The DVD-RAM format for DVD recorders was the second to be introduced, in June 1998. The DVD-RAM disc looks like a regular DVD disc, but it is considered to be closer to a random access memory. The DVD-RAM discs are housed in cartridges that come in two types. The first type discs available come in sealed cartridges. The second type of cartridges allow the discs to be removed.
The DVD-RAM format was invented by Matsushita (the parent company of Panasonic) and is endorsed by the DVD Forum.
Some of the manufacturers are JVC, Panasonic, Samsung and Toshiba.
Writing or reading a DVD-RAM disc is similar to accessing a computer's hard drive.
DVD-RAM Features
- Recording and playback functions can be performed at the same time;
- A DVD-RAM drive records only on available (blank) spaces on the disc;
- A DVD-RAM disc lasts up to 100.000 recording cycles;
- The non linear data storing allows you to perform cut and insert operations when editing the disc. Editing can be performed before disc finalization;
- The defect management feature enables data storing in a non-defective area on the disc;
- Compatibility: DVD-RAM discs have playback compatibility problems with almost all DVD players and computer DVD-ROM drives, due to random access & defect management features; all recordable drives can read DVD-ROM discs;
- Capacity: 4.37 GB for a single sided DVD-RAM disc; double-sided discs are also available;
- Price: a single sided DVD-RAM disc is $8, a double sided one can be up to $15;
- Life span: 30 years.
There's also a compact-size for DVD-RAM discs (2.8 billion bytes of memory) that is used in DVD-RAM camcorders from Hitachi and Panasonic. They are available for $30.
Today, only the DVD players created by Panasonic after 2001 are sure to be DVD-RAM compatible.
Panasonic also offers two “combo” drives, DMR-E85H and DMR-E65 that can write DVD-RAM and DVD-R discs.