Dual Layer Dvd: Double Sided Dvd

Thursday, 18 October 2012

Double Sided Dvd

In computer science, a double-sided disk is a disk of which both sides are used to store data.
Early floppy disks only used one surface for recording. The term "single sided disk" was not common until the introduction of double-sided disks, which offered double the capacity in the same physical size. Initially, the double-sided floppy disks had to be removed and flipped over to access data on the other side, but eventually devices were made that could read both sides without the need to eject the disk.
A commercially-made floppy disk "notcher"
Manufacturers sold both single-sided and double-sided disks with the double-sided disks being typically 50% more expensive than single-sided disks. While the magnetic-coated medium was coated on both sides, the single-sided floppies had a read-write notch on only one side, thus allowing only one side of the disk to be used. When users discovered this, they began buying the less-expensive single-sided disks and "notch" them using scissors, a hole punch, or a specially-designed "notcher" to allow them to write to the reverse side of the disk.