DVD-RAM

DVD-RAM

[¦dē¦vē¦dē ′ram] (communications) DVD-rewritable

DVD-RAM

Digital Versatile Disk Random Access Memory

DVD-RAM

A rewritable DVD disc endorsed by the DVD Forum. Using phase change technology, DVD-RAMs are like removable hard disks, and the media can be rewritten 100,000 times compared to 1,000 times for DVD-RW and DVD+RW. The first DVD-RAM drives with a capacity of 2.6GB (single sided) or 5.2GB (double sided) became available in the spring of 1998. DVD-RAM Version 2 discs with 4.7GB arrived in late 1999, and double-sided 9.4GB discs in 2000. DVD-RAM drives typically read DVD-Video, DVD-ROM and all types of CD media. See DVD, DVD storage capacities, DVD+RW, DVD-RW and optical disc.

Panasonic Drive and Media
In 1998, Panasonic was the first to debut a DVD-RAM drive, which supported both caddy-based and caddyless media. DVD-RAM discs were placed in the caddy for writing, but CDs and all other DVD media were read bare. (Image courtesy of Panasonic Industrial Company.)

Phase Change Recording
In rewritable DVDs, different intensities of the laser turn bits in the phase change recording layer between a crystalline state and an amorphous state.