In attempts to develop a standard for a new high density disc format, two formats were proposed in the early 1990s: the Multimedia CD (MMCD), proposed by Philips and Sony, and the Super Density Disc (SDD), proposed by a consortium of Toshiba, Matsushita, and Time Warner. In 1995, a high density format was accepted, largely based on the SDD format the Digital Versatile Disc (DVD), also called the Digital Video Disc.
The reasons you would want to install a DVD drive in your PC are still a little vague beyond your desire to sit at your PC and watch movies. However, because a DVD drive also reads CDs. it may be a good hedge against future technologies should more DVD software or media become available. Many experts are saying that the DVD RAM will be the CD R of the future, but this is still open to debate and remains to be seen.
DVD Technology
A DVD can store the equivalent of 17 gigabytes (GB) or about 25 times more than a CD ROM. Through the use of MPEG (Motion Pictures Experts Group) and Dolby compression technologies, a DVD can also store hours of high quality audio visual content,
such as a full length movie plus other supporting content. One layer of a DVD Audio stores 4.7GB of data, which means that each second on a DVD Audio stores more than 1,100 times more information than one second on an audio CD. One DVD Audio can hold up to 400 minutes of 2 channel stereo sound or 74 minutes of 6 channel sound.
The DVD was designed to be backward compatible with an existing CD ROM, which means DVD drives are able to read the CD formatting. The DVD uses a read mechanism that includes a dual focus pick up to read the disc. The DVD is the same size as a CD ROM, and the DVD drive uses the same form factor as the CD ROM drive, but the formatting on the DVD is considerably different than that used on the CD. Table 10 2 shows a comparison of a DVD Audio to a CD DA.
There are probably more types of DVDs available than you think.. Here are the primary DVD types:
DVD-ROM This is a read only form of DVD that stores interactive media, data, audio, and video. This type of DVD is not compatible with DVD Video players (the kind connected to TVs), but they will play back DVD Video movies. DVD ROM drives are the type installed in PCs and notebook computers.
DVD-R (Recordable) A WORM type disc that can record up to 3.95GB. DVD R is recorded using the same dye layer technology as the CD R.
DVD-RAM This type of DVD, which looks more like a big diskette than a CD ROM, is a rewritable form of DVD that uses essentially the same technology as a CD R. A DVD RAM has a capacity of 4.7GB per side and is available in both single sided and double sided versions. A DVD RAM drive will read most DVD Videos and DVD ROMs, as well as all types of CD media.
DVD-RW (Read/Write) A version of rewritable DVD that competes with the DVD RAM, the DVD RW also holds 4.7GB per side and is capable of being rewritten more than 1,000 times. A DVD RW does not require a unique drive like the DVD RAM and can be read in a DVD ROM drive.
Installing a DVD Drive in Your PC
Installing a DVD drive in your PC requires a DVD kit. This kit will usually include an ATAPI/EIDE DVD drive, an MPEG 11 decoder card, the various cables required to connect the drive, and perhaps some software as well. The process of installing the DVD drive is the same as installing a CD ROM or CD R drive, with the possible exception of loading some DVD software. Some computers have DVD software already loaded, but using software decompression can really impact the performance of some PCs. It is recommended you use hardware decoding if it's available.
When installing the DVD drive, the MPEG decode card is installed in a PCI expansion bus slot, the DVD drive is connected to an EIDE connector, and an audio cable is used to connect the decoder card to the sound card. Some DVD kits install a cable to connect the decoder card to your video card as well. On Windows systems, the decoder card, because it is in a PCI slot, will be automatically detected and you will be prompted to load the device drivers, which usually come with the drive on a CD. After the DVD drive is installed in your PC, you will be able to read regular CDs and view DVD movies using the DVD controller software usually included in the kit.
To support a DVD drive, your PC should be at least a Pentium with at least a 20OMHz clock speed, 32MB of RAM, a free PCI slot for the MPEG decoder, a PCI video card with at least 2MB of video RAM that supports DirectX and Direct Draw technologies, and a Sound Blaster compatible sound card. Windows 98 and 2000 Pro have built in DVD support and nearly all DVD software is written for Windows.
