PC Maintenance: Preparing for A+ Certification Chapter 13: Managing CD Drives

Chapter 13 Objectives Identify types of optical drives Identify types of optical drives Understand measurements of drive performance Understand measurements of drive performance Install a CD drive Install a CD drive Understand CD-R and CD-RW Understand CD-R and CD-RW Understand DVD drives Understand DVD drives Troubleshoot optical drive problems Troubleshoot optical drive problems

Types of Optical Drives Standard CD Standard CD Writeable CD (CD-R, CD-RW) Writeable CD (CD-R, CD-RW) Standard DVD Standard DVD Writeable DVD (DVD-R, DVD-RW, DVD+R, DVD+RW, CD-R, CD-RW) Writeable DVD (DVD-R, DVD-RW, DVD+R, DVD+RW, CD-R, CD-RW)

What is “X”? Theoretical maximum data transfer rate Theoretical maximum data transfer rate Multiple of 150Kbps it can read. For example, 32X CD = 4.8Mbps Multiple of 150Kbps it can read. For example, 32X CD = 4.8Mbps Transfer rate is only theoretical due to hardware limitations Transfer rate is only theoretical due to hardware limitations Also refers to rotational speed Also refers to rotational speed

Access Time Elapsed time between PC’s request and drive’s delivery Elapsed time between PC’s request and drive’s delivery Measure of mechanical ability of drive to move read head to correct spot Measure of mechanical ability of drive to move read head to correct spot 75ms is typical 75ms is typical

Constant Linear Velocity (CLV) Found in older regular CD-ROM drives Found in older regular CD-ROM drives Found in all PC-based writeable drives Found in all PC-based writeable drives Data read at the same area per second Data read at the same area per second Disk spins faster when head is near center Disk spins faster when head is near center

Constant Angular Velocity Found in newer regular CD-ROM drives Found in newer regular CD-ROM drives CD rotates at a constant speed CD rotates at a constant speed Amount of data per second varies depending on spot on disk being accessed Amount of data per second varies depending on spot on disk being accessed

Other Performance Factors Interface (IDE, SCSI, USB) Interface (IDE, SCSI, USB) Competition for interface bandwidth Competition for interface bandwidth Drive cache Drive cache CPU usage CPU usage DMA usage DMA usage

Installing a CD Drive 1. Set any jumpers on drive needed 2. Insert drive in bay 3. Connect ribbon cable 4. Connect power cable 5. (Optional) Connect audio cable

Audio Cable Allows CD drives to play audio CDs in analog mode Allows CD drives to play audio CDs in analog mode Connects directly from sound card to CD drive Connects directly from sound card to CD drive

Real-Mode CD Drivers Config.sys: Config.sys: DEVICE=[driver] /D:[name] DEVICE=[driver] /D:[name] Example: DEVICE=SSCDROM.SYS /D:SSCD0001 Example: DEVICE=SSCDROM.SYS /D:SSCD0001 Autoexec.bat: Autoexec.bat: MSCDEX.EXE /D:[name] MSCDEX.EXE /D:[name] Example: MSCDEX /D:SSCD0001 Example: MSCDEX /D:SSCD0001

DVD 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 minutes of video Holds at least 4.7GB of data or 135 minutes of video Single and double-sided Single and double-sided Single and double-layered Single and double-layered

MPEG Decoders Required to play DVD movies Required to play DVD movies Hardware or software Hardware or software Typically software on newer systems Typically software on newer systems

Troubleshooting CD Problems CD will not eject: Insert wire into release hole on front of drive CD will not eject: Insert wire into release hole on front of drive

Troubleshooting CD Problems Noisy drive: Noisy drive: Replace drive Replace drive CD drive not bootable: CD drive not bootable: Enable CD booting in BIOS setup Enable CD booting in BIOS setup Change boot order to bypass other boot disks if needed (such as hard drive) Change boot order to bypass other boot disks if needed (such as hard drive) Ensure that the CD being read is bootable Ensure that the CD being read is bootable

How CD-R Works Laser hits photosensitive dye on surface of blank disc Laser hits photosensitive dye on surface of blank disc Where laser touches, surface becomes less reflective Where laser touches, surface becomes less reflective CD drive perceives less reflective area as a pit CD drive perceives less reflective area as a pit

Troubleshooting CD-R Recording Buy a CD-RW drive with a large buffer Buy a CD-RW drive with a large buffer Do not use PC while recording Do not use PC while recording Place an IDE CD drive on its own ribbon cable Place an IDE CD drive on its own ribbon cable Do a test write first Do a test write first Lower the recording speed Lower the recording speed Create a disc image rather than copying CD-to-CD Create a disc image rather than copying CD-to-CD

How CD-RW Works Laser has three power settings Laser has three power settings High: Heats area, creating a non-reflective area simulating a pit High: Heats area, creating a non-reflective area simulating a pit Low: Re-heats the same area again, causing it to revert back to original reflectivity Low: Re-heats the same area again, causing it to revert back to original reflectivity Lowest: Reads data without changing it Lowest: Reads data without changing it

Bootable CDs Contain two files for booting: Contain two files for booting: BOOTCAT.BIN: A catalog file BOOTCAT.BIN: A catalog file BOOTIMG.BIN: An image file containing a virtual floppy disk BOOTIMG.BIN: An image file containing a virtual floppy disk Create a bootable CD: Create a bootable CD: Use a CD writing utility program Use a CD writing utility program Create a bootable floppy first Create a bootable floppy first Use utility to create a BOOTIMG.BIN on disk matching that bootable floppy’s content Use utility to create a BOOTIMG.BIN on disk matching that bootable floppy’s content