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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 occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Technology
Information technology (IT) is the use of computers to create, process, store, retrieve, and exchange all kinds of data . and information. IT forms part of information and communications technology (ICT). An information technology system (IT system) is generally an information system, a communications system, or, more specifically speaking, a computer system — including all hardware, software, and peripheral equipment — operated by a limited group of IT users. Although humans have been storing, retrieving, manipulating, and communicating information since the earliest writing systems were developed, the term ''information technology'' in its modern sense first appeared in a 1958 article published in the ''Harvard Business Review''; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shader
In computer graphics, a shader is a computer program that calculates the appropriate levels of light, darkness, and color during the rendering of a 3D scene - a process known as ''shading''. Shaders have evolved to perform a variety of specialized functions in computer graphics special effects and video post-processing, as well as general-purpose computing on graphics processing units. Traditional shaders calculate rendering effects on graphics hardware with a high degree of flexibility. Most shaders are coded for (and run on) a graphics processing unit (GPU), though this is not a strict requirement. ''Shading languages'' are used to program the GPU's rendering pipeline, which has mostly superseded the fixed-function pipeline of the past that only allowed for common geometry transforming and pixel-shading functions; with shaders, customized effects can be used. The position and color (hue, saturation, brightness, and contrast) of all pixels, vertices, and/or textures us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 According to the Berkeley UNIX man page, Version 4 Unix, which AT&T released in 1973, included a null device. Usage The null device is typically used for disposing of unwanted output streams of a process, or as a conve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Models 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 Functional models Functional models include: * Abstract rew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 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 subrecursive hierarchies, formal methods, and formal languages. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nintendo
is a Japanese Multinational corporation, multinational video game company headquartered in Kyoto, Japan. It develops video games and video game consoles. Nintendo was founded in 1889 as by craftsman Fusajiro Yamauchi and originally produced handmade playing cards. After venturing into various lines of business during the 1960s and acquiring a legal status as a public company, Nintendo distributed its first console, the Color TV-Game, in 1977. It gained international recognition with the release of ''Donkey Kong (video game), Donkey Kong'' in 1981 and the Nintendo Entertainment System and ''Super Mario Bros.'' in 1985. Since then, Nintendo has produced some of the most successful consoles in the video game industry, such as the Game Boy, the Super Nintendo Entertainment System, the Nintendo DS, the Wii, and the Nintendo Switch, Switch. It has created numerous major franchises, including ''Mario (franchise), Mario'', ''Donkey Kong'', ''The Legend of Zelda'', ''Pokémon'', '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smart Cards
A smart card, chip card, or integrated circuit card (ICC or IC card) is a physical electronic authentication device, used to control access to a resource. It is typically a plastic credit card-sized card with an embedded integrated circuit (IC) chip. Many smart cards include a pattern of metal contacts to electrically connect to the internal chip. Others are contactless, and some are both. Smart cards can provide personal identification, authentication, data storage, and application processing. Applications include identification, financial, mobile phones (SIM), 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, or SIM card, is also a type of smart card. , 10.5billion smart card IC chips are manufactured annually, including 5.44billion SIM card IC chips. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, 8-bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-reader
An e-reader, also called an e-book reader or e-book device, is a mobile electronic device that is designed primarily for the purpose of reading digital e-books and 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. This is because an e-reader is capable of holding thousands of books while weighing less than one book, and the convenience provided due to 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 to a tablet computer, but often features electronic paper 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 kind of display include a slow refresh rate and (usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-ink
Electronic paper, also sometimes electronic ink, e-ink or electrophoretic display, are display devices that mimic the appearance of ordinary ink on paper. Unlike conventional flat panel displays that emit light, an electronic paper display reflects ambient light like paper. This may make them more comfortable to read, and provide a wider viewing angle than most light-emitting displays. The contrast ratio in electronic displays available as of 2008 approaches newspaper, and newly (2008) developed displays are slightly better. An ideal e-paper display can be read in direct sunlight without the image appearing to fade. Many electronic paper technologies hold static text and images indefinitely without electricity. Flexible electronic paper uses plastic substrates and plastic electronics for the display backplane. Applications of electronic visual displays include electronic shelf labels and digital signage, bus station time tables, electronic billboards, smartphone displays, and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8250 UART
The 8250 UART (universal asynchronous receiver/transmitter) is an integrated circuit designed for implementing the interface for serial communications. The part was originally manufactured by the National Semiconductor Corporation. It was commonly used in PCs and related equipment such as printers or modems. The 8250 included an on-chip programmable bit rate generator, allowing use for both common and special-purpose bit rates which could be accurately derived from an arbitrary crystal oscillator reference frequency. The chip designations carry suffix letters for later versions of the same chip series. For example, the original 8250 was soon followed by the 8250A and 8250B versions that corrected some bugs. In particular, the original 8250 could repeat transmission of a character if the CTS line was asserted asynchronously during the first transmission attempt. Due to the high demand, other manufacturers soon began offering compatible chips. Western Digital offered WD8250 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FIFO (computing And Electronics)
Representation of a FIFO queue In computing and in systems theory, FIFO is an acronym for first in, first out (the first in is the first out), a method for organizing the manipulation of a data structure (often, specifically a data buffer) where the oldest (first) entry, or "head" of the queue, is processed first. Such processing is analogous to servicing people in a queue area on a first-come, first-served (FCFS) basis, i.e. in the same sequence in which they arrive at the queue's tail. FCFS is also the jargon term for the FIFO operating system scheduling algorithm, which gives every process central processing unit (CPU) time in the order in which it is demanded. FIFO's opposite is LIFO, last-in-first-out, where the youngest entry or "top of the stack" is processed first. A priority queue is neither FIFO or LIFO but may adopt similar behaviour temporarily or by default. Queueing theory encompasses these methods for processing data structures, as well as interactions between s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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