DVD+RW

DVD+RW. It is a rewritable optical disc format forming a key part of the broader DVD family of storage media. Developed by the DVD+RW Alliance, it allows users to record, erase, and re-record data multiple times. The format found widespread application in computer data backup, home video recording, and as a distribution medium for various software and multimedia content.

Overview

The format was engineered to offer a high degree of compatibility with existing DVD-Video players and DVD-ROM drives, a critical factor in its market adoption. Unlike write-once formats, its rewritable nature provided significant flexibility for consumers and professionals. Major electronics corporations, including Philips and Sony, were instrumental in its promotion and technical refinement. The underlying technology utilizes a phase-change recording layer, typically composed of a special metal alloy, which can be switched between crystalline and amorphous states by a laser.

Technical specifications

A standard single-sided, single-layer disc holds 4.7 gigabytes of data, matching the capacity of a DVD-R or DVD+R. The recording process employs a technology known as Lossless Linking, which allows for seamless editing and prevents interruptions during video recording. The disc's physical dimensions are identical to other DVD formats, with a diameter of 120 millimeters. The data transfer rate for writing and reading evolved through specifications like 2.4x and 8x, as defined by the governing DVD Forum and the rival DVD+RW Alliance. The reflective layer and phase-change material are protected by a polycarbonate substrate.

Compatibility and usage

Compatibility with standalone DVD players was a major battleground in the format wars, with many later-generation players supporting both DVD-RW and DVD+RW. For computer use, drives labeled as DVD±RW became commonplace, offering support for all major recordable formats. The format was extensively used with Windows XP and later operating systems for creating data archives and video DVDs. Software suites from Roxio and Nero AG provided robust authoring tools. Its adoption in set-top boxes and digital video recorders, such as those from Panasonic, provided a tangible alternative to VHS tapes for television recording.

Comparison with other rewritable formats

The primary competitor was the DVD-RW format, which was developed by the DVD Forum and championed by Pioneer Corporation. A key technical difference was the use of a wobble groove pre-format and ADIP addressing on DVD+RW, compared to the Land Pre-Pit method on DVD-RW. This often resulted in marginally better compatibility with older DVD-ROM drives for the "+" format. The later DVD-RAM format, supported by companies like Toshiba, offered superior robustness and random-access capabilities but required a special caddy and had very low player compatibility. In the subsequent high-definition era, both formats were largely supplanted by Blu-ray Disc technologies.

History and development

The format was officially announced in 1997 by a consortium that included Philips, Sony, and HP, challenging the established DVD-R standard. The DVD+RW Alliance was formed to promote the specification, setting the stage for a prolonged rivalry with the DVD Forum. The first commercial drives reached the market in 2001, with Ricoh being an early producer of key controller chips. Throughout the early 2000s, it gained significant market share, particularly in the European Union and North America. Its development and legacy are intrinsically linked to the broader history of optical storage, preceding the advent of HD DVD and Blu-ray Disc.

Category:Computer storage media Category:Optical disc authoring Category:DVD