD-ROM Drive or optical drive is the device used to read them. CD-ROM drives have speeds ranging from 1x all the way up to 72x, meaning it reads the CD roughly 72 times faster than the 1x version. As you would imagine, these drives are capable playing audio CDs and reading data CDs. Below is a picture of the front and back of a standard CD-ROM drive.

95Made By:- VISHWARANJAN PATHIK

Below are the different interfaces that allow a CD-ROM and other disc drives to connect to a computer.IDE/ATA - One of the most commonly used interfaces for disc drives.Panasonic - Older proprietary interface.Parallel - Interface used with old external CD-ROM drives.PCMCIA (PC Card) - Interface sometimes used to connect external disc drives to laptop computers.SATA - Replacing IDE as the new standard to connect disc drives.SCSI - Another common interface used with disk and disc drives.USB - Interface most commonly used to connect external disc drives.

Drives (such as the hard drive, floppy drive, CD-ROM, CD-R, CD-RW, and DVD-ROM drives) are the hardware devices that read computer data from disks.

Data can be read once the disc spins (for one to two seconds) and the operating system has located and identified the drive. The CD-ROM's own file system is standardized in ISO 9660.

96Made By:- VISHWARANJAN PATHIK

97Made By:- VISHWARANJAN PATHIK

DVD Version Description and Storage Capacity

DVD-5 Single-sided, single-layered disc with 4.7Gb capacity

DVD-9 Single-sided, double-layered with 8.5Gb capacity

DVD-10 Double-sided, single-layered disc with 9.4Gb capacity

DVD-18 Double-sided, double-layered disc with 17Gb capacity

DVD Versions and Storage Capacity

Unlike standard CDs, DVD disks have varying storage capacities, expressed as a numeral.

98Made By:- VISHWARANJAN PATHIK

THE TYPES OF PC CD/DVD RECORDER DRIVES

Your PC may have a CD/DVD recorder drive, which allows you to create your own CD or DVDs, recording data, music, or video. On the CD and DVD recording scene, you find five types of drives:

CD-R/CD-RW drives: Can store around 700MB on a CDDVD-R/DVD-RW drives: Can store 4.7GB on a DVDDVD-RAM drives: Can store 9.4GB on a double-sided DVDDVD+R/DVD+RW drives: Can store 4.7GB on a DVDDual Layer (DL) DVD+R drives: Can store 8.5GB on a DVD

The RW in the drive moniker stands for rewriteable, which means that you can reuse a CD-RW, DVD-RW, or DVD+RW over and over. All these recorders can produce audio CDs and standard data CDs and DVDs, but only the drives that can record the DVD-R and DVD+R formats are likely to create DVD movies that can be played in your standalone DVD player. 99Made By:- VISHWARANJAN PATHIK

Formats:These are the standard DVD media formats:DVD+R (plus R) and DVD-R (dash R) - These two are the record once formats.DVD+RW and DVD-RW - These are the rewritable formats and can be rewritten over 1000 times.DVD Storage Capacity:DVDs have various storage capacities. They're determined by the number of layers a disc has and whether or not it can be written to one or both sides. The original and still very popular is the single-sided, single layer (DVD-5). Data is written to one side only. These hold 4.7 GB of data or 2 hrs. of video. Supported by DVD+/-R and DVD +/-RW formats. Other DVD sizes are listed below.Double-Sided Single Layer (DVD-10): Data can be written to both sides-like a cassette tape. Stores 8.75 GB or about 4.5 hrs of video. Also supported by DVD+/-R and DVD +/-RW.Single-Sided Dual Layer (DVD-9): Records to one side but that one side has two layers built into it. Stores 8.5 GB of data or 4 hrs. of video. Supported by DVD+R and DVD-R. They are normally termed DVD+R DL and DVD-R DL.Double-Sided Double Layer (DVD-18): Stores 15.9 GB of data or over 8 hrs. of video.In order to play or record these formats a DVD burner must support them. Fortunately, most DVD writers support multiple formats. In addition to a DVD burner, all these formats need some kind of burning software to write DVDs.

100Made By:- VISHWARANJAN PATHIK

DVD-RAM:DVD-RAM discs can be rewritten over 100,000 times and are either single-sided or double-sided - single-sided having a capacity of 4.7 GB and double-sided a capacity of 9.4 GB. Unlike the aforementioned formats, DVD-RAM does not require burning software-they function like hard drives and are available with or without a cartridge. However, they are not as compatible as the other types and are a bit more expensive.

Blu-Ray (BD):Blu-Ray (BD) is the latest video disc. It gets its name from a blue laser used when recording to and reading a disc. All the other DVD formats utilize a red laser. This blue laser has a shorter wavelength, thus allowing the storage of extremely large amounts of data. Blu-ray is primarily for high-definition content and comes in single and dual layer. Single layer discs store up to 25 GB - that's 2 hrs. of hi-def content or 13 hrs. of standard video. Dual layer stores 50 GB, which is 4.5 hrs of hi def video or 20 hrs of regular video.

101Made By:- VISHWARANJAN PATHIK

IRQ (interrupt request)

Short for Interrupt ReQuest, an IRQ is a signal that is sent to the computer processor to stop the processor momentarily while it decides which task it should perform next. IBM compatible computers go up to IRQ 15 and are prioritized in the computer according to the importance of the device. Today, most users don't need to worry about IRQ settings because all devices are now Plug-and-Play, which means they are configured automatically. The following table is an overview of the traditional IBM IRQ's, I/O ports, and their related devices

Technically there are 16 IRQs if you count IRQ 0. The system timer and all IRQs above 15 are known as virtual IRQs and are assigned and handled by both the operating system and APIC.

102Made By:- VISHWARANJAN PATHIK

IRQ DEVICE I/O PORT BUS SLOT CARD Type

00 System Timer None NO NONE

01 Keyboard None NO NONE

02 Cascade Controller2nd PIC

None NO NONE

03 COM 2 and 4 COM 2: 02F8h (02F8 or 2F8)COM 4: 02E8h (02E8 or 2E8)

YES 8 or 16-BIT

04 COM 1 and 3 COM 1: 03F8h (03F8 or 3F8)COM 3: 03E8h (03E8 or 3E8)

YES 8 or 16-BIT

05 SoundParallel Port 2

PARALLEL PORT 2:0278h - 0378h

YES 8 or 16-BIT

06 Floppy 03F0 - 03F5 YES 8 or 16-BIT

07 Parallel Port 1 0278h - 0378h YES 8 or 16-BIT

08 Real-time Clock None NO NONE

09 Redirected IRQ 2Open

Network Available

None YES 8 or 16-BIT

10 Open None YES 8 or 16-BIT

11 OpenSCSI

Video

VIDEO:3B0-3DF

YES 8 or 16-BIT

12 OpenPS2

None YES 8 or 16-BIT

13 Coprocessor None NO NONE

14 OpenPrimary hard drive (master)

Hard Drive Controller

1ST IDE: 1F0 YES 8 or 16-BIT

15 Open2nd hard drive (slave)

2ND IDE: 170 YES 8 or 16-BIT

103Made By:- VISHWARANJAN PATHIK

Types of Computer Monitors

A computer monitor, technically termed as a visual display unit, can be plainly described as an electronic device that transmits information from the computer onto a screen, thereby acting as an interface and connecting the viewer with the computer. At present, computer monitors are available in a variety of shapes, designs, and colors. However, based on the technology used to make computer monitors, they can be broadly categorized into three types.

CRT (Cathode Ray Tube)LCD (Liquid Crystal Display)LED (Light-Emitting Diodes)

104Made By:- VISHWARANJAN PATHIK

CRT (Cathode Ray Tube) Monitors

These monitors employ the CRT technology used most commonly in the

manufacturing of television screens. In this, a stream of intense high energy

electrons is used to form images on a fluorescent screen. A cathode ray tube is a

basically a vacuum tube containing an electron gun at one end and a fluorescent

screen at another end. From this electron gun, a process called thermionic

emission generates a strong beam of electrons. These electrons travel through a

narrow path within the tube with high speed using various electro-magnetic

devices and finally strike the phosphor points present on the fluorescent screen,

thus creating an image. There are several advantages of using CRT monitors:•These monitors are highly reliable and efficient, and are capable of generating a resolution of up to 2048 x 1536 pixels, thereby providing a clear picture quality. Also, CRT monitors that are now available are capable of producing thousands of different colors.•Secondly, CRT monitors are affordable and cost effective.•Unlike conventional CRT monitors, modern technological •advancements have resulted in the development of flat •screen CRT monitors that reduce the glare and are good •for the eyes.However, the only concern with buying CRT monitors is that they are heavy and

can occupy a great deal of work space. Also, these devices get heated up very

easily.

105Made By:- VISHWARANJAN PATHIK

LCD (Liquid Crystal Display) MonitorsLiquid crystal display, also known as liquid crystal diode, is one of the most advanced

technologies available at present. Typically, an LCD monitor consists of a layer of color or

monochrome pixels arranged schematically between a couple of transparent electrodes

and two polarizing filters. Optical effect is achieved by polarizing the light in varied

amounts and making it pass through the liquid crystal layer. At present, there are two

types of LCD technology available. These include the active matrix or TFT and a passive

matrix technology. Among these, TFT technology is more secure and reliable, and

generates better picture quality. On the other hand, passive matrix has a slow response

time and is slowly becoming outdated.

In recent times, LCD monitors have become increasing popular with consumers. Some

major advantages of using an LCD monitor include:

•These monitors are compact, lightweight, and do not consume much desk space.•Secondly, these monitors do not consume much electricity and can even be operated by using batteries.•Also, the images transmitted by these monitors do not get •geometrically distorted and have little flicker.However, LCD monitors do have certain disadvantages.

Most importantly, these monitors are very expensive. Secondly,

image quality is not constant when viewed from different angles.

Also, an LCD monitor’s resolution is always constant. Any alterations can result in a

reduced performance. 106Made By:- VISHWARANJAN PATHIK

LED (Light-Emitting Diodes) Monitors

LED monitors are the latest types of monitors in the market today. Like LCD, it is again a flat panel display making use of light-emitting diodes for back-lightning instead of Cold Cathode Fluorescent (CCFL) back-lightning used in LCDs. Primarily, the display is of LCD only but the back-lightning is done by LEDs.LED monitors are said to use much lesser power than CRT and LCD. Thus, they are also considered environmental friendly. Other core advantages of LED monitors are:They produce images with higher contrastThey have less negative environmental impact when disposedLifespan and durability of LED monitors is more than CRT or LCD monitorsBecause of the technology, the monitor panels can be made very thinDo not produce much heat while runningLED monitors are little expensive than the former types. There are multiple ways by which LED back-lightning is done.White-edge LEDs are fixed around the rim of the monitor. It used a special diffusion panel to spread light evenly behind the screen.An array of LEDs are placed behind the screen. Their brightness is not controlled individually.Again an array of LEDs are placed behind the screen, but the brightness of each individual LED is controlled separately.

107Made By:- VISHWARANJAN PATHIK

Types of TFT LCD DisplaysTFT stands for thin-film transistor, and this variety of LCD represents the highest-end commercially available liquid crystal display screen. TFT is the technology used in televisions and computer monitors, though the latest crop of mobile phones and tablet devices also use TFT LCD displays.

However, not all TFT displays are created equal. If you need your TFT display for a certain function, if you're passionate about viewing angles and color brilliance, or if you just want to be in the know about LCD technology, you need to be aware of the many different types of TFT LCD displays.

Twisted Nematic (TN) - TN displays are the cheapest type of TFT LCD displays. They have 6-8 bit color technology, and their max contrast when viewed straight on is 1000:1. When viewed from a 60 degree angle, TN displays only have 10:1 contrast. The max horizontal viewing angle is 60 degrees and the max vertical viewing angle is 15 degrees.

Multi-domain Vertical Alignment (MVA) - MVA displays are a mid-range type of TFT LCD displays. With 6000:1 contrast, they improve upon TN technology, but they tend to be more expensive. The horizontal viewing angle is increased to 100 degrees while the vertical angle is 30 degrees, making it easier to use on a mobile phone or tablet that may be held and used at an angle. The max color quality of MVA LCD displays is 10-bit.

Super In-Plane Switching (S-IPS) - Also known as Super-LCD displays, S-IPS displays rival AMOLED displays in terms of quality. They are a mid-ranged option that are less expensive than their LED counterparts, and they use significantly less energy than either TN displays or MVA displays. The level of contrast doesn't change as drastically with a wider viewing angle, though the contrast is comparable to TN displays. S-IPS displays offer near 180-degree vertical angle viewing and a stunning 150 degree horizontal angle viewing. 108Made By:- VISHWARANJAN PATHIK

Types of Mouse and How They Work

109Made By:- VISHWARANJAN PATHIK

WIRELESS MOUSE:The Mouse without wire or cord is called wireless mouse or cordless mouse. Most wireless mice use radiofrequency (RF) technology to communicate information to your computer. Since RF devices require two main components: a transmitter and a receiver,thats why wireless mouse also requires it.Working :• The transmitter is housed in the mouse. It sends an electromagnetic (radio) signal that encodes the information about the mouse’s movements and the buttons you click.• The receiver, which is connected to your computer, accepts the signal, decodes it and passes it on to the mouse driver software and your computer’s operating system.• The receiver can be a separate device that plugs into your computer, a special card that you place in an expansion slot, or a built-in component.

GSTICK MOUSE:Gordon Stewart designed the Stick to add a more authentic and natural feel to artistic manipulations on both Macs and PCs. These mice are Wireless and pocket-sized. It looks like a pencil. gStick mouse is like a pencil. It can be used for web browsing, office work or whatever you do with your traditional mouse, with more comfort. It also features a scroll wheel that can be manipulated with a finger or thumb a button on either side of the wheel. It’s claimed that a single AAA battery will power the gStick for between three and five months. 110Made By:- VISHWARANJAN PATHIK

OPTICAL MOUSE:An optical mouse is an computer pointing device that uses a light-emitting diode an optical sensor, and digital signal processing ( DSP ).This mouse doesn’t have mouse ball and electromechanical transducer. Movement is detected by sensing changes in reflected light, instead of interpreting the motion of a rolling sphere.an optical mouse does not have moving parts thats why there is no need of cleaning .Also there is no mechanical fatigue and failure in this type of mice. The optical mouse takes microscopic snapshots of the working surface at a rate of more than 1,000 images per second. If the mouse is moved, the image changes . The best surfaces reflect but scatter light; an example is a blank sheet of white drawing paper. Some surfaces do not allow the sensor and DSP to function properly because the irregularities are too small to be detected. An example of a poor optical-mousingsurface is unfrosted glass.

A TRACKBALL MOUSE:A trackball mouse is a pointing device.It consists of a ball held by a socket containing sensors to detect a rotation of the ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a pointer. the operator just continues rolling with trackball but a mouse would have to be lifted and re-positioned. Some trackballs, such as Logitech’s optical-pickoff types, have notably low friction, as well as being dense (glass), so they can be spun to make them coast. Large trackballs are common on CAD workstations. 111Made By:- VISHWARANJAN PATHIK

MECHANICAL MOUSE OR BALL MOUSE:

In 1972, Bill English (builder of Engelbart’s original mouse) invented the ball mouse, while working for Xerox PARC. In this, a single mouse was replaced by the external wheels, which could roll in any direction.Mechanical mouse is a device integrated with an internal metal or rubber ball, which can spin in all directions (left, right, up and down). Thus, the display cursor moves as the mouse detects the direction. The ball in the mechanical mouse spins when it comes in contact with surface on which it is placed.

112Made By:- VISHWARANJAN PATHIK

113Made By:- VISHWARANJAN PATHIK

PrinterA printer is an external hardware output device that takes the electronic data stored on a computer or other device and generates a hard copy of it. For example, if you created a report on your computer you could print several copies to hand out at a staff meeting. Printers are one of the most popular computer peripherals and are commonly used to print text and photos. The picture to the right is an example of an inkjet computer printer, the Lexmark Z605.

Types of printersBelow is a list of all the different types of computer printers. Today, the most common printers used with a computer are Inkjet and Laser printers.•3D printer•All-in-one (AIO) printer•Dot matrix printer•Inkjet printer•Laser printer•LED printer•Multifunction printer (MFP)•Plotter•Thermal printer

114Made By:- VISHWARANJAN PATHIK

Printer interfaces

There are a few different ways a printer can connect to and communicate with a computer (referred to as interfaces). Today, the most common connection types are by USB cable or via Wi-Fi. Below is a full list of cables and interfaces used to connect a computer to a printer.Cat5FirewireMPP-1150Parallel portSCSISerial portUSBWi-Fi

History of the printer

Mechanical printerThe first mechanical printer was invented by Charles Babbage, for use with the Difference Engine, which Babbage developed in 1822. Babbage's printer utilized metal rods with printed characters on each rod to print text on rolls of paper that were fed through the device.

115Made By:- VISHWARANJAN PATHIK

Inkjet printerWhile inkjet printers started being developed in the late 1950s, it wasn't until the late 1970s that they were able to reproduce acceptable digital images. These better quality inkjet printers were developed by multiple companies, including Canon, Epson, and Hewlett-Packard.

Laser printerIn the early 1970s, Gary Starkweather invented the laser printer while working at Xerox. He modified a Xerox 7000 copier to be a laser printer, by having a laser output electronic data onto paper. However, it wasn't until 1984 when Hewlett-Packard introduced the HP LaserJet that laser printers became more widely available and affordable. The following year, Apple introduced the Apple LaserWriter, which introduced PostScript technology to the printer market.

116Made By:- VISHWARANJAN PATHIK

MS DOS COMMANDS

117Made By:- VISHWARANJAN PATHIK

Microsoft Disk Operating System is full form of MS DOS. It is system software. MS-DOS is a single user operating system. MS-DOS support CUI (Character User Interface). At first operating system is Microsoft Disk Operating System from first introduce computer. Here we are going to discuss the MS-DOS commands. MS-DOS is machine language that links between application software and hardware and control all activities. The activities are-

1. MS DOS control by the commands.2. MS-DOS is a single user single task operating system.3. MS-DOS have some utility and necessary to use.4. Only Keyboard used in MS-DOS.5. MS-DOS support CUI.

118Made By:- VISHWARANJAN PATHIK

Types of Files in MS-DOS Commands : Two types of MS-DOS files-System File: These files are controlled to Booting of MS-DOS. Normally three types of files are maintained in DOS. These are- IO.SYS, MSDOS.SYS & COMMAND.COM. The main file of DOS is COMMAND.COM.Start-up File: The Booting time the Start-up File commands are normally run.MS-DOS COMMANDS:MS-DOS commands are used to the function of file and disk activities. There are two types of MS-DOS commands.Internal Command: Internal Command is work by Command.Com file. The features of Internal Command is-•The working speed of this command is very fast.•This command is used much time.•Do not erase Internal Command.•The length of Internal Command is very short.The example of Internal Command is: –DATE, TIME, VOL, VER, CLS,COPY CON, DIR, MD, DEL, REN, TYPE, PROMPT, PAUSE etc.External Command: Some commands are used in external part that is known as External Command. The features of External Command is-The length of External Command is very long.Erased this commands.Working speed is very slow. Example:-ATTRIB, SORT, EDIT, TREE, MOVE, DISKCOPY, FIND, XCOPY, MORE, LABLE, FORMATE etc.

119Made By:- VISHWARANJAN PATHIK

120Made By:- VISHWARANJAN PATHIK

121Made By:- VISHWARANJAN PATHIK

122Made By:- VISHWARANJAN PATHIK

123Made By:- VISHWARANJAN PATHIK

124Made By:- VISHWARANJAN PATHIK

125Made By:- VISHWARANJAN PATHIK

126Made By:- VISHWARANJAN PATHIK

127Made By:- VISHWARANJAN PATHIK

128Made By:- VISHWARANJAN PATHIK

129Made By:- VISHWARANJAN PATHIK

130Made By:- VISHWARANJAN PATHIK

131Made By:- VISHWARANJAN PATHIK

132Made By:- VISHWARANJAN PATHIK

133Made By:- VISHWARANJAN PATHIK

134Made By:- VISHWARANJAN PATHIK

135Made By:- VISHWARANJAN PATHIK

136Made By:- VISHWARANJAN PATHIK

137Made By:- VISHWARANJAN PATHIK

138Made By:- VISHWARANJAN PATHIK

139Made By:- VISHWARANJAN PATHIK

140Made By:- VISHWARANJAN PATHIK

141Made By:- VISHWARANJAN PATHIK

142Made By:- VISHWARANJAN PATHIK

143Made By:- VISHWARANJAN PATHIK

144Made By:- VISHWARANJAN PATHIK

145Made By:- VISHWARANJAN PATHIK

146Made By:- VISHWARANJAN PATHIK

147Made By:- VISHWARANJAN PATHIK

148Made By:- VISHWARANJAN PATHIK

149Made By:- VISHWARANJAN PATHIK

150Made By:- VISHWARANJAN PATHIK

151Made By:- VISHWARANJAN PATHIK

152Made By:- VISHWARANJAN PATHIK

153Made By:- VISHWARANJAN PATHIK

154Made By:- VISHWARANJAN PATHIK

Computer

Networking

155Made By:- VISHWARANJAN PATHIK

156Made By:- VISHWARANJAN PATHIK

Following is the list of hardware's required to set up a computer network.•Client Computer/WorkStation•Server Computer•Network Cables•Switches•Routers•Internal Network Cards•Wireless Network Cards

157Made By:- VISHWARANJAN PATHIK

Local Area Network(LAN),

• which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.

Local Area Network (LAN)

158Made By:- VISHWARANJAN PATHIK

DEFINITION

What is a Topology ?

The physical topology of a network refers to the configuration of cables, computers and other peripherals.

159Made By:- VISHWARANJAN PATHIK

TYPES OF NETWORK TOPOLOGY

Three commonly used network topologies are:-

Bus Topology

Ring Topology

Star Topology

160Made By:- VISHWARANJAN PATHIK

BUS TOPOLOGY

All computers and devices

connected to central cable or bus.

Consists of a main run of cable

with a terminator at each end.

Popular on LANs because they

are inexpensive and easy to

install.

161Made By:- VISHWARANJAN PATHIK

BUS TOPOLOGY

162Made By:- VISHWARANJAN PATHIK

RING TOPOLOGY

Cable forms closed ring or loop,

with all computers and devices

arranged along ring.

Data travels from device to

device around entire ring, in

one direction.

Primarily is used for LANs,

but also is used in WANs.

163Made By:- VISHWARANJAN PATHIK

RING TOPOLOGY

164Made By:- VISHWARANJAN PATHIK

STAR TOPOLOGY

All devices connect to a

central device, called

hub.

All data transferred

from one computer to

another passes through

hub.

165Made By:- VISHWARANJAN PATHIK

STAR TOPOLOGY

166Made By:- VISHWARANJAN PATHIK

STAR TOPOLOGY

167Made By:- VISHWARANJAN PATHIK

• In the mesh topology each computer are connected with each other by separate cable. Create point to point connection to every device on network. If one cable fail data always has alternative path to get to its destination.

• On a large scale, you can connect multiple LANs using mesh topology with leased line.

• This type topology generally use in military area.

MESH TOPOLOGY

168Made By:- VISHWARANJAN PATHIK

DIFFERENTIATION BETWEEN THE THREE TYPES OF NETWORK TOPOLOGY

WHAT ARE THE ADVANTAGES AND DISADVANTAGES OF THE THREE OF NETWORK TOPOLOGY?

169Made By:- VISHWARANJAN PATHIK

SUMMARY

BUS TOPOLOGY

DEFINITION

•All computers and devices connected to central cable

ADVANTAGE

•Easy to connect a computer or peripheral to a linear bus.

•Requires less cable length than a star topology.

DISADVANTAGE

•Entire network shuts down if there is a break in the

main cable.

•Terminators are required at both ends of the backbone

cable.

•Difficult to identify the problem if the entire network

shuts down.

170Made By:- VISHWARANJAN PATHIK

SUMMARY

RING TOPOLOGY

DEFINITION

•Cable forms closed ring or loop, with all computers and devices arranged along ring.

ADVANTAGE

•Data is quickly transferred without a ‘bottle neck’.

•The transmission of data is relatively simple as packets travel

in one direction only.

DISADVANTAGE

•Data packets must pass through every computer between the sender and recipient therefore, this makes it slower.

•If any of the nodes fail then the ring is broken and data cannot be transmitted successfully.

•It is difficult to troubleshoot the ring.

171Made By:- VISHWARANJAN PATHIK

SUMMARY

DEFINITION

•All devices connect to a central device, called hub.

ADVANTAGE

•Easy to install and wire.

•Security can be implemented in the hub/switch.

DISADVANTAGE•Requires more cable length than a linear topology.

If the hub or concentrator fails, nodes attached are disabled.

More expensive than linear bus topologies because of the cost of the concentrators.

STAR TOPOLOGY

•Easy to detect faults and to remove parts

172Made By:- VISHWARANJAN PATHIK

1.Provide redundant path between device.

SUMMARY

DEFINITION

•In the mesh topology each computer are connected with each other by separate cable..

ADVANTAGE

•1.Provide redundant path between device..

The network can be expanded without disruption to current user..

DISADVANTAGERequire more cable then other topology .

Complicated implementations.

MESH TOPOLOGY

173Made By:- VISHWARANJAN PATHIK

CLASSIFICATION OF AREA BY THEIR GEOGRAPHY

NETWORK

PAN LAN WAN MAN CAN

174Made By:- VISHWARANJAN PATHIK

LOCAL AREA NETWORK(LAN)

• LAN is a network which is designed to operate over a small physical area such as an office, factory or a group of buildings.

• LAN’s are easy to design and troubleshoot

• Exchange of information and sharing of resources becomes easy because of LAN.

• In LAN all machines are connected to a single cable.

• Different types of topologies such as star, tree, bus, ring, etc Can be used

• It is usually a privately owned network.

175Made By:- VISHWARANJAN PATHIK

Local Area Network (LAN)• A LAN is a network that is used for communicating among

computer devices, usually within an office building or home.

• LAN’s enable the sharing of resources such as files or hardware

devices that may be needed by multiple users.

• Is limited in size, typically spanning a few hundred meters, and

no more than a mile.

• Is fast, with speeds from 10 Mbps to 10 Gbps.

• Requires little wiring, typically a single cable connecting to

each device.176Made By:- VISHWARANJAN PATHIK

METROPOLITAN AREA NETWORK(MAN)

• It is in between LAN & WAN technology that covers the entire city.

• It uses similar technology as LAN.

• It can be a single network such as cable TV network, or a measure of connecting a number of LAN’s o a large network so that resources can be shared LAN to LAN as well as device to device.

177Made By:- VISHWARANJAN PATHIK

•A metropolitan area network (MAN) is a large computer network that usually spans a city or a

large campus.

•A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks

of buildings to entire cities.

•A MAN might be owned and operated by a single organization, but it usually will be used by

many individuals and organizations.

•A MAN often acts as a high speed network to allow sharing of regional resources.

•A MAN typically covers an area of between 5 and 50 km diameter.

•Examples of MAN: Telephone company network that provides a high speed DSL to customers

and cable TV network

178Made By:- VISHWARANJAN PATHIK

PERSONAL AREA NETWORK(PAN)

• A personal area network is a computer network organized around an individual person.

• It generally consists of a mobile computer, a cell phone or personal digital assistant. PAN enables the communication among these devices.

• It can also be used for communication among personal devices themselves for connecting to a digital level network and internet.

• The PANs can be constructed using wireless or cables.

179Made By:- VISHWARANJAN PATHIK

Personal Area Network (PAN)

180Made By:- VISHWARANJAN PATHIK

CAMPUS AREA NETWORK(CAN)

• The campus area network is made up of an interconnection of LAN with limited geographical area.

• Network equipments such as switches, routers and the transmission media i.e. optical fibre etc are almost entirely owned by the campus owner.

181Made By:- VISHWARANJAN PATHIK

WIDE AREA NETWORK(WAN)

• When network spans over a large distance or when the computers to be connected to each other are at widely separated locations a local area network cannot be used. A wide area network(WAN) is installed.

• The communication between different users of WAN is established using leased telephone lines, satellite links and similar channels.

• It is cheaper and more efficient to use the phone network for the link.

• Most WAN networks are used to transfer large blocks of data between its users.

182Made By:- VISHWARANJAN PATHIK

WAN

MAN

CAN

PAN

LAN

183Made By:- VISHWARANJAN PATHIK

PARAMETERS LAN WAN MAN

Ownership of network

Private Private or public Private or public

Geographical area covered

Small Very large Moderate

Design and maintenance

Easy Not easy Not easy

Communication medium

Coaxial cablePSTN or satellite

links

Coaxial cables, PSTN, optical fibre,

cables, wireless

Bandwidth Low High moderate

Data rates(speed) High Low moderate

DISTINGUISH BETWEEN LAN,WAN,MAN

184Made By:- VISHWARANJAN PATHIK

NETWORK CLASSIFICATION BY THEIR COMPONENT ROLE

LOCAL AREA NETWORK

PEER TO PEER NETWORK CLIENT SERVER NETWORK

185Made By:- VISHWARANJAN PATHIK

PEER TO PEER NETWORK

• In peer to peer network each computer is responsible for making its own resources available to other computers on the network.

• Each computer is responsible for setting up and maintaining its own security for these resources.

• Also each computer is responsible for accessing the required network resources from peer to peer relationships.

• Peer to peer network is useful for a small network containing less than 10 computers on a single LAN .

• In peer to peer network each computer can function as both client and server.

• Peer to peer networks do not have a central control system. There are no servers in peer networks.

• Peer networks are amplified into home group.

186Made By:- VISHWARANJAN PATHIK

ADVANTAGES & DISADVANTAGES OF PEER TO PEER NETWORK

Advantages:

▪ Use less expensive computer hardware

▪ Easy to administer

▪ No NOS required

▪ More built in redundancy

▪ Easy setup & low cost

Disadvantages:

▪ Not very secure

▪ No central point of storage or file archiving

▪ Additional load on computer because of resource sharing

▪ Hard to maintain version control

187Made By:- VISHWARANJAN PATHIK

188Made By:- VISHWARANJAN PATHIK

CLIENT/SERVER NETWORK

• In client-server network relationships, certain computers act as server and other act as clients. A server is simply a computer, that available the network resources and provides service to other computers when they request it. A client is the computer running a program that requests the service from a server.

• Local area network(LAN) is based on client server network relationship.

• A client-server network is one n which all available network resources such as files, directories, applications and shared devices, are centrally managed and hosted and then are accessed by client.

• Client serve network are defined by the presence of servers on a network that provide security and administration of the network.

189Made By:- VISHWARANJAN PATHIK

ADVANTAGES AND DISADVANTAGES OF CLIENT-SERVER NETWORK

Advantages:

▪ Very secure

▪ Better performance

▪ Centralized backup

▪ very reliable

Disadvantages:▪ requires professional

administration

▪ More hardware-intensive

▪ More software intensive

▪ Expensive dedicated software

190Made By:- VISHWARANJAN PATHIK

TYPES OF SERVERS

SERVERS

File server Print serverApplication

serverMessage

severDatabase

server

191Made By:- VISHWARANJAN PATHIK

TYPES OF SERVERS

• File server: These servers provide the services for storing, retrieving and moving the data. A user can read, write, exchange and manage the files with the help of file servers.

• Printer server: The printer server is used for controlling and managing printing on the network. It also offers the fax service to the network users.

• Application server: The expensive software and additional computing power can be shared by the computers in a network with he help of application servers.

• Message server: It is used to co-ordinate the interaction between users, documents and applications. The data can be used in the for of audio, video, binary, text or graphics.

• Database server: It is a type of application server. It allows the uses to access the centralised strong database.

192Made By:- VISHWARANJAN PATHIK

Transmission media or communication Channel

(1) Guided Media - cables

(1) Unguided media – waves through air, water or vacuum i.e. microwaves, radiowaves and satelites.

193Made By:- VISHWARANJAN PATHIK

Cables

Following types of cables are used in networks

• Unshielded Twisted Pair (UTP) Cable

• Shielded Twisted Pair (STP) Cable

• Coaxial Cable

• Fiber Optic Cable

• Wireless LANs

194Made By:- VISHWARANJAN PATHIK

Unshielded Twisted Pair (UTP) Cable

Twisted pair cabling comes in two varieties:

shielded and unshielded. Unshielded twisted

pair (UTP) is the most popular and is

generally the best option for school networks

.

195Made By:- VISHWARANJAN PATHIK

Shielded Twisted Pair (STP) Cable

• A disadvantage of UTP is that it may be susceptible to radio and electrical frequency interference.

• Shielded twisted pair (STP) is suitable for environments with electrical interference; however, the extra shielding can make the cables quite bulky.

• Shielded twisted pair is often used on networks using Token Ring topology.

196Made By:- VISHWARANJAN PATHIK

Coaxial Cable

• Coaxial cabling has a single copper conductor at its center.

• A plastic layer provides insulation between the center conductor and a braided metal shield .

• The metal shield helps to block any outside interference from fluorescent lights, motors, and other computers.

• Outer shield provides the ground.

197Made By:- VISHWARANJAN PATHIK

Optical Fibers

•Fiber optic cabling consists of a center glass core surroundedby several layers of protective materials.

•It transmits light rather than electronic signals eliminatingthe problem of electrical interference.

•This makes it ideal for certain environments that contain alarge amount of electrical interference.

•It has also made it the standard for connecting networksbetween buildings, due to its immunity to the effects ofmoisture and lighting.

198Made By:- VISHWARANJAN PATHIK

Network Device

Modem• Modems are most frequently used to enable

computers to communicate with each other across telephone lines.

• Stands for Modulation – demodulation.• Converts digital signal to analog signal and

vice versa.• Two types- Internal and External

199Made By:- VISHWARANJAN PATHIK

RJ 45 Connector

• Register Jack 45 is an 8 wire connector which is commonly used to connect computers on LAN.

• Looks like RJ-11 telephone connector

200Made By:- VISHWARANJAN PATHIK

Ethernet Card

• Ethernet, is a LAN architecture

developed by the Xerox corporation in

1976, originally for linking

minicomputers at the Palo Alto

Research Center.

• Computers that uses Ethernet

architecture have to install ethernet

card .

• Now computers are coming fitted with

ethernet card.

201Made By:- VISHWARANJAN PATHIK

Hub

•A common connection point for devices in a network.

• Hubs are commonly used to connect segments of a LAN.

•A hub contains multiple ports.

• A passive hub serves simply as a conduit for the data, enabling it to go from one device (or segment) to another.

•Active hub electrically amplify the signal as it moves from one connected device to another.

•Support 8, 12 or 24 RJ-45 ports

•Used in star or ring topology.202Made By:- VISHWARANJAN PATHIK

Switch

• A switch (switching hub) in the context of networking refers to a device which filters and forwards data packets across a network.

Unlike a standard hub which simply replicates what it receives on one port onto all the other ports, a switching hub keeps a record of the MAC addresses of the devices attached to it.

When the switch receives a data packet, it forwards the packet directly to the recipient device by looking up the MAC address.

A network switch can utilise the full throughput potential of a networks connection for each device making it a natural choice over a standard hub.

In other words, say for instance you had a network of 5 PCs and a server all connected with 10Mbps UTP cable, with a hub the throughput (10Mbps) would be shared between each device, with a switch each device could utilise the full 10Mbps connection.

203Made By:- VISHWARANJAN PATHIK

Repeater• A repeater is an electronic device that receives a weak

or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation.

204Made By:- VISHWARANJAN PATHIK

Bridge – connects two LANS having the same protocol – (e.g. Ethernet or Token ring)

LAN A

Bridge

LAN B

Data notdestined forother network isprevented frompassing over thebridge.

205Made By:- VISHWARANJAN PATHIK

Bridge

• In telecommunication networks, a bridge is a product that connects a

local area network (LAN) to another local area network that uses the

same protocol (for example, Ethernet or Token Ring).

• You can envision a bridge as being a device that decides whether a

message from you to someone else is going to the local area network in

your building or to someone on the local area network in the building

across the street.

• A bridge examines each message on a LAN, "passing" those known to be

within the same LAN, and forwarding those known to be on the other

interconnected LAN (or LANs).

206Made By:- VISHWARANJAN PATHIK

Router

• Router is a specialized network device used to interconnect different types of computer network that uses different protocols e.g. Ethernet to a mainframe.

207Made By:- VISHWARANJAN PATHIK

Uses of Router

A router can be used to connect

• a Local Area Network (LAN) to another LAN,

• a Wide Area Network (WAN) to another WAN,

• a LAN to the Internet.

208Made By:- VISHWARANJAN PATHIK

Working of Router

• Routers transmit data packets through these networks

• determine the best path of transmission, based on a number of factors, including traffic load, line speed, and costs.

209Made By:- VISHWARANJAN PATHIK

Gateway

• Gateway is a device that connects dissimilar networks.

• Establishes intelligent connection between a local network and external networks with completely different structures.

• Gateway is the ISP that connects the user to the internet.

210Made By:- VISHWARANJAN PATHIK

LAN design- General Network Design Process

Access needs and costs

Model Network workload

Select topologies and technologies to satisfy needs

Simulate behavior under expected load

Perform sensitivity test

Rework design as needed211Made By:- VISHWARANJAN PATHIK