to the magnetic head of a hard disk drive. It also allows for the fastest writing speeds on recordable media (e.g. CD-R, DVD±R, BD-R) because the disc can spin at the highest physically possible angular speed throughout the entire writing process. A linear (data reading and writing) speeds of 2.4 times higher can be reached at the outer disc edge with the same angular (rotation) speed. CAV was used in the LaserDisc format for interactive titles; it was also used with special editions of certain films. CAV allowed for perfect still frames, as well as random access to any given frame on a disc. Playing time, however, was 30 minutes on each side (these discs are also known as "standard play"), as opposed to 60 minutes on each side for CLV-based discs ("extended play"). CAV is used with the Nintendo GameCube Game disc and Wii Optical disc, the original Xbox discs, and Sega's GD-ROM. Partial constant angular velocity (P-CAV) If the used media (e.g. DVD-RAM variants) has a linear (writing) speed limitation that can not be attained with physically supported angular (rotation) speeds at the inner edge of the recordable area, the disc writing can start off with a constant angular velocity, until the increasing linear velocity has reached the writing speed limitation of the disc. At that point, the drive transitions into writing with a constant linear velocity. See also Constant linear velocity (CLV) Zone bit recording (ZCAV) References External links http://www.pcguide.com/ref/hdd/geom/tracksZBR-c.html Rotating disc computer storage media Audio storage Video storage Optical computer storage