Chapter 9

Multimedia Devices and Mass Storage

You Will Learn…• How multimedia works on a PC• About multimedia devices such as sound cards, digital

cameras, and MP3 players• About optical storage technologies such as CD and

DVD• How certain hardware devices are used for backups

and fault tolerance• How to install and troubleshoot multimedia and mass

storage components

Multimedia on a PC• Goal

To create or reproduce lifelike representations of sight and sound

• Challenge Data storage is digital Sights and sounds are analog

CPU Technologies for Multimedia• MMX, SSE, and 3DNow!

Improve speed of processing graphics, video, and sound

Use improved methods of handling high-volume repetition during I/O operations

• Software must be written to use the specific capabilities

Multimedia Devices• Sound cards

Record sound, save it to a file on hard drive, play it back

• Externally attached devices Digital cameras MP3 players

Stages of Computerized Sound• Digitize or input sound (analog to digital)

Includes sampling• Data is measured at a series of representative points• Sampling rate = cycles per second, or hertz (Hz)

• Store digital data in compressed data file

• Reproduce or synthesize sound (digital to analog)

Sound Card Manufacturers

Installing a Sound Card• Physically install the card in an empty PCI slot

on the motherboard

• Install sound card driver

• Install sound applications software

Installing a Sound Card

Verifying Installation of a Sound Card and Driver

Digital Cameras• Scan field of image and translate light signals

into digital values Digital values can be stored as a file and viewed,

manipulated, and printed with software that interprets them appropriately

• Use TWAIN format for transferring images

A Flash RAM Card

Digital Camera Manufacturers

MP3 Players

MP3 Players• A device that plays MP3 files (a version of

MPEG compression)

• MP3 can reduce size of a sound file as much as 1:24 without much loss in quality

Compression Methods Used with MP3 Players

• MPEG (Moving Pictures Experts Group) standard Tracks movement from one frame to the next and

stores only what changes Can yield compression ratio of 100:1 for full-

motion video Cuts out or drastically reduces sound that is not

normally heard by the human ear

MPEG Standards• MPEG-1

Used in business and home applications to compress images

• MPEG-2 Used to compress video films on DVD-ROM

• MPEG-3 Used for audio compression

• MPEG-4 Used for video transmissions over the Internet

How MP3 Players Work• Play MP3 files downloaded from a PC, using

internal memory and flash storage devices (eg, SmartMedia, CompactFlash, or Memory Stick)

MP3 Player Manufacturers

Video Capture Card• Captures input from a camcorder or directly from TV

• Features to look for: IEEE 1394 (FireWire) port Data transfer rates Capture resolution and color-depth capabilities Ability to transfer data back to digital camcorder or VCR Stereo audio jacks Video-editing software

Video Capture Card Manufacturers

Optical Storage Technology• Patterns of tiny pits on disc surface represent

bits, which are readable by a laser beam

• Major optical storage technologies CD-ROM drives

• Use CDFS (Compact Disc File System) or UDF (Universal Disk Format)

DVD drives• Use only UDF

CD-ROM• Read-only; data

physically embedded into disc surface

• Surface laid out as one continuous spiral of sectors of equal length that hold equal amounts of data

CD-ROM• Used to distribute software and sound

files

• Combines constant linear velocity (CLV) and constant angular velocity (CAV)

• Look for multisession feature• CD-ROM drives are read-only and slower to

access than hard drives

CD-ROM Drive Manufacturers

CD-ROMs• Caring for CD-ROM drives and discs

Use precautions when handling

• CD-ROM drive interface with motherboard IDE interface (most common) SCSI interface Proprietary expansion card that works only with CD-ROMs

from a particular manufacturer Proprietary connection on sound card Portable drive; plug into external port on PC

Installing a CD-ROM Drive

Installing a CD-ROM Drive

CD-R and CD-RW• CD-R (CD-recordable)

Enables “burning” your own CDs Cannot edit or overwrite Bottom of disk is tinted (eg, blue, black); CDs are silver Inexpensive Can be read by all CD-ROM drives

• CD-RW (CD-rewritable) Allows overwriting old data with new data Cannot always be read by older drives

DVD (Digital Video Disc)• Storage capacity

8.5 GB (one side) 17 GB (both sides)

• Uses shorter wavelength laser than CD; a second opaque layer also holds data

• Uses MPEG-2 video compression; requires MPEG-2 controller to decode compressed data

• Audio is stored in Dolby AC-2 compression

DVD Device

DVD Devices

DVD Drive Manufacturers

Installing a DVD Drive

DVD Decoder Card

Rear Panel of DVD Drive

Rear Panel of DVD Drive

Installing a DVD Drive

Installing a DVD Drive

Hardware Used for Backups and Fault Tolerance

• On standalone PCs or small servers Tape, Zip, and Jaz drives Read-write CDs

• In a business environment with PC connected to file server Back up data to file server

Tape Drives• Advantages

Inexpensive and convenient

Large capacity Several types and

formats

• Disadvantage Sequential access

Tape Drive Manufacturers

How a Tape Drive Interfaces with a Computer

• External Parallel port

• Internal IDE ATAPI interface

• External or internal SCSI bus Proprietary controller card or floppy drive interface

External Drive UsingParallel Port

An ATAPI IDE Tape Drive

Tapes Used by a Tape Drive• Full-sized data

cartridges

• Minicartridges

Several Tape Drive Standards

Tape Formats and Tape Types• Quarter-Inch Committee (QIC) or quarter-inch

cartridge standards Developed in 1983; only a few in use today

• Travan by 3M Different levels (TR-1 through TR-5), each based

on a different QIC standard

Removable Drives• Can be internal or external

• Increase overall storage capacity of a system

• Make it easy to move large files from one computer to another

• Serve as a convenient medium for making backups of hard drive data

• Make it easy to secure important files

Removable Drives• Considerations when purchasing

Drop height Half-life of the disk Plug and Play compliance

Types of Removable Drives• Iomega 3½ Zip drive

Stores 100 MB or 250 MB of data Drop height of 8 feet

• SuperDisk by Imation or Maxell Stores 120 MB or 240 MB, respectively Backward compatibility with regular floppy disks

• Iomega Jaz drive Stores 1 GB or 2 GB of data Drop height of 3 feet

Zip Drive

Installing a Removable Drive• Internal removable drive

Similar to installing a hard drive

• External removable drive Different process

RAID (Redundant Array of Independent Disks)

• Data protection methods used to improve performance and/or automatically recover from a failure

• Most often used on high-end, high-cost file servers

Common RAID Levels

RAID 0(Disk Striping without Parity)

• Increases logical drive capacity by treating two or more drives as a single logical drive

• Includes only one copy of data; does not enable recovery from failure

RAID 1 (Disk Mirroring or Disk Duplexing)

• Designed to protect data from hard drive failure by writing data twice, once to each of two drives

• Disk mirroring Two hard drives use same controller

• Duplexing Each hard drive has its own controller on its own

adapter card

RAID 1 Disk Mirroring• Advantages

If either drive fails, data is safe on other drive Disk reads are speeded up

• Disadvantages Expensive Cuts hard drive capacity in half Disk writes are slowed down

RAID 4(Disk Striping with Parity)

RAID 5 (Disk Striping with Distributed Parity)

• Currently most popular RAID implementation

• Provides optimum fault tolerance and improves drive capacity

• Requires at least three hard drives

• Distributes parity information over all the drives, thus removing performance bottleneck created by having a single parity drive (as in RAID 4)

Windows Support for RAID

Troubleshooting Guidelines• Do not touch chips on circuit boards or disk

surfaces where data is stored

• Do not stack components on top of one another

• Do not subject them to magnetic fields or ESD

Problems with CD-ROM orDVD Installation

• Computer does not recognize the drive (no drive D listed in Windows 9x Explorer)

Troubleshooting Sound Problems• Problem with sound card itself

• Result of system settings

• Bad connections

Troubleshooting Tape Drives• A minicartridge does not work

• Data transfer is slow

• Drive does not work after installation

• Drive fails intermittently or gives errors

Chapter Summary• Multimedia devices

What they can do How they work How to support them

• Storage devices; installation and troubleshooting CD DVD Removable drives Tape drives