|
RK03
Digital Equipment Corporation's RK05 is a disk drive whose removable disk pack can hold about 2.5 megabytes of data. Introduced 1972, it is similar to IBM's 1964-introduced 2310, and uses a disk pack similar to IBM's 2315 disk pack, although the latter only held 1 megabyte. An RK04 drive, which has half the capacity of an RK05, was also offered. Systems on which it can be used include DEC's PDP-8, PDP-11, and PDP-15. Overview The RK05 was a moving head magnetic disk drive manufactured by DEC. It stored approximately 2.5 MB on a 14", single-platter IBM-2315-style front-loading removable disk cartridge. The cartridge permitted users to have relatively unlimited off-line storage and to have very fast access to such data. The PDP systems to which it could be attached had numerous operating systems for each computer architecture, so by changing disk pack another operating system could also be booted. Although the 14-inch cartridge could not fit in a shirt pocket, unlike DE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diablo Data Systems
Diablo Data Systems was a division of Xerox created by the acquisition of Diablo Systems Inc. for US$29 million in 1972,Xerox Factbook 2003-2004 , p.43 a company which had been founded in 1969 by George E. Comstock, Charles L. Waggoner and others. The company was best known for the HyType I and HyType II typewriter-based s, the daisywheel printers, as well as removable hard disk drives that were used in the |
RK05
Digital Equipment Corporation's RK05 is a disk drive whose removable disk pack can hold about 2.5 megabytes of data. Introduced 1972, it is similar to IBM's 1964-introduced 2310, and uses a disk pack similar to IBM's 2315 disk pack, although the latter only held 1 megabyte. An RK04 drive, which has half the capacity of an RK05, was also offered. Systems on which it can be used include DEC's PDP-8, PDP-11, and PDP-15. Overview The RK05 was a moving head magnetic disk drive manufactured by DEC. It stored approximately 2.5 MB on a 14", single-platter IBM-2315-style front-loading removable disk cartridge. The cartridge permitted users to have relatively unlimited off-line storage and to have very fast access to such data. The PDP systems to which it could be attached had numerous operating systems for each computer architecture, so by changing disk pack another operating system could also be booted. Although the 14-inch cartridge could not fit in a shirt pocket, unlike DECt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide
Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes. They are used as iron ores, pigments, catalysts, and in thermite, and occur in hemoglobin. Iron oxides are inexpensive and durable pigments in paints, coatings and colored concretes. Colors commonly available are in the "earthy" end of the yellow/orange/red/brown/black range. When used as a food coloring, it has E number E172. Stoichiometries Iron oxides feature as ferrous ( Fe(II)) or ferric ( Fe(III)) or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are significant at the earth's surface, particularly wüstite, magnetite, and hematite. * Oxides of FeII ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox
Xerox Holdings Corporation (; also known simply as Xerox) is an American corporation that sells print and electronic document, digital document products and services in more than 160 countries. Xerox is headquartered in Norwalk, Connecticut (having moved from Stamford, Connecticut, in October 2007), though it is incorporated in New York (state), New York with its largest population of employees based around Rochester, New York, the area in which the company was founded. The company purchased Affiliated Computer Services for $6.4 billion in early 2010. As a large developed company, it is consistently placed in the list of Fortune 500 companies. On December 31, 2016, Xerox separated its business process service operations, essentially those operations acquired with the purchase of Affiliated Computer Services, into a new publicly traded company, Conduent. Xerox focuses on its document technology and document outsourcing business, and traded on the NYSE from 1961 to 2021, and the N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS/8
OS/8 is the primary operating system used on the Digital Equipment Corporation's PDP-8 minicomputer. PDP-8 operating systems which precede OS/8 include: * R-L Monitor, also referred to as MS/8. * P?S/8, requiring only 4K of memory. * PDP-8 4K Disk Monitor System * PS/8 ("Programming System/8"), requiring 8K. This is what became OS/8 in 1971. Other/related DEC operating systems are OS/78, OS/278, and OS/12. The latter is a virtually identical version of OS/8, and runs on Digital's PDP-12 computer. Digital released OS/8 images for non-commercial purposes which can be emulated through SIMH. Overview OS/8 provides a simple operating environment that is commensurate in complexity and scale with the PDP-8 computers on which it ran. I/O is supported via a series of supplied drivers which uses polled (not interrupt-driven) techniques. The device drivers have to be cleverly written as they can occupy only one or two memory pages of 128 12-bit words, and have to be able to run in any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unibus
The Unibus was the earliest of several computer bus and backplane designs used with PDP-11 and early VAX systems manufactured by the Digital Equipment Corporation (DEC) of Maynard, Massachusetts. The Unibus was developed around 1969 by Gordon Bell and student Harold McFarland while at Carnegie Mellon University. The name refers to the unified nature of the bus; Unibus was used both as a system bus allowing the central processing unit to communicate with main memory, as well as a peripheral bus, allowing peripherals to send and receive data. Unifying these formerly separate busses allowed external devices to easily perform direct memory access (DMA) and made the construction of device drivers easier as control and data exchange was all handled through memory-mapped I/O. Unibus was physically large, which led to the introduction of Q-bus, which multiplexed some signals to reduce pin count. Higher performance PDP systems used Fastbus, essentially two Unibusses in one. The syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daisy Chain (electrical Engineering)
In electrical and electronic engineering, a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring, similar to a garland of daisy flowers. Daisy chains may be used for power, analog signals, digital data, or a combination thereof. The term ''daisy chain'' may refer either to large scale devices connected in series, such as a series of power strips plugged into each other to form a single long line of strips, or to the wiring patterns embedded inside of devices. Other examples of devices which can be used to form daisy chains are those based on Universal Serial Bus (USB), FireWire, Thunderbolt and Ethernet cables. Signal transmission For analog signals, connections usually consist of a simple electrical bus and, especially in the case of a chain of many devices, may require the use of one or more repeaters or amplifiers within the chain to counteract attenuation (the natural loss of energy in such a system). Digital signal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Crash
A head crash is a hard-disk failure that occurs when a read–write head of a hard disk drive makes contact with its rotating platter, slashing its surface and permanently damaging its magnetic media. It is most often caused by a sudden severe motion of the disk, for example the jolt caused by dropping a laptop to the ground while it is operating or physically shocking a computer. Head details A head normally rides on a thin film of moving air entrapped at the surface of its platter (some drives manufactured by Conner Peripherals in the mid-1990s used a thin liquid layer instead). The distance between the head and platter is called the flying height. The topmost layer of the platter is made of a Teflon-like material that acts like a lubricant. Underneath is a layer of sputtered carbon. These two layers protect the magnetic layer (data storage area) from most accidental touches of the read-write head. The disk read-and-write head is made using thin film techniques that in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HEPA
HEPA (, high-efficiency particulate air) filter, also known as high-efficiency particulate absorbing filter and high-efficiency particulate arrestance filter, is an efficiency standard of air filters. Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove—from the air that passes through—at least 99.95% (ISO, European Standard) or 99.97% (ASME, U.S. DOE) of particles whose diameter is equal to 0.3 μm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm. HEPA filters capture pollen, dirt, dust, moisture, bacteria (0.2-2.0 μm), virus (0.02-0.3 μm), and submicron liquid aerosol (0.02-0.5 μm). Some microorganisms, for example, ''Aspergillus niger'', ''Penicillium citrinum'', ''Staphylococcus epidermidis'', and ''Bacillus subtilis'' are captured by HEPA filters with photocatalytic oxidation (PCO). A HEPA filter is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encoder (position)
An encoder is a sensor which turns a position into an electronic signal. There are two forms: * Absolute encoders give an absolute position value. * Incremental encoders count movement rather than position. With detection of a datum position and the use of a counter, an absolute position may be derived. The position may be measured as either linear or angular position * Linear encoder, converts linear position to an electronic signal * Rotary encoder A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to analog or digital output signals. There are two main types of rotary encoder: absolute and increm ..., converts rotary position to an electronic signal See also * Encoder (other) {{Set index ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Coil
A voice coil (consisting of a former, collar, and winding) is the coil of wire attached to the apex of a loudspeaker cone. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it. The term is also used for voice coil linear motors, such as those used to move the heads inside hard disk drives, which produce a larger force and move a longer distance but work on the same principle. Operation By driving a current through the voice coil, a magnetic field is produced. This magnetic field causes the voice coil to react to the magnetic field from a permanent magnet fixed to the speaker's frame, thereby moving the cone of the speaker. By applying an audio waveform to the voice coil, the cone will reproduce the sound pressure waves, corresponding to the original input signal. Design considerations Because the moving parts of the speaker must be of low mass (to accurately reproduce high-frequency sounds without being damped too much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Bearing
Fluid bearings are bearings in which the load is supported by a thin layer of rapidly moving pressurized liquid or gas between the bearing surfaces. Since there is no contact between the moving parts, there is no sliding friction, allowing fluid bearings to have lower friction, wear and vibration than many other types of bearings. Thus, it is possible for some fluid bearings to have near-zero wear if operated correctly. They can be broadly classified into two types: fluid dynamic bearings (also known as hydrodynamic bearings) and hydrostatic bearings. Hydrostatic bearings are externally pressurized fluid bearings, where the fluid is usually oil, water or air, and is pressurized by a pump. Hydrodynamic bearings rely on the high speed of the journal (the part of the shaft resting on the fluid) to pressurize the fluid in a wedge between the faces. Fluid bearings are frequently used in high load, high speed or high precision applications where ordinary ball bearings would have shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
