DVD-RAM Idaho

DVD-RAM (DVD–Random Access Memory) is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.

The term DVD-RAM is a misnomer based on the false assumption that RAM means "read-and-write memory"; the opposite of ROM (Read-Only Memory). However, RAM stands for Random Access Memory (computer chips) and DVDs cannot inherently use the random access method.

Compared with other writeable DVDs, DVD-RAM is more closely related to hard disk technology, as it has concentric tracks instead of one long spiral track. Unlike the competing formats DVD+R, DVD-R, DVD+RW and DVD-RW, special DVD burning software is not required to write or read DVD-RAMs on a computer. DVD-RAMs can be accessed like a usual floppy disk or hard drive.

Microsoft Windows XP supports DVD-RAM operation directly, while earlier versions of Windows require device drivers or the program InCD. The optical drives in Apple Macintosh computers do not support DVD-RAM operation, but a third party DVD-RAM-compatible drive can be connected and used with software such as DVD Studio Pro.

A DVD format wherein DVD-RAM discs can be recorded and erased repeatedly but are only compatible with devices manufactured by the companies that support the DVD-RAM format. DVD-RAM discs are typically housed in cartridges.

The specification distinguishes between

DVD-RAM 1.0
Single-sided, one layer discs with a capacity of 2.58 GB
Double-sided one layer discs with a capacity of 5.16 GB

DVD-RAM 2.0
Single-sided, one layer discs with a capacity of 4.7 GB
Double-sided one layer discs with a capacity of 9.4 GB

Physically smaller DVD-RAM discs also exist with a capacity of 1.46 GB, but they are uncommon. DVD-RAMs were originally solely sold in cartridges; recent DVD recorders however also work with no-cartridge discs – some devices even do not support cartridges anymore. A cartridge disc is about 50% more expensive than a disc without cartridge.