Utilize PC Fundamentals www.utilizewindows.com

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Fundamentals about computers and related technologies in Windows environment. If you would like to learn basic terms when it comes to computer administration, this is the book for you

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Utilize PC Fundamentals www.utilizewindows.com

  1. 1. This e-book is a collection of articles that were originally published on www.utilizewindows.com. As we update articles on our site, we will also update this e-book. Check our site for the latest version of this e-book on www.utilizewindows.com/e-books This e-book is published under Creative Commons Attribution- NonCommercial-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0 We offer free quizzes which you can use to test your knowledge about Windows operating systems. You can find them here: www.utilizewindows.com/quizzesIf you have a comment or if you would like to report some error, please use our contact form: www.utilizewindows.com/contact-us If you would like to support us, you can take action (www.utilizewindows.com/support-us) or you can donate (https://flattr.com/thing/710994)
  2. 2. ContentsBasics ............................................................................................................................................................... 3 Overview of Computer Hardware and Software ................................................................................................. 3 Types of Computer Cases and Motherboard Factors .......................................................................................... 7 Common Ports and Connectors ........................................................................................................................ 15 Internal Components of a Desktop PC .............................................................................................................. 20 Electrostatic Discharge (ESD) ............................................................................................................................ 26 Protection and Safety Measures ....................................................................................................................... 30 Disposal of Waste Materials ............................................................................................................................. 32 Maintaining PC Systems ................................................................................................................................... 34 Introduction to Uninterruptible Power Supply (UPS) ........................................................................................ 36 Introduction to Operating Systems ................................................................................................................... 41 Hardware Abstraction Layer in Windows NT .................................................................................................... 44 Devices in Windows .......................................................................................................................................... 46 Applications and Windows ............................................................................................................................... 51 Windows Installation Sources ........................................................................................................................... 54 Windows Installation Types .............................................................................................................................. 56 Introduction to Automated Windows Installation ............................................................................................ 60 Windows System Image Manager - Overview .................................................................................................. 65 Introduction to Sysprep ..................................................................................................................................... 69 Drivers in Windows ........................................................................................................................................... 73 User Account in Windows ................................................................................................................................. 76 Migrating User Profiles and Data to New Windows Installation ...................................................................... 80 Microsoft Management Console ...................................................................................................................... 84 Introduction to Active Directory........................................................................................................................ 85 Group Policy Overview ...................................................................................................................................... 88 Customized URLs in Windows ........................................................................................................................... 91 Task Manager Overview ................................................................................................................................... 93 Check System Configuration ............................................................................................................................. 96 Registry Editor................................................................................................................................................. 102 Installer Files in Windows ............................................................................................................................... 106Components ................................................................................................................................................. 108
  3. 3. Power Supply .................................................................................................................................................. 108 Motherboard Components ............................................................................................................................. 112 Expansion Slots ............................................................................................................................................... 122 Central Processing Unit ................................................................................................................................... 127 Random Access Memory ................................................................................................................................. 133 CMOS, BIOS and Boot Process ........................................................................................................................ 146 Video Adapter ................................................................................................................................................. 150 Heat Management.......................................................................................................................................... 153Devices ......................................................................................................................................................... 159 Serial Interface ................................................................................................................................................ 159 Parallel Interface ............................................................................................................................................. 161 PS/2 Connector ............................................................................................................................................... 164 Universal Serial Bus (USB) Interface ............................................................................................................... 166 IEEE 1394 (FireWire) Interface ........................................................................................................................ 172 Different Computer Input Devices ................................................................................................................... 175 Cathode Ray Tube (CRT) Monitor ................................................................................................................... 178 Liquid Crystal Display (LCD) Monitor .............................................................................................................. 184 Common Video Ports and Connectors ............................................................................................................ 187 Sound Card ...................................................................................................................................................... 194 Different Types of Portable Computers and Their Specifics ............................................................................ 200 Power Management Concepts on Portable Computers .................................................................................. 209 Common Issues With Portable Computers...................................................................................................... 212Storage ......................................................................................................................................................... 219 Computer Storage Devices .............................................................................................................................. 219 CD Versions and Variations ............................................................................................................................. 228 DVD Versions and Variations .......................................................................................................................... 231 Blu-ray Disc (BD) ............................................................................................................................................. 234 File System Introduction ................................................................................................................................. 236 File Names, Extensions, Properties and Security ............................................................................................. 239 Important RAID Arrays Explained ................................................................................................................... 247 Hardware and Software Disk Optimization .................................................................................................... 254Printers ........................................................................................................................................................ 257 Types of Printers And Their Interfaces ............................................................................................................ 257 Printer Configuration Concepts ....................................................................................................................... 263
  4. 4. Network Printer Configuration Overview ....................................................................................................... 266Optimization ................................................................................................................................................ 269 What Are Updates And Why Do We Need Them ............................................................................................ 269 Different Options For Backup And Restore in Windows.................................................................................. 272 What is Virtual Memory and Why Do We Need It .......................................................................................... 276 Typical System Errors And How To Deal With Them ....................................................................................... 279 Different Boot Options in Windows ................................................................................................................ 283 Overview of Windows Recovery Options ........................................................................................................ 287Installation ................................................................................................................................................... 291 Different Versions of Windows Operating System .......................................................................................... 291 Typical Windows Installation Steps ................................................................................................................ 295 Tasks to Complete After Every Windows Installation ..................................................................................... 298
  5. 5. BasicsOverview of Computer Hardware and SoftwareParent Category: PC FundamentalsCategory: BasicsWhat do computers really do? Well, computers take information from the outside world, processthat information and then show us the result of that process. There are several ways in which we caninput information to our computer and there are several ways in which we can get the result of dataprocessing.Before you startObjectives: learn which devices are used to input data, to process data and to output processed dataso we can use it. Learn what makes computers modular, how computers can communicate and whatis the part of software.Prerequisites: no prerequisites.Key terms: hardware devices, internal hardware, internal components, software, internalcomponents, processing, data storage, input devices, keyboard, mouse, touchscreen, output devices,monitor, audio, printer, network, modularity.Hardware versus SoftwareThe first thing to remember is that our PC consist of hardware and software. The PC hardwareincludes the electronic components that we see when we open up the computer case. The PChardware, by itself, cant really do much of anything. Our PC needs something that gives thathardware set of instructions that tell it what to do. This is what the software is used for. PC softwarecan be stored as programs on a hard drive or even stored as programs inside of some specialhardware chips on the system itself.Internal ComponentsThe internal hardware provides three main functions.ProcessingFirst, it provides processing functionality. The main processing unit in our PC is the Central ProcessingUnit (CPU). Its job is to process data according to a set of instructions. It takes the input and doessomething with it.Short Term Data Storage 3
  6. 6. BasicsSecond functionality is short term data storage. This is done using Random Access Memory or RAM.RAM is the place where the CPU stores the data its currently working on. In addition, theinstructions that the CPU is currently using are also stored in RAM. Remember, RAM is not persistent.That means that if we shut down our PC, data that was stored in RAM will be erased. RAM is used forshort-term storage because of speed.Long Term Data StorageFor long-term storage we use a variety of storage mediums. The most important one is the Hard DiskDrive or HDD. It can store bunch of data and it can retrieve it relatively quickly, but not as nearly asfast as RAM. Thats why we dont use a Hard Drive instead of RAM. Remember, data saved on long-term storage is persistent. That means that if we shut down our PC, the data saved on the Hard Drivewill be intact.There are other types of long-term storage medium as well. One of the older ones which we dontuse a lot anymore is Floppy Disc Drive or FDD. Back in the old days computers didnt have a HDD,they only had an FDD. We dont use FDD anymore because they are slow and cant store a lot of data.The advantage of FDD is that the medium is removable. Another option for long-term storage areoptical drives. These include CD as well as DVD drives. With CD or DVD drive we can store hugeamounts of information on an optical disc. These optical storage devices come in two differentvarieties. We have the Read Only version, for example CD-ROM, which means Compact Disk - ReadOnly Memory. We can read information from that medium, but we can not save new information.The same is with the DVD-ROM drives. However, we have a writable versions as well, like CD-R, orCD-RW. These allow us to both read information from the CD as well write information to it. It is thesame with the DVD and Blu-ray drives.One more type of long-term storage medium is a Flash Drive. Unlike RAM, memory chips used inFlash Drives are persistent. This is great because flash memory is fast and it can store a lot of data.Input DevicesLets take a look at some key components that let us bring some information from the outside andput it inside of the PC. Theres three main sources of input.KeyboardThe first one is the keyboard. Keyboard allows us to send information to the internal PC hardware bypressing a key. When we press a key on the keyboard, electronic signals are sent through the wire (orether) into the internal PC hardware where that signal is picked up and sent to the CPU (CentralProcessing Unit). Before the Personal Computers emerged, data were sent to the CPU using punchcards which ran trough the card reader.MouseThe second important input device is the mouse. Mouse works different than keyboard. Keyboardhas a chip that checks which key has been pressed and sends an appropriate code for the particularkey to the PC hardware. Mouse has little sensors along with the roller ball. When we move themouse, the sensors keep track of which direction the ball is rolling and moves the cursor on thescreen accordingly. Optical or laser mouse works a little differently but the principle is the same.
  7. 7. BasicsTouchscreenThe third input device is the touchscreen. When we have a touchscreen we dont have to use thekeyboard or the mouse. Touchscreen applies an overlay on top of the PC monitor. This overlayconsist of two layers between which is an empty space. When we press on a particular place on thescreen, the first layer gets bent in and touches the second layer, which then sends an electrical signalto the PC hardware consisting of X and Y coordinates of the screen. Software then does what it isprogrammed to do when we press on particular point on the screen.Output DevicesTo get information out of the PC we need to have output devices connected to it.MonitorThe most important output device is a Monitor. Information being processed by the CPU can bedisplayed on the screen so we can see what we are working with. Monitors were not used as soon asthe Computer emerged. Before monitors, we used Punch-cards to input data to to the computer andthe results of the processing would be printed on the paper instead of the screen.AudioThe second type of output is audio. Again, today we take audio for granted, but in the beginningcomputers could not produce audible signals.PrinterThe third device that we use to output data from the PC is a Printer. With printers we can printdocuments or whatever we see on our PC monitor. Printer takes information from the PC and using avariety of different technologies prints the formatted information onto a piece of paper.CommunicationAnother thing that we have to mention is how multiple computers can communicate together. Thatsdone using a computer network. A special interface is installed on each computer and we connectthem together using a predefined type of wire or radio signal. This way, information processed onone computer can be sent to another computer on the network. Network acts as both input andoutput medium.ModularityThe great thing about modern PC system is the fact that it is modular. All PC components that we talkabout are built on a modular basis and are standardized. That means that we can add or removecomponents to customize our PC or to replace bad parts. Standards allows us to buy differentcomponents from a variety of different manufacturers, put them all together into a system and havethem interoperate correctly.RememberThe PC hardware, by itself, cant really do much of anything. Our PC needs something that gives thathardware set of instructions that tell it what to do. This is what the software is used for. The internal
  8. 8. Basicshardware provides three main functions: processing, short term and long term data storage. Themain processing unit in our PC is the Central Processing Unit (CPU). Short term data storage is done isdone using Random Access Memory or RAM. For long-term storage we use a variety of storagemediums. The most important one is the Hard Disk Drive or HDD. Theres three main sources ofinput: keyboard, mouse and touchscreen. The most important output devices are: monitor, audiodevice and printer. Computers can communicate using computer network. All computer componentsare standardized and because of that modern PC systems are modular.
  9. 9. BasicsTypes of Computer Cases and Motherboard FactorsParent Category: PC FundamentalsCategory: Basics When purchasing a new computer we have to make a decision of how big or what type of system case we might want. Were going to take a look at some of the differences and similarities between the cases and the motherboards that fit inside those cases. Before you startObjectives: learn about the common types of computer cases, names and sizes of usual motherboardform factors and which motherboard fits which computer case.Prerequisites: no prerequisites.Key terms: types of computer cases, case size, full tower, mid tower, mini tower, slim line, small formfactor, motherboard form factors, atx, micro atx, mini atx, mini itx, btx, nlx, riser cardComputer CasesThe most common system case type is the tower. Depending on the specific number of internal drivebays and the height of the tower, these cases can be further classified into mini-size, mid-size andfull-size tower cases. One of the biggest considerations when choosing between case sizes is thenumber of slots and the number of devices we would like to add to those cases.Full TowerFull-tower cases are generally big with a height that is about or more than 30 inches (more than 76cm). The number of internal drive bays inside these cases can be between 6 and 10.
  10. 10. BasicsImage 113.1 - Tower Computer CaseMid TowerAnother case that might be a step down, would be classified as a mid tower case. Mid-tower casesare the most widely used computer cases. Mid Tower cases are about 18 to 24 (45 to 60 cm) incheshigh and they usually contain 2 to 4 internal drive bays and a similar number of external bays (forCD/DVD readers and similar).
  11. 11. BasicsImage 113.2 - Mid Tower Computer CaseMini TowerMini-tower usually have up to 2 or sometimes 3 internal drive bays. Mini-cases normally stand at aheight of 12 to 18 inches (30 to 45 cm). Expandability is a problem with these cases.Image 113.3 - Mini Tower Computer CaseSlim Line Case
  12. 12. BasicsImage 113.4 - Slim Line Computer CaseSlim line cases are simply tower cases turned on their sideways. They can hold a monitor on top ofthe case.Small Form Factor (SFF) CaseSmall form factor or SFF cases are custom cases that are designed to minimize the spatial volume of adesktop computer. SFFs are available in a variety of sizes and shapes, including shoe boxes, cubes,and book-sized PCs.Image 113.5 - Small Form Factor Computer CaseMotherboard Form FactorTheres one important consideration we need to be aware of when choosing the case size and that isthe size of the motherboard. They need to match. The size of the motherboard is often called theForm Factor and there are several standards. The form factor identifies the size of the circuit board,the location of the slots as well as the location of the faceplate that comes out the back of the
  13. 13. Basicscomputer. The form factor also identifies the location of the holes that are used to mount themotherboard into the system case. For example, the full tower has more than enough room to fit anATX motherboard. Mid-tower case can also accommodate an ATX motherboard in most cases.ATX (Full ATX)Probably the most common form factor for a motherboard is the ATX form factor. The board isapproximately 12" x 9.6" (30cm x 24cm).Image 113.6 - ATX Form FactorMini ATXA mini-ATX motherboard is a slightly smaller variation of the full ATX size that measures 11.2" x 8.2"(28cm x 21cm). The main difference between ATX and mini-ATX is the number of buses and possiblymemory slots on the motherboard. Mounting holes for both are located in the same place, makingthem interchangeable in most cases. A case that supports an ATX motherboard can also supportmini-ATX motherboard.Micro ATXThe micro-ATX form factor is an even smaller version of the ATX standard, with a maximum size of9.6" x 9.6" (24cm x 24cm). The faceplate line up to the exact same position as in all other versions ofATX. System case that can hold an ATX motherboard can also hold micro ATX motherboard. Thesmaller mid or mini tower cases would likely be too small for a full ATX motherboard but shouldaccommodate micro ATX motherboard. The terms mini-ATX and micro-ATX are often usedinterchangeably.
  14. 14. BasicsImage 113.7 - Micro ATX Form FactorMini ITXGoing down in size we have a mini ITX motherboard with a maximum size of 6.7" x 6.7" (17cm x17cm). Notice that there is a single expansion slot and the motherboard itself is considerably smallerthan the ATX and even the micro ATX. Also notice that the faceplate still line up and the holepositions still match the ATX hole positions. Theoretically we could take this micro ITX motherboardand place it inside a full tower case. However we are going to use a small form factor case for thismotherboard.Image 113.8 - Mini ITX Form FactorThe ATX form factor and its variations are the most common motherboard form factors.BTX Form FactorThere are a few main differences with the BTX form factor. Notice that the faceplate is on theopposite end. Another difference is that the hole positions are different. Also, the processor socket isslightly rotated so that it is at an angle to the system board. This rotation is to aid in the airflowacross the processor to assist in cooling the processor. The BTX motherboard will only fit within asystem case that is designed for a BTX motherboard. In many cases this means that an ATX system
  15. 15. Basicscase will not work with a BTX system board, although there are system cases that are able toaccommodate both the ATX and the BTX form factors.Image 113.9 - BTX Form FactorNLX Form FactorThe NLX is an older style form factor that is not used very often anymore. We might see it in someolder motherboards but its not likely to encounter it with newer motherboards.Image 113.10 - NLX Form FactorNLX is an older form factor used for slimline desktop-style computers. NLX is an improvement overan even earlier LPX form factor. Notice that this motherboard has no expansion slots for the PCI orISA bus. The NLX form factor is used in slim line cases that are very short.
  16. 16. BasicsImage 113.11 - NLX With Riser CardIn order to accommodate expansion cards we use a tab on the edge of the motherboard. We insert aRiser Card on the end of the motherboard. Riser Card is then used for expansion cards, so that nowexpansion cards lay flat rather than being perpendicular to the motherboard. The riser card does nothave built-in ports for audio, joystick, USB, network or modem.RememberWhen choosing a system case, other than considering the size of the computer that we want, themost important thing is to match the motherboard form factor with the form factor supported by thecomputer case. The most common system case type is the tower. Tower cases are: Full tower, Midtower and Mini tower. Slim line cases are simply tower cases turned on their sideways. Small formfactor or SFF cases are custom cases that are designed to minimize the spatial volume of a desktopcomputer. The size of the motherboard is often called the Form Factor. The most common formfactor for a motherboard is the ATX form factor. When considering the size of ATX we differentiateFull ATX, Mini ATX, Micro ATX and Mini ITX. When comparing with ATX, BTX form factor has thefaceplate on the opposite side, hole positions are different and the processor socket is slightlyrotated. The BTX motherboard will only fit within a computer case that is designed for a BTXmotherboard. The NLX is an older style form factor that is not used very often anymore.
  17. 17. BasicsCommon Ports and ConnectorsParent Category: PC FundamentalsCategory: Basics In this article we will visually identify basic ports and connectors on a PC. The first two connectors are mouse and keyboard connectors. Before you start Objectives: learn how common connectors look like, what do we call them andwhat are they used for. We have another article in which we discuss video ports and connectors indetail.Prerequisites: no prerequisitesKey terms: connector, port, mouse, keyboard, serial, parallel, spdif, network, rj-45, rj-11, network,phone line, audio, vga, db-15, s-video, dvi, analog, digital, firewire, usb,Mouse and Keyboard ConnectorsMouse and keyboard connectors are called Mini-DIN connectors. They are also often called PS/2because these were the type of ports IBM invented for their PS/2 line of computers. The green Mini-DIN is used to connect the mouse and the purple one is used to connect the keyboard. Most PCmanufacturers will follow that convention. There is also one other convention which says that themouse connector goes on top, and the keyboard connector goes on the bottom. This convention isused when the connectors are not colored in green and purple. Older systems used larger connectorscalled DIN connectors.Image 135.1 - MIni DINSerial PortSerial port uses the DB-9 connector (9 pins, D shape). This connector is used to connect serial devicesto the PC, such as a mouse, modem or even a serial printer.
  18. 18. BasicsImage 135.1 - SerialParallel PortParallel connector uses a DB-25 connector (25 pins, D shape). It is used to connect parallel deviceswith the PC such as a printer, scanner or even external hard drive.Image 135.3 - ParallelS/PDIFS/PDIF stands for Sony/Philips Digital Interface. This interface is used to transfer audio, and it can bedesigned for coaxial cable or optical cable.Image 135.4 - S/PDIFNetwork
  19. 19. BasicsOver the years various types of network connectors have been used in PC systems. Today the mostpopular type of network is an ethernet network. Therefore many motherboards have thoseconnectors implemented. The ethernet network connector uses an RJ-45 socket.Image 135.5 - RJ-45PhonePhone line connector is used to connect dial-up modems with phone lines. It is also called RJ-11.Image 135.6 - ModemUSBUSB allows us to connect a variety of external devices. We can connect up to 127 devices using seriesof USB hubs. We can connect printers, digital cameras, external hard drives, TV tuners, and manyother devices.Image 135.7 - USBAudioThe next is the audio interface. On most systems we will always see the Line-in connector which wecan use for connecting external audio source (blue). We will also see the green connector which isthe Line-out connector. That connector is used to connect speakers to our PC system. The lastconnector, usually pink one, is the Microphone jack. We can use it to record audio from themicrophone. The colors that we mentioned here (blue, green and pink) are fairly well standardized inthe PC industry. If some other colors are used, then those connectors are usually labeled. On somemotherboards we can even have more audio connectors which are then multiple channels. Forexample, Dolby audio uses black connector for rear speaker and orange connector for subwoofer.Image 135.8 - AudioVGA
  20. 20. Basics>The first video connector that we will mention is the DB-15 connector. This DB connector has threerows and we can recognize it because of that. It is usually called a VGA connector.Image 135.9 - VGAS-VideoSome motherboards can also have s-video connector. We can use it to connect our PC to the TV.Image 135.10 - S-VideoDVIThe third video connector is the DVI connector. That connector is used to connect digital monitors tothe PC. VGA monitors are actually analog monitors. We had to convert digital signal from the PC intoan analog signal for the monitor to display. DVI connector allows us to take that digital signal andsend it to a digital monitor right away.Image 135.11 - DVIFireWireThe next connector is the IEEE 1394, also known as the FireWire port. FireWire functions much in thesame fashion as a USB. It is used to connect things like digital cameras, external hard drives, scannersand others.
  21. 21. BasicsImage 135.12 - FireWireRememberMouse and keyboard connectors are called Mini-DIN or PS/2 connectors. The green Mini-DIN is usedto connect the mouse and the purple one is used to connect the keyboard. Serial port uses the DB-9connector (9 pins, D shape). Parallel connector uses a DB-25 connector (25 pins, D shape). S/PDIFinterface is used to transfer audio. The Ethernet network connector uses an RJ-45 socket. Phone lineconnector (RJ-11) is used to connect dial-up modems with phone lines. We can connect up to 127devices using series of USB hubs. Colors for audio connectors are blue (line in), green (line out) andpink (microphone). DB-15 connector is often called VGA. VGA monitors are actually analog monitors.S-Video is used to connect our PC with TV. DVI connector is used to connect digital monitors to thePC. IEEE 1394, also known as the FireWire port, functions much in the same fashion as a USB.
  22. 22. BasicsInternal Components of a Desktop PCParent Category: PC FundamentalsCategory: Basics In this article we are going to visually identify internal components of a desktop PC system. All components that we will mention here are necesary to make a functional computer. Some items are not mentioned because they are generally included with other components, for example cables that come with motherboards. Similarly, peripherals such as a mouse, keyboard, computercase and monitor are also not mentioned.Before you startObjectives: learn to visually identify each basic computer component.Prerequisites: no prerequisitesKey terms: power supply, motherboard, cpu, ram, video card, expansion slot, long-term storagePower SupplyThe first component is power supply. It converts AC power from the wall into DC power that can beused by the components in the PC system.Image 147.1 - ATX Power SupplyMotherboardThe motherboard contains all of the wiring thats necessary for the different devices to communicatewith each other. It can also be called main-board or planar.
  23. 23. BasicsImage 141.2 - MotherboardCPUThe next component is the CPU or processor, the brain of the computer system. This will be theprimary factor in how fast the system is. CPUs get really hot so to keep them cool, we use a fan andheat-sink to dissipate the heat.Image 141.3 - CPURAMThe next component is the memory. The memory is where the CPU stores the applications and datathat its currently working on.
  24. 24. BasicsImage 141.4 - RAMVideo CardUnless the motherboard comes with a built-in video card, we will have to install a separate videocard into the computer system. Graphic or video cards are typically needed to deal with PC gaming,high definition video and multiple displays.Image 141.5 - Video CardSound CardSound cards enable the computer to output, record and manipulate sound. Now it is common tohave a bult-in sound card on motherboards, when talking about personal computers.Image 141.6 - Sound CardExpansion SlotsThe next components are the expansion slots. PCs are customizable and theyre modular. If we wantour PC to perform some additional function, we can add expansion board and install it in one ofthese expansion slots.
  25. 25. BasicsImage 141.7 - Expansion SlotsStorageThe next components are long-term storage mediums. The problem with RAM or memory is that itisnt persistent. When we shut down our system the contents of RAM is lost. To save data long term,we have to have long-term storage devices. Hard drives stores data magnetically on a spinning disk. Itcan be written to or it can be read from.Image 141.8 - Hard DriveWhen talking about saving data long-term, we can also mention floppy disk drive. The floppy diskdrive allows us to insert a floppy disk in and save a small amount of data on a removable piece ofmedia. Today it is rarely used.
  26. 26. BasicsImage 141.9 - Floppy Disk DriveImage 141.10 - Floppy DiskIn addition, we also have our DVD or CD drives.Image 141.11 - DVD DriveImage 141.12 - Blank MediaAll these devices have to connect to the motherboard in some way. Most motherboards come withnecessary interfaces built in. For example, hard disk can connect to the motherboard using SATAinterface, DVD drive using ATA interface, etc.
  27. 27. BasicsImage 141.13 - Components inside of PC caseRememberPower Supply converts AC power from the wall into DC power that can be used by the components inthe PC system. Motherboard contains all of the wiring thats necessary for the different devices tocommunicate with each other. CPU is the brain of the computer system. The RAM is where the CPUstores the applications and data that its currently working on. Graphics card is needed to deal withvideo. Sound card manipulates with sound. Expansion slots are used to extend capabilities of ourcomputer. Hard disks are used for long-term data storage.
  28. 28. BasicsElectrostatic Discharge (ESD)Parent Category: PC FundamentalsCategory: BasicsStatic electrical charge is created whenever two objects that were in contact, separate. Duringcontact and separation, electrons from atoms on one object can move to atoms on another object.When this happens, second object that has excess of electrons becomes negatively charged, andobject with shortage of electrons becomes positively charged. Electrostatic discharge (ESD) occurswhen two objects that have different charge levels come together. ESD can be very destructive to acomputer.Before you startObjectives: learn how to protect sensitive components from electrostatic discharge by using antistatic mat, anti static wrist strap and how to behave around computer components in general.Prerequisites: no prerequisites.Key terms: static charge, discharge, components, static mat, static wrist strap, esd, damage,humidity, protectionDischargeIf we have one object that has a really high positive charge and another object that has a really highnegative charge, the charge from the object with the higher electrical potential flows or jumps to theobject with the lower potential. That discharge can damage electronic equipment. Computercomponents such as memory chip, CPU, motherboard, hard drives, and expansion cards can bedamaged by an electrostatic discharge as small as 100 volts or less. 100 volts sounds like a lot, butESD discharge must be about 3000 volts before we can see it or feel it. That means that we could bedamaging computer components with smaller voltage which we dont see or feel. Damage can occursimply by placing a fingertip too close to a component inside an open computer case. ESD can causeimmediate failure of components, or could gradually degrade components, causing only intermittentproblems. To suppress ESD, we can keep the relative humidity between 40-70% and temperaturebetween 72-77 degrees Fahrenheit (22 to 24 degrees Celsius). We should avoid dry air in thecomputer repair location.ProtectionBefore we touch any PC component we should discharge ourselves. There are different ways to dothat, but the simplest way is to touch the case frame of the PC system. When we do that anydifference in electrical potential is immediately discharged. We can also use a static mat that allowsus to equalize electrical potential between us and the PC system. We can also use static floor mats oreven static floor materials. Now static floor mat is designed to keep us in balance with the electricalpotential of everything around us.
  29. 29. BasicsAnother thing to consider is, whenever we are handling an electrical component, such as a memorychip or CPU, we should not touch the gold or silver leads on the bottom of the component, or evenon the expansion board cards. If a static discharge occurs it will go through those leads. In addition,we should store components in static shielded bags. They have an additional layer built underneaththe plastic that absorbs electrical discharges as they occur and dissipates them around thecomponent, instead of letting them go through the component themselves.Two materials that can easily cause static charges are plastic and Styrofoam. These two materials canbuild up a lot of electrical charge in us and subsequently shock our components. We should storesensitive components in static-shielded bags (also called anti-static bags) which are usually tintedgray. Static resistant bags are not that effective (usually tinted pink or blue).HumidityHumidity helps us to deal with electrostatic discharge. The higher the humidity is, the harder it is foran electrostatic discharge to occur. The humidity in the air acts as a resistor. That means that itdoesnt allow current through it as easily as regular dehumidified air. To keep static down we shouldkeep the relative humidity, if possibly, between 40-70% and temperature between 72-74 degreesFahrenheit or 22-24 degrees Celsius.Static MatIf often work with PC hardware we should get a static mat to prevent ESD damage from occurring. Astatic mat is composed of a conductive surface which is designed to conduct electricity. For example,if we take a piece of memory or a CPU and set it on a static mat, it will establish connectivitybetween that device and the mat. That way, any charge that does get built up dissipates between thepart and the mat and whatever the mat is connected to. We can see an example of static mat on thepicture below.Image 165.1 - Anti Static MatWhen we work on a PC we have to establish connectivity between the case, the mat and us, to makesure that the static charges between us and the case are equalized. Using the mat is the best way todo this. First we take the case and put it on the mat. Then we can use that little alligator clip toconnect the mat to the case (to ground the case). That way we have connectivity established, so nodifference in static charge can be built up between the mat and the case. However, we are also
  30. 30. Basicsbuilding up a static charge. So, we have to establish connectivity between us and the case. To do thatwe can use anti static wrist strap. Some mats will also have a second wire which we can use toconnect ourselves to the mat.Anti Static Wrist StrapImage 165.2 - Anti-static Wrist StrapWe can use this second wire ie. anti static wrist strap to connect us with the case. We put the strapon our wrist and connect it to the case with a clip. As you can see on the picture above, the wriststrap has a little metal plate that establishes connectivity between us and the case, and also betweenthe case and the mat. When we set up things this way there can be no static charge built up betweenus, the case and the mat. Anything that does build up immediately gets dissipated through thesystem. We should ground both ourselves and the computer to the same ground. This provides asingle path for the flow of electrical potential. If we dont have a wrist wrap, we should keep ourbody in constant contact with the metal frame when working inside the computer.Important PrecautionWe need to make sure that the case is unplugged before we ground ourselves. This is very important,because if the power supply has a fault, we could end up being connected to 110/220 volts. Weshould not rely on the power cord for an electrical ground. If the current goes through thecomponents which we are grounded to, we could get a shock. Old power supplies had a physicalswitch that broke the current between the wall and the power supply when we turn off our system.The new power supplies dont do that. Even though the system is turned off, newer power suppliesstill provide current to the motherboard. Well, on the motherboard side of the power supply its DCcurrent and it probably wont hurt us much, but if the power supply has a fault we could get in
  31. 31. Basicstrouble. So, we must unplug the system before we start working on it with the static mat and wristwrap.RememberElectrostatic discharge can damage electronic equipment. Before we touch any PC component weshould discharge ourselves. The simplest way to do that is to touch the case frame of the PC system.We should not touch the gold or silver leads on the bottom of any component. Two materials thatcan easily cause static charges are plastic and Styrofoam. The higher the humidity is, the harder it isfor an electrostatic discharge to occur. If often work with PC hardware we should get a anti-staticmat and anti-static wrist strap to prevent ESD damage from occurring. We need to make sure thatthe case is unplugged from the wall before we start working on it.
  32. 32. BasicsProtection and Safety MeasuresParent Category: PC FundamentalsCategory: BasicsWhen working around electronic equipment our responsibility is to ensure that we work in safeenvironmet so that we dont harm ourselves or others.Before you startObjectives: learn about sources of hazard in electronic devices.Prerequisites: no prerequisitesKey terms: current, voltage, laser, heat, fire, protectionCurrentWe should never work on any device until we have powered it down and unplugged it from the wall.If we are working on a portable computer, we have to make sure the battery is out. Power thatcomes from the wall is Alternating Current (SC), about 115 volts at 60 cycles in USA or 220 volts at 50cycles in EU. Also, we have to ensure that the grounding pin on a PC power plug is intact. AC can beenough to stop our heart. Power coming out of a wall can be retained even after the device isunplugged from the wall. It is retained in the devices power supply, in capacitors. Because of that weshould avoid opening the power supply since capacitors store a large charge of electricity. Newpower supplies constantly pull power from the socket so we have to unplug the system before westart to work on internal components. To protect components against ESD we should use anti-staticwrist strap. This can also reduce the chance of accidental electrical shock, so we should groundourselves before working with components.High VoltageCapacitors in a high voltage power supply can retain enough current, enough power, to kill us evenhours after the device is unplugged from the wall. This is why a power supply in a computer is an FRU(Field Replaceable Unit). It is not a serviceable part of the computer. We should avoid servicinganything to do with high voltage, including computer power supplies. Another source of high voltageis a CRT monitor, so we should not work inside a CRT monitor. CRT monitors can store 20,000 to30,000 volts of electricity, even when unplugged, so if we must work within a CRT, we have todischarge the high voltage first. When talking about CRT monitors, we have to mention that CRT tubein a monitor contains toxic substances, such as lead, phosphorous, cadmium, barium and mercury, sowe should not try to open it or break it. The important thing to remember is not to wear ESD bracelet(anti-static wrist strap) around high voltage devices like monitors, power supplies, LCD panels, etc. Ifwe are grounded in this case, we become the path of least resistance for current and the high voltagecurrent will flow trough us.Heat
  33. 33. BasicsAnother safety consideration is thermals or heat. Any component which has a heat sink, the printinghead of a dot matrix printer, or components inside a laser printer can be hot. We should allow asystem to cool for minute or two before we work on it, to avoid burns.Printers can also present a safety hazard. Laser printers use laser light that can damage our eye. Theyalso use toner which we can inhale, so we should not locate laser printers immediately next to us.The toner is fused, or melted onto the paper by fuse rollers which can get very hot. Other printersthat present a hazard are dot matrix printers. Solenoids, little coils in the print head get very hot. Ingeneral, if the component has a heat sink, or a heat spreader on it, that tells us to let the device cooldown before we touch it.Laser LightDVD and CD drives write the data with laser light which can damage our eyes. Also, we should neverlook down the end of a fiber optic cable. Instead, we can shine the light into our hand and look for adot.Fire ProtectionWe should always have a Class C fire extinguisher available. A Class C fire extinguisher is made forelectrical fires.Any component that presents a potential hazard ships with its own MSDS (Materials Safety DataSheet) or PSDS (Product Safety Data Sheet). An MSDS explains, among other things, what to do if youcome in contact with something relating to an electronic component thats potentially dangerous toyou.RememberWe should never work on a device until we have powered it down and unplugged it from the wall.The important thing to remember is not to wear ESD bracelet around high voltage. We should allow asystem to cool for minute or two before we work on it. Laser light that can damage our eye. Weshould always have a Class C fire extinguisher available.
  34. 34. BasicsDisposal of Waste MaterialsParent Category: PC FundamentalsCategory: BasicsWhen working with PCs we come into contact with some materials that must be disposed ofcorrectly. In most parts of the world thera are laws that tell us what kind of materials can be put inthe common trash and which types of materials have to be disposed of in some other manner. Thelaws vary around the world. We need to check what the laws are in our local community and findhow we can dispose our waste materials.Before you startObjectives: learn which computer components represent the greatest concern in caring for theenvironment.Prerequisites: no prerequisites.Key terms: protection, batteries, CRT monitor, PC system, cartridges, solutions, solvents,environmentBatteriesThere are some general rules that we should consider. For example, the batteries that we find inmost notebook PC systems are an issue. Those batteries are some kind of Ni-Cad, NIMH or LIHbattery that provide power if a power outlet isnt available. The problem is that a lot of times theydont last more than two to maybe three years. The question is what do we do with the oldbatteries? In most countries its against the law to throw these batteries in the common trashbecause theyre loaded with toxic chemicals. We should dispose them in the manner dictated bylocal law. We should check and see if there is a recycling facility available in the near.CRT MonitorsAnother issue are old Cathode Ray Tube monitors. CRT monitor is loaded with bad substances. Inaddition to nasty substance they can also keep a charge. Theres a capacitor inside a CRT monitorthat retains a very strong AC charge, up to 20,000 volts. We should not throw old monitors in thegarbage. Its also probably illegal so we should check and see if there is any place where we can takeold monitors.PC SystemsAs we all know, computer that worth $2000 or $3000 few years ago, today might be worth $50 oreven less. Were probably going to find ourselves throwing away whole PC systems. Again, itsprobably illegal to throw the PC system in the common trash. In a PC system theres actually a lot ofprecious metals inside. There are some companies that recycle these systems to extract the gold andthe silver and other precious metals that are inside the PC. Most PC systems have about five to $20worth of precious metals.
  35. 35. BasicsPrinter CartridgesPrinter cartridges run out of toner all the time. Again, we shouldnt throw them in the trash. Mostmanufacturers will accept the empty cartridges back from us, they will refill them and then resellthem again. This reduces waste and it provides less expensive printer cartridges in the end. Arecycled printer cartridge costs about the half of the price of a new one.Solutions and SolventsSometimes we use cleaning solutions or solvents to clean our computer components and cases.Often it is against the law to pour this down the drain. Every cleaning solution that we work withshould have a Material Safety Data Sheet (MSDS) associated with it. This sheet will tell us the dangersassociated with using it, how it should be used, and it should tell us how it should be disposed of.RememberIn most parts of the world there are laws that tell us what kind of materials can be put in thecommon trash and which types of materials have to be disposed of in some other manner. Wastematerials include batteries, CRT monitors, whole PC systems, printer cartridges, solutions andsolvents.
  36. 36. BasicsMaintaining PC SystemsParent Category: PC FundamentalsCategory: BasicsThere are some things on which we can impact and which will create the proper environment for ourcomputer hardware.Before you startObjectives: learn about optimal air temperature and humidity, how to protect from EMI, RFI,magnetic fiels, and what to keep in mind when cleaning computer components.Prerequisites: no prerequisites.Key terms: protection, cleaning, temperature, humidity, EMI, RFI, interference, cabling, alcohol,vacuumAirWe should keep the air temperature between 70 and 74 degrees Fahrenheit (21 to 24 degreesCelsius), and keep the humidity level between 40 and 70 percent (to prevent Electrostatic Discharge(ESD)). In professional environments we have to ensure that computer rooms have separate andredundant cooling systems and ensure a supply of clean filtered air. We can accomplish this by usinga positive pressure systems. Positive pressure systems protect the air quality in the facility by causingair to be forced out through doors, windows, and other openings. Negative pressure systems drawair in, potentially bringing in airborne particles such as dust or smoke. Positive pressure systems aremore energy effective. If our systems need to operate in a dirty, dusty or smoky environment, wehave to frequently clean those.EMI and RFIInterference is a signal that corrupts or destroys regular signals. Interference affects signals used bytwo devices which communicate on a network. We should try and protect our systems and networkcabling from Electromagnetic Interference (EMI). EMI is generated, for example, by electric motors orflorescent lights. To protect network cabling from EMI we can use shielded cables or run cablestrough leads to protect signals sent on Ethernet twisted pair cabling. Also, fiber optic cable is notsusceptible to EMI so we can use that type of cable if we can not get rid of EMI. RFI or RadioFrequency Interference can disrupt wireless network traffic. RFI can be generated by cordlessphones, microwaves and other home appliances. Wireless networks that operate within the 2.4gigahertz range are particularly susceptible to RFI.Magnetic FieldsMagnetic fields located close to a computer can cause undesired effects or even data loss. Data thatis stored on magnetic media is at risk from any source of a magnetic field. Floppy drives, hard drives,and tape storage devices use magnetic charges on a disk or a tape for storing data. While hard disks
  37. 37. Basicsare shielded and protected from all but the strongest magnets, be careful with floppy disks andtapes. Getting a magnet too close to these components could erase data. Those can be speakers,motors and fans, space heaters and even CRT monitors. Magnets near a CRT monitor can distort theimages on the screen. On the other hand solid state and flash storage devices are not susceptible tothis kind of data loss.CleaningDust and dirt will insulate PC components, trap heat and shorten the life of our computer. Somecommon cleaning supplies include a lint free cloth, compressed air, an anti static and micro filteringvacuum cleaner, denatured alcohol or Isopropyl alcohol. Keep in mind that we should always powerdown a system before cleaning and use caution with liquid based cleaners. We should never apply aliquid directly to a PC component. To clean electrical contacts we can use denatured alcohol. CRTmonitor screens can be cleaned with a household glass cleaner. To clean LCD screens we can simplyuse a dry, lint free cloth or a special LCD cleaning solution. If we have a mouse with a roller ball wecan clean it with household soap and warm water, and clean the rollers inside the mouse with warmwater or denatured alcohol. Keyboards should be cleaned with a small PC vacuum cleaner orcompressed air. Inkjet print heads should be cleaned with a manufactures supplied utility. Excesstoner should be removed from a laser printer with an anti static and micro filtering vacuum cleaning.To clean floppy disk drives and CD or DVD drives we should use a special cleaning disk and its relatedsoftware. CD and DVD disks can be cleaned with a soft, dry cloth.Another thing we should do is allow the new commponents that came from outside to sit for fewhours in a room temperature before we use it. This will dissipate any condensation that may havebeen caused by a rapid change in temperature or humidity. We should also use covers and cases toprotect equipment when its not in use.RememberWe should keep the air temperature between 70 and 74 degrees Fahrenheit (21 to 24 degreesCelsius), and keep the humidity level between 40 and 70 percent (to prevent Electrostatic Discharge(ESD)). We should try and protect our systems and network cabling from ElectromagneticInterference (EMI). Magnetic fields located close to a computer can cause undesired effects or evendata loss. Dust and dirt will insulate PC components, trap heat and shorten the life of our computer.Components which came from outside shouldnt be used right away.
  38. 38. BasicsIntroduction to Uninterruptible Power Supply (UPS)Parent Category: PC FundamentalsCategory: Basics A part of protecting the PCs by managing the electrical power thats supplied to the system can be critical. There are a variety of problems that can occur with power, for instance, power surge. Power problems can be devastating to our PC systems.Before you startObjectives: learn why should you use UPS, when should you use it and which different types of UPSsexist.Prerequisites: no prerequisites.Key terms: power, ups, battery, power surge, current, protectionPower Surge, Power Dip and BlackoutPower surge means that instead of getting 110 or 120 volts (220 in Europe) we might get a spike of alot more volts coming down the power line (over-voltage that lasts seconds). It can happen, forexample, if theres a lightening storm. Also, we can have power dips which means that the powerdrops down from regular voltage to, for example, 80 or 60 volts. We can also have a brown out(under-voltage that lasts seconds) or black out which means that theres too much demand on theelectrical grid, theres not enough power to go around to everybody who wants to use it (completepower failure). This often means that something has happened to the power grid, for example ashort that caused the power to go away.If we lose power, the whole system goes down and we risk losing valuable data, which can be a realserious problem. Today data is the most valuable asset, it is what makes businesses run. We need toprotect that information and not let, for instance, power surge destroy our hard disks. Its not amatter of will it happen, its a matter of when.Protecting from SurgeTo protect our system from surge we can plug our PC systems into what are called surge protectorsor power strips. A surge protector protects against over voltages. Theyre designed to capture andfilter out power surges that come down the line, by either conditioning the power or by just having acircuit breaker that trips off when bad power comes down the line. These are good, however theyonly protect against surges, they dont protect against power dips, brown outs or blackouts. A powerstrip provides multiple power outlets from a single plug-in, but is not necessarily a surge protector.Surge protectors can be destroyed by surges and lose their ability to protect. We can also use a lineconditioner which modifies the power signal to remove noise and create a smooth alternatingcurrent (AC) signal. During certain conditions, such as an electrical storm or when the power supply is
  39. 39. Basicsconstantly going up or down, we might need to unplug the computer to protect it. Simply turning itoff might still damage the components because some power remains supplied to the system. In thecase of an electrical storm, keeping the system plugged in leaves it susceptible to power spikes.Protecting from Dips and BlackoutsTo protect critical systems we need to use an Uninterruptible Power Supply or UPS. Typically the dataon the servers is absolutely critical. So we want to use UPS just there and not on every PC. We decidewhat systems need to be protected and which ones dont.UPSUPS is a battery back up for our PC. When the power goes off, the UPS kicks in and continues tosupply power for some period of time to the particular system. In addition, most UPS units alsoprovide power conditioning, like a power strip or a surge protector. They prevent power spikes fromcoming through and hitting sensitive computer components. There are two different types of UPSswe need to be aware of.Online UPSOnline UPS is probably the best kind and the most expensive type of UPS. Essentially, power from thewall outlet comes into the UPS, which has a battery in it. The PC system is then plugged into an outleton the UPS which then supplies power for the system.Image 189.1 - Online UPSIn this situation the PC does not draw power directly from the wall outlet. Instead it is constantly fedby the battery in the UPS. UPS continually recharges the battery, which is continually being drawndown by the PC system. This type of system provides the best protection and its also the mostexpensive. Also, because this battery is continually being drained and then recharged, the batteriestend to go bad relatively fast.Offline UPS
  40. 40. BasicsAnother kind of UPS is called Offline UPS, which functions a little bit differently from the Online UPS.The difference is that an Offline UPS uses a bridge. The Offline UPS uses the 110 or 220 volt currentcoming in to charge the battery. However it also bridges the current for the computer system. Thatmeans that instead of running on battery all the time, like with an Online UPS, this system runs on110 or 220 volt from the wall all the time.Image 189.2 - Offline UPSThe battery doesnt need to be charged all the time because the PC system isnt using it. Its using110 or 220 volt wall current. If the current coming out of the wall drops below certain threshold, forexample in the case of a blackout, theres a switch inside the UPS that converts over to the battery,so then the PC starts running off of battery.So the difference between those two systems is that the battery in an Online UPS is continuallycharged and the PC draws its power directly from the battery. The PC never gets power from the walloutlet. With an Offline UPS the PC draws power through the UPS, from the wall outlet until thecurrent drops below a certain point. At that point the system starts pulling power from the battery.Offline UPS is usually a bit less expensive and because we are not continually draining and rechargingthe battery, the batteries in an Offline UPS tend to last longer than the batteries in an Online UPS.However an Offline UPS has one disadvantage and that is the fact that when the power drops belowthe threshold, there is a delay when switching over from the wall current to the battery. For a fewmilliseconds, while the current is switched over, our system is without power. Typically, inside thepower supply of a PC there is enough current stored up, as its being converted to DC current, tokeep the system running for just a few milliseconds while the switching inside a UPS is over. Thisusually works, however if our power supply is too small for our system, we could have a problem.Then the system will probably shut down even though we have got it hooked up to a UPS.Usage of UPSsFor critical systems, such as servers, we should use Online UPS. We dont want the power to go downon a server. For workstations we can use the Offline UPSs because theyre less expensive. But in theend, its up to us. When choosing a UPS we also have to keep in mind the battery power, because notall UPSs are the same. Some UPSs have bigger batteries and can supply power for a longer period oftime as opposed to other UPSs. UPSs come with a rating which tells us how long a UPS can supply
  41. 41. Basicspower to the system. For example, the rating can be 20 minutes, but in general we can take abouthalf of what they advertise and use the rest of the time with caution. If we plug more than one PCinto the power supply, then we need to cut the amount of remaining time in half.UPS CapacityUPS capacity is measured by the volt-amp (VA) rating. The capacity of the UPS determines thenumber of devices and how long the devices can run when power is interrupted. Laser printersrequire more power than most UPS systems are capable of providing. For this reason we should notconnect a laser printer to a UPS. If we must provide power to a laser printer we should get adedicated UPS for that device.Configuration OverviewWhen we have a UPS, we need to, of course, plug it into the wall outlet. Most new UPSs have tocharge for 12 to 24 hours before we can start using it. So, the first thing we do is plug it in and chargeup that battery before we start plugging things into it. When this battery is fully charged we can plugthe PC system into one of the outlets on the UPS. Many UPSs will have three or four or five or six orseven different outlets on them. However not all of them will be protected with UPS power. SomeUPSs have maybe two outlets that are protected by UPS power and the rest, there might be seven oreight of them, are just conditioned power, meaning that it is basically acting like a surge protector ora power strip. If we plug our system into one of those other outlets were not going to have any backup battery power. Now, if the power goes off that it will keep the system running for some period oftime. During that period we should get to the PC and shut it down before the battery runs out. If wedont do that, we basically have another power outage. We can also hope that the power will comeback on before the UPS runs out of power. Well, the thing is that we really dont have to worry aboutthat because we can configure the UPS to work with our PC system. That way if the power goes out,the system will automatically shut down after a certain amount of time, protecting our data. To dothat we take a second cable which is usually a USB or, for an older power supply thats a serial cable,and we connect the UPS to the PC system. Then on the PC system we load drivers which are able tocommunicate with the UPS. That way, when the UPS loses power, the UPS can send a signal throughthe USB or serial cable to the PC system, to the drivers running on the PC and then the system canrespond in whatever way we chose. For instance if the power goes out, we can configure it to shutdown after 5 minutes or immediately shut down the system.Most of the UPSs come with software application thats used to configure the behavior of the systemin the case of a power outage. If we work with important data we should really consider getting aUPS before we lose valuable data. Most UPSs sound an alarm when the AC power is lost. This alarmcontinues until AC power is restored, although many UPSs have a switch to mute the alarm.RememberPower surge means that instead of getting 110 or 120 volts (220 in Europe) we might get a spike of alot more volts coming down the power line (over-voltage that lasts seconds). To protect our systemfrom surge we can plug our PC systems into what are called surge protectors or power strips. Toprotect critical systems we need to use an Uninterruptible Power Supply or UPS. UPS is a batteryback up for our PC. In Online UPS, power from the wall outlet comes into the UPS, which has a
  42. 42. Basicsbattery in it. The PC system is then plugged into an outlet on the UPS which then supplies power forthe system. The Offline UPS uses the 110 or 220 volt current coming in to charge the battery.However it also bridges the current for the computer system. UPS capacity is measured by the volt-amp (VA) rating.
  43. 43. BasicsIntroduction to Operating SystemsParent Category: PC FundamentalsCategory: BasicsHardware without an operating system cant really do much of anything. We need something thatwill control and utilize all devices on our computer. This is where the operating system comes intoplay.Before you startObjectives: learn what is operating system, why do we need it, what are the most importantcomponents, and what types of user interfaces are available.Prerequisites: no prerequisites.Key terms: system, hardware, applications, interface, kernel, utilities, platformInterfaceThe operating system serves as an interface between the applications that are running on thecomputer and the computers hardware itself. Operating systems performs actions such as managingthe file system, receiving user input from input hardware devices such as the keyboard or mouse,controlling the use of processing devices by applications, serving as a platform for applications,moderating hardware and sending user output to output hardware devices such as the monitor or aprinter.ModularityThe computer hardware and the operating system are modular. That means that we could take a PCwith Windows, remove Windows off of it and install a different operating system on top of it. Forexample, we can install Windows, Linux or NetWare on the same hardware. The same is withMacintosh hardware. We could take Mac OS off of a Macintosh PC and install Linux on top of it. Thething is, the hardware and the operating system are not tied together.Application PlatformOperating system provides a platform for our applications. Applications need a place to run and aredesigned for specific operating systems. The applications themselves cannot run directly on the PChardware. There has to be an operating system sitting in between. The OS is installed and runs ontop of the PC hardware. On top of the operating system we install many different applications.Hardware AccessOperating system also provides means for the applications to access the hardware in the PC. OScontains special routines that allow the programmer whos writing an application to access a certainpiece of hardware in the PC. Because of that, the programmer does not have to know how specific
  44. 44. Basicshardware actually works. Operating system takes care of that. So, OS provides an applicationplatform and moderates the hardware for the applications, as well.SecurityOperating system also provides security. In the old days, for example, there was no login andeverything just worked without authentication. Today thats not the case. Any operating system thatwe are going to use, such as Windows XP, Mac OS or Linux, is going to require us to provide somekind of credentials to use the PC.File SystemOperating system also manages our file system. The file system encompasses all the different storagedevices that are installed on the computer. In this case, were talking about working with specificpieces of hardware, such as the hard disk drive, the floppy disk drive, a CD or DVD drive, or a flashROM drive. The operating system is responsible for organizing and storing the data that we areworking on, on storage devices.Parts of the OSThe OS itself is composed of different parts. The first part of the operating system is the Kernel.KernelThe kernel is the core of the operating system. It is loaded into memory when the system boots upand it does most of the critical operating system jobs. Its responsible for managing the file system,managing security, working with the hardware and providing a platform for applications to run on.The kernel is running behind the scenes and we, as a user, dont work with it. Most of the time wework with utilities.UtilitiesUtilities are another component of a typical operating system. Most operating systems come withlots of utilities. For example, when we are working with files on our computer, we are actually usingutilities that are interacting with the kernel to do a particular job.User InterfaceEvery operating system comes with an interface of some sort. The interface is what allows us tointeract in some way with the kernel and the utilities. Theres two different basic types of userinterfaces. The first is the Command Line Interface or CLI.CLIFor example. DOS used a command line. In command line we have to type in the commands forsomething to happen. The command line is more popular in Linux operating systems. Command lineinterfaces are really powerful but they can be very difficult for end users to use. Thats why we havea Graphical User Interface or GUI.GUI
  45. 45. BasicsWith a GUI, instead of using a command line, we represent things graphically on the screen. GUI isused a lot in Windows OS. Linux itself also includes a Graphical User Interface that isnt quite asadvanced as perhaps the GUI used by Windows or the Mac OS, but it is getting very close. Bothinterfaces are good for different purposes. CLI provides great flexibility, but in a day-to-day work GUIis more practical.RememberThe operating system serves as an interface between the applications that are running on thecomputer and the computers hardware itself. The hardware and the operating system are not tiedtogether, which means that computers are modular in general. Operating system also providessecurity and manages our file system. Parts of the OS are Kernel and Utilities. User interface can beCommand Line Interface (CLI) or Graphical User Interface (GUI).
  46. 46. BasicsHardware Abstraction Layer in Windows NTParent Category: PC FundamentalsCategory: Basics In Windows NT, applications and device drivers are no longer allowed to deal with hardware directly and must use Hardware Abstraction Layer (HAL) to determine hardware specific information. We need to be aware of why this architecture is important. Before you startObjectives: learn what is HAL and something about Windows NT architecture.Prerequisites: no prerequisites.Key terms: pc, hardware, mode, system, abstraction, layer, multiprocessor, uniprocessor, executive,communicationUser Mode vs Kernel ModeWindows actually works in two modes. The first mode is User mode and the second one isPrivilegedmode (also called Kernel mode). Kernel, the most important component of Windows, works inPrivileged mode. This is the core of our operating system. Above the Kernel we have ExecutiveServices. Executive services are all the services that are running on top of the Kernel. Examples ofExecutive services are Virtual Memory Manager, Local Security Agent, etc. These services bring us allfunctionalities of Windows. Programs and subsystems in User mode are limited in terms of whatsystem resources they have access to, while the Kernel mode has unrestricted access to the systemmemory and external devices.Hardware Abstraction Layer (HAL)Underneath the Kernel we have the Hardware Abstraction Layer (HAL). HAL controls communicationbetween the kernel (operating system) and the hardware. The function of the HAL is to mask thehardware from the actual Kernel component. It hides hardware dependent details such as I/Ointerfaces, interrupt controllers, and multiprocessor communication mechanisms. Among otherthings, HAL enables us to use different processors and to use multiple processors at the same time.We have several types of HAL. To check which HAL is used by your system, you can go to DeviceManager and select Computer. In our example we have an Windows XP machine, and we can seethat we have an ACPI Uniprocessor PC.
  47. 47. BasicsImage 211.1 - ACPI Uniprocessor PCSome of the other HALs which we can come into are Standard PC, MPS Uniprocessor PC, MPSMultiprocessor PC, Advanced Configuration and Power Interface (ACPI) PC, ACPI Multiprocessor PC,ACPI x64 based PC, etc. Notice that Uniprocessor is used for single processors, and Multiprocessor formultiple processors. The system will automatically detect the number of processors and try to usethe appropriate HAL.RememberWindows works in two modes. The first mode is User mode and the second one is Privileged mode.Kernel, the most important component of Windows, works in Privileged mode. Underneath theKernel we have the Hardware Abstraction Layer (HAL). HAL controls communication between thekernel (operating system) and the hardware.
  48. 48. BasicsDevices in WindowsParent Category: PC FundamentalsCategory: BasicsTo add new hardware to the computer we have to manually install it. For many of our older devicesthis means that we have to open up the case, find an available slot, put the device in, and then bootup the computer. If we have a CD that came with our device, we can install appropriate drivers rightaway. You can notice that today we have a new trend, in which we just plug the device into the USBor Firewire port. This allows us to add new hardware quickly, without opening the case.Before you startObjectives: learn the difference between plug-and-play and legacy devices, different types ofhardware, different hardware resources and general management concepts.Prerequisites: no prerequisites.Key terms: device, hardware, types, system, manager, bus, driver, settings, resourcesResources for DevicesWhen we install a new device, certain system resources must be assigned to the device. Thecomputer uses these assignments to communicate with the device. Those resources are:IRQ settingsDMA channelsI/O addressesIRQ or Interrupt Request Line is the method by which devices can interact with the CPU. An IRQallows a device to interrupt the CPU and request processing time. It can be a hardware IRQ, IRQ 0through 15 or a logical IRQ supplied by Plug-and-Play. All new devices allow sharing of an IRQ, whileolder (legacy) devices had to be assigned a unique IRQ.DMA or direct memory access allows a device to read and write directly to and from memory withoutusing the processor. Devices such as hard drives, CD-ROM drives, tape drives, and sound cards canuse DMA channels to increase the speed of data transfers. Devices must have a unique DMA channel.Every device must have an I/O address. In fact, every device will have several I/O addresses. I/Oaddresses allow two devices in a computer to send information to each other. When a device wantsto send information to another device, it addresses the data to the receiving I/O port number andsends it out on the system bus. Each device in a computer must have its own I/O address. An addressis in a form of hexadecimal number.Plug and Play
  49. 49. BasicsThe plug and play (PnP) was introduced in 1995. Plug and play automatically assigns hardwareresources to new devices. In order for PnP to work the system BIOS, the operating system and thedevice must be plug and play compliant. Plug and Play allows IRQ sharing and ensures that DMA andI/O resources used by each device are unique. Plug and Play does not replace the need for a driver.The operating system still requires a driver to be able to configure and use the device. Windows willautomatically try to install appropriate drivers for PnP devices. However, there are older devices inwhich this was not the case. A legacy device is one that does not support Plug and Play. In thatcase we had to manually configure all of the required resources. These are often set up using tipswitches or jumper switches, and for some devices we could do that in Device Manager in Windows.We have to be careful when we manually configure legacy devices, so they dont interfere withexisting devices that are already installed on our system. Troubleshooting of legacy systems ofteninvolved finding and resolving resource conflicts.Device ManagerSometimes our system will not recognize newly added device. This is generally what occurs with ourlegacy devices. To find more information about those devices after we have added them to thecomputer, we can use Device Manager. By going to the Device Manager, we can see a lot of thestatuses of our various devices. As we look at our devices, we can see whether they are working ornot. If the icon for the device is not there, then Windows did not detect the device. We can try toscan for new hardware or rebooting the system to detect the device. A normal icon means the devicewas configured, the appropriate driver was installed, and the device is working properly. If device isnot working, we will see a yellow question mark on our device. If this is the case, we may have toinstall the drivers manually. Drivers are small software components that allow the operating systemto interface with the actual hardware so that it can control it and make it actually work. An icon witha yellow exclamation mark means the device was detected, but could not be configured properly. Inthis case, we should make sure that we have the latest driver for the device. An icon with a red Xmeans the device is disabled. To identify the system resources used by a device, we should open thedevice properties and use the Resources tab.Types of DevicesYou will notice that we differentiate devices based on how they communicate with the computer.Some of the different types are listed below.IDEWhen adding IDE devices, remember that each IDE host bus adapter supports a maximum of twodevices. When two devices per adapter are configured, we have to use Jumpers to identify a Masterand a Slave device. The CMOS and BIOS typically auto-detects the devices attached to each adapter.We have to configure the BIOS to identify which devices can be used to boot the computer.SCSIWhen talking about SCSI devices, we should know that some computers have a built-in SCSI host busadapter. For other computers, we have to install an adapter card in the PCI bus. Devices areconnected in a chain. Most host bus adapters allow an internal chain and an external chain of
  50. 50. Basicsdevices. Most SCSI implementations have a limitation of seven devices (including the host busadapter). Each device (including the host bus adapter) in the chain must have a unique ID number.This number might be set with switches or through the software. The end of the SCSI chain must beterminated. Some devices are self-terminating. Other devices require a special termination plug. Wehave to modify the system BIOS to boot from a SCSI device (set the device type to 0 or not installed).ParallelWhen talking about Parallel devices, we should know that Parallel ports originally supported onlyprinters. Now we can attach a wide variety of devices to the parallel port. Windows identifies eachparallel port with the designation LPT1, LPT2, etc. Parallel ports operate in three different modes:SPP (standard), EPP (enhanced, to support non-printer devices), and ECP (extended, for improvedprinter support). Virtually all computers support all three modes. In most cases, Windowsautomatically detects the device connected to a parallel port and sets the mode accordingly. Toconfigure the port mode manually (such as to disable EPP for a port), we have to edit BIOS settings.SerialWhen talking about Serial devices, we should know that most computers have one or two serialports. Modems and direct computer-to-computer connections typically use serial ports. Windowsallocates resources to serial devices using COM1, COM2... designations. Windows XP supports up to256 COM ports. For each serial port we can configure the data speed, data/stop bits, parity, and flowcontrol settings. Conflicts might occur if two devices share the same COM port number.USBWhen talking about USB devices we should know that USB devices connect through hubs to form atree bus structure. Hubs are either self-powered or bus-powered (receiving their power fromanother hub). Bus-powered hubs have a maximum of four ports, and supply a maximum of 100 mAof power per port. Self-powered hubs supply up to 500 mA per port and can have many ports. USBdevices can be self-powered or hub-powered (receiving their power from the hub). Connect lowpowered devices (such as a mouse or keyboard) to either self-powered or bus-powered hubs.Connect high-powered devices (such as video cameras or scanners) to either a self-powered hub orplug the device into its own power supply. The USB bus is self-terminating and automatically assignsIDs to each device.FireWireWhen talking about FireWire devices, we should know that FireWire (also called IEEE 1394) is similarto USB, but is targeted mainly towards audio/video data transfer. FireWire is typically used for videocameras and devices requiring high-speed and guaranteed bandwidth. FireWire devices areconnected in a chain. The controller automatically assigns device IDs. No termination is needed.Windows detects and configures FireWire devices automatically as they are plugged in.WirelessWhen talking about Wireless devices, we should know that common wireless interfaces include IrDA(infrared) and BlueTooth (radio frequency). BlueTooth devices are typically used for networking suchas to allow a laptop to connect to a network without wires, or with other devices like mobile phones.
  51. 51. BasicsBoth the host computer and communicating devices require a transmitter/receiver. With IrDA,devices must be close and have a direct line of sight path. With BlueTooth, devices can be furtheraway (up to 10 meters) and separated by walls or other objects in the path.Hot Swappable DevicesHot swappable devices can be added and removed without powering down our system. Technicallyspeaking, hot plug refers to automatically detecting and configuring devices that are added, whilehot swap refers to the ability to both add and remove devices. Hot swapping must be supported bythe BIOS, the bus type or controller, the device, and the driver/operating system. Some examples ofhot swappable devices are firewire, USB and even SATA devices. IDE drives are not hotswappable. When we connect a hot swappable device, Windows automatically detects the device,configures a driver (if one is not already installed), and enables the device. Before removing devicefrom the system we should safely remove a device. We safely remove a device by clicking on thesafely remove icon in system tray.Installation and DeinstallationBefore we purchase a new device we should ensure the compatibility with our version of Windows.To do that we can check the product documentation, manufacturers website, and check MicrosoftsHCL (Hardware Compatibility List) and to ensure compatibility. When installing new devices weshould begin by adding the device to the system or plugging the device in. Windows automaticallydetects and installs drivers for plug and play devices. Only members of the Administrators group caninstall new drivers, but any user can install a device and have it work with Windows if Windowsalready has a preinstalled driver for that device. For undetected legacy devices, we might need to runthe setup program that came with the device, or use the Add New Hardware wizard to install adevice driver manually, or manually set IRQ, DMA, or I/O addresses, or manually select and install thedriver.If a device is no longer used on our computer, we should begin by physically removing the device. Inmost cases, Windows will detect that the hardware no longer exists, and it will remove thecorresponding icon in the Device Manager. If the icon remains after the hardware is removed, we canright-click the icon and select Uninstall option. This uninstalls the device from the system. If thedevice is no longer used, but it can not be physically removed from the computer, we can use theDisable option in Device Manager instead. For example, suppose that we have a network card thatsintegrated on the motherboard, but we have installed a new network adapter and we dont want touse the integrated NIC. In this case, we can use the Disable option to prevent the integrated networkadapter from being used by Windows. Although the device still appears in the Device Manager, it canno longer be used.TroubleshootingLets say that we have just added new device to our computer, but as we power on our machine wedont see Add New Hardware wizard. As a result of that we never saw device drivers get installed. Aswe go into the Device Manager, we may notice that either the device is not there, or it may berepresented by yellow exclamation point. In this particular case we have several options. Since thePlug and Play did not work for us, as we go into the Device Manager, we could tell it to scan for new
  52. 52. Basicshardware. Sometimes this will work, but generally it wont, because it has already scanned fordevices when we powered on our computer.Sometimes, if a device has a problem its because it is in conflict with some other device. In this case,we should edit the properties of the device, in Device Manager. To do that, we have to right-click onthe device and select the Properties option. First we want to check the Device status information onthe General tab. Then, typically, we need to go to the Resources tab where we can see resourcesettings for our device. We should check the I/O Range, and IRQ resources. At the bottom of thewindow, we can see if we have a conflicting device. We can choose typical settings from the Settingbased on drop down list. If you have problems with I/O ranges, try to change Setting based on tosome other Basic configuration 000X. Also, if we have problems with our IRQ resources, we shouldclick on IRQ icon, and select the free IRQ value. We have to restart our computer after changingthose options.Another thing which we can do is use the setup software that came with our hardware device. Byrunning the setup, it can force the system to automatically detect the hardware, install theappropriate drivers, and any other software for that particular device (for example, if it is a printer,we could get a color management software). If that particular option does not work either, then wecan use the Add Hardware Wizard and see if we can force the system to recognize the new deviceand then be able to configure that device. As we open the Add New Hardware, it will try to scan forthe devices. This often does not give any results, because the system has already scanned it when weboot up the system. If he finds one, he will ask us how to configure it, or where are its drivers.Otherwise we will have to manually go through the system and tell it where to find the drivers, sothat the device can work properly.If a red X appears next to the device the device is disabled. We can simply re enable the device indevice manager.ExamplesRead article Devices in XP to see how to manage and troubleshoot devices in XP.RememberFor Plug and Play devices Windows will automatically detect the device and try to install appropriatedriver. The settings that are required to set up the legacy devices are IRQ settings, DMA channels andI/O addresses. To find more information about devices in Windows we can use Device Manager.Some general types of devices are IDE, SCSI, Parallel, Serial, USB, FireWire, Wirelles.

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