|
Fastrand
FASTRAND was a magnetic drum mass storage system built by Sperry Rand Corporation (later Sperry Univac) for their UNIVAC 1100/2200 series, UNIVAC 1100 series and 418/490/494 series computers. A FASTRAND subsystem consisted of one or two Control Units and up to eight FASTRAND units. A dual-access FASTRAND subsystem included two complete control units, and provided parallel data paths that allowed simultaneous operations on any two FASTRAND units in the subsystem. Each control unit interfaced to one (optionally two) 1100 Series (36-bit), or 490 Series (30-bit), parallel I/O channels. A voice coil actuator moved a bar containing multiple single track recording heads, so these drums operated much like moving head disk drives with multiple disks. The heads "flew" on self-acting hydrodynamic air bearings. The drums had a plated magnetic recording surface. An optional feature called Fastband included 24 additional tracks with fixed read/write heads. This feature provided rapid access (35 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Drum
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. Many early computers, called drum computers or drum machines, used drum memory as the main working memory of the computer. Some drums were also used as secondary storage as for example various IBM drum storage drives and the UNIVAC FASTRAND series of drums. Drums were displaced as primary computer memory by magnetic core memory, which offered a better balance of size, speed, cost, reliability and potential for further improvements. Drums were then replaced by hard disk drives for secondary storage, which were both less expensive and offered denser storage. The manufacturing of drums ceased in the 1970s. Technical design A drum memory or drum storage unit contained a large metal cylinder, coated on the outside surface with a ferromagnetic recording material. It could be considered the precursor to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Storage Density
Density is a measure of the quantity of information bits that can be stored on a given physical space of a computer storage medium. There are three types of density: length (''linear density'') of track, area of the surface (''areal density''), or in a given volume (''volumetric density''). Generally, higher density is more desirable, for it allows more data to be stored in the same physical space. Density therefore has a direct relationship to storage capacity of a given medium. Density also generally affects the performance within a particular medium, as well as price. Storage device classes Solid state media Solid state drives use flash memory to store non-volatile media. They are the latest form of mass produced storage and rival magnetic disk media. Solid state media data is saved to a pool of NAND flash. NAND itself is made up of what are called floating gate transistors. Unlike the transistor designs used in DRAM, which must be refreshed multiple times per second, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Story Of Mel
The Story of Mel is an archetypical piece of computer programming folklore. Its subject, Melvin Kaye, is an exemplary " Real Programmer" whose subtle techniques fascinate his colleagues. Story Ed Nather's ''The Story of Mel'' details the extraordinary programming prowess of a former colleague of his, "Mel", at Royal McBee Computer Corporation. Although originally written in prose, Nather's story was modified by someone into a "free verse" form which has become widespread. Little is known about Mel Kaye, beyond the fact that he was credited with doing the "bulk of the programming" on the 1959 ACT-1 compiler for the Royal McBee LGP-30 computer. In Nather's story, Kaye is portrayed as being prone to avoiding optimizing assemblers in favor of crafting code to take advantage of hardware quirks, for example taking advantage of the rotation of the LGP-30's drum memory to avoid writing delay loops into the code. The story, as written by Nather, involved Kaye's work on rewriting a bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Computing Hardware
The history of computing hardware spans the developments from early devices used for simple calculations to today's complex computers, encompassing advancements in both analog and digital technology. The first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. In later stages, computing devices began representing numbers in continuous forms, such as by distance along a scale, rotation of a shaft, or a specific voltage level. Numbers could also be represented in the form of digits, automatically manipulated by a mechanism. Although this approach generally required more complex mechanisms, it greatly increased the precision of results. The development of transistor technology, followed by the invention of integrated circuit chips, led to revolutionary breakthroughs. Transistor-based computers and, later, integrated circuit-based computers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of UNIVAC Products
This is a list of UNIVAC products. It ends in 1986, the year that Sperry Corporation merged with Burroughs Corporation to form Unisys as a result of a hostile takeover bid launched by Burrough's CEO W. Michael Blumenthal. The Remington Rand years (1950 to 1955) Calculating devices * UNIVAC 40 * UNIVAC 60 * UNIVAC 120 Computer systems *UNIVAC I *UNIVAC 1101 * UNIVAC 1102 * UNIVAC 1103 * UNIVAC 1104 Peripherals Storage * UNISERVO tape drive Display and print * UNIVAC High speed printer 600 line/min printer Offline tape handling units * UNIPRINTER 10 char/s printer with tape drive * UNITYPER keyboard with tape drive *UNIVAC Tape to Card converter card punch with tape drive * UNIVAC Card to Tape converter card reader with tape drive * UNIVAC Paper Tape to Tape converter paper tape reader with tape drive The Sperry Rand years (1955 to 1978) Calculating devices * UNIVAC 1004 * UNIVAC 1005 Computer systems Embedded systems *AN/USQ-17 – the Naval Tactical Data Syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Controller
A disk controller is a controller circuit that enables a CPU to communicate with a hard disk, floppy disk or other kind of disk drive. It also provides an interface between the disk drive and the bus connecting it to the rest of the system.{{Cite book , url=https://ieeexplore.ieee.org/document/955038 , access-date=2023-10-18 , date=2001 , doi=10.1109/ICCD.2001.955038 , s2cid=3084914 , language=en-US , last1=Jeppesen , first1=J. , last2=Allen , first2=W. , last3=Anderson , first3=S. , last4=Pilsl , first4=M. , title=Proceedings 2001 IEEE International Conference on Computer Design: VLSI in Computers and Processors. ICCD 2001 , chapter=Hard disk controller: The disk drive's brain and body , pages=262–267 , isbn=0-7695-1200-3 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 bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Device
A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core component of the computer. A peripheral can be categorized based on the direction in which information flows relative to the computer: * The computer receives data from an ''input device''; examples: mouse, keyboard, scanner, game controller, microphone and webcam * The computer sends data to an ''output device''; examples: monitor, printer, headphones, and speakers * The computer sends and receives data via an ''input/output device''; examples: storage device (such as disk drive, solid-state drive, USB flash drive, memory card and tape drive), modem, router, gateway and network adapter Many modern electronic devices, such as Internet-enabled digital watches, video game consoles, smartphones, and tablet computers, have interfaces f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seek Time
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: #Access time, access time and #Data transfer rate, data transfer time (or rate). Access time The ''access time'' or ''response time'' of a rotating drive is a measure of the time it takes before the drive can actually Data transmission, transfer data. The factors that control this time on a rotating drive are mostly related to the mechanical nature of the rotating disks and moving Disk read-and-write head, heads. It is composed of a few independently measurable elements that are added together to get a single value when evaluating the performance of a storage device. The access time can vary significantly, so it is typically provided by manufacturers or measured in benchmarks as an average. The key components that are typically added together to obtain the access time are: * #Seek time, Seek time * #Rotati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperry Rand
Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs Corporation, which merged the combined operation under the new name Unisys. Some of Sperry's former divisions became part of Honeywell, Lockheed Martin, Raytheon Technologies, and Northrop Grumman. The company is best known as the developer of the artificial horizon and a wide variety of other gyroscope-based aviation instruments like autopilots, bombsights, analog ballistics computers and gyro gunsights. In the post-WWII era the company branched out into electronics, both aviation-related, and later, computers. The company was founded by Elmer Ambrose Sperry. History Early history The company was incorporated on April 14 1910 by Elmer Ambrose Sperry as the Sperry Gyroscope Company, to manufacture navigation equipment—chief ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
