PC Maintenance: PC Maintenance: Preparing for A+ Preparing for A+

CertificationCertificationChapter 13: Managing CD DrivesChapter 13: Managing CD Drives

Chapter 13 ObjectivesChapter 13 Objectives

Identify types of optical drivesIdentify types of optical drives Understand measurements of drive Understand measurements of drive

performanceperformance Install a CD driveInstall a CD drive Understand CD-R and CD-RWUnderstand CD-R and CD-RW Understand DVD drivesUnderstand DVD drives Troubleshoot optical drive problemsTroubleshoot optical drive problems

Types of Optical DrivesTypes of Optical Drives

Standard CDStandard CD Writeable CD (CD-R, CD-RW)Writeable CD (CD-R, CD-RW) Standard DVDStandard DVD Writeable DVD (DVD-R, DVD-RW, Writeable DVD (DVD-R, DVD-RW,

DVD+R, DVD+RW, CD-R, CD-RW)DVD+R, DVD+RW, CD-R, CD-RW)

What is “X”?What is “X”?

Theoretical maximum data transfer rateTheoretical maximum data transfer rate Multiple of 150Kbps it can read. For Multiple of 150Kbps it can read. For

example, 32X CD = 4.8Mbpsexample, 32X CD = 4.8Mbps Transfer rate is only theoretical due to Transfer rate is only theoretical due to

hardware limitationshardware limitations Also refers to rotational speedAlso refers to rotational speed

Access TimeAccess Time

Elapsed time between PC’s request and Elapsed time between PC’s request and drive’s deliverydrive’s delivery

Measure of mechanical ability of drive to Measure of mechanical ability of drive to move read head to correct spotmove read head to correct spot

75ms is typical75ms is typical

Constant Linear Velocity (CLV)Constant Linear Velocity (CLV)

Found in older regular CD-ROM drivesFound in older regular CD-ROM drives Found in all PC-based writeable drivesFound in all PC-based writeable drives Data read at the same area per secondData read at the same area per second Disk spins faster when head is near centerDisk spins faster when head is near center

Constant Angular VelocityConstant Angular Velocity

Found in newer regular CD-ROM drivesFound in newer regular CD-ROM drives CD rotates at a constant speedCD rotates at a constant speed Amount of data per second varies Amount of data per second varies

depending on spot on disk being accesseddepending on spot on disk being accessed

Other Performance FactorsOther Performance Factors

Interface (IDE, SCSI, USB)Interface (IDE, SCSI, USB) Competition for interface bandwidthCompetition for interface bandwidth Drive cacheDrive cache CPU usageCPU usage DMA usageDMA usage

Installing a CD DriveInstalling a CD Drive

1.1. Set any jumpers on drive neededSet any jumpers on drive needed

2.2. Insert drive in bayInsert drive in bay

3.3. Connect ribbon cableConnect ribbon cable

4.4. Connect power cableConnect power cable

5.5. (Optional) Connect audio cable(Optional) Connect audio cable

Audio CableAudio Cable

Allows CD drives to play audio CDs in Allows CD drives to play audio CDs in analog modeanalog mode

Connects directly from sound card to CD Connects directly from sound card to CD drivedrive

Real-Mode CD DriversReal-Mode CD Drivers

Config.sys:Config.sys: DEVICE=[driver] /D:[name]DEVICE=[driver] /D:[name] Example: Example:

DEVICE=SSCDROM.SYS /D:SSCD0001DEVICE=SSCDROM.SYS /D:SSCD0001 Autoexec.bat:Autoexec.bat:

MSCDEX.EXE /D:[name]MSCDEX.EXE /D:[name] Example:Example:

MSCDEX /D:SSCD0001MSCDEX /D:SSCD0001

DVDDVD

Digital Versatile Disc (data)Digital Versatile Disc (data) Digital Video Disc (movies)Digital Video Disc (movies) Holds at least 4.7GB of data or 135 Holds at least 4.7GB of data or 135

minutes of videominutes of video Single and double-sidedSingle and double-sided Single and double-layeredSingle and double-layered

MPEG DecodersMPEG Decoders

Required to play DVD moviesRequired to play DVD movies Hardware or softwareHardware or software Typically software on newer systemsTypically software on newer systems

Troubleshooting CD ProblemsTroubleshooting CD Problems

CD will not eject:CD will not eject:Insert wire into release hole on front of Insert wire into release hole on front of drivedrive

Troubleshooting CD ProblemsTroubleshooting CD Problems

Noisy drive:Noisy drive: Replace driveReplace drive

CD drive not bootable:CD drive not bootable: Enable CD booting in BIOS setupEnable CD booting in BIOS setup Change boot order to bypass other boot disks Change boot order to bypass other boot disks

if needed (such as hard drive)if needed (such as hard drive) Ensure that the CD being read is bootableEnsure that the CD being read is bootable

How CD-R WorksHow CD-R Works

Laser hits photosensitive dye on surface of Laser hits photosensitive dye on surface of blank discblank disc

Where laser touches, surface becomes Where laser touches, surface becomes less reflectiveless reflective

CD drive perceives less reflective area as CD drive perceives less reflective area as a pita pit

Troubleshooting CD-R Troubleshooting CD-R RecordingRecording

Buy a CD-RW drive with a large bufferBuy a CD-RW drive with a large buffer Do not use PC while recordingDo not use PC while recording Place an IDE CD drive on its own ribbon Place an IDE CD drive on its own ribbon

cablecable Do a test write firstDo a test write first Lower the recording speedLower the recording speed Create a disc image rather than copying Create a disc image rather than copying

CD-to-CDCD-to-CD

How CD-RW WorksHow CD-RW Works

Laser has three power settingsLaser has three power settings High: Heats area, creating a non-reflective High: Heats area, creating a non-reflective

area simulating a pitarea simulating a pit Low: Re-heats the same area again, causing Low: Re-heats the same area again, causing

it to revert back to original reflectivityit to revert back to original reflectivity Lowest: Reads data without changing itLowest: Reads data without changing it

Bootable CDsBootable CDs

Contain two files for booting:Contain two files for booting: BOOTCAT.BIN: A catalog fileBOOTCAT.BIN: A catalog file BOOTIMG.BIN: An image file containing a BOOTIMG.BIN: An image file containing a

virtual floppy diskvirtual floppy disk Create a bootable CD:Create a bootable CD:

Use a CD writing utility programUse a CD writing utility program Create a bootable floppy firstCreate a bootable floppy first Use utility to create a BOOTIMG.BIN on disk Use utility to create a BOOTIMG.BIN on disk

matching that bootable floppy’s contentmatching that bootable floppy’s content