EET 450 - Advance Digital

Chapter 12

CD - CDR - DVD

Compact Disk Technology

• Information stored on a reflective surface, read with a laser beam.

• 74 minutes or 640 Mb of data storage– Current 80 min/700 Mb

• CD-ROM is a read only version.– Data is recorded at manufacture using a

printing-style operation

• Transfer rates have been increasing – See Table for speeds

• A more important measure is access time.– Massive (relatively) mechanism means slow

response to move the read head into position to read information.

CD Drive Speed Data Rate Kbps

1x 150

4x 600

10x 1,500

12x 1,800

24x 3,600

32x 4,800

40x 6,000

48x 7,200

100x 15,000

Drive Speed Access Time (ms)

1x 400

2x 300

3x 200

4x 150

6x 150

8x – 12 x 100

16x – 24x 90

32x – 52x or greater 85-75 or less

• CD-R - Recordable media

• Same storage capacity, but media uses an organic dye– Some makers now featuring 700Mb (80min)

• The dye reflectivity is changed with a low power laser.– Storage is a WORM variety

CD-R Media Color

• Reflective layer/Die Layer– Gold-gold – Phthalocyanine dye

• Less tolerance for power variations

– Gold-green – Cyanine dye• More forgiving

• 10 yr life span

– Silver-blue – Azo dye• Similar to green, but rated to 100 years.

• CD-RW - Re-writable CD

• Uses a phase-change technology

• Same storage capacity as CD

• active layer of CD-RW is Ag-In-Sb-Te– Silver - indium - antimony - tellurium – polycrystalline structure is reflective– High power laser heats to 500-700 degrees

– This solidifies in a non-reflective state– To erase, a lower power laser heats to 200

degrees, which solidifies in the original reflective state.

CD-ROM Disc & Drive Formats

• Red Book– Digital Audio CDs (CDDA)

• Yellow Book– Computer CDs– Mode 1: ISO 9660– Level 1: PC, Apple, UNIX, DVI– Level 2: CDTV

CD-ROM Disc & Drive Formats

• White Book– Video CD– MPEG-1, MPEG-2

• Orange Book– Writeable CDs – CDR

• Green Book– Combination of Red and Yellow Books– CD-I

• CD + (Enhanced CD)– Combines Music and computer Data on 1 CD

• Data Standard: ISO 9660

• High Sierra Format

• CD-CA (digital Audio)

• CD-ROM XA – extended architecture– Multi-session CDs

DVD

• Digital Versatile Disk– initial capacity 4.7 G - 135 minutes of video

with three audio and four sub-title channels.– 8.5 G dual layer disks - use a semi reflective

top layer.– double sided

• 9.4G single layer

• 17G double layer

• Additional capacity from– smaller pit length– reduced track pitch– larger data area on disk– More efficient modulation– More efficient error correction code– less sector overhead

• Short wave-length laser reads

• fast transfer rate - ~ 9x by CD-Rom standards

• interface - standard IDE/ATA or SCSI

Standard DVD FormatsFormat Size S/layers Capacity

DVD-5 120mm S/s 4.7G

DVD-9 120mm S/d 8.5G

DVD-10 120mm D/s 9.4G

DVD-14 120mm D/d 13.24G

DVD-18 120mm D/d 17G

DVD-1 80mm S/s 1.4G

DVD-2 80mm S/d 2.7G

DVDR-1 120mm S/s 2.58G

DVDR-2 120mm D/s 9.4G

• Recordable DVD– Two standards– DVD-R

• WORM type

– DVD-RAM• re-writable like CD-RW

Recordable DVD Standards

• DVD-RAM – 2.6 G/side – Not compatible w/ DVD ROM $25/disk

• DVD-R – 4.7G (1999 version)– Almost all can read this format $40/disk

• DVD-RW – 4.7G– Almost all can read this format $40/disk

• DVD+RW – 2.8G/side– A few current from Sony or Phillips $30/disk

DVD Ram encoding

DVD-Ram

DVD-R Wobbled Groove

DVD-R

MultiRead & MultiRead2Media MultiRead MultiRead2

CD-DA (audio) X X

CD-ROM X X

CD-R X X

CD-RW X X

DVD-ROM - X

DVD-Video - X

DVD-Audio - X

DVD-Ram - X

References

• http://www.toshiba.com/taecdpd/products/docs/dvdramwhitepaper.shtml

• Mueller, S., Upgrading and Maintaining PC’s 12e, 2000, Que Corp.