Double-sided disk
Encyclopedia
In computer science
, a double-sided disk is a disk
of which both sides are used to store data.
Early floppy disk
s 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 disk
s 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.
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.
DVD
s also are available in single-sided and double-sided formats. When used for movie releases, double-sided DVDs typically have the widescreen
(or letterbox
) version of the movie on one side, and the pan and scan
(sometimes called "fullscreen") version on the opposite side. Some releases place the feature on one side, and the "extras" on the opposite. It is more common, however, for movies to be released on single-sided, dual-layer discs, with the film and extras on the same side, and widescreen and letterbox versions packaged separately. In the case of Oliver!
, the film is too long to fit on one dvd (as DVDs can hold up to 120 minutes maximum), so the movie was split and two parts, with the second part on the other side of the same disc. The film was modified to include "End of Side One" after the "Intermission" card was displayed.
When DVDs are used for computer data storage, dual-layer discs are preferred over double-sided ones, to avoid the inconvenience of needing to remove and re-insert discs. However, there is some interest, especially in the development of discs that are both double-sided and dual-layer, effectively quadrupling the amount of information that can be stored as compared to the original, single-sided recordable DVDs. Because of the increased storage available, and the increasing number of computers equipped with drives capable of reading and writing DVDs, many new games are starting to be released on DVDs, and the format is common for personal and business backup
needs.
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
, a double-sided disk is a disk
Disk storage
Disk storage or disc storage is a general category of storage mechanisms, in which data are digitally recorded by various electronic, magnetic, optical, or mechanical methods on a surface layer deposited of one or more planar, round and rotating disks...
of which both sides are used to store data.
Early floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
s 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 disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
s had to be removed and flipped over
Flippy disk
A flippy disk is a double-sided 5¼" floppy disk, specially modified so that the two sides can be used independently in single-sided drives...
to access data on the other side, but eventually devices were made that could read both sides without the need to eject the disk.
DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....
s also are available in single-sided and double-sided formats. When used for movie releases, double-sided DVDs typically have the widescreen
Widescreen
Widescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....
(or letterbox
Letterbox
Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes above and below it; these mattes are part of the image...
) version of the movie on one side, and the pan and scan
Pan and scan
Pan and scan is a method of adjusting widescreen film images so that they can be shown within the proportions of a standard definition 4:3 aspect ratio television screen, often cropping off the sides of the original widescreen image to focus on the composition's most important aspects...
(sometimes called "fullscreen") version on the opposite side. Some releases place the feature on one side, and the "extras" on the opposite. It is more common, however, for movies to be released on single-sided, dual-layer discs, with the film and extras on the same side, and widescreen and letterbox versions packaged separately. In the case of Oliver!
Oliver!
Oliver! is a British musical, with script, music and lyrics by Lionel Bart. The musical is based upon the novel Oliver Twist by Charles Dickens....
, the film is too long to fit on one dvd (as DVDs can hold up to 120 minutes maximum), so the movie was split and two parts, with the second part on the other side of the same disc. The film was modified to include "End of Side One" after the "Intermission" card was displayed.
When DVDs are used for computer data storage, dual-layer discs are preferred over double-sided ones, to avoid the inconvenience of needing to remove and re-insert discs. However, there is some interest, especially in the development of discs that are both double-sided and dual-layer, effectively quadrupling the amount of information that can be stored as compared to the original, single-sided recordable DVDs. Because of the increased storage available, and the increasing number of computers equipped with drives capable of reading and writing DVDs, many new games are starting to be released on DVDs, and the format is common for personal and business backup
Backup
In information technology, a backup or the process of backing up is making copies of data which may be used to restore the original after a data loss event. The verb form is back up in two words, whereas the noun is backup....
needs.