Page 114 - DCAP303_MULTIMEDIA_SYSTEMS

Multimedia Systems

notes In December 1995, nine major electronics companies (Toshiba, Matsushita,
Sony, Philips, Time Waver, Pioneer, JVC, Hitachi and Mitsubishi Electric)
agreed to promote a new optical disc technology for distribution of multimedia
and feature-length movies called DVD.
6.3.6 CD-roM

A Compact Disc or CD is an optical disc used to store digital data, originally developed for storing
digital audio. The CD, available on the market since late 1982, remains the standard playback
medium for commercial audio recordings to the present day, though it has lost ground in recent
years to MP3 players.
An audio CD consists of one or more stereo tracks stored using 16-bit PCM coding at a sampling
rate of 44.1 kHz. Standard CDs have a diameter of 120 mm and can hold approximately 80 minutes
of audio. There are also 80 mm discs, sometimes used for CD singles, which hold approximately
20 minutes of audio. The technology was later adapted for use as a data storage device, known as
a CD-ROM, and to include record once and re-writable media (CD-R and CD-RW respectively).
The CD-ROMs and CD-Rs remain widely used technologies in the computer industry as of 2007.
The CD and its extensions have been extremely successful in 2004, the worldwide sales of CD
audio, CD-ROM and CD-R reached about 30 billion discs. By 2007, 200 billion CDs had been
sold worldwide.

6.3.7 CD-roM players
Compact disc read-only memory (CD-ROM) players have become an integral part of the
multimedia development workstation and are important delivery vehicle for large, mass-produced
projects. A wide variety of developer utilities, graphic backgrounds, stock photography and
sounds, applications, games, reference texts, and educational software are available only on this
medium.
The CD-ROM players have typically been very slow to access and transmit data (150 k per second,
which is the speed required of consumer Red Book Audio CDs), but new developments have led
to double, triple, quadruple, speed and even 24× drives designed specifically for computer (not
Red Book Audio) use. These faster drives spool up like washing machines on the spin cycle and
can be somewhat noisy, especially if the inserted CD is not evenly balanced.

6.3.8 CD recorders
With a CD recorder, you can make your own CDs using special CD recordable (CD-R) blank
optical discs to create a CD in most formats of CD-ROM and CD-Audio. The machines are made
by Sony, Phillips, Ricoh, Kodak, JVC, Yamaha and Pinnacle. Software, such as Adaptec’s Toast
for Macintosh or Easy CD Creator for Windows, lets you organize files on your hard disk(s) into
a “virtual” structure, then writes them to the CD in that order. The CD-R discs are made differently
than normal CDs but can play in any CD-Audio or CD-ROM player. They are available in either a
“63 minute” or “74 minute” capacity for the former, that means about 560 MB, and for the latter, about
650 MB. These write-once CDs make excellent high-capacity file archives and are used extensively by
multimedia developers for premastering and testing CDROM projects and titles.

6.3.9 videodisc players
Videodisc players (commercial, not consumer quality) can be used in conjunction with the
computer to deliver multimedia applications. You can control the videodisc player from your
authoring software with X-Commands (XCMDs) on the Macintosh and with MCI commands in
Windows.
The Digital Videodisc player employs a laser system. To prevent direct
exposure to the laser beam, do not try to open the enclosure or defeat the
safety interlocks.

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