COMPUTERAn electronic device capable of processing data (input) into meaningful information (output), stored, and retrieved by the live ware (user) when needed.

DATA (INPUT): Are raw facts that are fed into the computer for processing into meaningful information. Example; keyboard, mouse, scanner, joystick, flash drive, CD-Rom

INFORMATION (OUTPUT)It is the process data of which definite meaning can be achieved. Example: Monitor, Printer, Speaker, etc

ELECTRONIC DEVICEAre the gadgets/peripherals that use electricity to accomplish the mission of the computer and the user as well.

STORAGEIs an area where information is kept over a period of time and it can be either internal (primary) or external (secondary).

BOOTINGIs the act of causing the major components within the computer to initialize and operate as it was.

COOL BOOTINGIt is the situation whereby the computer is witch on for the first time while it was at rest.

WARM BOOTINGThe process of restarting the computer with the reset button on the system unit, the keyboard (ctrl + Alt + Del) or the mouse.

KEYBOARDIt is an input device used to feed data to the CPU for processing. There are different types of keyboard as shown below;Standard Keyboard: 5 pins din male connectorPS/2 / USB Connector: PS – Place Station.Enhanced Keyboard: 6 pins/mini din male connector.

KEYBOARD KEYSFunctional Keys (F1 – F12)Special KeysTyping Keys/ Alpha-numeric KeysHome Page KeysCursor Ctrl KeysNumeric Keypad

INSIDE THE PERSONAL COMPUTER (PC)Most Computers contains the following inside a case; System Board: Containing CPU, Memory and other components. Drives: floppy drive, hard disk, CD-ROM, Tape drive, etc. Power Supply with power cables supplying electricity to all the devices. Circuit Boards: are boards that hold microchips or integrated circuits (ICs)

and the circuitry that connect these chips. It is used by the Central Processing Unit (CPU) to communicate with the devices inside and outside.

COMPLEMENTARY METAL OXIDE SEMICONDUCTOR (CMOS)CMOS chips require less electricity to hold data longer after electicity is turn off and produce less heat. The devices that the CPU communicates, that are not directly on the system board are called P eripheral devices and are linked to the CPU through a connection to the system board. Expansion cards are installed in long narrow slots on the system board called Expansion Slots.

There are two types of cables inside the case, Data Cable (Ribbon Cables) which connect drives to the system board and all data cables are flat and wider.

Core Cable, which also supply power from the power supply to the drives and are round and small in size. However, the best way to identify the cables is to tract it source and destination.

SYSTEM BOARDIt is the largest and most important circuit board in a computer and it is sometimes called System Board, Main board or Mother Board that contains; micro CPU, the component that processes all data. This board is one of the complicated peaces of equipment inside a case. All devices must either have direct or indirect link to this board through a port on the system board or by expansion cards to communicate with the CPU on the system board.

PURPOSE OF SYSTEM BOARDIt is to house the CPU and allow all devices to communicate with it and each other. The most popular system boards are Older AT and Newer ATX. The AT board has a power connection of +5V and +12V from the power supply while the ATX has a connect ion of +5V, +12V and +3.3V power supply.

MAIN COMPONENT OF THE SYSTEM BOARD.1. CPU and its accompanying chipset2. System Clock.3. ROM BIOS4. CMOS Chip and Battery5. RAM and ROM Cache6. System Bus with Expansion slots7. Jumpers (recognition) and DIP Switches8. Power Supply.

CPU AND THE CHIPSET

Chipset (Northbridge) is the nervous system of a computer. The Southbridge also regulates the activities of a computer.Computer manufacturers today use a microprocessor chip made by “INTEL” or one of its competitors AMD (Advanced Micro Device). Early CPU by Intel is identified by model numbers 8088, 80286, 80386 and 80486. The next CPU introduced after 486 was name ‘PENTIUM’ and all CPUs after that had Pentium in their names, eg. Dell Pentium IV. The name Pentium comes from ‘PENTE’, a Greek word for five. AMD, CYRIX are other manufacturers, CYRIX used the X86 names to name their CPUs.

PENTIUM AND IT’S COMPETITORSThe lastest CPU microchip introduced by Intel are the Pentium series. A Pentium has two arithmetic units meaning that it can perform tow calculations at a time. It is therefore a true multi-processor Pentiums have a 64bexternal path size and a 32b internal paths, one for each Arithmetic Logic Unit (ALU).

PROCESSORS SPEEDIt is the speed at which the CPU is operating internally. If the CPU operates at 150MHz internally but 75MHz externally. The processors speed is 150MHz and the memory speed is 75MHz. the CPU is operating twice the speed of a bus and this factor is called MULTIPLIER.Processors Speed = Memory bus speed × the multiplier

CLASSIC PENTIUMThe first Pentium chip introduced in March, 1993 and has now become affectionately known as Classic Pentium but early problems on this PC was attributed to a spreadsheet calculation error which was later resolved. This processor is no longer manufactured.

PENTIUM MMX (Multi Media eXtention)The Pentium MMX targets the home/market. It speeds up graphical applications and performs well with games and MMX softwares. It was improved upon by the production of Pentium Pro, which runs at a maximum speed of 200MHz.

PENTIUM IIIt was design for graphical intensive workstations and service. It works well with 3D graphic manipulations (Computer Aided Design) and MMX presentations. It is classified within the range of 200 – 450MHz. Pentium III was later introduced with much faster system bus and later to Pentium IVs. Intel’s two competitors, AMD and CYRIX Company have the goals to produce CPUs that are just faster and powerful as Intel’s but at a lower cost. Intel’s processors operate in a real and protected mode. Celeron, Athlon, Duron, Ceptron are a few types of other processors in modern PCs.

CPU COOLING FANSBecause micro-CPUs generate much heat, most system uses cooling fans and aluminium heat sinks to keep the temperature below the maximum allowed

limits of 1800F. Good CPU cooling fan can maintain temperature between 800 – 100F.

CPU SLOTS AND SOCKETSSlots and Sockets is a physical connection used to connect device (CPU to the system board). This type of slot/socket provided by the system board to the processor much with what require by the processor. Slot 1&2 are proprietary Intel slot and slot A is AMD slot. The processor may be either a socket or a cartridge type.

Socket Type Pins4 Classic Pentium 2735 Classic Pentium (75, 90, 100, 200MHz) 3207 Pentium MMX, CYRIX M, AMD (K5, K6) 3218 Pentium Pro. 387

PGA, Pentium III PGA, Celeron 370

Slot Type Pins1 Pentium II and III 242A AMD 2422 Pentium II and III, Xeon 320

The 486 and early Pentium uses Pin Grid Array (PGA) socket where pins are alive in uniform row around the socket. Socket 370 is used by two types of processors with two types of package form factors PPGA (Plastic PGA) and FCPGA (Flip Chip PGA). Both have pins on the under side of the processor that insert into the pin hole on the socket 370. Current sockets are referred to as Zero Insertion Force (ZIF) because less force is exerted on the processor.

SYSTEM CLOCK.It keeps e beat for many system boards’ activities. Unit called HERTZ are used in defining the frequency of the clock. It can be express in Megahertz (106/sec), Gigahertz (109/sec) or even Tetra hertz (trillion times/sec). We can now realise how fast the computer processes signals.

BIOS (BASIC INPUT OUTPUT SYSTEM)BIOS (Basic Input Output System) is presented in a chip/module or integrated with the system board. It is encoded with instructions/software that is not fed manually by users. It can be referred to as FIRMWARE (which is a hardware component encoded with a software that’s not fed manually by the livewire) and are in two (2) types namely FLASH & ROM BIOS

FLASH BIOS: Are BIOS provided within the circuitry of the system board and they are sometimes difficult to be identified since they are provided in tiny microchips. The software in this can be upgraded using the requisite (require) upgrade, which can be obtained from the manufacturer or it website.

ROM BIOS: Is a chipset encoded with software that keep the system configuration that is mounted on a BIOS socket and it is replaceable. It can be found in various versions depending on the manufacturer. There are different types of ROM BIOS, some can be assigning to specific component to perform specific task. E.g. Keyboard and Video bios. Some BIOS will display on the screen what key to press to get into the setup.

BIOS Key for setupPhoenix F2, DelAward Del, Ctrl+Alt+DelAMI F2, Ctl+Alt+DelCompaq F10Gateway F2IBM F1Zenix F2

USES OF BIOSIt contains or stored system software programsTo determine the compatibility of a PC

BIOS WRITERSPROM blasters and EPROM programmer

CMOS Chip and BatteryIs a power souce that energised/helps in save guarding and updating information within the ROM BIOS and it is commonly called the LITHNIUM. Manufacturers of these cells/batteries include; Sony, Panasonic, Sanyo, etc. there are various of this type include the THRUM(oldest types of battery found on XT ands some AT boards always soldered on board), COIN battery (spherical in shape, different size as DC voltages 3 – 5 volts). The thrum is also called the Block battery and the Coin (Tablet battery).

RAM and ROM CacheCACHE MEMORYIs a small amount of RAM (Static RAM (SRAM)) that is much faster than the Dynamic RAM (DRAM) because it losses data rapidly and must be refresh often. A memory cache is included on the CPU micro-chip itself is called Internal Cache, Primary Cache, Level 1 (L1) Cache. A cache outside the CPU microchip is called External Cache, Secondary Cache, and Level 2(L2) Cache. L2 caches are usually 128kb, 512kb, or 1MB in size. Some Pentium III CPU contains L2 cache directly the same size as the processor-core and is called Advance Transfer Cache (ATC), which make it difficult to distinguish between L1 and L2 cache.

RAM (RANDOM ACCESS MEMORY)

The CPU uses temporal or primary storage, which is much faster to access than permanent storage. Primary storage is provided by device on the system board and other circuit boards called MEMORY. RAM chips can be installed individually directly in the system board or in banks of several chips on a small board that plug in the system board.TYPES OF RAMThere are many different types of RAM. The type of memory bank you have on the computer determine the type of RAM associate with it.

1. Static Random Access Memory (SDRAM): This kind of memory uses multiple transistors, typically from six, for each memory cell but do not have a capacitor in each cell. It is used primarily for Cache.

2. DYNAMIC RAM (DRAM): DRAM has a memory cell with a paired transistor and capacitor requiring constant refreshing.

3. FAST PAGE MODE DRAM (FPMDRAM): This type of memory was the original form of DRAM. It waits through the entire process of locating a bit of data by column and row and then reading the bit before it starts on the next bit. The maximum transfer rate to L2 cache is approximately 178MB/s

4. EXTENDED DATA-OUT DRAM (DO DRAM): it does not wait for all the processing of the 1st bit before continuing to the next one. As soon as the address of the 1st bits is located, EDO DRAM begins locating for the next bit. It is also about five times faster than FPMDRAM with the maximum transfer rate to L2 cache of 264MB/s.

5. Synchronous DRAM (SDRAM). This type of RAM takes the advantage of the burst mode concept to greatly improve performance. It does this by staying on row containing t he requested bit and moving rapidly through the columns, reading each bit as it goes. The idea is that, most of the time the data needed by the CPU will be in sequence. SDRAM is five percent faster than EDO DRAM, which is the most common form in desktops today with the maximum transfer rate to L2 cache is 528MB/s.

6. DOUBLE DATA RATE SDRAM (DDR SDRAM): It is just like SDRAM except that it has higher bandwidth meaning greater speed with transfer rate to L2 cache of 1,064MB/s (133MHz).

7. Rambus DRAM (RDRAM) isa radial departure from the previous DRAM architecture designed by Rambus. RDRAM uses a RAM bus In-line Memory Module (RIMM) which is similar in size and pin configuration to a standard DIMM (Dual In-line Memory Module). What makes RDRAM so different is similar is, it use of special high-speed data bus called Rambus Channel. RDRAM memory chip operate at a speed of 800MHz / 1,600MB/s, which is faster than all the available RAMs. Due to that, it generate much more heat than the other types of chips and to help dissipate the excess heat, Rambus chips are filtered with a heat spreader (sink) which look like a long thin wafer. in real

MEMORY BANKIt determines the types of memory chips located on the system board. The types of banks that hold memory chips are;

SIPP: Single In-line Pin Package – this is outmoded – zero cut.SIMM: Single In-line Memory Modules – 30 and 72 pin SIMMDDRAM: Dual Data RAM – 184 pin DDRAMRIMM: Rambus In-line Memory Modules – 184 pins RIMMRDRAM: Rambus Dynamic RAM

What ever is stored in the primary memory is lost because RAM need a continues supply of power to hold data stored in them is called VOLATILE/UNSTABLE. By contrast, memory that holds it data permanently such as that of the etched into ROM Chips is NON-VOLATILE/STABLE.

SYSTEM BUS WITH EXPANSION SLOTSBUS: Is a pathway along which signal, data, and power and communication are sent from one component to the other.

ECONOMIC IMPORTANCE OF BUSES Provide wide seat for expansion slot. Determines the speed of a system. Signal carriers. Channels for communication. Major communication component.

PROTOCOL: A Set of rules and standards that any two entities used for communication.

BINARY DIGITS (O’s or 1’s)Binary digits travel down this path side by side. Some buses have data paths that are 8, 16, 32, 63, etc wide. A bus that has 32b/lines that data can travel on is called 32b. a system can have more than one bus, each using different protocol, speed, data path, size, etc. the lines of a bus often terminate at expansion slot. The size and shapes of expansion slot determine the kind of bus it’s using. Therefore one way to determine the kind of bus you have is to examine the expanision slot on the system board. The major expansion slot in modern computers are (PCI – Peripheral Component Interconnect for high speed of IO devices (64b)), AGP (Accelerated Graphic Port – meant for video cards only and ISA (Industrial Standard Architecture for older and slower devices)

BIT(b)A bit (b) is a binary digit, the smallest increament of data on a computer. A bit can hold only one of two values; either 0 or 1, off or on. Bits are usually assembled into a group of eight to form a byte (B). Mathematically, 8.192b = 1B.

BYTE (B)

A byte contains enough information to store characters, example ‘A’, ‘m’, etc. A kilobyte (KB) is 1,024bytes (1,024B) not one thousand bytes (1000B) because computers uses binary (base two) and not decimal (base ten) system.One megabytes (1MB) is 1,024kilobytes (1,024KB) or 1,048,578bytes (1,024x1,024B).

Interface cards/expansion cardsCircuit other than the system board on the computer are called Adaptor board/Cards, Expansion Card/Interface cards or simply cards are mounted on the system board. Some cards include Video, Sound,Network, Modem, etc that enable the CPU to connect to an external device. The easiest way to identify an expansion card is to look at the port on the end of the card. The type of expansion slot found on the motherboard determines the type of interface card to bemounted on them as well as the data path and the speed of transmission.

SOUND EXPANSION (INTERFACE) CARDIt’s an interface card that convert electronically energy into sound energy. On this card are various micro-chips that helps in pre-amplifying electrical signals directed to the loud speaker. This card can either be integrated or separate and it can either be represented as PCI Sound Interface, ISA/EISA, depending the type of skirt associated with the card. The sound interface has a game port that establishes a connection to joysticks and other based station devices. It can be called as Musical Instrument Digital Interface (MIDI) port DB15 Female in two row. It also contains 1/15th inch RJ that serves as a medium of outputting sound or a speaker port from the computer which has a GREEN colour in modern computers. This card also has the Line-input that allows input signal into the system with a BLUE/SEA-BLUE colour. A microphone port can also be identified on this card with a REDDISH/PINK colour. Mono and Stero are the types of speakers. Some speakers have built in amplifiers/boasters which enhances the sound quality from the computer.

MODEMIs an abbreviated word means Modulation and Demodulation. Modulation is the act of transmitting signal for a source while Demodulation is the act of receiving a signal from a transmitted source. This interface is normally linked with a telephone line for communication to establish within a computer and the internet(International Network). The modem can be integrated or on an interface card in a form of PCI, ISA/EISA. The rael of this card has a line-in, line-out port called RJ11 and RJ13 as well as 1/18th inche RJ for microphone and earphone. The RJ11 has four terminals.

NETWORK CARD/ADAPTORIs a card used for computer networking by way of sharing informations on a Local Area Network (LAN) where concerntration of computers are arranged with the view that/ of sharing information as well as resources. The port associated withthis is RJ45 which has eight (8) terminals and it’s bigger than RJ11. it canbe integreated on the system board or separeat on an interface card which also can be found on ISA/EISA depending on the data path.

VIDEO INTERFACE CARDThe video interface have various types (AGP, PCI, ISA/EISA) and can also integrate on the sytem board. The AGP(Accellerated Graphic Port) is an

enhanced bus specifically mean’t for video only.it’s enable one connect to a higher speed of graphics output. It’s for a modern monitor and has (16b, 32b, 64b and above) of data transfer. It enables high quality three dimentionas (3D) graphics to be produce. Video port is called DB15 female iin three rows.

MULTIFUNCTION (I/O) INTERFACE CARDSIs an interface that controls both internal I/O and external I/O. the internal i/O’s are the devices (HD, FD, CD, etc) and the external I/O devices are (printer and PS/2 mouse, COM1& COM2). This interface are mostly linked by a ribbon cable (IDE, SCSI, FLOPPY). Modern computers have their I/O interface card integrated on/within the system board.

MONITORIt is the main basic output device that display information on the screen and also enable the user to monitor exactly what was input into the computer.. Monitors may be of various sizes (8”, 12”, 14”, 15”, 17”, 19”, 21”, 222, 24” and above) the port attached to the cable is DB 15 Male in 3 rows. Those VDU’s that has the number of pins less than 10 are Black and White There are two types of monitors namely CRT (Cathode Ray Tube) and FPD (Flap Panel Display). The CRTs is also in two groups; Digital and Analog

TYPES OF CRTs ( DIGITAL AND ANALOG CRT)DIGITAL CRTIt have low resolutions egMGA – Monochrome Graphic Adaptor (2 colours)CGA - Colour Graphic Adaptor with 4 colours (320×200 pixels)EGA – Enhanced Graphic Adaptor with 14-16 colours (640×350 pixels)

ANALOG CRTVGA – Video Graphic Adaptor (16, 32, 64 colours : 640×480 pixels)SVGA – Super Video Graphic Adaptor support upto 256 colours (800×600 pixels)XGA – eXtra Graphic AdaptorUXGA – Ultra eXtra Graphic AdaptorUSVGA – Ultra SVGA

FLAP PANEL DISPLAY (FPD)LCD – Liquid Crystal DisplayGPD – Gas Plasm DisplayELD – Electron Luminicent Display

RESOLUTIONSIt’s the quality representation of video signal. The higher (bigger) the resolution the clearer (quality) the graphics. These resolutions are set of colours available for viewing on the screen and the colours represent themselves in a tiny dot on the screen which is highly invisible and these dots are called PIXELS. As such are said to be picture element of the monitor. The more the pixels on the VDU’s

the sharper the image would be displayed and so on. Most oftern the graphic card helps to produce such quality graphics. Accelerated Graphics Port (AGP) is the fastest GA which gives advanced colours.

POWER SUPPLY.This is a black box located at the back of the system unit that convert AC to DC. We have the older AT power supply and the new ATX as well.

AT power supply = 5v, 12v.

ATX power supply = 5v, 3.3v and 12v

POWER CABLESThey are cables that extend from the power supply to the drives and are called Molex and Berg respectively.MOLEX – It’s the most commonly and larger connector used by most drives which have four relatively thick wires extending from its back, One yellow, one red, and two black wires..

BERG – It is a power cable that supply power to floppy drives only.

SAFETY PRECAUTIONSThe most common threat tohardware is electricity discharge (ESD) commonly known as Static Electricity Discharge . Damage by ESD can cause catastrophic failure that produce unpresentable malfunction of components whch are often difficult to detect/diagnose.

BEST PRECAUTION AREA grounded strap - It contains resistance that prevents currents from flowing through it. A grounded mat - It is often equip within a cord plug into ground wall outlet and attach one end to the ground strap of the case. A static shielding bag - New components can ship in static shielding bags. ASSEMBLING AND DISASSEMBLING OF PCNever touch any components inside while it turns on.Never touch any component when you are not grounded.Don’t work on carpet because it collect static electricityespecially in cold weather.Check your power supply of the component.Always turn off PC before moving it.Don’t touch chips with magnetized screw driver.Keep disk away from magnet.Keep notes of components movement.

MS DOS (MICRO-SOFT DISK OPERATING SYSTEMIs a command driving system which contains various commands both internal and external. The prompt always indicates the drives in which your find yourself. To indicate a drive letter, an alphabet followed by a colon should be specidifed.e.g. A:, B:, C:, D:, etc.

CHANGING DRIVE LETTERSA:\> C:\> , E:\> A:\>¬

CLS COMMAND (CLEAR SCREEN)It means clear the screen. Eng. A:\> cls

LABEL COMMAND Is used in assigning names to various drives for identification purposes. E.g.C:\> label D: Saints

DATE AND TIMEIt’s used to display the current date and time for configureation whennto correct. A:\> Date, C:\> Time

VER COMMANDTo display the parameter/properties of a drive.e.g. C:\> ver

DIRECTORY COMMAND (DIR) This is used in displaying the content of a drive as well as a directory. Example are, C:\> dir D:, D:\> dir C:, etc.

SWITCHES COMMANDC:\> dir D:/p = display D: in a pause formD:\> dir C:/p/w = display C: in pause and wide form.A:\> dir C:/w = display C: in a wide form.

CHANGE DIRECTORY COMMAND (CD)It is used to moved from a root to parent (Sub) directory. E.g. C:\> cd Saint, D:\> cd kofiTo come out a directory. cd\ or cd. Takes you from the parent to the root straight. The cd.. takes you back one after theother. Example are; C:\> cd., C:\> cd.., etc.

MAKE DIRECTORY (MD) COMMANDIt’s used in creating directory, as well as sub directories. A directory can be any name so long as files can be organised under them. Eg. D: :\> md rasisa, C:\> md saint024, C:\> md confidence, etch

REMOVE DIRECTORY (RD) COMMANDIs used to/in removing /delecting directory in a parent/sub dir,e.g. C:\> rd rasisa, C:\> rd political/saint/ legasy/ confidence means remove confidence under legasy under saint under political

CREATING FILES (EDIT) COMMANDIt is used to creat files under the command promptC: :\> edit filename.extension, then press Alt F, the X and y to save.

e.g. C:\> edit confidence.you, D:\> edit Saint024.wap

TYPE COMMANDIt is used to view the content of a file. Eg. C:\> type filename.extension,e.g. C:\> type Saint024.wap

RENAME (REN) FILE COMMANDIs used to re-assign a name to a file nor directory, like C:\> Ren D: saint024.wap rasisa.mms.C:\> ren fcc\class1\confidence.for saint024.wap

CHECK DISK (CHKDSK) COMMMANDUsed to check disk parameters/properties. Example C:\> chkdsk, D:\> ckdsk, etc.

COPY COMMANDUse to copy files from one directory to the other , for exdamplyk C:\> copy saint024\confidence.mms rasisa\class1.C:\My Documents\OS\BOOT C:\My Documents, etc.

GLOBAL X’CHARACTERS*.* = to copy all files. ExampleC :\> copy My Documents\OS\BOOT\*.* My Documents\OSC :\> copy My Documents\Os\*.* My Documents

?.? = To copy one by one. For exampleC :\> copy My Documents\Os\?.? My Documents.

MOVE COMMANDTo copy all the entire content of a folder to a particular target.C :\> move My Documents\Os\*.* My Documents

TRY QUESTION1. a) Create a directory call West Africa on C: under it sub-directories as Ghana, Nigeria and Togo. Create four files under Ghana namely Volta.bbc, Accra.joy, Kumasi.fox and Takoradi.sky. b) Copy Takoradi.sky to Nigeria and rename it as Abuja.joy.c) Move all files in Ghana toTogo.

X - COPY (XCOPY) COMMANDTo copy all files from C: to D:. this is also used to create unexisting files/directories when copying to a target.e.g. C :\> Xcopy My Documents\Os\*.* C: DocumentsD : xcopy win98/*.* C : Win98

DELECT (DEL) COMMANDIt is used to delet a created files/directories.C:\> del saint024\confidence.mms

To delet all files/directoriesC:\> del saint024\confidence.mms\*.*

FORMAT (F) COMMANDIs is used to erase/clear a disk and prepare it to accept a new information. EgC:\> format F: for normal formatting.C:\> format F:/q for quick formatting.

CHANGING PROMPT$Date – Date$G – Greater than (>)$L – Less than (<)$P – Path$T – TimeExampleC:\> $P Saint $G = C:\Saint>C:\> Saint $t$d$g = C:\ Saint time date >

RESERVE FILES MEANING.bat Batch file .bmp Bit Map file (picture).com System command file.dll Data logic link.doc Document file.exe Executable file.ini Initialization.log Logarithmic file.pif command file.tmp Temporal file.txt Text file.sys System Configuration file.wmf Windows Metal file.xls Spreadsheet file

SYSTEM FILESThey are the main files that the computer would boot from. They are the command.com (Ms Dos.sys and I/O.sys), Autoexec.bat and Config.sys.Command.com - initialise the operating system.Autoexect.bat - how to boot the operating system by loading the batch files.Config.sys - load all the system files.

PARTITION, FORMATTING AND INSTALLATION OF OPERATING SYSTEM (OS)PARTITIONIs the process of creating logical on the hard disk so that, different O/Ss can be found on the same disk.

FORMATTING

Is the process of preparing the disk to accept information. We have normal and quick formatting. There are two types of formatting namely; NTFS and FAT

NTFS is a format the support only higher versions of operating system like Win 2000 and above.

FAT( File Allocation Table)is a type of formatting that support both lower and higher versions of operating system, i.e. from Win 95 upwards.

INSTALLATION OF WIN 98Boot the computer with Diskette support and it would send you to A:\>Make a partition on the disk if necessary, A:\ fdisk>, then follow on screen message to create the partition.Format the disk with FAT A:\ format c:, and change the drive A:\> D:Display the content of D, D:\ dirChoose Win 98, D:\ cd win98 = D:\win 98Disk copy, D:\win 98> copy*.* C:\win 98Go to setup, C:\win 98> setup.Follow on screen messages to complete the installation.

INSTALLATION OF O/SIs the method of downloading O/S into the fixed disk of a computer system. We have typical and custom installation respectively.STEPS IN INTALLING O/SInsert your bootable/bootup disk in either drive A: or E:Follow the screen messages to complete the installeation.

HOW TO CREATE A START-UP DISKOpen my computer and next to control panelGo to add/remove progamms and double click on it to produce a dialogue box.Click on start-up disk, then insert a diskette (floppy disk) and select create. Or

In DOSC: format A:/sThen insert a CD which is a copy of windows O/S and select OK,Wait until it is done successfully and click OK.Remove the CD (Source) and the floppy disk as well.

VIRUSComputer virus is a programming bug/fault/defect with this sole aim of sabotaging efficiency and performance of acomputer. The virus may affect document, application or worst of all system files. The virus only infects software of the computer system and not the hardware. In worse of all, where virus cause irrepairable software but the PC can recovered by reformatting the FDisk and re-installing or new O/S but all of the information stored on the PC would be lost forever.

TYPES OF VIRUSThere are many types ofd computer viruses include Boot Sector, Program, Polymophic, Macro, Trojan horse, Worms, Multipartite, etc.

BOOT SECTOR VIRUSESThey occupies the boot sector of disk (floppy disk, hard disk, CD, etc) and loadsinto memory during the boot-up process. While in memory it would attempt to infect the bootsector or any disk that is used on the computer.

PROGRAM VIRUSESThey infect executable program files such as those with exention like .bin, .drv, .exe, .sys. these programs are loaded in memory in their extensions taken the virus in within. The virus becomes active in memory duplicating itself and infecting files on disk.

POLYMOPHIC VIRUSIs a highly breed of boot sector and program virus.

TROJAN HORSEAlthough they are not virus but opposes a greater trend to the integrity of computer system privacy than any other attack. They attack the Pc directly by huchkers using (floppy disk, flash disk, CD, etc ) or installed using executable load. Once installed, the virus begins to log every key pressed on keyboard and subsequently, attack credit card numbers, personal informations, network which often lead to Trojan horses been label password snippers.

WORMS VIRUSThey posses a greater threat by duplicating themselves independently of human interaction. They ar e often design to read computer users e-mail and others. Worms copy themselves from computer to computer rather than files to files. They spreed easily than regular computer virus and findly they cause PC to crash or even run very slow.

ANTI-VIRUS SOFTWARE PROGRAMSThere are various tyupes of anti-virus software programmes include INNOCULAN, MC AFFEE, NORTON’S DISK DOCTOR(NDD), AVG, KASPEKSY, RAV , etc. these programs can be updated on the internet online. Due to various versions of anti-viruses, it is always adviceable to have an anti-virus intalled updated.

SOURCES OF ANTI VIRUSESIt can be found on floppy disk, compact disk (CD), flash disk, etc.

PRINTERSAre output devices that enable soft copy to be on a hard copy (paper). Ther are various types of pdrinters include Dot Matrix, Ink/Desk Jet, Laser and Plotter. Printers are considered with the following characteristics/factors;

CostSpeed.Print quality.Commercial/Domestic structure.Cost of upgrading as compared to the earlier one

DOT MATRIX PRINTERIs one of the cheapest printers available in a marker whcich can be purchase by any use and it print s normal. The print out look similar like typewriter which is used in private and commercial purposed and it medium (means) of printing is Ribbon Cartridge.

DISADVANTAGESPoor print quality since it can be altered/change/erase at any time.Slow in printing as compare to other printers.

INK/DESKJET PRINTERSIt expensive as compared to that of dot matrix. It also print in colour and black and white but used ink cartridges in printing. It print out is difficult to alterate and can be used for all seasons. It print quality is better and faster than dot matrix.

LASER PRINTERIs a type of printer that is best used for all occations and used powdered ink called TONER for printing. It print quality is the best, faster and economical for commercial and private use. But the problem is cost of maintenance.

PLOTTERSSIs a commercial and industrial printer used in printing archetechtural drawing as well as land-scape drawings. It is not for prionting letters, as such can not be found in various offices. It is most expensive among all and highly industrial.

HOW TO ISNTALL PRINTERSteps:Connect the power capble of the printer to an AC source.Connect the communication cable (either USB or LPT) from the printer to it correspondent port on the system unit.Click on Start menu and select printers and faxes to display a dialogue box.Click on add printer to add a hardware component of the particular printer you want to use.The follow the add printer wizard to complete the installation.It is always recommendable to warm boot the computer system after installation of any hardware.

UPGRADING OF COMPUTER SYSTEM

Upgrading is the process of moving from a lower version of a hardware/software components to a higher version. Hardware and software components can be upgraded on the computer. Hardware components are BIOS, System board, Interface cards, Drives (SCSI, IDE/EIDE, Optical dtc) and software components too are O/S, Application Softwares, Utility Softwares (Anti- Virus programmes, etc), etc. various peripherals can also be upgraded such as VDU, Keyboards, Scanners, Mouse, Printers, Speakers, etc.

BIOS (Basic Input Outpu System)The BIOS chip on the system board is design to provide the link between hardware (devices, CPU, chipset, Video) and Software (O/S). The BIOS chip often called ROM BIOS because it’s read only memory chip whose content can’t be erased but to upgrade it, there is the need to reprogrammed the software within it. As such, the need for eraseable, reprogrammable ROM is called FLASH BIOS. The bios on the system board is known as system BIOS.

FACTORS CONTRIBUTING TO THE UPGRADINGWhen higher version of hardware component are provided, there is always the need to upgrade the BIOS to comform with the upliftment. E.g Hard disk faster than 8GB, newer and higher processors and faster IDE/EIDE as well as SCSI drives.

To determine whether the BIOS needs to be updated because of hardware capacity, limitation, document according to the limits of the BIOS must be sorted. E.g. if the computer was assemble before 2000, and there are newer hardware product manufactured in 2005 to be used on the computer, there is the need for the BIOS to be compatible/upgraded to suite the newer product.

PROCEDURE OF UPDATING BIOSThere are two things of updating the system BIOS. With the old system chip, swapping (replacement) is necessary where old system BIOS is remove and the new chip is inserted in its place. With the newer versions of the system BIOS, Flashing is necessary, the updated software is downloaded and stored on a disk which is used to boot the computer. It’ll take about 3 – 5 minutes to complete. When doing, it is recommended (advisable) to engage the services of UPS (Un-interrupted Power Supply) i.e. to ensure power stability during t he process. You have to ensure the old BIOS manufacturer is the same as the new.

UPDATING / UPGRADING OPERATING SYSTEM (O/S)There are certain tools to acquired, the greatest among them is the source of the O/S (upgrading O/S, the license and it compatibility). E.g. if win98 is previously on your computer, you cannot update it with Linux/Unix since they are highly compatible. The upgrade can be done using Ms Products. If the product is not having the upgade option/support, then it cannot be upgrade.

PRINTERSFACTORS FOR UPRAING PRINTER

Printers speed.Qualitity of print outCost of upgrading as compared to the earlier one.Commercial viability of the printer.Availability of parts replacements, e.g. ribbon, ink cartridges, tonners, etc.

VDUs(MONITERS)FACTORS FOR UPGRADINGQuality of graphics produces (resolutions).Sizes and cumbasome nature of it.Types of work to be done, e.g. Desktopo publishing, Architectural drawings,etc.

BUSESAll buses and it interfaces are also be to looked at carefully since some buses runs slowly and others faster. Some of the interfaces can be upgraded easily include Video interface card, Sound blaster interface card, modem (internal and external) interface card, network interface card(wireless, PCMCIA, internal), etc.

TROUBLE SHOOTINGThis is a state where problems created by the PC is resolved with logical procesures. All hardware components have a pecuiliar problems to solved them and be unique.

KEYBOARD TROUBLE SHOOTINGKeyboards error are usually caused by two (2) simple problems. These are defective cables and stuck keys. Here are some symptons, problems and their solutions on keyboard.

Symptoms Problems Solutions

No Keyboard Operating,Alls keys produce error,Wrong characters.

Defective Cable

Swap keyboard with working ones.Replace the cable.

Stuck key orKeyboard error

Stuck key Look up for the stuck key and correct it.

Keyboard fail to respond

Broken keyboard pin (Plug)

Change the cable with the pin (plug)

Known working keyboard does not work when connected.

Damage systemboard keyboard connector.

Use volt/digit meter to check the voltage that is coming.If the port is ps/2, try using USB keyboard.

TROUBLE SHOOTING MOUSE

If you’re experiencing problems with your mouse, you must look for two (2) general places; i.e. hardware components or software because mice are basically simple devices. Looking at the hardware takes very little time. Detecting and correcting simple problem can take a little longer. Below are tthe sytems, problems and solutions association with mice.

Symptoms Problems Solutions

Dirt or dust on rollers, balls & sensors.

Jerky mouse pointer

Clean the dirt on dust, rollers and sensors.

Mouse won’t work at all.

Defective mouse Replace the mouse with known working one.

Defective port Check from the CMOS if the port is disable, endable it.

Radio Ctrl mouse had dead battery

Check batteries in mouse, replace it if dead.

Mouse doesn’t work properly

Re-install mouse driver.

PRINTER TROUBLE SHOOTINGVarious printers and the way they are trouble shoot, it becames difficult if one fail to understand the procesure of printing and identifying the individual component within them,e.g. heads, fuser lamp, etc.

Symptons Printer type Causes Solution

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Laser Jam paper Use paper stored at proper temperature and humidity

Ink jet Wrong paper type/print settings

Use ink related paper and mark resolution paper type/size.

Laser and Ink jet Some nossils are blocked.

Re – seat the catridge, run cleaning utility

White lines through printed text/graphics

Ink jet Some nossils are block, plug or chock

Use nossil cleaning routine on printer or replace printer catridge when series of texts looks futal, service fusing rollers.

Paper jam Laser and ink jet Incorrect paper loading, paper too damp, wrinkle, too heavy for printing

Use paper that is in proper condition. Don’t over fill paper trade.

Can’t print All printers No power, no communication cable connected

Check power, switch on printer and connect com cable to the printer.

OPTICAL DRIVE TROUBLE SHOOTINGIf your CD-ROM drive fails to read, try t he following,Check the scratches on the CDs data surfaces.Check the drive for dirt and dust.Make sure the disk drive show as a working device in the system properties.Try a known good CD.

DVD ROM DRIVES TROUBLE SHOOTINGCheck compatibility: Some old drive can’t read, here replace the drive with a newer faster model.Many early model of DVD drives can’t read CD-R and CD-RW media because of lower reflectivity of media.It is adviceable to replace the drive.

TROUBLE SHOOTING OUTPUT DEVICESMONITER (VDU – VISUAL/VIDEO DISPLACE UNIT)Symptons Causes Solutions

No picture Defective video calbe

Check VDU and Video data cables, replace with known working one.

Check brightness and contrast ctrls and adjust them when necessary.

No picture, no power light on VDU

No power flowing through VDU

Loss cable

Check power calbes, surge protector, replace them if faulty.

Plug the cable firmGittery picture VDU display not

adjustedRun the system in safe mode to reduce pixel gitter.

AUDIO HARDWARE

The common problems with audio adaptor is no sound/music effect or sound is repeated over and over or even cause your PC to freeze. This situation is called device/hardware conflict and its centered around the interrupt request (IRQ) and the I/O settings.

Symptons Problems Solutions

Skipping, jerky sound/system lock ups(freezing)

Sound card using the same IRQ as another device

For plug and play (PnP) device, disable auto config.

Incorrect or mixing speakers wires

No sound Plug speakers into correct jacks.Adjust master vol ctrl settings.Power the system down for transmission.

Low volume Speakers plug into phono jack

Use higher powered RJ if separate jack are provided.Adjust the volume.

Scratch sound Audio card i s picking interference

Move away from the other card/source of interference.

Can’t play DVD audio/mp3 files

Hardware resource not enable on sound card or volume set too low.

Enable hardware resources or adjust volume for ceorrecet playback devices.

ENERGY STAR COMOPLIENCE/CONSERVATIONENERGY STAR COMPUTERS/GREEN STAREnergy star computers and peripherals are those that satisfied energy conserving standards of the U.S. Device that can carry the green star labels are Computers, Monitors, Printers, Fax machines, etc. Such devices are design to decrease overall consumption of electricity to protect and preserved our natural resources. These standards are sometimes called the green standards generally means that, the computer consumption has a standbye program that switch the device to sleep mode when is not been used.

During sleep mode, the device must not used more than 30W of power. Though sometimes created overall energy saving about 50%.

ENERGY STAR PCComputers used power management methods to conserve energy and these include,ADVANCE POWER MANAGEMENT (APM) champion by intel and Microsoft.ADVANCE TECHNOLOGY ATTACHMENT (ATA) for IDE drives.DISPLACE POWER MANGEMENT SIGNALLY (DPMS) standards for monitors in video cards.

These energy saving feautures are design to work in increamental steps depending on how long the PC is idle. The feature seen sometimes be enable and adjusted using CMOS setup or O/S.

The energy star CMOS features includeDOSE TIME: Time that elapses before the system reduces 80% of it power consumption.

STANDBYE TIME: Time before the system reduces 92% of its power consumption.

SUSPEND TIME: Time before the system reduces 99% of its power consumption. The way the reduction is accomplished varies. The CPU clock might be stop and the video signal suspended. After entering suspend mode, the system need a warm up time so that the CPU, Monitor and other component can reach full activity.

SUMMARY ON NETWORKNETWORKIt is the way of connecting computers and other devices.

NETWORKINGIs the concept of connecting computers mainly to share resources.

PURPOSE OF NETWORKTo share resourcesTo share hardware and software.Centralised administration and support.

TWO MAJOR TYPES OF NEWORKThere are two major types of network namely; Local Area Network (LAN) and Wide Area Network (WAN). Metropolitan Area Network is a way of connecting computers within a defined metropolis/geographical area.

LOCAL AREA NETWORK (LAN)It is a way of sharing resources within a defined geographical area.

WIDE AREA NETWORK (WAN)The act of connecting computers and other devices on opposite sides of the world which has no geographical area.

TYPES OF FILE SHARINGPEER – PEER NETWORKIt is the way of connecting computers whereby they function as both a server and a client.

SERVER – BASED NETWORK

They are computers within a network provide shared resources to its uses or client.

SERVERAre computers that provide shared resources to network (it) users (clients).

CLIENTAre also computers that access s hared resources on a network provided by a server.

MEDIAThey are wires that make the physical connections

RESOURCESAny service/device available for use within a network.

DEDICATED SERVERAre computers functions only as a server and for complex tasks.

ADVANTAGES

FACTORS FOR CHOOSING A NETWORKSize of an organisationLevel of security requiredType of businessLevel of network administrative support availableAmount of network trafficNeeds of the ntwork usersNetwork budget

Server-based network Peer – Peer Network

1 Shared resources are centrally administrated and controlled.

All users can share any of their resources in any manner they choose.

2 Security is the main/primary aim of a server – based network.

Clients/users set their own security

3 Support thousands of users Few number of users (client)

NETWORK TOPOLOGY

TOPOLOGYIs the arrangement/physical layout of computers, calbes and other components on a network.

Network STANDARD TOPOLOGIESBUS/LINEAR BUS TOPOLOGYThe way computers and other devices connect to a common cable.

STAR TOPOLOGYThe process of whereby connected computers that branch out from a central point (hub).

RING TOPOLOGYThe method whereby connected computers to a cable that form a loop.

MESH TOPOLOGYIt is the way of connecting all computers in a network to each other with a separate cable.

HUBAre device that regenerate and retransmit signals within a network. There are three types of hub namely; Active, Passive and Hybrid hubs

ACTIVE HUBThey are devices that regenerate and transmit signals as a repeater does because hubs have eight to twelve or more ports for network computers and its sometimes called Multiport repeaters. Active hubs require electrical power to run.

PASSIVE HUBIs a component that act as a connection points and do not amplifiers or regenerate the signals that passes through it. All passive hubs do not require power to run.

HYBRID HUBIs an advanced hub that will accommodates several different types of cables.

BENEFITS OF A HUBWiring systems can be changed/expanded as neededDifferent ports cna be used to accommodate a variety of cabling typesMonitoring of network activity and traffic can be centralised.

NETWORK INTERFACEBuses (ISA, EISA, PCI, USB), BNC/RJ45, Wirless bus

MEDIACoaxial cable – 75ohms.ADVANTAGES AND DISADVANTAGES OF ALL THE TOPOLOGIESTOPOLOGY ADVANTAGES DISADVANTAGESBUS Use of cable is economical.

Media is inexpensiveand easy to work with.System is simple and reliable.Bus is easy to extend.

Netwrok slow down in heavy traffic.Problems are difficult to isolate.Calbe break can affect many users.

RING System provides equall accessfor all computers. Failure of one computer does not affect the entire network.

Failure of one computer can impact on all.

STAR Modify8ing system and adding new computers is easy.Failure of one computer does not affect the entire network

If the centralised point fails, the entire network fails.

MESH System provides increase reliability, Easy of troubleshooting.

System is expensive to install since it uses alot of cabling.

NETWORK CABLINGAre transmission media that carries signals between computers.

MAJOR GORUPS OF CABLESCoaxial CablesTwisted-pair (Unshielded and Shielded) cableOptic Fibre cable.

COAXIA CABLEA cable consists of a core of copper wire surrounded by installation, a braided metal shielding and an outer cover.

SHIELDINGA woven/other material that surrounds some types of cabling.

CROSSTALKSignal overflow from an adjacent wire.

ATTENUATIONIs the loss of signal strength as it travels further along a copper cable.

TYPES OF COAXIAL CABLES

THIN (THINNET) CABLE:A flexible coaxial cable about 0.25 inches thick which is flexible and easy to work with.

THICK (THICKNET) CABLEIs a relatively rigid coaxial cable about o.25inches in diameter and it is sometimes called as standard Ethernet.

COAXIA CABLE CONNECTIONSBothe thin and thick net cables use a connection component called BNC Connector.

TWISTED PAIR CABLEIt consists of two insulated strands of copper wire twisted around each other.

UNSHIELDED TWISTED PAIR (UTP) CABLIs a cable, which does not have a woven jacked mainly to protect the transmitting signals from electromagnetic waves, noise, etc.

SHIELDED TWISTED PAIR (STP) CABLEA cable that uses a woven jacket/other materials to protect the transmitting signals from disturbances/noise. STP uses a foil wrap around each of the wire pairs which gives excellent shielding to protect the transmitted data from outside interference.

CATEGORIES OF CABLES IN NETWORKCATEGORY 1It is a UTP telephone cables that can carry voice but not data transmittions.

CATEGORY 2A UTP cable used for data transmissions up to 4mb/s and consist of four(4) twisted pairs of copper wire.

CATEGORY 3It is a UTP cable for data transmission upto 16mb/s.

CAGORY 4A UTP calbe used for data transmission which is upto 20mb/s.

TWISTED PAIR CABLE COMPONENTSTwisted pair calbe determine the number of twists and its ability to transmit data and all twisted pair cabling uses RJ-45 connector (larger and houses 8 pins/terminals).Jack couplers are single or double RJ-45 jacks snap into patch panels and wall plates. Wall plates also support two/more couples.

FIBRE OPTIC CABLE

Is a cable which carry signals in the form of modulated pulse of light and it transmit signal in 1GB/s.BROADBAND TRANSMITTIONBand is a collection of frequencies and Duall Band is also a collection of two (2) bands.All broadband uses analogue signalling and a range of frequencies. Signals flow in unidirectional.

SIMPLEXIs a process whereby date is sent only in one direction, i.e. from sender to receiver. E.g. Radio, TV and so on.

HALF-DUPLEX TRANSMISSIONIt is the way inwhich data is sent in both directions, but only in one direction at a time. E.g. Shortwave radios (SW), Walkie-Talkie, etc.

FULL DUPLEX TRANSMISSIONIt is how data is transmitted and received at the same time. E.g. Telephone.

COLOUR CODING OF CABLES WITHIN A NETWORKThere are two main colour coding within a network which determine the type of network cabling you have namely; The CROSS OVER (568A) AND STRAIGHT THROUGH (568B)

CROSS OVER (568A) Is a way of arranging cables pins in RJ-45 plugs to connect two computers/when when cascading a hub.

STRAIGHT THROUGH (568B)This is the process whereby all connected compters networked to a centralised device called hub.

COLOURSThere are four colours in a network cable that mixed/striped with another four to form eight cables for the RJ- 45 jack/socket. They are as follows;Orange - Strip with whiteGreen - Strip with WhiteBlue - Strip with WhiteBrown - strip with White

COLOUR ARRANGEMENTSWhite Orange 1

Orange 2White Green 3

Blue 4White Blue 5

Green 6White Brown 7

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Receiving (Rx)

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Brown 8

ARRANGING WIRES INTO RJ-45 PLUG1. STRAIGHT THROUGH (568B)

SYSTEM HUBWhite Orange 1 1 White Orange

Orange 2 2 OrangeWhite Green 3 3 White Green

Blue 4 4 BlueWhite Blue 5 5 White Blue

Green 6 6 GreenWhite Brown 7 7 White Brown

Brown 8 8 Brown 2. CROSS OVER (568A)

SYSTEM HUBWhite Orange 1 1 White Orange

Orange 2 2 OrangeWhite Green 3 3 White Green

Blue 4 4 BlueWhite Blue 5 5 White Blue

Green 6 6 GreenWhite Brown 7 7 White Brown

Brown 8 8 Brown

MODEMIt is a hardware component /device that make it possible for computers to communicate over a telephone line. Modem means Modulation (the act of transmitting signal) and Demodulation ( the act of receiving signals). All computers send digital signal/electronic pulse (signals). Telephone line is also send only analog waves. A sending modem, modulates digital signal into analogue signals and also the receiving modem too, demodulates analogue back into digital signals.

BASIC FUNCTION OF MODEM.1. Modem at the sending end converts computer’s digital signals into

analogue wave transmitted onto the telephone line.2. Modem at the receiving end also convert analogue back into digital signal

for the receiving computer.

TYPES OF MODEMSASYNCHRONOUS (ASYNC): is the most wide spread of connectivity in the world which doesn’t need a circuitory and components involved in it transmission. E.g. Dial-up connection.

SYNCHRONOUS (SYNC): is a modem which lies on timing scheme for its transmission.

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INTERNET PROTOCOL (I. P) ADDRESSPROTOCOL: it is a way of ensuring that a particular task in done and also the language use within network area.

OCTETS:They are three sets of numbers multiply by four (4).

NETWORK ADDRESSIt is an address used to locat a computer within a network.

NODE / CLIENT ADDRESSIs the identification of class where a networked computers belongs to. E.g. A, B, and C.

COOKIESAre small text files that contains users information related to a website which can be opened with notepad or any text editor.

CACHEThe process of storing webpages in a folder on a PC (temporary Internet files), and it is in other words called caching of web pages.

CLASS INTERNET PROTOCOL (IP) ADDRESS

A xxx xxx xxx xxx

Ranges: 1-127 1-255 1-255 1-255

Name: Net Address

Node/Client Address

Example:

010 100 200 210

B xxx xxx xxx xxx

Range: 128-191 1-255 1-255 1-255

Name: Network Address Node/Client Address

Example:

172 024 221 025

C xxx xxx xxx xxx

Range: 192-225 1-255 1-255 1-255

Name: Network Address Node

Example:

198 028 122 211

WIDE AREA NETWORK (WAN)

This medium of communication can either beWirelsss: Radio wave, Microwave, Satelite, Bluetooth and Wire: Cable, e.g. telephone line.

INTERNET SERVICE PROVIDER (ISP) It is an individual or organisation that have the ability/direcet link to the internet. E.g. Gh telecom, African On-Line, Ucom, Zipnet, Tigo, MTN, Zain, American Online, etc.

ROMOTE ACCESS: is a medium of communication, the fastest and expensive to installed.

TRANSCEIVER: Any device capable of transmitting and receiving signals at the same time. E.g. modem.

INTERNATIONAL NETWORK (INTERNET) Is a collection of computer networked spread all over the world that uses a common sets of protocol to link them. Internet is established with Dial-up lines/ISDN communications, ISP (e.g. MTN, African Online, Zipnet, Ucom, Gh Telecom, Tigo, Zain, etc) and so on.

DIAL UP LINESThey uses two types of IP accounts, i.e.SLIP which is the simplest protocol that can be used to access the internet by using telephone line. It also doesn’t provide error control and security.

PPP is an improved/updated version of SLIP which provide additional functions like error control, security and dynamic IP addressing.

INTEGRATED SERVICE DIGITAL NETWORK (ISDN) It is a telecommunication service that connects networks using digital lines. It provides faster connection than dial-up and more economical if the service is available locally.

INTERNET SERVICESEmail, Gopher, World Wide Web File Transfer Protocol (FTP).

WORLD WIDE WEB (WWW)Is an internet MMS that contains hypertext documents in Hypertext Mark-up Language (HTML).

HYPERTEXT is a method by which text, images, sounds and videos are linked in a non-sequential web of associates.

GOPHER: It is a tool by the internet to allow the user to browse for information without bothering about it location.

FILE TRANSFER PROTOCOL (FTP)

Is a protocol that allows transfer of documents in the form of files and supported by TCP/IP. IMPORTANCE OF INTERNETInternet is used for many services such as Research, Communication, E. Commerce (Shopping/doing business online e.g., goods and services can be purchased on the web), etc.

CONNECTING LAN TO THE INTERNET THROUGH A GATEWAYIt is a method of linking computer to the internet and allows his workgroup within the LAN browse the internet through him (default gateway).

DIAGRAMATIC EXPLANATIONSetup the IP addresses of the above computers and then use the servers IP address as the default gateway address for the clients so that they can access the internet through the residential gateway.

CLIENT CONFIGURATIONGo to control panel, internet options, connections, LAN settings (Check proxy server box), address (default gateway/server IP address), port number (8080/6588), OK, Ok again. This configuration would be done for all the computers except the server.

Network communication can either be;One (1) - One (1)One (1) - MulitpleMultiple - One (1)Mulitple - Muliple

FIREWALL is the method of implementing security of a network.

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Server

A B

CIP: 1.21.122.214

IP: 1.21.122.118D.g: 1.21.122.214

IP: 1.21.122.118D.g: 1.21.122.214

IP: 1.21.122.118D.g: 1.21.122.214 Network Printer

Hub