other uses2 Disc Unreferenced date December 2009 File CIRCLE 1.svg thumb A disk is the region bounded by a circle . An open disk is the interior topology interior of the disk excluding the bounding circle, while a closed disk see closed set is the open disk together with the bounding circle. In geometry , a disk also Spelling of disc spelled disc is the region in a plane geometry plane bounded by a circle . A disk is said to be closed or open according to whether or not it contains the circle that constitutes its boundary. In Cartesian coordinates , the open disk of center math a, b math and radius R is given by the formula math D x, y in mathbb R 2 x a 2 y b 2 R 2 math while the closed disk of the same center and radius is given by math overline D x, y in mathbb R 2 x a 2 y b 2 le R 2 . math The area geometry area of a closed or open disk of radius R is R sup 2 sup see pi . The Ball mathematics ball is the disk generalised to metric spaces . In context, the term ball may be used instead of disk . In theoretical physics a disk is a rigid body which is capable of participating in collisions in a two dimensional gas . Usually the disk is considered rigid so that collisions are deemed elastic collision elastic . Geometry The Euclidean disk is Circular symmetry circular symmetrical . Topological notions The open disk and the closed disk are not homeomorphic, since the latter is compact ... also that of a closed or open disk is 1. Every continuous map from the closed disk to itself ... disk consider for example math f x,y left frac x sqrt 1 y 2 2 ,y right math which maps every point of the open unit disk to another point of the open unit disk slightly to the right of the given one. See also Unit disk , a disk with radius one Annulus mathematics Ball mathematics , the usual term for the 3 dimensional diskDisk algebra Lentoid Moment of inertia of a uniform disc DEFAULTSORT Disk Mathematics Category Euclidean geometry Category Rigid bodies ar bs Krug ca Disc ... more details
Image Nashua diskpack.jpg thumb Disk pack manufactured by Nashua, USA, without its protective cover. A 3.5 modern hard drive is shown for comparison. A Disk pack is a layered grouping of hard disk platter s circular, rigid discs coated with a magnetic data storage device data storage surface . A disk pack is the core component of a hard disk drive. In modern hard disks, the disk pack is permanently sealed inside the drive. In many early hard disks, the disk pack was a removable unit, and would be supplied ... and a separate bottom that completed the sealed package. To remove the disk pack, the drive would ... shell inserted and twisted to unlock the disk platter from the drive and secure it to the top shell. The assembly would then be lifted out and the bottom cover attached. A different disk pack could then be inserted by removing the bottom and placing the disk pack with its top shell into the drive. Turning the handle would lock the disk pack in place and free the top shell for removal. The first removable disk pack was invented in 1965 by two IBM engineers, Thomas G. Leary and R. E. Pattison. The 14 ... vendors producing IBM compatible drives and disk packs. Examples of a hard disks with removable disk packs are the IBM magnetic disk drives IBM 1311 IBM 1311 , and the Digital Equipment Corporation Digital RP04. gallery File Fotothek df n 10 0000117.jpg Operator selects a disk pack File Fotothek df n 10 0000118.jpg Bottom cover is removed File Fotothek df n 10 0000119.jpg Disk pack is ready for insertion File IBM2314DiskDrivesAndIBM2540CardReaderPunch.jpg IBM 2314 s with removable disk packs and empty covers on top File Disk Pack.jpg A removable pack in place gallery References http www 03.ibm.com ... for Drum and Disk Records, U.S. Patent 3,206,214, 1965 R.E. Pattison, Portable Memory for Data Processing Machine, U.S. Patent 3,176,281, 1965 See also commons category Removable disk packs disk cartridge , History of hard disk drives DEFAULTSORT Disk Pack Category Rotating disc computer storage ... more details
An occulting disk is a small disk used in a telescope to block the view of a bright object in order to allow observation of a fainter one. The coronagraph , at its simplest, is an occulting disk in the focal plane of a telescope , or in front of the entrance aperture , that blocks out the image of the solar disk, so that the corona can be seen. Notes, References and Sources http www.daviddarling.info encyclopedia The Encyclopedia of Astrobiology, Astronomy, and Spaceflight astronomy stub Category Telescopes Category Optical devices de Kegelblende ... more details
Image Circle arc.svg thumb 300px A circular sector is shaded in green A circular sector or circle sector , is the portion of a disk mathematics disk enclosed by two radius radii and an Arc geometry arc , where the smaller area geometry area is known as the minor sector and the larger being the major sector. In the diagram, is the central angle in radian s, math r math the radius of the circle, and math L math is the arc length of the minor sector. A sector with the central angle of 180 is called a semicircle . Sectors with other central angles are sometimes given special names, these include ... to any point on the circumference that is not in the sector is equal to half the central angle. Area The total area of a circle is math pi r 2 math . The area of the sector can be obtained by multiplying the circle s area by the ratio of the angle and math 2 pi math because the area of the sector is proportional ... of a sector is the sum of the arc length and the two radii math P L 2r theta r 2r r left theta ... that the sector is a part of to the center of mass of the sector is two thirds of the corresponding distance for the center of mass of the arc of the sector. In particular, as the central angle approaches zero the center of mass of the arc is at distance r from the center of the circle, so that of the sector ... of the arc converges to the center of the circle, whence so does that of the circular sector. See also Circular segment the part of the sector which remains after removing the triangle formed by the center ... sector References Gerard, L. J. V. The Elements of Geometry, in Eight Books or, First Step ...&pg PA285&dq 22circular sector 22 octant&ei BfjBS667MISUzgTK24HMAg&cd 10 v onepage&q 22circular ... and properties of a circle sector with interactive animation MathWorld urlname CircularSector title Circular sector Category Circles ar az Sektor ca Sector circular cs Kruhov v se sn Bandiko da Cirkeludsnit de Kreissektor es Sector circular eo Cirkla sektoro fr Secteur circulaire ... more details
Disk swapping refers to the practice of inserting and removing, or swapping, floppy disks in a floppy disk drive based computer system . In the early days of personal computer s, before hard drives became commonplace, most fully outfitted computer systems had 2 floppy drives addressed as A and B on CP M and MS DOS. Disk drives were expensive, however, and having two was seen as a luxury by many computer users who had to make to with a single drive. The purpose of 2 floppy drives was so that the disk containing the Application software application program could remain in the drive while the data disk containing the user s files could be accessed in the second drive. In order to use a function of the program not loaded into memory, the user would have to first remove the data disk, then insert the program disk. When the user then wanted to save their file, the reverse operation would have to be performed. On some less than user friendly systems, this could result in data loss when, for example, files were saved onto the program disk. Disk swapping was an infamous feature of early Macintosh 128k systems, which were extremely RAM starved. Category Floppy disk computer storage ... more details
In Sun Microsystems Solaris operating system Solaris computer operating system , disk partition s are sometimes known as slices . This is a conceptual reference to the slicing of a cake into several pieces. A slice is composed of a contiguous range of blocks on a disk. The term slice is also used in the FreeBSD operating system to refer to PC BIOS hard disk partitions, to avoid confusion with FreeBSD s own BSD disklabel disklabel based partitioning scheme. See also wikibooks Guide to Unix Explanations Partitioning Disks Partitioning Disks Disk partitioning BSD disklabel List of disk partitioning software References http docs.sun.com app docs doc 817 5093 disksconcepts 20068?l en&a view Solaris 10 System Administration Guide Devices and File Systems http www.freebsd.org doc en US.ISO8859 1 books handbook disks adding.html FreeBSD Handbook Compu stub Category Disk file systems Category Disk partitioning software Category Operating system technology Category Sun Microsystems software ... more details
Disk Manager was a popular 1980s and 1990s software and documentation package for MS DOS and PC DOS computers, useful for self installing personal computer Hard disk drive hard disk s. It was written by Ontrack, a company later acquired by Kroll Inc. Installation covered different aspects explaining personal computer hardware concepts documenting switches of many of the existing disks putting into place custom device driver s which circumvented Enhanced BIOS BIOS limitations , notably those related to maximum disk or partition size and logical block addressing providing testing and informational utilities Drivers could be either DOS type, or replacement master boot record code. Diskettes with Disk Manager were provided by some disk manufacturers e.g. IBM , in custom OEM versions, supporting all of their models. In recent years Kroll switched to the business of providing computer disk data recovery services as Kroll Ontrack Data Recovery . External links http www.ontrackdatarecovery.com Kroll Ontrack Data Recovery Category Windows software Category Utility software Windows software stub ... more details
unreferenced date May 2010 The disk controller is the Electronic circuit circuit which enables the Central processing unit CPU to communicate with a hard disk , floppy disk or other kind of disk drive . Early disk controllers were identified by their storage methods and data encoding. They were typically implemented on a separate controller card. Modified frequency modulation MFM controllers were the most common type in small computers, used for both floppy disk and hard disk drives. Run length limited RLL controllers used data compression to increase storage capacity by about 50 . Priam created a proprietary storage algorithm that could double the disk storage. Shugart Associates Systems Interface Shugart Associates System Interface SASI was a predecessor to SCSI . Modern disk controllers are integrated into the disk drive. For example, disks called SCSI disks have built in SCSI controllers. In the past, before most SCSI controller functionality was implemented in a single chip, separate SCSI controllers interfaced disks to the SCSI bus. The most common types of interfaces provided nowadays by disk controllers are Parallel ATA PATA IDE and Serial ATA for home use. High end disks use SCSI , Fibre Channel or Serial Attached SCSI . Disk controller versus host adapter The correct term for the components that allows a computer to talk to a peripheral bus is host adapter or host bus adapter HBA . On the other hand, a disk controller allows a disk to talk to the same bus. Those two are often confused, especially in the Advanced Technology Attachment PC world . In fact signals read by a disk read and write head are converted by a disk controller, then transmitted over the peripheral ..., and then read by the CPU . Sometimes there may be yet another controller between a host adapter and a disk controller a disk array controller that allows RAID Hardware RAID hardware RAID to be formed ... also Disk array controller Floppy disk controller Forensic disk controller Controller computing ... more details
mergefrom Staging data discuss Talk Disk staging Merger proposal date October 2010 Unreferenced date December 2009 Disk staging is using hard disk disks as an additional, temporary stage of backup process before finally storing backup to magnetic tape data storage tape . Backups stay on disk typically for a day or a week, before being copied to tape in a background process and deleted afterwards. The process of disk staging is controlled by the same software that performs actual backups, which is different from virtual tape library where intermediate disk usage is hidden from main backup software. Both techniques are known as D2D2T disk to disk to tape . Restoring data Data is restored from disk if possible . But if the data exists only on tape it is restored directly no backward staging on restore . Reasons Reasons behind using D2D2T increase performance of small, random access restores disk has much faster random access than tape increase overall backup restore performance although disk and a tape have similar streaming throughput, you can easily scale disk throughput by the means of Data striping striping and tape striping is a much less established technique increase utilization of tape drive s tape shoe shining effect is eliminated when staging note that it may still happen on tape restores See also Backup Virtual tape library DEFAULTSORT Disk Staging Category Computer storage kk zh ... more details
Refimprove date May 2009 distinguish page cache File Fujitsu MPG3307AH ms avrs 110909.jpg thumb The disk buffer sits on the controller board of the hard drive. In computer storage , disk buffer often ambiguously Fact date September 2007 called disk cache or cache buffer Fact date September 2007 is the embedded ... and the physical hard disk platter that is used for storage. Modern hard disks come with 8 ... from the disk platter. The disk buffer is physically distinct from and is used differently than the page cache typically kept by the operating system in the computer s main memory . The disk buffer is controlled by the microcontroller in the hard disk drive , and the page cache is controlled by the computer to which that disk is attached. The disk buffer is usually quite small, from 8 ... cache is reused multiple times, the data in the disk buffer is rarely reused. Fact date September 2007 In this sense, the terms disk cache and cache buffer are misnomers the embedded controller s memory is more appropriately called the disk buffer. Note that disk array controller s, as opposed to disk controller s, usually have normal cache memory of around 0.5&ndash 8 GiB. Uses Read ahead read behind When executing a read from the disk, the disk arm moves the Disk read and write head read ... system. The disk s embedded computer typically saves these unrequested sectors in the disk buffer, in case the operating system requests them later. Speed matching The speed of the disk s I O interface ... the hard disk platter . The disk buffer is used so that both the I O interface and the disk read write head can operate at full speed. Write acceleration The disk s embedded microcontroller may signal the main computer that a disk write is complete immediately after receiving the write data, before ... from the disk buffer, and the file system on the disk may be left in an inconsistent state. On some ... of data is deemed more important than write performance. Another option is to send data to disk in a carefully ... more details
The term disk space is an amount of computer storage space on random access memory devices, such as on a hard drive , floppy or USB flash drive . Citation needed date September 2011 Disk space units are commonly measured in large numbers of bytes , such as kilobytes , megabytes , and gigabytes , with each unit 1024x times larger than the previous unit. The term originated in the 1950s, for the storage area on a hard disk drive , which internally had disk shaped platters to rotate quickly. As storage devices have been created in other shapes, the term disk space has still been used to refer to areas of permanent storage on various storage devices. The total disk space can span multiple devices, such as areas on an array of disk drives. ref NT Server and Disk Subsystem Performance , Microsoft.com, 2010, webpage http technet.microsoft.com en us library cc767920.aspx MS2 . ref The broader term storage space is so widely used that it can be mistaken for property storage, as with items stored in a closet or storage bin. Hence, the term disk space has remained in use, even when the storage devices are no longer shaped as disks. When storage of data is not permanent, then the common term memory space is often used instead. References Reflist Category Computer memory ... more details
Otheruses2 Disc Image Unit disk open.svg thumb right An open Euclidean unit disk In mathematics , the open unit disk or disc around P where P is a given point in the plane mathematics plane , is the set ... disk around P is the set of points whose distance from P is less than or equal to one math bar D 1 P Q P Q leq 1 . , math Unit disks are special cases of disk mathematics disks and unit ball s. Without further specifications, the term unit disk is used for the open unit disk about the origin mathematics ... plane C , the unit disk is often denoted math mathbb D math . The open unit disk, the plane, and the upper ... analytic and bijective function from the open unit disk to the plane its inverse function is also analytic. Considered as a real 2 dimensional analytic manifold , the open unit disk is therefore isomorphic to the whole plane. In particular, the open unit disk is homeomorphic to the whole plane. There is however no conformal map conformal bijective map between the open unit disk and the plane. Considered as a Riemann surface , the open unit disk is therefore different from the complex plane . There are conformal bijective maps between the open unit disk and the open upper half plane . So considered as a Riemann surface, the open unit disk is isomorphic biholomorphic , or conformally equivalent ... unit disk. One bijective conformal map from the open unit disk to the open upper half plane is the M bius ... so that the upper half plane becomes the disk s interior and the real axis forms the disk s circumference ... unit disk to the open upper half plane can also be constructed as the composition of two stereographic projection s first the unit disk is stereographically projected upward onto the unit upper half ... sphere opposite to the touching point as projection center. The unit disk and the upper half plane ... space The open unit disk is commonly used as a model for the Hyperbolic space hyperbolic plane ... the open unit disk and the upper half plane, this model can be turned into the Poincar half ... more details
Orphan date April 2012 Infobox Software name Private Disk logo Image Private Disk logo.png screenshot Image Private disk main window.PNG 285px caption developer Dekart latest release version 2.12 If you update this, don t forget to update Comparison of disk encryption software latest release date November ... NT family , Windows 7 genre Disk encryption software language 17 languages license shareware price USD 65 website http www.dekart.com products encryption private disk www.dekart.com products encryption private disk Overview Private Disk is a disk encryption application for the Microsoft Windows ... Disk s key selling points is in its ease of use, which is achieved by hiding complexity from ... the use of AES 256 encryption. Although Private Disk uses a NIST certified implementation of the AES ... of Private Disk the encryption hash library used ref http www.dekart.com fileadmin company ... Secure 20Hash 20Standart.pdf ref and not to Private Disk as a complete system. Feature highlights NIST certified implementation of Advanced Encryption Standard AES 256 bit, and SHA 2 . Private Disk ... FIPS 180 2 Disk Firewall , an application level filter, which allows only trusted programs to access ... the encrypted container format compatible with containers used by SecuBox disk encryption software ... them to an encrypted disk Compatibility with Windows 9x and Windows NT based operating systems including ... when a virtual disk is mounted or dismounted Encrypted backup of an encrypted image Password quality meter Automatic backup of a disk s encryption key Built in password recovery tool Compatibility with 64 bit platforms Awards Existing versions There are multiple versions of Private Disk, which provide a different feature set http www.dekart.com products encryption private disk Private Disk hard disk encryption software that uses 256 bit AES encryption, is highly configurable, offers application level protection, USB disk portability, etc. http www.dekart.com products encryption private disk ... more details
Multiple issues unreferenced December 2009 context October 2009 Image HP HASS NIKE.jpg thumb Hewlett Packard disk arrays HASS top and NIKE OEM d Data General SCSI Clariion Image EMC Clariion CX500.jpg thumb EMC Corporation EMC CLARiiON CX500 Cover removed on one Shelf Image EMC Symmetrix DMX1000 Front.jpg thumb EMC Corporation EMC Symmetrix DMX1000 A disk array is a disk storage system which contains multiple disk drive s. It is differentiated from a disk enclosure , in that an array has cache computing cache memory and advanced functionality, like redundant array of independent disks RAID and Storage virtualization virtualization . Components of a typical disk array include Disk array controller s Cache computing Cache memories Disk enclosure s Power supply Power supplies Typically a disk array provides increased availability, resiliency and maintainability by using additional, redundant components controllers, power supplies, fans, etc. , often up to the point when all single point of failure single points of failure SPOFs are eliminated from the design. Additionally those components are often hot swappable. Typically, disk arrays are divided into categories Network attached storage NAS arrays storage area network SAN arrays Modular SAN arrays Monolithic SAN arrays Utility Storage Arrays Storage virtualization DEFAULTSORT Disk Array Category Computer storage Category Fault tolerant computer systems Category RAID de Disk Array fr Baie de stockage ja pl Macierz dyskowa ru ... more details
unreferenced date April 2012 Image DOM.JPG thumb right 250px Disk on module A disk on module DOM is a Solid state drive flash drive with either 40 44 pins Parallel ATA IDE Standard ATA Interface USB or SATA Interface to be used as a computer hard disk drive HDD . The flash to IDE converter simulates a harddisk, and therefore the modules can be used without additional software or drivers. They are used particularly within embedded computing systems where they can often be deployed in to very harsh environments where mechanical hard disk drives would simply fail , or in a thin client because of small size, low power consumption and silent operation. DOMs are highly reliable as they do not have any moving parts like regular hard disks and are small in size and light in weight. However, after a disk crash in traditional hard disk, some data may still be recoverable by scanning the physical media using specialized equipment, but there is no known method to recover lost data from a physically damaged DOM. Citation needed date July 2010 Currently storage capacities range from 32MB to 32GB with various form factor including vertical or horizontal orientation. The DOM works the same way as a solid state drive , but it is generally plugged directly to the motherboard. DEFAULTSORT Disk On Module Category Solid state computer storage media Compu hardware stub de Disk on Module fr Disk On Module it Disk on module nl Disk on module ru Disk on Module ... more details
Notability date August 2009 Primary sources date August 2009 Infobox software name Disk Order logo Deleted image removed Image Disk Order.png 48px screenshot Image Diskorder.png 250px caption Screenshot of Disk Order developer Like Mac Group latest release version 3.1 operating system Mac OS X genre File manager license Proprietary software Proprietary website http www.likemac.ru english www.likemac.ru english Disk Order is a shareware Norton Commander like file manager File Manager OFM for Mac OS X . See also Comparison of file managers Comparison of FTP client software External links http www.likemac.ru english The official site of Disk Order File managers Category Mac OS X software Category FTP clients mac software stub ru Disk Order ... more details
zone. Life could exist on either side of the disk, though close to the sun the heat would make ..., only a perpetual twilight . This could be solved by forcing the sun to bob up and down within the disk, lighting first one side then the other. In popular culture An Alderson disk the Godwheel was a prominent ... used technology and one which used magic paranormal magic each occupied separate sides of the disk . Author Larry Niven designed the Godwheel and wrote stories surrounding certain events on it. A disk shaped planet similar to an Alderson disk though far smaller served as the home world of the fantasy ... disk, the Aysle diskworld works according to fantasy physics, including a gravity plane that bisects the disk laterally, so that opposite sides fall towards the plane. The diskworld of Aysle had a bobbing sun and multiple inner layers. Both sides of the disk were inhabited, as were the internal layers. The Alderson disk is discussed in Larry Niven s Bigger than Worlds essay, 1974, which can be found ... Earth is placed on an Alderson disk built around a black hole by Alien space bats ASB s. See also Dyson ... more details
Unreferenced stub auto yes date December 2009 Infobox Software name Disk Copy logo Deleted image removed Image Disk Copy.png Disk Copy icon screenshot caption developer Apple Computer latest release version 10.2 operating system System Software 6 , System 7 Macintosh System 7 , Mac OS 8 , Mac OS 9 , Mac OS X v10.0 , Mac OS X v10.1 , Mac OS X v10.2 genre disk image emulator license Disk Copy was the default utility for handling disk image s in System 7 Macintosh System 7 through Mac OS X 10.2 Usable in System Software 6 as well . In later versions of Mac OS X it has been replaced by DiskImageMounter for mounting the images and Disk Utility for creating them. Although the last official public release of Disk Copy for Mac OS 9 was version 6.3.3, there was to be a version 6.5 that supported the newer DMG image format introduced with Mac OS X. But because Apple had stopped support for OS 9 already, support for the old OS was eventually removed in favour of OS X. As such the OS 9 version of 6.5 only ever made it to beta 13 before development on it stopped. There was also a developer version 6.4 that 6.5 was based on and had most of the same functionality, but as a developer version it was never released. Although version 6.4 and 6.5 will read DMG images when the system is booted into OS 9, they can only do so if the image is not compressed. Disk Copy was also the name of an Apple utility distributed with some of the earliest version of the Mac OS. In order to copy 400K floppy disks using as few disk swaps as possible on a machine with only 128K of RAM, the original Disk Copy used the screen buffer to store binary data from the disk being copied as a result, the screen other than ... image formats Disk Copy Disk Copy 4.2 DiskSet PC drive container raw disk image See also DiskImageMounter The Mac OS X 10.3 and later successor. Disk Utility Creates disk images in Mac OS X 10.3 and later. RaWrite and RaWrite2 for MS DOS and Microsoft Windows dd Unix Category Mac OS Category Disk ... more details
In data storage device data storage , disk mirroring or RAID1 is the replication of logical disk volumes onto separate physical hard disk s in Real time computing real time to ensure continuous availability ... on the disk array controller or via server computing server software . It is typically a proprietary ... of a disk hardware failure a system can continue to process or quickly recover data. Mirroring may be done locally where it is specifically to cater for disk unreliability, or it may be done ... solutions such as disk array s or in software within the operating system. There are several scenarios for what happens when a disk fails. In a hot swap system, in the event of a disk failure, the system itself typically diagnoses a disk failure and signals a failure. Sophisticated systems may automatically activate a hot standby disk and use the remaining active disk to copy live data onto this disk. Alternatively, a new disk is installed and the data is copied to it. In less sophisticated systems, the system is operated on the remaining disk until such time as a spare disk can be installed ..., system performance is usually degraded as the disk system is fully occupied in copying data from one disk to the other. It is often misunderstood that mirroring of disks is a substitute for taking regular backups as it is incorrectly assumed that the only cause of data loss is disk failure. In fact ... to say It is differentiated from a disk snapshot snapshot in that there are no remaining links ..., disk mirroring can allow each disk to be accessed separately for reading purposes. Under certain circumstances ... disk can seek most quickly to the required data. This is especially significant where there are several tasks competing for data on the same disk, and thrashing where the switching between tasks takes ... configurations that frequently access the data on the disk. In some implementations, the mirrored disk can be split off and used for data backup, allowing the first disk to remain active. However merging ... more details
About the perforated disk used to modulate air jets to produce sounds Siren disambiguation A siren disk is a disk with holes variously spaced, such that when spun in front of an air jet, the holes modulate the jet in a primarily binary on off fashion, to directly produce sound. Typical usages of siren disks Siren disks were once used as the active element of sirens, but the majority of siren disks currently manufactured are used as instructional aids in teaching the mechanics of sound and music. For example, the Ontario Science Centre has a metal siren disk set up as an interactive teaching exhibit for children. Siren disk hole spacing The harmonic portion of the siren disk Most siren disks include several concentric circles of spaced holes, so that an air jet can be directed at different radii to get different effects. For example, the outermost eight hole circles include uniformly spaced holes, in which the number of holes increases along a harmonic series, so that eight notes of a musical scale can be played by directing an air jet sequentially at each circle. The nonharmonic portion of the siren disk Typically there are further holes near the central part of the disk, with various non uniform patterns, such as random spacing, and the like. Typical numbers of holes in siren disks ... notes of the most common kind of siren disk. The last eight circles of holes give the following ... 8 holes of the siren disk are br C, D, E, F, G, A, B, C br A similarly generated minor scale can be made by making a siren disk having the following ratios of hole numbers br 1, 9 8, 6 5, 4 3, 3 2, 8 ... the number of holes to make a minor scale siren disk br 1, 9 8, 6 5, 4 3, 3 2, 8 5, 9 5, 2 8 5 3 br br 120 135 144 160 180 192 216 240 br Typical siren disk setup The typical siren disk setup consists ... organ style keys so that children can play music on the siren disk by pressing the keys to open ... spaced holes of the siren disk. See also Siren noisemaker Category Rotating aerophones Category ... more details
SAN Disk may refer to Storage Area Network computer storage devices SAN disks SanDisk SanDisk Corporation formerly known as SunDisk disambig ... more details
Infobox Software name Jungle Disk logo screenshot caption author developer Jungle Disk, Inc. released 2007 operating system Microsoft Windows Windows Mac OS X Linux language English language English license Proprietary website http jungledisk.com jungledisk.com Jungle Disk is an Remote backup service online backup tool that stores its data in Amazon S3 or Rackspace Rackspace Cloud Cloud Files Cloud Files . It was highlighted by Amazon as one of the earliest S3 clients ref name techcrunch s3 cite web url http www.techcrunch.com 2006 07 12 amazon releases early info on s3 storage use author Kirkpatrick, Marshall publisher TechCrunch title Amazon releases early info on S3 storage use ref The basic Jungle Disk software is sold as a monthly subscription model, and the customer is billed directly by Amazon for data storage and transfer. Jungle Disk can periodically back up selected files or folders. It provides a local webdav server and a local web interface that synchronize to the user s S3 Cloud Files account, optionally encrypting backed up data on the client side. For a monthly fee, the company ... cite web url http www.eweek.com c a Data Storage Jungle Disk Aids Amazon Storage author Jason Brooks work eWeek publisher Ziff Davis title Jungle Disk Aids Amazon Storage ref Jungle Disk supports Linux , Mac OS X and Microsoft Windows Windows . On October 22, 2008, Jungle Disk entered into an agreement to be acquired by Rackspace Hosting, Inc. Rackspace purchased Jungle Disk in order to expand their cloud hosting services. Although owned by Rackspace, Jungle Disk continued to provide services with no changes ... Disk s security ref Cite web author Colin Percival title Insecurity in the Jungle disk url http www.daemonology.net ... of a file stored via Jungle Disk, they could transform it into anything they want planting ... attack on the Jungle Disk password. See also List of online backup services References reflist External ... storage de Jungle Disk ... more details
Disk cleaners are computer programs that find and delete potentially unnecessary or potentially unwanted files from a computer. The purpose of such deletion may be to free up disk space, to eliminate clutter or to protect privacy. Disk space consuming unnecessary files include temporary file s, trash computing trash , old backup s and web cache s made by web browsers. Privacy risks include HTTP cookie s, local shared object s, Computer data logging log files or any other trace that may tell which computer program opened which files. Disk cleaners must not be mistaken with antivirus software which delete malware , registry cleaner s which clean Windows Registry or data erasure software which securely delete files , although multifunction software such as those included below may fit into all these categories. Software Disk cleaning software with an article on Wikipedia CCleaner CleanGenius Disk Cleanup SlimWare Utilities Products SlimCleaner Temp File Cleaner Utility software with an article on Wikipedia that have disk cleaning functionality Acronis True Image Advanced SystemCare Advanced System Optimizer SlimWare Utilities Products FixCleaner Glary Utilities Jv16 powertools Norton Utilities Revo Uninstaller System Mechanic TuneUp Utilities Category Utility software type Software type stub ... more details
F6 disk is a colloquial name for a floppy disk containing a Microsoft Windows NT device driver for a SCSI or RAID system. F6 disks are used by all NT based versions of Windows, including Windows 2000 , Windows Server 2003 , and Windows XP . Starting with Windows Vista , floppy F6 disks are obsolete its setup process supports loading third party drivers from USB flash drive USB drives and CD ROM CD ROMs . Usage An F6 disk is named after the manner in which it is used. During the installation process for Windows, the Setup program must load device drivers for the disk system on which Windows will be installed. Unless the disk system has been established on the market before the finalization of the particular Windows release being installed, the drivers are not included on the Windows installation discs, and they must be loaded by means of an F6 disk. An F6 disk is loaded in Windows setup by pressing the Function key F6 key immediately when Windows Setup starts. The message Press F6 if you need to install a third party SCSI or RAID driver... is briefly flashed on the screen every time Windows Setup starts. An F6 disk contains device drivers in its root directory . Prior to Windows Vista, F6 disks were always floppy disks because, at the point the F6 prompt is shown, Windows Setup has not loaded the drivers for any media type other than floppy disks. Support for USB drives and CD ROMs was added in Windows Vista. Device drivers for RAID and other disk controllers are often provided on CD ROMs by the manufacturers, but they must be copied to an F6 disk if they are to be used during Windows Setup. An alternative approach is to slipstream computing slipstream the required SATA SCSI SAS RAID EIDE drivers into the Windows installation files directory e.g. i386 for the x86 variety by means of software like nLite and then create an ISO image that can be burned to CD or DVD media. References Microsoft support, http support.microsoft.com ?kbid 313348 KB313348 Category RAID Category ... more details
without drive emulation tmpfs refimprove date June 2009 A RAM disk or RAM drive is a block of Random ... as if the memory were a disk drive secondary storage . It is sometimes referred to as a virtual RAM ... containing RAM, which is a type of solid state drive . Performance The performance of a RAM disk is in general ... , hard disk drive hard drive , tape drive , or optical disk drive optical drive . ref cite web ... and type of file system , as well as others. File access time is greatly decreased since a RAM disk ..., alignment or positioning necessary. Second, the throughput maximum throughput of a RAM disk is limited ... disk can also improve the speed of loading pages . ref http www.macosxhints.com article.php?story 20040827132909881 Using a RAM disk for browsing the web on Macs http www.ghacks.net 2007 12 14 use a ramdisk to increase firefox security Using a RAM disk to improve security in firefox ref In many cases, the data stored on the RAM disk is created, for faster access, from data permanently stored elsewhere, and is re created on the RAM disk when the system reboots. Implementation Software RAM disks ... kernel , it is possible to also create and manage a RAM disk by way of a user space application ... due to the temporary nature of the information stored in the RAM disk, but an uninterruptible power ... RAM disk for microcomputers was invented and written by Jerry Karlin in the UK in 1979 80. The software, known as the Silicon Disk System was further developed into a commercial product and marketed ... the CPU could directly address. Making bank switched RAM behave like a disk drive was much faster than the disk drives especially in those days before hard drives were readily available on such machines. The Silicon Disk was launched in 1980, initially for the CP M operating system and later for MS ... Commodore computers, a RAM disk was also a popular application on Commodore 64 and Commodore 128 systems ... would automatically allocate a RAM drive named tt RAM tt . Microsoft added a RAM disk to MS DOS version ... more details
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