14-10-2016, 10:07 AM
1458897838-CDDVDbyAaronRinacaMikeFerrisMikeBurkerSteveMathieu2001SPR.ppt (Size: 251.5 KB / Downloads: 5)
Brief History of Compact Digital Media
1980: The first Compact Disk player is produced by Sony/Phillips.
1982: The first Compact Disk is manufactured for sale, Billy Joel’s “52nd Street”
1984: First portable Compact Disk players enter the market followed by car CD players shortly after.
1985: Sony/Philips announce the standard for compact disc storage of computer data, the CD-ROM
1987: Video CD format is designed.
1991: CD-R (Compact Disk Recordable) technology is introduced as a new storage technology.
1996: Digital Versatile Disk(DVD) technology is introduced
1997: DVD’s and DVD players begin to enter the market
1998: DVD Recordable systems invented and begin to enter the market
2000: DVD movies become mainstream and replace analog VHS as the format of choice.
Compact Disk (CD) Basics
Uses Digital Technology to store data in binary values of Zero and One
Uses “Pits” and “Lands” to signify binary values
CD’s Read at a Constant Linear Velocity (CLV)
Capable of Storing Large Amounts of Data (up to 700MB)
Uses Error Correction for reliable data retrieval even if the CD becomes lightly scratched.
Types Of Compact Disks
CD Audio – The first type of CD that was available. This allows for the storage of digital audio. These are playable in all current CD drives and car audio systems including DVD players.
CD-ROM – Computer Data is stored on these units such as games, applications, and other files. Only readable on computers.
CD-R – Allows users to write data once to a recordable Compact Disk. Can not be re-written and can be read in all current players depending on wither the disk holds Audio or Data.
CD-RW – Users Can Write and Re-Write these special disks. However because of the disk format, they cannot be read in Audio CD players or DVD players.
CD Basic Technology Principles
Printed Label : The image on the top of the CD, more of a “secondary” protection device than anything else.
Protective Lacquer: This protects the CD from scratches and helps reflect the CD player’s laser.
Aluminum Layer: This is the reflective layer that primarily bounces the CD player’s laser back.
Polycarbonate: Known industry wide as a very durable substance, Polycarbonate is a clear covering designed to protect the pits and lands in the CD surface.
CD Audio: How Does It Work?
Sound is Sampled at 40,000 Times per Second or Higher
Each Sample Must be Represented by at least a 16-bit number
Therefore, with 40,000 samples per second, and 16-bits per sample,
that’s over 640,000 bits per second! Therefore a 1 minute long
music clip would take over 38,400,000 bits (+/- 38MB) for storage!
Computer CD-ROM’s
Divided Into Sectors Containing User Data and Error Correction Codes. Set up similar to hard drives however they do not have a “FAT” sector, instead sectors are opened and closed with special pit and land combinations.
File Systems are used to store data for easy and quick access