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BBN Time-Sharing System
The BBN Time-Sharing System was an early time-sharing system created at Bolt, Beranek and Newman (BBN) for the PDP-1 computer. It began operation in September 1962. History J. C. R. Licklider left MIT to become a vice president at Bolt Beranek and Newman in 1957. He learned about time-sharing from Christopher Strachey at a UNESCO-sponsored conference on Information Processing in Paris in June 1959. Digital Equipment Corporation's prototype PDP-1 was ready in November, 1959, and the machine was featured in the November/December issue of ''Datamation'' magazine. BBNer Ed Fredkin saw a prototype system at the Eastern Joint Computer Conference in Boston in December 1959, and was extremely interested. Given BBN's interest, DEC's founder and President Ken Olsen visited and explained that DEC had just completed construction of a prototype PDP-1, and that they needed a test site for a month. BBN agreed to be the test site, at its regular hourly rates, and then in early 1960 obtain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBN Technologies
Raytheon BBN (originally Bolt, Beranek and Newman, Inc.) is an American research and development company based in Cambridge, Massachusetts. In 1966, the Franklin Institute awarded the firm the Frank P. Brown Medal, in 1999 BBN received the IEEE Corporate Innovation Recognition, and on 1 February 2013, BBN was awarded the National Medal of Technology and Innovation, the highest honors that the U.S. government bestows upon scientists, engineers and inventors, by President Barack Obama. It became a wholly owned subsidiary of Raytheon in 2009. History BBN has its roots in an initial partnership formed on 15 October 1948 between Leo Beranek and Richard Bolt, professors at the Massachusetts Institute of Technology. Bolt had won a commission to be an acoustic consultant for the new United Nations permanent headquarters to be built in New York City. Realizing the magnitude of the project at hand, Bolt had pulled in his MIT colleague Beranek for help and the partnership betwee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an '' interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking and system calls, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. History Hardware interrupts wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-sharing Operating Systems
In computing, time-sharing is the concurrent sharing of a computing resource among many tasks or users by giving each task or user a small slice of processing time. This quick switch between tasks or users gives the illusion of simultaneous execution. It enables multi-tasking by a single user or enables multiple-user sessions. Developed during the 1960s, its emergence as the prominent model of computing in the 1970s represented a major technological shift in the history of computing. By allowing many users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive applications. History Batch processing The earliest computers were extremely expensive devices, and very slow. Machines were typically dedicated to a particular set of ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-sharing System Evolution
This article covers the evolution of time-sharing systems, providing links to major early time-sharing operating systems, showing their subsequent evolution. The meaning of the term ''time-sharing'' has shifted from its original usage. From 1949 to 1960, time-sharing was used to refer to multiprogramming; it evolved to mean multi-user interactive computing. Time-sharing Time-sharing was first proposed in the mid- to late-1950s and first implemented in the early 1960s. The concept was born out of the realization that a single expensive computer could be efficiently utilized by enabling multiprogramming, and, later, by allowing multiple users simultaneous interactive access. In 1984, Christopher Strachey wrote he considered the change in the meaning of the term ''time-sharing'' to be a source of confusion and not what he meant when he wrote his original paper in 1959. Without time-sharing, an individual user would enter bursts of information followed by long pauses; but with a g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Operating Systems
This article presents a timeline of events in the history of computer operating systems from 1951 to the current day. For a narrative explaining the overall developments, see the History of operating systems. 1950s * 1951 ** LEO I 'Lyons Electronic Office' was the commercial development of EDSAC computing platform, supported by British firm J. Lyons and Co. * 1953 ** DYSEAC - an early machine capable of distributing computing * 1955 ** General Motors Operating System made for IBM 701 ** MIT's Tape Director operating system made for UNIVAC 1103 * 1956 ** GM-NAA I/O for IBM 704, based on General Motors Operating System * 1957 ** Atlas Supervisor (Manchester University) (''Atlas computer project start'') ** BESYS (Bell Labs), for IBM 704, later IBM 7090 and IBM 7094 * 1958 ** University of Michigan Executive System (UMES), for IBM 704, 709, and 7090 * 1959 ** SHARE Operating System (SOS), based on GM-NAA I/O 1960s * 1960 ** IBSYS (IBM for its 7090 and 7094) * 1961 ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core Memory
Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (laboratory), a highly specialized shared research resource * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the central part of a fruit * Hydrophobic core, the interior zone of a protein * Nuclear reactor core, a portion containing the fuel components * Pit (nuclear weapon) or core, the fissile material in a nuclear weapon * Semiconductor intellectual property core (IP core), is a unit of design in ASIC/FPGA electronics and IC manufacturing * Atomic core, an atom with no valence electrons * Lithic core, in archaeology, a stone artifact left over from toolmaking Geology and astrophysics * Core sample, in Earth science, a sample obtained by coring ** Ice core * Core, the central part of a galaxy; see Mass deficit * Core (anticline), the central part of an anticline or syncline * Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Drum Memory
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] |
Microsecond
A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is to one second, as one second is to approximately 11.57 days. A microsecond is equal to 1000 nanoseconds or of a millisecond. Because the next SI prefix is 1000 times larger, measurements of 10−5 and 10−4 seconds are typically expressed as tens or hundreds of microseconds. Examples * 1 microsecond (1 μs) – cycle time for frequency (1 MHz), the inverse unit. This corresponds to radio wavelength 300 m (AM medium wave band), as can be calculated by multiplying 1 μs by the speed of light (approximately ). * 1 microsecond – the length of time of a high-speed, commercial strobe light flash (see air-gap flash). * 1 microsecond – protein folding takes place on the order of microseconds (thus this is the speed of carbon-based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word (computer Architecture)
In computing, a word is any processor design's natural unit of data. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word size'', ''word width'', or ''word length'') is an important characteristic of any specific processor design or computer architecture. The size of a word is reflected in many aspects of a computer's structure and operation; the majority of the registers in a processor are usually word-sized and the largest datum that can be transferred to and from the working memory in a single operation is a word in many (not all) architectures. The largest possible address size, used to designate a location in memory, is typically a hardware word (here, "hardware word" means the full-sized natural word of the processor, as opposed to any other definition used). Documentation for older computers with fixed word size commonly states memory sizes in words rather than bytes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megabyte
The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities. In the computer and information technology fields, other definitions have been used that arose for historical reasons of convenience. A common usage has been to designate one megabyte as (220 B), a quantity that conveniently expresses the binary architecture of digital computer memory. Standards bodies have deprecated this binary usage of the mega- prefix in favor of a new set of binary prefixes, by means of which the quantity 220 B is named mebibyte (symbol MiB). Definitions The unit megabyte is commonly used for 10002 (one million) bytes or 10242 bytes. The interpretation of using base 1024 originated as technical jargon for the byte m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC FASTRAND
FASTRAND was a magnetic drum mass storage system built by Sperry Rand Corporation (later Sperry Univac) for their 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 ms. average access time) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marvin Minsky
Marvin Lee Minsky (August 9, 1927 – January 24, 2016) was an American cognitive scientist, cognitive and computer scientist concerned largely with research in artificial intelligence (AI). He co-founded the Massachusetts Institute of Technology's AI laboratory and wrote extensively about AI and philosophy. Minsky received many accolades and honors, including the 1969 Turing Award. Early life and education Marvin Lee Minsky was born in New York City, to Henry, an eye surgeon, and Fannie (Reiser), a Zionism, Zionist activist. His family was Jewish. He attended the Ethical Culture Fieldston School and the Bronx High School of Science. He later attended Phillips Academy in Andover, Massachusetts, Andover, Massachusetts. He then served in the United States Navy, US Navy from 1944 to 1945. He received a B.A. in mathematics from Harvard University in 1950 and a Doctor of Philosophy, Ph.D. in mathematics from Princeton University in 1954. His doctoral dissertation was titled "Theory of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
