I recently attended a press preview of Philips' latest DVD home theater system - the Philips DVDR 1000 (slated for launch Q3, 2001)- and had an earful on how the technology actually works. Also on show was the concept of SACD, or Super Audio CD, a new hybrid audio disc technology that plays on standard CD players but outputs multi-channel audio if played on an SACD-compatible machine.
Touted as the future replacement for the Video Cassette Recorder (VCR), DVD+RW (note the '+') is set to create significant impact to the data recording industry in the near-future. But first, before we delve into how different is the +RW from the -RW, let's first understand how DVD actually has evolved to the standard it is today.
Since its market introduction in 1996, the Digital Versatile Disc (DVD) has garnered a major sales boost, propelled perhaps by the idea that significant amount of information that can be stored onto one single-layer 4.7GB disc. DVD-Video, in particular, attracted great public attention, and it was only a matter of time before recordable DVD systems, began to make appearances in the home consumer electronics market.
Like CDs, DVDs store data in miniscule grooves on its disc surface. The laser beams from DVD drives scan the disc surface where small reflective bumps (called "lands") and non-reflective holes (called "pits") aligned on the grooves will be translated by the drive into zeroes and ones to be converted into digital information. Unlike CDs however, the tracks on the DVDs are 0.74 microns wide, which is much smaller than the 1.6 microns found on CDs. This is one of the reasons why DVDs have higher capacities than CDs.
There are basically three major standards of DVDs today. The first of these is the DVD-ROM, which is generally the packaged and commercially available DVD-Videos and DVD-Audio discs you find in the shops. Then there is the recordable DVD, which is based on the write-once standard, meaning that you can only write on these DVD-Rs only once and that's it (like CD-R). The first-generation of DVD-Rs could record up to 3.95GB but the newer versions could now take up to 4.7GB. Finally, and this is where interest perks up, is the third major standard of DVD which is the rewritable DVD. Rewritable DVDs let you record on a DVD multiple times and still retain the quality and value of the data recorded. It is this third type of DVD which we are looking at in this insight.
Unlike DVD-RAM and DVD-RW, the DVD+RW disc format will be compatible with upcoming DVD+RW home video recorders, DVD-Video hi-fi players, DVD-RW and DVD-ROM drives for the PC.