Computers and Computers and ApplicationsApplications

CCNA Discovery: Chapter 1CCNA Discovery: Chapter 1

ContentsContents

Section 1-1: Section 1-1:

Computer Systems

Applications

Types of Computers

Binary Numbers

Section 1-2Section 1-2

Computer System Requirements

Computing Devices

Installations and Upgrades

Computer SystemsComputer Systems

In order for a computer system to In order for a computer system to operate, these 3 components must operate, these 3 components must work togetherwork together HardwareHardware Operating System softwareOperating System software Application SoftwareApplication Software

Hardware Hardware

HardwareHardware - the physical components - the physical components of the computer, or the electronic of the computer, or the electronic pieces that make up a computer pieces that make up a computer systemsystem

Hardware includes external and Hardware includes external and internal componentsinternal components

SoftwareSoftware

SoftwareSoftware - the programs that tell the - the programs that tell the computer what to docomputer what to doOperating SystemOperating System software is a set of software is a set of computer programs that manages the computer programs that manages the hardware of a computer.hardware of a computer. An operating system controls the An operating system controls the resources on a computer, including resources on a computer, including memory and disk storage. memory and disk storage. Examples: Windows XP, Windows Vista, Examples: Windows XP, Windows Vista, Linux, Mac OSLinux, Mac OS

Application SoftwareApplication Software

Application software Application software is a program loaded is a program loaded on the computer that performs a specific on the computer that performs a specific task for a user or another application.task for a user or another application.

Examples: word processor, web browser, Examples: word processor, web browser, graphics editor, spreadsheet, mail readergraphics editor, spreadsheet, mail reader

ApplicationsApplications

The computer is only as useful as the The computer is only as useful as the program or application on it. program or application on it.

Applications can be divided into two Applications can be divided into two general categories: general categories:

Business/Industry Software Business/Industry Software – designed to be – designed to be used by specific businessesused by specific businesses

Examples: The Medical industry, CAD programsExamples: The Medical industry, CAD programs

General Use Software General Use Software – designed for a wide – designed for a wide range of usersrange of users

Example: Graphic Editors, Office SuitesExample: Graphic Editors, Office Suites

Local vs. Network ApplicationsLocal vs. Network ApplicationsLocal applications Local applications - Programs, such as word - Programs, such as word processors, that are stored on the hard disk of the processors, that are stored on the hard disk of the computer. computer.

The application runs only on that computer.The application runs only on that computer.

Network applications Network applications – Programs that are designed to – Programs that are designed to run over a network, such as the Internet. run over a network, such as the Internet.

A network application has two components, one that runs on the A network application has two components, one that runs on the local computer and one that runs on a remote computer. local computer and one that runs on a remote computer.

Server: runs on the remote computerServer: runs on the remote computer Client: runs on the local computerClient: runs on the local computer Examples: Email, Web browser, FTP, File SharingExamples: Email, Web browser, FTP, File Sharing

Most computers have a combination of local and network Most computers have a combination of local and network applications installed. applications installed.

Classes of ComputersClasses of ComputersThere are many different types of computers There are many different types of computers available including:available including: Mainframes Mainframes ServersServers DesktopsDesktops WorkstationsWorkstations Laptops Laptops Hand-held portable devicesHand-held portable devices

Each type of computer is designed with a Each type of computer is designed with a particular purpose in mindparticular purpose in mind

MainframesMainframes

Mainframes:Mainframes: a mainframe is a large, powerful a mainframe is a large, powerful computer stored in a secure location, which computer stored in a secure location, which allows users access through dumb terminalsallows users access through dumb terminals Dumb terminals usually consist of just a monitor, Dumb terminals usually consist of just a monitor,

keyboard, and a communication port to the keyboard, and a communication port to the mainframemainframe

Mainframes are very secure because management is Mainframes are very secure because management is centralized and users have very little control over the centralized and users have very little control over the systemsystem

Although mainframes are expensive, the use of dumb Although mainframes are expensive, the use of dumb terminals can be a low cost alternative to providing terminals can be a low cost alternative to providing users with complete computer systemsusers with complete computer systems

ServersServersServersServers are high performance computers used are high performance computers used in businesses and other organizations. in businesses and other organizations. Servers provide services to many end users or Servers provide services to many end users or clients. clients. Services: file storage, email storage, web pages, print Services: file storage, email storage, web pages, print

sharing sharing

Servers usually have specialized hardware that Servers usually have specialized hardware that is optimized for quick response time to multiple is optimized for quick response time to multiple network requests. network requests. multiple Central Processing Units (CPUs)multiple Central Processing Units (CPUs) large amounts of Random Access Memory (RAM) large amounts of Random Access Memory (RAM) multiple high capacity disk drivesmultiple high capacity disk drives

Redundancy and SecurityRedundancy and Security

The services provided by a server are The services provided by a server are often important and may need to be often important and may need to be available to users at all times.available to users at all times.Servers, therefore, often contain duplicate, Servers, therefore, often contain duplicate, or or redundant,redundant, parts to prevent them from parts to prevent them from failing. failing. Automatic and manual backups of data Automatic and manual backups of data are also usually done on a regular basis. are also usually done on a regular basis. Servers are usually kept in Servers are usually kept in securesecure areas areas where access is controlled. where access is controlled.

Server DesignServer Design

Servers Servers come in many different designscome in many different designs standalone tower designstandalone tower design rack mountedrack mounted blade design. blade design.

A server is typically used as a storage point and A server is typically used as a storage point and not a day-to-day end-user device, so it may not not a day-to-day end-user device, so it may not have a monitor or keyboard, or may share a have a monitor or keyboard, or may share a monitor and keyboard with other devicesmonitor and keyboard with other devices

DesktopsDesktops

Desktop PCsDesktop PCs: a desktop PC is a stand-alone : a desktop PC is a stand-alone computer, that is not dependent on other computer, that is not dependent on other computers to operatecomputers to operate Desktop PCs are cheaper than mainframe systems, Desktop PCs are cheaper than mainframe systems,

and allow users to use a GUI (graphical user and allow users to use a GUI (graphical user interface) instead of text-based entryinterface) instead of text-based entry

They are also standardized in terms of hardware and They are also standardized in terms of hardware and operating systemsoperating systems

Desktops support many different types of hardware Desktops support many different types of hardware and application softwareand application software

WorkstationsWorkstationsWorkstationsWorkstations are high-powered business computers are high-powered business computers that are designed for specialized, high-end applicationsthat are designed for specialized, high-end applications

Engineering programs like CAD Engineering programs like CAD 3-D graphics design3-D graphics design Video animation Video animation Virtual reality simulation. Virtual reality simulation.

They may also be used as management stations for They may also be used as management stations for telecommunications or medical equipment. telecommunications or medical equipment. Workstation Hardware is usually more advanced than a Workstation Hardware is usually more advanced than a desktop PC: desktop PC:

multiple CPUsmultiple CPUs large amounts of RAM large amounts of RAM multiple, high-capacity disk drives multiple, high-capacity disk drives powerful graphics capabilities powerful graphics capabilities large monitor or multiple monitorslarge monitor or multiple monitors

Portable DevicesPortable DevicesPortable devices vary in size, power and graphic capability: Portable devices vary in size, power and graphic capability:

Laptop or notebook PCLaptop or notebook PC Tablet PCTablet PC Pocket PCPocket PC Personal Digital Assistant (PDA)Personal Digital Assistant (PDA) Gaming device Gaming device Cell phonesCell phones

LaptopsLaptops are comparable to desktops in usage and are comparable to desktops in usage and processing capability. processing capability.

Built to be lightweight and use less powerBuilt to be lightweight and use less power Many hardware is built-in: mouse, monitor and keyboardMany hardware is built-in: mouse, monitor and keyboard Have a limited number of configurations available, such as video Have a limited number of configurations available, such as video

options and connection typesoptions and connection types Not as easily upgradeable as the desktopNot as easily upgradeable as the desktop

PDAs and Pocket PCsPDAs and Pocket PCsPDAs and pocket PCs have less hardware capabilitiesPDAs and pocket PCs have less hardware capabilities

less powerful CPUs than a laptopless powerful CPUs than a laptop less RAM than a laptop less RAM than a laptop small screens with limited display capabilities small screens with limited display capabilities small input keyboard. small input keyboard.

Multi-Function Devices:Multi-Function Devices: combines a PDA, cell phone, digital camera, and music playercombines a PDA, cell phone, digital camera, and music player provides Internet access and wireless networking capabilityprovides Internet access and wireless networking capability limited processing power similar to the PDAlimited processing power similar to the PDA

Advantages of Portable Computers: Advantages of Portable Computers: information and services are available immediately, almost information and services are available immediately, almost

anywhereanywhere

BinaryBinaryIn a computer, information is represented and stored in a In a computer, information is represented and stored in a digital binary format. digital binary format.

Computers are electronic devices, made up of millions of Computers are electronic devices, made up of millions of tiny circuits, which act like switchestiny circuits, which act like switches

Each switch can have 2 states: Each switch can have 2 states: onon or or offoff

A computer relies on the binary number system to A computer relies on the binary number system to process data: it uses the numbers process data: it uses the numbers 11 and and 00 to represent to represent on and offon and off

Everything that is done on a computer must be Everything that is done on a computer must be translated into a series of 1’s and 0’s, so the computer translated into a series of 1’s and 0’s, so the computer can interpret itcan interpret it

The term The term bitbit is an abbreviation of binary digit and is an abbreviation of binary digit and represents the smallest piece of data – a 1 or 0represents the smallest piece of data – a 1 or 0

ASCII CodeASCII Code•Computers use binary codes to represent and interpret Computers use binary codes to represent and interpret letters, numbers and special characters with bits. letters, numbers and special characters with bits.

•The ASCII Code is used to represent each character as a The ASCII Code is used to represent each character as a string of bits.string of bits.

•Each character is assigned a number, which is then Each character is assigned a number, which is then converted to binaryconverted to binary

Capital letter: A = 01000001Capital letter: A = 01000001

Number: 9 = 00111001Number: 9 = 00111001

Special character: # = 00100011Special character: # = 00100011

ASCII ChartASCII Chart

Data CapacityData Capacity

Information or data capacity in computers is Information or data capacity in computers is measured in terms of the measured in terms of the bitbitEach group of Each group of eight bitseight bits, such as the , such as the representations of letters and numbers, is representations of letters and numbers, is known as a known as a byte.byte.

UnitUnit MeasurementMeasurement Used to measureUsed to measurebit bit a 0 or 1a 0 or 1 a binary decisiona binary decisionbyte byte 8 bits8 bits 1 character1 characterKilobyte (KB)Kilobyte (KB) 1,000 bytes1,000 bytes text documentstext documentsMegabtye (MB)Megabtye (MB) 1 million bytes1 million bytes (1,000 kb)(1,000 kb) multimedia files, RAMmultimedia files, RAMGigabyte (GB)Gigabyte (GB) 1 billion bytes1 billion bytes (1,000 mb)(1,000 mb) hard drives, DVDshard drives, DVDsTerabyte (TB)Terabyte (TB) 1 trillion bytes1 trillion bytes (1,000 gb)(1,000 gb) High capacity driveHigh capacity drivePetabyte (PB)Petabyte (PB) 1,000 terabytes (21,000 terabytes (25050 bytes) bytes) National databasesNational databasesExabyte (EB) Exabyte (EB) 1 billion GB 1 billion GB (1 quintillion bytes) (1 quintillion bytes) all words ever spoken = 5 EBall words ever spoken = 5 EB

Note: 1kb = 1 kilobit while 1KB = 1 kilobyte Note: 1kb = 1 kilobit while 1KB = 1 kilobyte

BandwidthBandwidth

Bandwidth Bandwidth is a measurement of how much is a measurement of how much information can be transferred within a particular information can be transferred within a particular period of timeperiod of time

Bandwidth is measured in terms of Bandwidth is measured in terms of bits per secondbits per second

Kilobits per SecondKilobits per Second (Kbps)(Kbps)

KiloBytes per SecondKiloBytes per Second (KBps)(KBps)

Megabits per Second Megabits per Second (Mbps)(Mbps)

MegaBytes per Second MegaBytes per Second (MBps)(MBps)

Gigabits per Second Gigabits per Second (Gbps)(Gbps)

GigaBytes per Second GigaBytes per Second (GBps)(GBps)

Bandwidth Calculations: Bandwidth Calculations:

Download Time Download Time = = Size of FileSize of File

BandwidthBandwidth

Example: How long would it take to transfer a 10 MB file over 1.54 Example: How long would it take to transfer a 10 MB file over 1.54 Mbps connection?Mbps connection?

TimeTime = = 10 MB 10 MB

1.54 Mbps1.54 Mbps

(10 MB x 8) = (10 MB x 8) = 80 Mb 80 Mb

1.54 Mb/s1.54 Mb/s

Time =Time = 80 Mb80 Mb

1.54 Mb/s1.54 Mb/s

Time =Time = 80 80

1.54 s1.54 s

Time =Time = 52 seconds52 seconds

Decimal Numbering SystemDecimal Numbering System

Example:2134 = (2x103) + (1x102) + (3x101) + (4x100)

Binary NumbersBinary Numbers

• The binary number system uses only two The binary number system uses only two symbols – symbols – 00 and and 11 – instead of the ten – instead of the ten symbols used in the decimal numbering symbols used in the decimal numbering system. system.

• The position, or place, of each digit The position, or place, of each digit represents the number 2 – the base represents the number 2 – the base number – raised to a power (exponent), number – raised to a power (exponent), based on its position (20, 21, 22, 23, 24, based on its position (20, 21, 22, 23, 24, etc.) etc.)

Binary Numbering SystemBinary Numbering System

256: The magic number256: The magic number

How many different number combinations How many different number combinations can be made with 8 bits?can be made with 8 bits?If you do the math you will see that 8 bits, If you do the math you will see that 8 bits, or 1 byte, can represent 256 different or 1 byte, can represent 256 different valuesvalues The numbers 0 to 255 = 256 possible valuesThe numbers 0 to 255 = 256 possible values

The number 256 is important in The number 256 is important in computing: computing: the RGB color scheme contains 256 values the RGB color scheme contains 256 values

for each of red, green, and blue. for each of red, green, and blue.

Binary to Decimal ConversionBinary to Decimal Conversion

= (1 x 128) + (0 x 64) + (0 x 32) + (1 x 16) + (1 x 8) + (0 x 4) + (0 x 2) + (1 x 1)

= 128 + 0 + 0 + 16 + 8 + 0 + 0 + 1

= 153

1. Write out each bit in the binary number over its place value

2. Multiply out each bit value (0 or 1) by its place value (ex. 1 x 128)

3. Add up all the numbers to get the decimal equivalent

1 0 0 1 1 0 0 110011001 =

Decimal to Binary ConversionDecimal to Binary Conversion

Example:

Convert the decimal number 199 to a binary number.

1. Divide the Decimal number by the highest order bit in the 8-bit binary number (the 128th place)

2. If the decimal number can be divided at least once by the place value (ex. 200 / 128), then put a 1 in that place value, and carry the remainder

3. If the number can not be divided by the place value, put a 0 in that place value and carry the remainder

4. Continue to divide the decimal number by each binary place value, until you get to the 1’s place

1 1 0 0 0 1 1 11 1 0 0 0 1 1 1 R71 R7 R3 R1

199 =

Counting in BinaryCounting in BinaryIt is very useful to be able to count in binary, It is very useful to be able to count in binary, at least up to the number 15, when working at least up to the number 15, when working with computers and networkswith computers and networksCounting in binary is usually done using Counting in binary is usually done using only the 4 only the 4 least-order bitsleast-order bits the first 4 bits on the right side of an 8 bit the first 4 bits on the right side of an 8 bit

number are called the least-order bitsnumber are called the least-order bits These represent the 8’s, 4’s, 2’s and 1’s These represent the 8’s, 4’s, 2’s and 1’s

placeplaceThe 4 high-order bits on the left (128, 64, 32 The 4 high-order bits on the left (128, 64, 32 and 16 place) are assumed to be all 0’s, and 16 place) are assumed to be all 0’s, therefore they can be left outtherefore they can be left out..

Binary CountingBinary CountingFull BinaryFull Binary Decimal Decimal Binary Counting Binary Counting

0000000000000000 00 000000000000000100000001 11 000100010000001000000010 22 001000100000001100000011 33 001100110000010000000100 44 010001000000010100000101 55 010101010000011000000110 66 011001100000011100000111 77 011101110000100000001000 88 100010000000100100001001 99 100110010000101000001010 1010 1010101000001010 00001010 1111 1011101100001100 00001100 1212 1100110000001101 00001101 1313 1101110100001110 00001110 1414 1110111000001111 00001111 1515 11111111

Bit PatternsBit Patterns

As you start working with IP addresses and As you start working with IP addresses and subnets, it will be very useful to learn to subnets, it will be very useful to learn to recognize some common bit patterns that are recognize some common bit patterns that are used in computing and networking. used in computing and networking.

Common bit Patterns in Networking: Common bit Patterns in Networking: 10000000 = 12810000000 = 12811000000 = 19211000000 = 19211100000 = 22411100000 = 22411110000 = 24011110000 = 24011111000 = 24811111000 = 24811111100 = 25211111100 = 25211111110 = 25411111110 = 25411111111 = 25511111111 = 255

Computer System RequirementsComputer System Requirements

There are many types of computers. There are many types of computers.

What makes one computer better for a certain What makes one computer better for a certain task are the components and peripherals that task are the components and peripherals that make up the computer system.make up the computer system.

It is important to determine the intended uses for It is important to determine the intended uses for a computer before deciding on the type of a computer before deciding on the type of computer and components to purchase.computer and components to purchase.

The final product must match the requirements The final product must match the requirements of the end user. of the end user.

Important ComponentsImportant Components

Important components to consider when Important components to consider when purchasing a computer: purchasing a computer: MotherboardMotherboard ProcessorProcessor RAMRAM StorageStorage Adapter cardsAdapter cards Case Case Power SupplyPower Supply

Purchase OptionsPurchase Options

When purchasing a computer, there are 2 When purchasing a computer, there are 2 main options:main options:

1.1. Preassembled computersPreassembled computers

2.2. Custom Built computersCustom Built computers

Each option has its advantages and its Each option has its advantages and its disadvantagesdisadvantages

Preassembled ComputersPreassembled Computers

Advantages:Advantages: Lower costLower cost Adequate to perform most applicationsAdequate to perform most applications No waiting period for assemblyNo waiting period for assembly Typically used by less knowledgeable Typically used by less knowledgeable

consumers who do not require special consumers who do not require special needsneeds

Disadvantages:Disadvantages: Often lack the performance level that can be Often lack the performance level that can be

obtained from custom built computersobtained from custom built computers

Custom Built ComputersCustom Built ComputersAdvantages:Advantages:

The end-user can specify exact components that The end-user can specify exact components that meet user needsmeet user needsGenerally support higher performance Generally support higher performance applications such as graphics, gaming, and applications such as graphics, gaming, and server applicationsserver applications

Disadvantages:Disadvantages:Generally more costly than a preassembled Generally more costly than a preassembled devicedeviceLonger waiting periods for assemblyLonger waiting periods for assembly

Computing DevicesComputing DevicesA computer performs A computer performs 4 main tasks, 4 main tasks, and each requires and each requires a different type of hardware devicea different type of hardware device Input Devices: Input Devices:

Allow the user to give data to the computerAllow the user to give data to the computerInput devices include: keyboard, mouse, scanner, tablet, Input devices include: keyboard, mouse, scanner, tablet, microphonemicrophone

Processing Device:Processing Device:Reads and executes data and instructionsReads and executes data and instructionsData must be read, organized and checked for accuracyData must be read, organized and checked for accuracyThe CPU (central processing unit) performs this taskThe CPU (central processing unit) performs this task

Output DevicesOutput DevicesAllow the computer to give data back to the userAllow the computer to give data back to the userOutput devices include: monitor, printer, speakersOutput devices include: monitor, printer, speakers

Storage DevicesStorage DevicesAllows data to be stored for use at a later dateAllows data to be stored for use at a later dateStorage devices include :hard drive, floppy drive, CD/DVD burner, Storage devices include :hard drive, floppy drive, CD/DVD burner, flash drives, tape backupsflash drives, tape backups

Types of Computing DevicesTypes of Computing DevicesThere are 4 types of Computing Devices:There are 4 types of Computing Devices: InputInput OutputOutput storage storage networking devicesnetworking devices

Examples:Examples: Input devices - trackball, joystick, scanner, digital Input devices - trackball, joystick, scanner, digital

camera, digitizer, barcode reader, microphonecamera, digitizer, barcode reader, microphone Output devices - printer, plotter, speakers, Output devices - printer, plotter, speakers,

headphonesheadphones Storage devices - secondary hard drive, external Storage devices - secondary hard drive, external

CD/DVD devices, flash drives CD/DVD devices, flash drives Networking - external modems, external NICNetworking - external modems, external NIC

MotherboardMotherboardThe motherboard is a large circuit board used to connect the The motherboard is a large circuit board used to connect the electronics and circuitry that make up the computer system. electronics and circuitry that make up the computer system. Motherboards contain connectors which allow major system Motherboards contain connectors which allow major system components such as the CPU and RAM to attach to the board. components such as the CPU and RAM to attach to the board. The motherboard moves data between the various connections and The motherboard moves data between the various connections and system components. system components. A motherboard can also contain connector slots for network, video A motherboard can also contain connector slots for network, video and sound cards. and sound cards. Many motherboards now come equipped with these features as Many motherboards now come equipped with these features as integrated components. integrated components.

Choosing a MotherboardChoosing a Motherboard

When selecting a motherboard it must:When selecting a motherboard it must:Support the selected Support the selected CPU typeCPU type and speed and speed

Support the amount and type of Support the amount and type of system RAMsystem RAM required by the applicationsrequired by the applications

Have Have sufficient slotssufficient slots of the correct type to accept of the correct type to accept all required interface cardsall required interface cards

Have Have sufficient interfacessufficient interfaces of the correct type of the correct type

Central Processing Unit (CPU)Central Processing Unit (CPU)The CPU is the nerve center of the computer The CPU is the nerve center of the computer system. system.

It is the component that processes all of the data It is the component that processes all of the data within the machine. within the machine.

The type of CPU should be the first decision The type of CPU should be the first decision made when building or updating a computer made when building or updating a computer system. system.

Important factors when selecting a CPU are: Important factors when selecting a CPU are: processor speed processor speed bus speedbus speed Socket type – must be Socket type – must be

compatible with the mobocompatible with the mobo

Processor SpeedProcessor Speed

Processor speed measures Processor speed measures how fast a CPU how fast a CPU cycles informationcycles information Usually measured in Usually measured in MHzMHz or or GHzGHz

The higher the speed the faster the performanceThe higher the speed the faster the performance

Faster processors consume more power and Faster processors consume more power and create more heatcreate more heat Mobile devices, such as laptop computers, typically Mobile devices, such as laptop computers, typically

use processors that are slower and consume less use processors that are slower and consume less power in order to extend the time they can operate power in order to extend the time they can operate using batteries.using batteries.

Bus SpeedBus Speed

CPUs transfer data between various types CPUs transfer data between various types of memory on the system board during its of memory on the system board during its operation. operation.

The The BusBus is the pathway for this movement is the pathway for this movement of dataof data

The faster the bus, the faster the computer The faster the bus, the faster the computer will bewill be

Choosing a CPUChoosing a CPU

When selecting a CPU, keep in mind that When selecting a CPU, keep in mind that applications continue to evolve, if the CPU is not applications continue to evolve, if the CPU is not sufficiently fast, the overall performance, sufficiently fast, the overall performance, measured in terms of response time, will be measured in terms of response time, will be slower.slower.

The CPU is mounted through a socket on the The CPU is mounted through a socket on the motherboard and is normally the largest motherboard and is normally the largest component on the board. component on the board.

The motherboard must be equipped with a The motherboard must be equipped with a compatible socketcompatible socket to accept the selected CPU. to accept the selected CPU.

Random Access Memory (RAM)Random Access Memory (RAM)RAMRAM is the temporary data storage in a is the temporary data storage in a computercomputerIt is used to store data and instructions It is used to store data and instructions that are currently being processed by the that are currently being processed by the CPU. CPU. Data in RAM is accessed in any order, or Data in RAM is accessed in any order, or at random, as needed. at random, as needed. All computer programs run from RAM. All computer programs run from RAM. Besides the CPU, the amount of RAM is Besides the CPU, the amount of RAM is the most important factor in computer the most important factor in computer performance.performance.

Choosing RAMChoosing RAMWhen choosing how much RAM to put in a When choosing how much RAM to put in a computer, you should consider the following: computer, you should consider the following:

1.1. The amount of Multi-Tasking requiredThe amount of Multi-Tasking requiredMost computers are capable of running multiple Most computers are capable of running multiple applications simultaneously, or multi-tasking. applications simultaneously, or multi-tasking. All of these applications require memory. All of these applications require memory. The more applications that need to run simultaneously, the The more applications that need to run simultaneously, the more RAM required.more RAM required.

2.2. How many processors the system hasHow many processors the system has More RAM is needed for multiple processor systemsMore RAM is needed for multiple processor systems

3.3. CPU and bus speedCPU and bus speed A faster CPU and bus require more RAMA faster CPU and bus require more RAM

4.4. The RAM configuration that the motherboard will The RAM configuration that the motherboard will supportsupport

Adapter CardsAdapter Cards

Adapter cards Adapter cards add functionalityadd functionality to a to a computer system. computer system. They plug into a connector or slot on the They plug into a connector or slot on the

motherboard motherboard Many motherboards have built-in components Many motherboards have built-in components

that perform the same functions as adapter that perform the same functions as adapter cardscards

On-Board components do not usually produce On-Board components do not usually produce the same level of performance as adapter the same level of performance as adapter cardscards

Adapter CardsAdapter Cards

Common adapter cards:Common adapter cards:Video cardsVideo cardsSound cardsSound cardsNetwork interface cardsNetwork interface cardsModemsModemsInterface cardsInterface cardsController cardsController cards

Video Card

Sound Card

NIC

NICsNICsA Network Interface Card (NIC) is the A Network Interface Card (NIC) is the computer's interface with the LAN. computer's interface with the LAN. The NIC communicates with the network The NIC communicates with the network through serial connections and through serial connections and communicates with the computer through communicates with the computer through parallel connections. parallel connections. NICs are expansion cards (PCI or ISA) NICs are expansion cards (PCI or ISA) that can be installed in one of the that can be installed in one of the computer's expansion slots. computer's expansion slots. The network cable plugs in to the The network cable plugs in to the computer through the adapter card or NIC. computer through the adapter card or NIC.

Choosing a NICChoosing a NICThere are 3 important considerationsThere are 3 important considerations to keep to keep

in mind when selecting a NIC to use on a in mind when selecting a NIC to use on a network:network:

The type of networkThe type of network – most NICs are designed for – most NICs are designed for Ethernet LANs, however there are other network Ethernet LANs, however there are other network typestypesThe type of mediaThe type of media – The type of port or connector – The type of port or connector that the NIC provides for network connection is for that the NIC provides for network connection is for specific media types such as twisted-pair, fiber-specific media types such as twisted-pair, fiber-optic, or wireless. optic, or wireless. The type of system bus of the PCThe type of system bus of the PC – The PCI slots – The PCI slots are faster than ISA. are faster than ISA.

Storage DevicesStorage Devices

Non-volatile storage provides permanent Non-volatile storage provides permanent storage of data and programsstorage of data and programs

Storage Devices:Storage Devices: Magnetic storage devices –DrivesMagnetic storage devices –Drives Optical storage devices – CD, DVDOptical storage devices – CD, DVD Static memory drives – Flash DriveStatic memory drives – Flash Drive

Magnetic Storage DevicesMagnetic Storage Devices

Magnetic storage devices, or drives, are Magnetic storage devices, or drives, are the most common form found in the most common form found in computers. computers.

Drives store information in the form of Drives store information in the form of magnetic fields. magnetic fields. Hard disk drivesHard disk drives Floppy drives Floppy drives Tape drivesTape drives

Optical DrivesOptical DrivesOptical storage devices use Optical storage devices use laser beamslaser beams to to record information by creating differences in record information by creating differences in optical densityoptical densityCDs and DVDs come in three different formats:CDs and DVDs come in three different formats: Read only: CD, DVDRead only: CD, DVD Write once: CD-R, DVD-RWrite once: CD-R, DVD-R Write many: CD-RW, DVD-RWWrite many: CD-RW, DVD-RW

Blu-ray discsBlu-ray discs: a type of DVD that uses a different : a type of DVD that uses a different type of laser to read and write data. type of laser to read and write data. The color of the laser used to store this information is The color of the laser used to store this information is

blue-violet. blue-violet. conventional DVDs use a red laseconventional DVDs use a red lase Blu-ray disks have storage capacities of 25 GB and Blu-ray disks have storage capacities of 25 GB and

moremore

Flash DevicesFlash Devices

Static memory devices, like Flash drives Static memory devices, like Flash drives use use memory chipsmemory chips to store information. to store information. This information is retained even after power This information is retained even after power

is turned off. is turned off. They connect to a USB port on the computer They connect to a USB port on the computer Many portable and hand-held devices rely Many portable and hand-held devices rely

entirely on static memory for storage.entirely on static memory for storage.

Choosing Storage DevicesChoosing Storage Devices

When purchasing storage for a computer system, it is When purchasing storage for a computer system, it is a good idea to have a mix of magnetic storage, optical a good idea to have a mix of magnetic storage, optical drives and static memorydrives and static memory

When determining storage requirements, be sure to When determining storage requirements, be sure to allow for growth by adding an additional 20% of allow for growth by adding an additional 20% of

storage above estimated needsstorage above estimated needs. .

Peripheral DevicesPeripheral Devices

A peripheral is a device that is added to A peripheral is a device that is added to the computer to expand its capabilities.the computer to expand its capabilities. devices that are not required for the basic devices that are not required for the basic

functioning of the computerfunctioning of the computer used to increase the usefulness of the used to increase the usefulness of the

machinemachine connected externally to the computer using a connected externally to the computer using a

specialized cable or wireless connectionspecialized cable or wireless connection

Peripheral DevicesPeripheral Devices

Computer CaseComputer Case

Once you have determined all of the Once you have determined all of the internal components and connections, the internal components and connections, the case is the next consideration. case is the next consideration. Case types:Case types: Desktop - easy access to interfaces and Desktop - easy access to interfaces and

drives but occupy valuable desk spacedrives but occupy valuable desk space Tower – access to interfaces is not as Tower – access to interfaces is not as

convenientconvenient

The case and power supply are usually The case and power supply are usually sold together as a unit. sold together as a unit.

Power SupplyPower SupplyThe power supply must be sufficient to power the system The power supply must be sufficient to power the system and any devices that are added to it in the future.and any devices that are added to it in the future.Computer systems require a steady supply of continuous Computer systems require a steady supply of continuous power. power. The power from many electricity supply companies is The power from many electricity supply companies is subject to voltage reductions and cuts. subject to voltage reductions and cuts. A poor power supply can affect the performance of A poor power supply can affect the performance of computer hardware and possibly damage it. computer hardware and possibly damage it. These power issues can also corrupt software and data. These power issues can also corrupt software and data. In order to help protect the computer system from these In order to help protect the computer system from these power problems, devices such as power problems, devices such as surge suppressorssurge suppressors and and uninterruptible power suppliesuninterruptible power supplies (UPS) have been (UPS) have been developed.developed.

Surge ProtectorsSurge ProtectorsA A surge protectorsurge protector, or suppressor is designed to remove , or suppressor is designed to remove voltage spikes and surges from the power line and voltage spikes and surges from the power line and prevent them from damaging a computer system. prevent them from damaging a computer system. Inexpensive and easy to installInexpensive and easy to installPlugged in between the power outlet and the computer Plugged in between the power outlet and the computer system system Many also have connectors for phone lines to protect Many also have connectors for phone lines to protect modems from damage due to voltage surges that may modems from damage due to voltage surges that may be carried through the telephone lines.be carried through the telephone lines.

UPSUPSA UPS is a device that A UPS is a device that continually monitors the powercontinually monitors the power to a computer system and to a computer system and maintains the chargemaintains the charge on an on an internal battery.internal battery.If the power is interrupted, the UPS provides backup If the power is interrupted, the UPS provides backup power to the system without interruption. power to the system without interruption. The backup power comes from a battery inside the The backup power comes from a battery inside the UPS and can only power the computer system for a UPS and can only power the computer system for a short period of time. short period of time. UPSs are designed to provide the end-user with UPSs are designed to provide the end-user with sufficient time to properly shut down a computer sufficient time to properly shut down a computer system should the main power fail. system should the main power fail. A UPS can also provide an even flow of power to the A UPS can also provide an even flow of power to the computer and prevent damage caused by voltage computer and prevent damage caused by voltage surgessurges..

ESDESDESD ESD (Electrostatic Discharge) is static electricity (Electrostatic Discharge) is static electricity that can be transferred from your body to that can be transferred from your body to electronic components in the computer.electronic components in the computer.Internal system components are especially Internal system components are especially sensitive to static electricity.sensitive to static electricity. ESD can cause catastrophic failures in components, ESD can cause catastrophic failures in components,

making them non-functional. making them non-functional. ESD can also cause intermittent faults which are very ESD can also cause intermittent faults which are very

difficult to isolate. difficult to isolate.

Proper grounding is important to prevent ESDProper grounding is important to prevent ESD A Wrist grounding strap can be used to connect the A Wrist grounding strap can be used to connect the

technician to the computer case. technician to the computer case. Grounding ensures that they both reach the same Grounding ensures that they both reach the same

voltage potential and ESD is prevented.voltage potential and ESD is prevented.

Lab SafetyLab Safety

Upgrading ComponentsUpgrading Components

Hot-swappableHot-swappable computer components are computer components are those that can be changed without turning off the those that can be changed without turning off the powerpower This allows the system to remain operational during This allows the system to remain operational during

repairs or upgrades and is usually found in high repairs or upgrades and is usually found in high performance servers.performance servers.

Example: Flash drives, USB devicesExample: Flash drives, USB devices

Inserting or removing components that are not Inserting or removing components that are not hot-swappable, while the power is on can cause hot-swappable, while the power is on can cause serious damage to the systemserious damage to the system

Installing and UpgradingInstalling and UpgradingAlways follow these procedures when installing and Always follow these procedures when installing and upgrading components:upgrading components:

1.1. Determine if the component is hot-swappable. If not, or if in doubt, Determine if the component is hot-swappable. If not, or if in doubt, unplug the system unit before opening the case.unplug the system unit before opening the case.

2.2. Attach a Attach a grounding strapgrounding strap from your body to the system chassis, to from your body to the system chassis, to prevent any damage which may be caused by ESD.prevent any damage which may be caused by ESD.

3.3. If replacing a component, remove the old component first. When If replacing a component, remove the old component first. When removing screws do not to let them drop on the system removing screws do not to let them drop on the system motherboard. Also, be careful not to break any plastic clips. motherboard. Also, be careful not to break any plastic clips.

4.4. Check the connection type on the new component. Each card is Check the connection type on the new component. Each card is designed to work only with a certain type of connector and should designed to work only with a certain type of connector and should not be forced when inserting or removing the card.not be forced when inserting or removing the card.

5.5. Place the new component in the correct connection slot, with the Place the new component in the correct connection slot, with the correct orientation, carefully following all installation instructions correct orientation, carefully following all installation instructions that may have accompanied the component. that may have accompanied the component.

Verifying OperationVerifying OperationOnce the component has been added or upgraded, close Once the component has been added or upgraded, close the case and reconnect the power and other cables. the case and reconnect the power and other cables. Switch on the system and watch for any messages that Switch on the system and watch for any messages that may appear on the screen. may appear on the screen. If the system fails to start, disconnect all cables and verify If the system fails to start, disconnect all cables and verify that the component was properly installed. that the component was properly installed. If the system still will not start with the new component If the system still will not start with the new component installed, remove it and try to start the system. installed, remove it and try to start the system. If the system starts without the new component, the If the system starts without the new component, the component may not be compatible with the current component may not be compatible with the current hardware and software and additional drivers might be hardware and software and additional drivers might be necessarynecessary Most common devices have drivers that are included in the Most common devices have drivers that are included in the

operating systemoperating system Some specialized devices may need separate drivers to be Some specialized devices may need separate drivers to be

installedinstalled It is always a good idea to download the latest drivers from the It is always a good idea to download the latest drivers from the

InternetInternet

Verifying OperationVerifying Operation2 common causes of new hardware failure: 2 common causes of new hardware failure:

Incorrect or missing driver filesIncorrect or missing driver files System Resource conflictSystem Resource conflict

Components are designed to make use of specific sets Components are designed to make use of specific sets of of system resources. system resources.

If 2 components try to use the same resources one, or both, will If 2 components try to use the same resources one, or both, will failfail

Change the resources used by one of the devicesChange the resources used by one of the devices Newer components and operating systems are able to Newer components and operating systems are able to

dynamically assign system resources. dynamically assign system resources.

If a device fails to function properly: If a device fails to function properly: verify that the correct and most recent driver is installedverify that the correct and most recent driver is installed check that the operating system has correctly detected and check that the operating system has correctly detected and

identified the deviceidentified the device power down the system, carefully reseat the component, and power down the system, carefully reseat the component, and

verify that all connections are correct. verify that all connections are correct. Check the component documentation for the correct settings.Check the component documentation for the correct settings.