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Appendix
Disc Types
AVS DVD Copy currently supports three types of optical disc formats that are available for consumer
use. This section will better explain the purpose of these formats and their place in history. With the
support of other disc types and formats the corresponding information will be added.
Compact Discs
Digital Versatile Discs
DVDs of different capacities
DVDs of different medium type
Blu-Ray Discs
Compact Discs
Digital Audio Compact Discs (CD-DA) were first introduced to the consumer audio market in 1980 by
Philips and Sony as an alternative to vinyl records and magnetic tape cassettes. In 1984, Philips and
Sony extended the technology to include data storage and retrieval and introduced a new format: the
Data Compact Disc (CD-ROM).
Since then, the Compact Disc has dramatically changed the way that we listen music and handle
electronic information. With a capacity of up to 700 megabytes of computer data or 80 minutes of high
quality audio, the Compact Disc has revolutionized the distribution of every kind of electronic
information.
In 1990, Philips and Sony extended the technology again and the Compact Disc became recordable
(CD-R). Before the introduction of the CD-R technology, compact discs were produced in commercial
replication plants by stamping the media with a pre-recorded master. Today, discs are produced in
replication plants where large quantities are required. For small production volumes (up to 500 copies
or more, depending on your location and manufacturers in your market), it can be significantly less
expensive to master your own discs using commercially available Compact Disc writing drives.
Whether a Compact Disc was stamped at a replication facility or "burned" using a compact disc
recorder, it can theoretically be read by any available CD-ROM drive. In reality, some inexpensive
media and CD players do not work very well together. Only the physical composition of a commercially
replicated disc and a CD-R disc are different. The former is coated with a reflective layer of aluminum
resulting in a typical silver color. The latter is coated with a reflective layer behind a thin layer of dye
(colors can range from blue, silver, green, and others).
In 1997 Compact Disc ReWritable (CD-RW) - a rewritable optical disc format - was introduced. While a
prerecorded compact disc has its information permanently stamped into its polycarbonate plastic
substrate, a CD-RW disc contains a phase-change alloy recording layer composed of silver, indium,
antimony and tellurium. An infra-red laser beam is employed to selectively heat and melt the
crystallized recording layer into an amorphous state or to anneal it at a lower temperature back to its
crystalline state. The different reflectance of the resulting areas make them appear like the pits and
lands of a prerecorded CD. A CD-RW recorder can rewrite 700 MB of data to a CD-RW disc roughly
1000 times.
A Compact Disc contain blocks (or sectors) of 2352 bytes each, going from the center hole to the outer
diameter. The block at logical address 0 (beginning of the disc) is located near the center of the disc;
the last addressable block (end of the disc) is located near the outer edge of the disc.