storage (DVD, formerly "Digital Video Disc") An optical
storage medium with improved capacity and bandwidth compared
for entertainment and later for computer users. [When was it
first available?]
A DVD can hold a full-length film with up to 133 minutes of
high quality video, in
MPEG-2 format, and audio.
The first DVD drives for computers were read-only drives
("DVD-ROM"). These provide over seven times the storage
capacity of CD-ROM (4.7 GBytes). DVD-ROM drives read existing
CD-ROMs and music CDs and are compatible with installed
sound and video boards. Additionally, the DVD-ROM drive can
read DVD films using an advanced (MPEG-2) video board,
required to decode the high resolution video format.
The first drives, using a single-layer disc of 4.7GB, were
expected to be available during the second half of 1996 from
dual-layer discs were expected to increase the disc capacity
to 8.5 GB. Double-sided, dual-layer discs will eventually
increase the capacity to 17 GB.
Write-once DVD-R ("recordable") drives record a 3.9GB DVD-R
disc that can be read on a DVD-ROM drive. The first DVD-R
drive was expected by mid 1997.
By the end of 1997, the rewritable DVD-RAM (by false analogy
available. DVD-RAM drives read and write to a 2.6 GB DVD-RAM
disc, read and write-once to a 3.9GB DVD-R disc, and read a
4.7 GB or 8.5 GB DVD-ROM. Also, it was expected that a
DVD-RAM disc would be readable on both the DVD-R and DVD-ROM
drives.
[Did this happen as predicted? Current state?]
(1999-07-08)