COMPUTER HARDWARE SERVICING

COMPUTER HARDWARE SERVICINGLEARNING MODULEBy:Gladys A. InventoComputer - electronic device that manipulates information, or data. It has the ability to store, retrieve, & process data. Computer use to type documents, send email, and browse the internetComponents of Computer1. Hardware2. Software3. PeoplewareComponents of ComputerHardware physical, touchable, electronic and mechanical parts of a computer - it has a physical structure

Examples of HardwareMonitor

Keyboard2. Software - set of instructions program that guides the hardware to operate effectively. Software can be split into two main types:a. System Software - Any software required to support the production or execution of application programsExamples of Software

LINUXWINDOWSMACb. Application Software - Designed to help the user to perform singular or multiple related tasks. Examples of application software are as follows:Word processing software - Creates, edits, saves, and prints documents. Example: MS Word, WordPerfect, Ami Pro, MacWrite.

Spreadsheet software - An electronic spreadsheet consisting of rows and columns is used to present and analyze data. Example: MS Excel, Lotus 123, Quattro Pro.

Database management software - Used to structure a database, a large collection of computer programs. Data is organized as fields and records for easy retrieval. Example: MS Access, dBase, Fox Pro, Oracle.

Graphic software - Graphics programs display results of data manipulation for easier analysis and presentation. Example: Macromedia Flash, Harvard Graphics, 3D Studio Max, Adobe Photoshop

Classification of Computer Parts1. System Unit2. Input Devices3. Output DevicesINPUT DEVICES- anyperipheral(piece ofcomputer hardwareequipment) that accepts data and instructions from the user or from another computer system.Examples: webcams, scanners, keyboards, microphones, joysticks, gamepads and many others.Input/Output or I/ODevicesEverything attached to computer that move data in and out of the computerTwo (2) Types of Input Devices

1. Keyboard Entry 2. Direct Entry 1. Keyboard Entry Data is inputted to the computer through a keyboard.

Keyboard - The first input device developed for the PC. Data is transferred to the PC over a short cable with a circular 6-pin Mini-din connector that plugs into the back of the motherboard.

First IBM PC has 83 keys then 84 key keyboard1986 IBM developed 101 key keyboard layout with 104 key that become todays standardERGONOMICSThe art and science of creating human friendly design with the goal of making products comfortable, safe, and efficient. Carpal Tunnel Syndrome2. Direct Entry input devices that dont to be keyed or typed using the keyboard

Three Categories of Direct Entry Devices

1.Pointing Devices 2. Scanning Devices3. Voice- Input Devices 1. Pointing Devices - An input device used to move the pointer (cursor) on screen.Mouse - The most common 'pointing device' used in PCs. Every mouse has two buttons and most have one or two scroll wheels.

History of MouseDouglas Engelbart invented the first mouse in 1968 made from the hollowed out wooden block with a button on topTypes of Mouseball/mechanical mouse- standard mouse - two buttons & a small wheel between button and cable connects to the PC- It has rubberized ball that attracts dirt. 2. Trackball mouse- it has platform to rest hand and a small wheel operated by thumb3. Optical mouse- latest innovation- uses tiny camera that detect mouse movement by imaging the surface the mouse moves over- captures 1,500 6000 images per second4. Touchpad- common in laptops- uses distortion sensing technologyOUTPUT DEVICESAny piece of computer hardware that displays results after the PC processed input data.Classification of Output Devices1. Computer Display Monitor2. LCD Projectors3. Smart Board 4. Printer5. Speaker 1. Computer Display Monitor

It displays information in visual form, using text and graphics.

The portion of the monitor that displays the information is called the screen or video display terminal.

Types of Monitor

A. CRT Monitors Cathode Ray Tubes (CRT) were the only type of displays for use with desktop PCs. They are relatively big (14" to 16" deep) and heavy (over 15 lbs).

Cathode Ray Tube Monitor

CRT uses electron guns to write the phosphor-coated screenRefresh rate the number of times electron guns write and refresh the phosphor in single secondHertz (Hz) refresh rate or cycles per second72 Hz standard refresh rate in Europe60 Hz standard refresh rate in USAB. LCD MonitorsLiquid Crystal Display (LCD) technology has been used in laptops for some time. It has recently been made commercially available as monitors for desktop PCs. Liquid Crystal Display Monitor

C. LED Monitors (LightEmittingDiode)A display and lighting technology used in almost every electrical and electronic product on the market, from a tiny on/off light to digital readouts, flashlights, traffic lights and perimeter lighting. HOW TO TAKE CARE OF MONITORFor CRT :dust with computer vacuum and clean fingerprints with lint free cloth use glass cleaners and non-abrasive cloth

For LCD: use manufacturers recommended cleaning tool LCD has antiglare screenENVIRONMENTAL CONCERNSPollutionInterference

The above shortens the lifespan of monitorRemember: Avoid smoking around monitorAvoid running hair dryer or other devices on the same circuitAvoid nearby magnet that bends or warps display screenMONITOR PROBLEMSFuzzines fuzzy/ out of focusmisalignment of electron gunsReplace monitor2. Missing color untightened video cable3. Missing pixel video card4. Dim screen adjust brightness electron guns for CRT worn out backlight for LCD5. No imageUnplug powerBrightness settingVideo cableVideo card

6. Bizarre image video card replacement2. LCD ProjectorsAnLCD projector (liquid-crystal display) is a type ofvideo projectorfor displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of theslide projectororoverhead projector.Projector Image

3. Smart Board A type of display screen that has a touch sensitive transparent panel covering the screen, which is similar to a touch screen.SMARTBOARD

4. Printer A device that prints text or illustrations on paper. TYPES OF PRINTERDot matrix uses pins (9 pins or 24 pins)that strike against the inked ribbon to print- also called impact printer because these printers work like a typewriter. - rough images, ragged texts- use in paycheck and invoices 2. Ink-Jet or Bubble-Jet PrinterSprays ink at a sheet of paper. Ink-jet printers produce high-quality text and graphics. Quality is measured in resolution expressed in dots per inch (dpi) 2,880 x 720 todays resolutionColors: black, cyan, magenta, yellowSpeed: 15 ppm black and white 1 ppm colored printing3. Laser Printer Uses the same technology as copy machines. Laser printers produce very high quality text and graphics. 15 ppm 50 ppm

When a document is sent to the printer, a laser beam "draws" the document on a selenium-coated drum using electrical charges. After the drum is charged, it is rolled in toner, a dry powder type of ink.

Laser Printer

4. LCD and LED Printeruses liquid crystals or light-emitting diodes rather than a laser to produce an image on the drum.LCD and LED Printer

5. Thermal PrinterAn inexpensive printer that works by pushing heated pins against heat-sensitive paper. Thermal printers are widely used in calculators and fax machines.

Thermal Printer

Points to consider in buying printer What are you going to print? How fast do you want to print?How much do you want to pay?Printer Problem ToolsPrinter guide maintenance programPrinter testPrinter error warningPrinter ProblemsNo print problemsa. Printer acts like printer, but nothing comes out- check paper- check ink/tonerb. Printer doesnt do anything- cable connection- power

2. Paper problemsPaper jamPaper pick-up tray wont grabCheck pick-up rollersPaper humidity3. Bad print problemsa. streak or spots called speckles- for laser use vacuum to clean- for inkjet clean the print cartridge- use the maintenance programb. fades- low toner/ink- shake toner- if spotted, paper is too dampc. fuzzy print-put- alignment problem5. Speakers Used to play sound. Speakers allow you to listen to music and hear sound effects from your computer.

Speakers

How Sound Works in PCComponents to capture soundSound cardSpeakersMicrophoneRecording/playback softwareSampling process of capturing/recording sound electronically.- It is measured in kilohertz, thousands of cycles per second11 Khz low quality like in telephone128 Khz ultra high quality the more you sample a sound wave, the better is the quality.Bit DepthAmplitude loudness of soundFrequency high or low tonesTimbre quality that differentiate the same note played on different instrumentsAll characteristics are translated to 1 and 0 to reproduce sound accurately.The greater the bit depth, the more is the quality.28 = 256 bits, cheap recording which is flat and thin216 = 65, 536 bits, good recordingTRACKSThe last aspect of sound1. monaural single track2. stereo two tracksCD QUALITY44 Khz sampling rate16 bit depthStereo trackSOUND FORMAT A 4 min song at 44Khz sampling rate, 16 bit depth, stereo has 40+ MB capacity.Programmers compress these audio files so they would take up lesser space.CODECS CODE/DECODE is a program or algorithm to compress and decompress filesAudio File Format is a kind of file used as means of storing digital audio data on a computerAudio FormatPCM Pulse Code Modulation FormatIts use in 1960 to carry telephone calls over the first digital linesThe same technology used in computer known as WAV format.WAV files are huge especially when sampled at high frequency and bit depth

2. Fraunhoffer MPEG Layer 3 or MP3MPEG - Moving Pictures Expert Group is an international standard for encoding and compressing video and audio files or dataMP3 has high quality file size which is 1/10 than the size of wav fileMP3 is popular which is played on iPod, Microsoft Zune and phones.3. WMA Windows Media Audio- developed for Microsoft4. MIDI Musical Instrument Digital Interface5. AIF Audio Interchange File - developed by Apple- played on Apple Quicktime and Apple iTunes6. RM Real Media Player1990 Dolby Digital become the standard in music industrySpeaker Standards1.) Stereo oldest speaker technology- consist of left and right speaker2.) 2.1 systems- standard stereo with subwooferSubwoofer is a speaker addition that provides low frequency tones.

3.) Surround speaker - pioneered by Dolby Digital Sound in 1990Five channelsFront leftRear - leftFront rightRear - rightFront center

4.) 5.1 System - five channels with subwooferMale connector is a connector attached to a wire, cable, or piece of hardware, having one or more exposed, unshielded electricalterminals, and constructed in such a way that it can be inserted snugly into a receptacle (female connector) to ensure a reliable physical and electricalconnection.

Female connector is a connector attached to a wire, cable, or piece of hardware, having one or more recessed holes with electrical terminals inside, and constructed in such a way that a plug with exposed conductors (male connector) can be inserted snugly into it

D. The Ports and their functionWhat is a Port? Incomputer hardware, a port serves as an interface between the computer and other computers or peripheral devices. generic term for any connector on the back of the PC Connect external devices (mouse, keyboard, headphones) or peripherals (monitor, back-up drive, etc) to the computerTYPES OF PORTS1. Serial Port- 9 pin male socket- Intended for serial type mouse and older camera

2. Parallel PortAlso called as printer port. This is only for old model printer. It has 25 pins. It is a female port.

TYPES OF PORTS

3. VGA (Video Graphic Array) Port Used to connect monitors. It has 15 pins in three rows female port.

4. USB (Universal Serial Bus) PortHigh speed serial interface that is used with almost all devices. It is used to connect latest model printers, pen drives, cell phones etc. It has 4 pins.

5. PS/2 (Personal System)PortSimple, 6-pin, low-speed serial connections commonly dedicated to a keyboard and mouse.

6. Power PortIntended for power cord.

7. S-Video PortS-Video connections are available on certain source components and video display devices, and offer a higher level of video performance over composite video signals.

8. Audio PortIntended for plugging in the speaker or headset.

Green line out speaker: to output/produce sound from computerBlue line in stereo/cd player/cassette: to import or record sound to computerPink for microphone9. LAN (Local Area Networking) PortA physical interface often used for terminating twisted pair type cables used to connect computers onto a local-area networks (LAN), especially Ethernet RJ-45 connectors

NETWORK Group of computers connected to each other for purpose of sharing data and hardware. CLASSIFICATION OF NETWORKLAN (Local Area Network- small area such as home, small office, school buildingB. CAN (Campus Area Network)- schools or university network operated by school

C. MAN (Metropolitan Area Network) - greater than LAN, smaller than WANCover entire city or municipality- Operated by government or big businesses.D. WAN (Wide Area Network)- cover great distances such as cities, provinces, countries or the world.E. Cables and Wires A cable is most often two or more wires running side by side and bonded, twisted or braided together to form a single assembly, but can also refer to a heavy strong rope.

1. Mouse & keyboard jacks- intended for the PS/2 port specifically for PS/2 type of keyboard and mouse.

2. Audio & Microphone jack- intended for the audio and microphone port.

3. S-video jack- for S-Video port

4. Monitor Jack - intended for the VGA (Video Graphic Array) port

5.USB (Universal Serial Bus) plug- intended for USB port. Modern or new model of peripherals like printer, camera, scanners and even other portable computer attachments used USB type of plugs.

6. printer cable jack - intended for the parallel port

7. Power Cordthe most important cord because it connects the computer to the main source of electricity to make it functional.8. Registered Jack (RJ 45)standardized networking interface and the "45" simply refers to the number of the interface standard) is a type of connector commonly used for Ethernetnetworking.

Motherhood is a necessity for all invention.~Unknown Quipster

Motherboard

Properly configured and functioning mobo provides a solid foundation for all other hardwareStable, solid, dependableMotherboardknown in the following names: Mainboard System Bard MOBOThe main circuit board of a computer. It contains all the circuits and components that run the computer.

MAJOR MOTHERBOARD MANUFACTURERSASUSGIGABYTEABIT

IBM laid the foundation of todays motherboard.Common Mobo Features1. CPU Socket/Slot2. CPU Fan Power Connector3. Memory Slots4. Power Connector (PI)5. EIDE and FDD Ports6. Chipset7. Expansion Slots8. Accelerated Graphics Port (AGP)9. Peripheral Component Interconnect (PCI)

Common Mobo Features9. Date and Time Battery (CMOS)10. Flash ROM (BIOS)11. Front Panel Connector12. Jumpers13. PS/2 Ports14. Parallel Port and Serial Ports15. USB Port16. Network Port17. Sound and Game Ports

HOW TO HANDLE MOTHEBOARDDo not touch components within the CPU socket area Hold it from the corners/sidesPERSONAL TOUR OF THE MOTHERBOARDMobo have many parts working together to keep PC running1. CPU Socket/SlotA place to insert the CPUCPU inserts into the mobo near one corner, on the opposite end from the expansion slots.MAJOR CPU MAKERSIntelAMD (Advanced Microdevices)CPUElectronic device that accepts input and performs hundreds of different types of functions on that inputMay be as simple as basic arithmetic functions like adding 2+2Or may be something more complex such as Take this value and send it to the video card so it can display a color on the screen.The collection of all functions that a CPU can perform is called CPUs instruction set.Commands sent to the CPU to tell the CPU to do something are called programs.

EMPTY MECHANICAL PENWhere are the Programs?Without programs the commands that tell the CPU what you want to do the CPU is useless.For the CPU to work, the PC must have a way to grab programs and send them to the CPU so the CPU can do whatever you want it to do. So where are the programs?Build a pc with only but very slowCpu process millions, even billions of commands. HD IS NOT ENOUGHPrograms loaded to RAM.RAM feed it to cpuRunning programMobo filled with tiny wires called tracesWires come out from cpu and run to a special helper called northbridgeNorthbridge connects cpu to ramMultiple wires to connect two or more devices is called busFront side bus connects cpu, northbridge and ramIdentify right cpu for moboMany cpu chips in past decayHow to identify a cpu?Cpu manufacturers, model, speed, packageCpu manufacturesIntel and ADVANCED MICRODEVICESINTEL processor wont work wit mobo designed for AMDProcessor modelI3, i5, i7Amd athlonCpu speedTo achieve speed reduce physical size of cpu to reduce the amount of voltage to run cpu which reduce the heat of processorManufacturer can crank up the speed of the processor without fear of overheating and you run games at super speeds and everybody is happyCPU packageShape, size, external featuresWhy so many different looks?Cpu became faster and smarter need more pins to link to to moboA modern cpu has more pins than older pinsDont assume two cpus of the same make and model share the same package typeBoth package is generically call pin grid array or pga

Example423 pin p4478 pin p4Intel will not work in sockets designed for amd and vise versaFive ways to identify cpuSystem informationStart -> programs -> accessories ->system tools -> system informationRight click my computer icon ->propertiesSlot CPU - Older Athlon, CeleronSocket CPU current Pentium 4, Athlon XPThe number on the socket identifies the type.Example:Socket 423 for Intel Pentium 4 CPUsSocket 462 for AMD Athlon XP

Intel Coreis a brand name used for various mid-range to high-end consumer and businessmicroprocessorsmade byIntel.In general, Core microprocessors are more powerful than entry level Celeron and PentiumThe current lineup of Core processors includes the latest:Intel Core i7Intel Core i5Intel Core i3Older:Intel Core 2 SoloIntel Core 2 DuoIntel Core 2 Quad,What's the difference between an Intel Core i3, i5 and i7?The numbers are simply indicative of their relative processing powers.Their relative levels of processing power are also signified by their Intel Processor Star RatingsSTAR RATINGi7 five stari5 four starsi3 3 starsPentium 2 starsCeleron 1 starSTAR RATING CRITERIAnumber of coresclockspeed (in GHz)size of cachenew Intel technologies like Turbo Boost and Hyper-ThreadingNumber of CoresThe more cores there are, the more tasks (known as threads) can be served at the same timeCore i3 - lowest number of cores, two coresCore i5 quad coreCore i5-661dual-core processor , clockspeed of 3.33 GHz

Cache sizeCache is just like RAM, only faster because its built into the CPU itselfBoth RAM and cache serve as holding areas for frequently used data.Basically,RAMminimizes interaction with the hard disk, while cache minimizes interaction with the RAM.larger cache, more data can be accessed quicklyAll Core i3 processors have 3MB of cache.Core i5 6MB of cacheCore i5 661 4MBCore i7 CPUs - 8MBi7 outperforms an i5 and why an i5 outperforms an i3.

Intel Turbo BoostIntel Turbo Boost Technology allows a processor to increase its clockspeed whenever the need arises. Core i5-661, its maximum allowable processor frequency is 3.6 GHzCore i3 CPUs have no Turbo BoostHyper-Threadingsingle core serve multiple threadsCore i3, which is only a dual core serve two threads per core. total of four threads can run simultaneouslyCore i5 dont support Hyper-Threading Core i7 processors are thecreme de la creme. Not only are they quad cores, they also support Hyper-Threading. Thus, a total of eight threads can run on them at the same time. Combine that with 8MB of cache and Intel Turbo Boost Technology, which all of them have, and youll see what sets the Core i7 apart from its siblings.

Intel Core i3The first Core i3 processors were launched on January 7, 20102. CPU Fan Power ConnectorCPU fan draws the heat and move the hot airFans are rated according to the amount of air they move, measured in cubic feet per minute CFM22 CFM average45 CFM high performanceREMEMBER!Plugging in the fan power connector incorrectly will cook the fan or short the power connector.3. Memory SlotsA place to insert the memoryATX motherboard have two, three, or four memory slots with 184 pins for DDR SDRAM DIMMS (Dual Data Rate Synchronous Dynamic Random Access Memory Dual Inline Memory Modules) and 168 pin SDRAM4. Power Connector (PI)

Provides connection between outlet and CPUan electrical connector for supplying direct current (DC) powerPowers CPU and memory3.3 volt, 5V, 12V

Pentium 4 (P4) Power SuppliesProvides extra 12-volt power to motherboards designed for Pentium 4 cpuP4 Power Connector A 12V power supply cable used withmotherboardsthat have anIntelPentium 4 processor Supply additional power to the motherboard

5. EIDE and FDD Ports

Along the edge of the mobo near RAM slots are three or five ports with many wires poking up. EIDE Enhanced Integrated Drive Electronic, provides standardized interface for hard drives and CD-media drivesEach 40 pin EIDE support two EIDE devicesFDD Floppy Disk Drive is a port for two floppy disk- each 34 pin can support two floppy disk drivesHARD DRIVE CABLESThree main types of hard drive data cables: IDE/PATASATASCSI1. IDE (Integrated Drive Electronics) known as PATA (Parallel Advance Technology Attachment) drives, are commonly found in personal computers. These drives usually are found only in older computers. An IDE/PATA hard drive cable is a ribbon cable containing 40 pins. Either one or two devices may be connected to an IDE/PATA cable.

2. SATA Cable (Serial Advance Technology Attachment) A SATA hard drive cable has seven conductors and is smaller than an IDE/PATA cable. A SATA cable connects a single hard drive to a single connector on the SATA controller, which is usually found on the computer's motherboard.

3. SCSI (Small Computer System Interface) SCSI cables look similar to IDE/PATA cables in that both drives use ribbon cables. However, SCSI cables have more pins than IDE cables. Depending on the SCSI interface, a SCSI cable may have 50 or 68 pins (IDE/PATA drives have 40). Like IDE, multiple SCSI devices can be connected to a single channel through "daisy chaining." Depending on the SCSI interface, as many as 7 or 15 devices may be connected to a single SCSI channel.

6. ChipsetFacilitates communication between CPU and other devices in the systemNorthBridge called thememory controller also called GMCH, forGraphic and Memory Controller Hub.in charge of controlling transfers between the CPU and the RAM and the AGP

2. SouthBridge also called theinput/output controlleror expansion controllerhandles communications between peripheral devices

7. Expansion Slots or Bus

Allows you to add other devices to your computerIt allows the CPU to talk to the other devices in the computer and vice versa.

TWO TYPES OF EXPANSION BUSPCI (Peripheral Component Interconnect) Slotthe most popular expansion bus use in today's computersGeneral-purpose, 32-bit,33MHz slots designed to enable quick communication between internal hardware add-ons and the CPUPCI BUS

EXPANSION CARD

2. AGP (Accelerated Graphic Port) Slotdesigned for the high demands of 3-D graphics exclusive for video cards 32-bit, 66MHz connection

AGP BUSCMOS is short for Complimentary Metal Oxide SemiconductorA battery that enables the system to retain accurate date and time settings even when the PC is power is off.9. Date and Time Battery (CMOS)

10. Flash ROM (BIOS)

BIOS is short for Basic Input Output System a small set of code that enables CPU to communicate properly with devices built into the motherboard. It is stored in a small chip called Flash ROM chip Award, AMI, Phoenix11. Front Panel Connector

Connectors on the front of the system unit, such as the following:power and reset buttonsPower and hard drive activity lightsPC speakerUSB power12. Jumpers

a pair of wires that you enable (turn on) or disable (turn off) by placing a small plastic and metal shunt over both wires. jumpers labeled on the mobo as JP#, where # is any whole number, such as JP1, JP213. PS/2 PortsTwo small round ports on the edge closest to the CPU are mini-DIN ports, commonly called PS/2 ports.6 pin ports for keyboard and mouseIntroduced by IBM14. Parallel Port and Serial Ports

Parallel port is a 25-pin D-shaped female port to attach printer, scanner and other parallel deviceSerial port is a 9-pin male ports to connect older serial devices such as external modems and old mouse15. USB Port

High speed serial interface that is used with almost all devices. It is used to connect latest model printers, pen drives, cell phones etc. It has 4 pins.

16. Network Port

A physical interface often used for terminating twisted pair type cables used to connect computers onto a local-area networks (LAN), especially Ethernet RJ-45 connectors17. Sound and Game Ports

Sound port is intended for plugging in the speaker or headsetGame port connects gaming devicesTypes of MotherboardAdvanced TechnologyAdvanced Technology Extended

AT MotherboardAT Motherboard - old-style for factor of moboInvented by IBM in early 80s and became the predominant form factorVery large like two pieces of paper laid side by sideLarge keyboard plug called DIN connectorSplit P8/P9 style of power socketBaby ATThe original AT mobo was then called Full AT, Regular AT, or sometimes just AT.The standardization of permanent elements enable people to swap one mobo for another,as long as they stayed within the AT standardDisadvantage: lack of external portsATX Motherboard has achieved strong position in mobo form factors and today is the standardProvides a standard for manufacturers to adhere to.ATX MOBO are relatively small compared to AT meaning that computers although more powerful, take up less desk space than ever.ATX MOBO improved external connectors designed to support the increasing demands of PC users and devicesOther improvements RAM close to northbridge and cpu for enhanced performanceTWO TYPES OF ATXMICRO ATXFLEX ATXMICRO ATXMicro ATX is to ATX what Baby ATX was to ATFurther reduce the size of moboPhysical size called a foot print and has three or four expansion slots FLEX ATX Created by INTEL in 19999 by 7.5 inches dimension which makes it the smallest mobo in the ATX standardCreated to reduce the size of the lowest-cost computersLimited expansion slots

PROPRIETY MOTHERBOARDSHEWLETT-PACKARDSONYThese companies make mobo that work only with their cases.These propriety mobo enable these companies to create systems that stand out from the generic ones and push clients to get service and upgrades from authorized dealersHard Disk Drive

Hard Disk DriveAlso known as hard drive, a magnetic storage device installed inside the computer. The hard drive is used as permanent storage for data. In a Windows computer, the hard drive is usually configured as the C: drive and contains the operating system and applications.

Hard Disk Driveinvented in the 1950soriginally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product).later became known as "hard disks" to distinguish them from "floppy disks."FLOPPY DISK

Afloppy disk, also called adiskette, is adisk storagemedium composed of a disk of thin and flexiblemagnetic storagemedium, sealed in a rectangular plastic carrier lined with fabric that removes dust particlesMAJOR HDD MANUFACTURERSSeagate Technology

IBM(International Business Machines)

Western Digital

Fujitsu

Parts of Hard drive

ENCLOSUREthe shell that houses the internal components of HDD

Logic Board

Logic Board

Also known as the hard drive controller circuit boardinstruction manual for the computer attempting to access the driveholds the read/write cache

HEADSReads the dataEvery platter requires two heads: top and bottom

Bonus Question:If a hard drive has four platters, how many heads does it have?

HDD SPINDLE MOTORHDD SPINDLE MOTORcontrolled by the logic boardholds a hard drives platters in placerotates the platters, or the disks

Desktop: 7,200 or 10,000 RPM (Revolution per minute)Notebook: 4200 or 5400 RPM

HDD PLATTER

A hard drive platter being accessed by an actuator arm.

HDD PLATTERHDD PLATTEROne or more aluminum, glass, or ceramic disk that is coated in a magnetic media and is located within a hard drive topermanently store computer'sdata.

HOW DATA IS STORED IN HDD?

Geometry physical placement of circles on tiny pits in the hard disk drive or CD

Tracks - concentric circles Sectors - pie-shaped wedges on a trackCylinder

Sector smallest storage area (universal atom)Each sector has 512 bytesBonus Question:If a sector is the smallest storage area on the HDD does a file smaller than 512 still uses an entire sector?

PARTITIONA discrete electronic chunk of a hard drive for organizing data on the hard driveDISCRETE: Separate and distinctUNLOCK TERM

How Hard Disks WorkThe logic board reads and amplifies the very weak, isolated magnetic fields that comprise your data.The logic board begins using the actuator to read information from the sectors in the requested cluster.Information is streamed into the hard drive cacheThe information is fed from the cache, to the hard drive controller, to you and your RAM!

User requests information on the hard drive.Operating system accesses the MFT, or master file table (An index of files and locations), via the motherboards hard drive controller to find the files cluster.Operating system tells the hard drives logic board, via the hard drive controller, that it wants a file from a cluster.The logic board spins up the platters on the spindle.The actuator arm is moved into position.

There are two ways to measure the performance of a hard disk:

Data rate- The data rate is the number of bytes per second that the drive can deliver to the CPU. Rates between 5 and 40 megabytes per second are common.Seek time- The seek time is the amount of time between when the CPU requests a file and when the first byte of the file is sent to the CPU. Times between 10 and 20 milliseconds are common.The other important parameter is thecapacityof the drive, which is the number of bytes it can hold.

HARD DRIVE CABLESThree main types of hard drive data cables: IDE/PATASATASCSIATA/PATA OR IDEATA Advanced Technology AttachmentPATA Parallel ATAIDE Integrated Drive Electronics1. IDE (Integrated Drive Electronics) known as PATA (Parallel Advance Technology Attachment) drives, are commonly found in personal computers. These drives usually are found only in older computers. An IDE/PATA hard drive cable is a ribbon cable containing 40 pins. Either one or two devices may be connected to an IDE/PATA cable.The traditional IDE data cable consists of two or three 40-pin connectors

233IDE cable can be used to connect up to 2 IDE devices if there are three connectors presentone which is used to connect to the IDE port on the motherboard and other two the IDE ports on the storage devices

2. SATA Cable (Serial Advance Technology Attachment) A SATA hard drive cable has seven conductors and is smaller than an IDE/PATA cable. A SATA cable connects a single hard drive to a single connector on the SATA controller, which is usually found on the computer's motherboard.

SERIAL ATA (SATA)first released in August2001and is a replacement for the Parallel ATA

capable of delivering 1.5Gbps(150MBps)3. SCSI (Small Computer System Interface) SCSI cables look similar to IDE/PATA cables in that both drives use ribbon cables. However, SCSI cables have more pins than IDE cables. Depending on the SCSI interface, a SCSI cable may have 50 or 68 pins (IDE/PATA drives have 40). Like IDE, multiple SCSI devices can be connected to a single channel through "daisy chaining." Depending on the SCSI interface, as many as 7 or 15 devices may be connected to a single SCSI channel.

Power cable

IDE hard drives receive power through a 4-pin molex connector