Comparison of several forms of disk storage showing tracks ( not-to-scale ); green denotes start and red denotes end .< nowiki >*</ nowiki > Some CD-R ( W ) and DVD-R ( W )/ DVD + R ( W ) recorders operate in ZCLV, CAA or CAV modes.

Some racing clutches use small multi-plate disk packs that are not part of the flywheel.

Some disk operating systems were the operating system for the entire computer system.

Some older tape drives-such as the DECtape, the ZX Microdrive and the Rotronics Wafadrive-were designed as inexpensive alternatives to disk drives which were at the time very expensive.

Some directory operations ( including < tt > unlink </ tt >( 2 )) are not synchronous on ReiserFS, which can result in data corruption with applications relying heavily on file-based locks ( such as mail transfer agents qmail and Postfix ) if the machine halts before it has synchronized the disk.

Some low-cost peripherals no longer contain non-volatile memory for firmware, and instead rely on the host system to transfer the device control program from a disk file or CD.

Comparison of several forms of disk storage showing tracks ( not-to-scale ); green denotes start and red denotes end .< nowiki >*</ nowiki > Some CD-R ( W ) and DVD-R ( W )/ DVD + R ( W ) recorders operate in ZCLV, CAA or CAV modes.

Some operating systems include tools for " collecting " entropy from the timing of unpredictable operations such as disk drive head movements.

Some versions of DOS don't assign the drive letter, beginning with C :, to the first active primary partition recognized upon the first physical hard disk, but on the first primary partition recognized of the first hard disk, even if it is not set active.

Some implementations do not neatly fit either category: a DOM approach can keep its persistent data on disk, cleverly organized for speed ( editors such as SoftQuad Author / Editor and large-document browser / indexers such as DynaText do this ); while a SAX approach can cleverly cache information for later use ( any validating SAX parser keeps more information than described above ).

Some disk imaging utilities omit unused file space from source media, or compress the disk they represent to reduce storage requirements, though these are typically referred to as archive files, as they are not literally disk images.

Some government agencies ( e. g., NSA ) require that all disk drives be physically pulverized when they are discarded, and in some cases, chemically treated with corrosives before or after.

Some bulges have similar properties to those of elliptical galaxies ( scaled down to lower mass and luminosity ); others simply appear as higher density centers of disks, with properties similar to disk galaxies.

Some calculations show that interaction with the disk can cause rapid inward migration, which, if not stopped, results in the planet reaching the " central regions still as a sub-Jovian object.

Some BIOSes ( like the IBM PC / AT ) perform the check only for fixed disk / removable drives, while for floppies and superfloppies it is enough to start with a byte greater or equal to < tt > 06h </ tt > and the first nine words not to contain the same value, before the boot sector is accepted as valid, thereby avoiding the explicit test for < tt > 0x55 </ tt >, < tt > 0xAA </ tt > on floppies.

Some machines have a serial number in ROM, while others do not, and so some other metric, such as the date and time ( to the second ) of initialization of the hard disk can be used.

Some of the performance parameters in the superblock included number of tracks and sectors, disk rotation speed, head speed, and alignment of the sectors between tracks.

Some software, e. g. ADTPro, makes use of this to store Apple II and Apple III versions of a program on the same disk, which is then bootable on both systems.

Comparison of several forms of disk storage showing tracks ( not-to-scale ); green denotes start and red denotes end .< nowiki >*</ nowiki > Some CD-R ( W ) and DVD-R ( W )/ DVD + R ( W ) recorders operate in ZCLV, CAA or CAV modes.

Some schools had simple local area networks of Scandis computers, where 10-20 machines shared one hard disk of typically 10MB capacity.

Some optical disk software, such as IsoBuster, can support Mount Rainier on non-MR drives.

Some ATs came with one high-density ( HD ) disk drive and one double-density ( DD ) 360 kB drive.

Some signals carry encryption and specify use conditions ( such as " may not be recorded " or " may not be viewed on displays larger than 1 m in diagonal measure ") backed up with the force of law under the WIPO Copyright Treaty and national legislation implementing it, such as the U. S. Digital Millennium Copyright Act.

Some consider emoticons and ASCII art, like smiley faces, to be leet, while others maintain that leet consists of only symbolic word encryption.

Some encryption schemes can be proven secure on the basis of the presumed difficulty of a mathematical problem, such as factoring the product of two large primes or computing discrete logarithms.

Some special and specific algorithms have been developed to aid in attacking some public key encryption algorithms-both RSA and ElGamal encryption have known attacks that are much faster than the brute-force approach.

Some modern scramblers are actually encryption devices, the name remaining due to the similarities in use, as opposed to internal operation.

Some are no longer relevant given the ability of computers to perform complex encryption, but his second axiom, now known as Kerckhoffs's principle, is still critically important.

( Some encryption algorithms, known as nonmalleable ones, prevent this, but others do not.

Some secure cryptoprocessors contain dual processor cores and generate inaccessible encryption keys when needed so that even if the circuitry is reverse engineered, it will not reveal any keys that are necessary to securely decrypt software booted from encrypted flash memory or communicated between cores.

Some phones include a special monitor mode ( activated with secret codes or special software ) which displays GSM operating parameters such as encryption while a call is being made.

Some virtual networks may not use encryption to protect the data contents.

Some modern modes of operation combine encryption and authentication in an efficient way, and are known as authenticated encryption modes.

Some of the methods of protecting e-business security and keeping information secure include physical security measures as well as data storage, data transmission, anti-virus software, firewalls, and encryption to list a few .< ref name =" canada "> Industry Canada | Industrie Canada.

Some protocols like FTP and Telnet transfer data and passwords in clear text, without encryption, and network scanners can see this data.

Some web servers will not communicate with a client unless it has a 128-bit encryption capability installed on it.

Some basic information about the MIFARE Classic or MIFARE DESFire chip can be read by any ISO / IEC 14443 type A compatible reader, but Oyster-specific information cannot be read without access to the encryption used for the Oyster system.

; Secret system: Some encryption systems will claim to rely on a secret algorithm, technique, or device ; this is categorized as security through obscurity.

Some of the newer pastebins provide features for comparing two or more pastes, synchronous notifications through IRC or XMPP, paste histories, encryption, password protection, and virtual subdomains.

Some encryption systems for which CAMs are available are Logiways, Nagravision, Viaccess, Mediaguard, Irdeto, KeyFly, Verimatrix, Cryptoworks, Mascom, Safeview, Diablo CAM and Conax.

* Some servers require passwords to be stored using reversible encryption.

Some also provide plausible deniability with deniable encryption techniques.

Some examples of file encryption software are GNU Privacy Guard and PGP ).

Some disk encryption software allows encrypted volumes to be resized.