Write-only Memory (engineering)
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Write-only Memory (engineering)
In information technology, a write-only memory (WOM) is a memory location or register that can be written to but not read. In addition to its literal meaning, the term may be applied to a situation when the data written by one circuit can be read only by other circuitry. The most common occurrence of the latter situation is when a processor writes data to a write-only register of hardware the processor is controlling. The hardware can read the instruction but the processor cannot. This can lead to problems in producing device drivers for the hardware. Write-only memories also find applications in security and cryptography as a means of preventing data being intercepted as it is being decrypted. Hardware uses In 1972, WOM, an antithesis of read-only memory (ROM), was introduced as an inside practical joke perpetrated by Signetics. However, it was soon recognized that this concept actually describes certain functionalities in microprocessor systems. The most frequent occurre ...
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Information Technology
Information technology (IT) is a set of related fields within information and communications technology (ICT), that encompass computer systems, software, programming languages, data processing, data and information processing, and storage. Information technology is an application of computer science and computer engineering. The term is commonly used as a synonym for computers and computer networks, but it also encompasses other information distribution technologies such as television and telephones. Several products or services within an economy are associated with information technology, including computer hardware, software, electronics, semiconductors, internet, Telecommunications equipment, telecom equipment, and e-commerce.. An information technology system (IT system) is generally an information system, a communications system, or, more specifically speaking, a Computer, computer system — including all Computer hardware, hardware, software, and peripheral equipment †...
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Data Buffer
In computer science, a data buffer (or just buffer) is a region of memory used to store data temporarily while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such as a microphone) or just before it is sent to an output device (such as speakers); however, a buffer may be used when data is moved between processes within a computer, comparable to buffers in telecommunication. Buffers can be implemented in a fixed memory location in hardware or by using a virtual data buffer in software that points at a location in the physical memory. In all cases, the data stored in a data buffer is stored on a physical storage medium. The majority of buffers are implemented in software, which typically use RAM to store temporary data because of its much faster access time when compared with hard disk drives. Buffers are typically used when there is a difference between the rate at which data is received and the rate ...
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National Semiconductor
National Semiconductor Corporation was an United States of America, American Semiconductor manufacturing, semiconductor manufacturer, which specialized in analogue electronics, analog devices and subsystems, formerly headquartered in Santa Clara, California, Santa Clara, California. The company produced power management integrated circuits, display drivers, Audio amplifier, audio and operational amplifiers, communication interface products and data conversion solutions. National's key markets included wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial and test and measurement applications. On September 23, 2011, the company formally became part of Texas Instruments as the "Silicon Valley" division. History Founding National Semiconductor was founded in Danbury, Connecticut, by Dr. Bernard J. Rothlein on May 27, 1959, when he and seven colleagues, Edward N. Clarke, Joseph J. Gruber, Milton Schneider, Robert L. Hopkins, ...
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Phonautograph
The phonautograph is the earliest known device for recording sound. Previously, tracings had been obtained of the sound-producing vibratory motions of tuning forks and other objects by physical contact with them, but not of actual sound waves as they propagated through air or other mediums. Invented by Frenchman Édouard-Léon Scott de Martinville, it was patented on March 25, 1857. It transcribed sound waves as undulations or other deviations in a line traced on smoke-blackened paper or glass. Scott believed that future technology would allow the traces to be deciphered as a kind of "natural stenography". Intended as a laboratory instrument for the study of acoustics, it was used to visually study and measure the amplitude envelopes and waveforms of speech and other sounds or to determine the frequency of a given musical pitch by comparison with a simultaneously recorded reference frequency. It did not occur to anyone before the 1870s that the recordings, called phonauto ...
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Null Device
In some operating systems, the null device is a device file that discards all data written to it but reports that the write operation succeeded. This device is called /dev/null on Unix and Unix-like systems, NUL: (see TOPS-20) or NUL on CP/M and DOS (internally \DEV\NUL), nul on OS/2 and newer Windows systems (internally \Device\Null on Windows NT), NIL: on Amiga operating systems, and NL: on OpenVMS. In Windows Powershell, the equivalent is $null. It provides no data to any process that reads from it, yielding EOF immediately. In IBM operating systems DOS/360 and successors and also in OS/360 and successors such files would be assigned in JCL to DD DUMMY. In programmer jargon, especially Unix jargon, it may also be called the bit bucket or black hole. History is described as an empty regular file in Version 4 Unix. The Version 5 Unix manual describes a device with modern semantics. Usage The null device is typically used for disposing of unwanted output streams of ...
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Models Of Computation
In computer science, and more specifically in computability theory and computational complexity theory, a model of computation is a model which describes how an output of a mathematical function is computed given an input. A model describes how units of computations, memories, and communications are organized. The computational complexity of an algorithm can be measured given a model of computation. Using a model allows studying the performance of algorithms independently of the variations that are specific to particular implementations and specific technology. Categories Models of computation can be classified into three categories: sequential models, functional models, and concurrent models. Sequential models Sequential models include: * Finite-state machines * Post machines ( Post–Turing machines and tag machines). * Pushdown automata * Register machines ** Random-access machines * Turing machines * Decision tree model * External memory model Functional models Functio ...
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Computability Theory
Computability theory, also known as recursion theory, is a branch of mathematical logic, computer science, and the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees. The field has since expanded to include the study of generalized computability and definable set, definability. In these areas, computability theory overlaps with proof theory and effective descriptive set theory. Basic questions addressed by computability theory include: * What does it mean for a function (mathematics), function on the natural numbers to be computable? * How can noncomputable functions be classified into a hierarchy based on their level of noncomputability? Although there is considerable overlap in terms of knowledge and methods, mathematical computability theorists study the theory of relative computability, reducibility notions, and degree structures; those in the computer science field focus on the theory of computational complexity theory ...
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Nintendo
is a Japanese Multinational corporation, multinational video game company headquartered in Kyoto. It develops, publishes, and releases both video games and video game consoles. The history of Nintendo began when craftsman Fusajiro Yamauchi founded the company to produce handmade ''hanafuda'' playing cards. After venturing into various lines of business and becoming a public company, Nintendo began producing toys in the 1960s, and later video games. Nintendo developed its first arcade games in the 1970s, and distributed its first system, the Color TV-Game in 1977. The company became internationally dominant in the 1980s after the arcade release of ''Donkey Kong (1981 video game), Donkey Kong'' (1981) and the Nintendo Entertainment System, which launched outside of Japan alongside ''Super Mario Bros.'' in 1985. Since then, Nintendo has produced some of the most successful consoles in the video game industry, including the Game Boy (1989), the Super Nintendo Entertainment Syste ...
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Smart Card
A smart card (SC), chip card, or integrated circuit card (ICC or IC card), is a card used to control access to a resource. It is typically a plastic credit card-sized card with an Embedded system, embedded integrated circuit (IC) chip. Many smart cards include a pattern of metal contacts to electrically connect to the internal chip. Others are Contactless smart card, contactless, and some are both. Smart cards can provide personal identification, authentication, data storage, and application processing. Applications include identification, financial, public transit, computer security, schools, and healthcare. Smart cards may provide strong security authentication for single sign-on (SSO) within organizations. Numerous nations have deployed smart cards throughout their populations. The universal integrated circuit card (UICC) for mobile phones, installed as pluggable SIM card or embedded eSIM, is also a type of smart card. , 10.5billion smart card IC chips are manufactured annually ...
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Frame Buffer
A framebuffer (frame buffer, or sometimes framestore) is a portion of random-access memory (RAM) containing a bitmap that drives a video display. It is a memory buffer containing data representing all the pixels in a complete video frame. Modern video cards contain framebuffer circuitry in their cores. This circuitry converts an in-memory bitmap into a video signal that can be displayed on a computer monitor. In computing, a screen buffer is a part of computer memory used by a computer application for the representation of the content to be shown on the computer display. The screen buffer may also be called the video buffer, the regeneration buffer, or regen buffer for short. Screen buffers should be distinguished from video memory. To this end, the term off-screen buffer is also used. The information in the buffer typically consists of color values for every pixel to be shown on the display. Color values are commonly stored in 1-bit binary (monochrome), 4-bit palettized, ...
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E-reader
An e-reader, also called an e reader or e device, is a Mobile computing, mobile electronic device that is designed primarily for the purpose of reading digital e-books and Periodical literature, periodicals. Any device that can display text on a screen may act as an e-reader; however, specialized e-reader devices may optimize portability, readability, and battery life for this purpose. Their main advantage over printed books is portability: an e-reader is capable of holding thousands of books while weighing less than one. Another advantage is the convenience provided by add-on features. Overview An e-reader is a device designed as a convenient way to read e-books. It is similar in Form factor (design), form factor to a tablet computer, but often features electronic paper ("e-ink") rather than an LCD screen. This yields much longer battery life — the battery can last for several weeks — and better readability, similar to that of paper even in sunlight. Drawbacks of this k ...
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E-ink
E Ink (electronic ink) is a brand of electronic paper (e-paper) display technology commercialized by the E Ink Corporation, which was co-founded in 1997 by MIT undergraduates JD Albert and Barrett Comiskey, MIT Media Lab professor Joseph Jacobson, Jerome Rubin and Russ Wilcox. It is available in grayscale and color and is used in mobile devices such as e-readers, digital signage, smartwatches, mobile phones, electronic shelf labels and architecture panels. History Background The notion of a low-power paper-like display had existed since the 1970s, originally conceived by researchers at Xerox PARC but had never been realized. While a post-doctoral student at Stanford University, physicist Joseph Jacobson envisioned a multi-page book with content that could be changed at the push of a button and required little power to use. Neil Gershenfeld recruited Jacobson for the MIT Media Lab in 1995, after hearing Jacobson's ideas for an electronic book. Jacobson, in turn, recr ...
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