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IBM Personal Computer AT
The IBM Personal Computer AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 80286 microprocessor. Name IBM did not specify an expanded form of ''AT'' on the machine, press releases, brochures or documentation, but some sources expand the term as ''Advanced Technology'', including at least one internal IBM document. History IBM's 1984 introduction of the AT was seen as an unusual move for the company, which typically waited for competitors to release new products before producing its own models. At $4,000–6,000, it was only slightly more expensive than considerably slower IBM models. The announcement surprised rival executives, who admitted that matching IBM's prices would be difficult. No major competitor showed a comparable computer at COMDEX Las Vegas that year. Features The AT is IBM PC compatible, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Computer
A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC game, gaming. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. The term home computer has also been used, primarily in the late 1970s and 1980s. The advent of personal computers and the concurrent Digital Revolution have significantly affected the lives of people. Institutional or corporate computer owners in the 1960s had to write their own programs to do any useful work with computers. While personal computer users may develop their applications, usually these systems run commercial software, free-of-charge software ("freeware"), which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process (power-on startup). The firmware comes pre-installed on the computer's motherboard. The name originates from the Basic Input/Output System used in the CP/M operating system in 1975. The BIOS firmware was originally proprietary to the IBM PC; it was reverse engineered by some companies (such as Phoenix Technologies) looking to create compatible systems. The interface of that original system serves as a ''de facto'' standard. The BIOS in older PCs initializes and tests the system hardware components ( power-on self-test or POST for short), and loads a boot loader from a mass storage device which then initializes a kernel. In the era of DOS, the BIOS provided BIOS interrupt calls for the keyboard, display, st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CMOS Memory
Nonvolatile BIOS memory refers to a small Memory (computers), memory on personal computer, PC motherboards that is used to store BIOS settings. It is traditionally called CMOS RAM because it uses a volatile memory, volatile, low-power CMOS, complementary metal–oxide–semiconductor (CMOS) Static random access memory, SRAM (such as the Motorola MC146818 or similar) powered by a small battery when system and standby power is off. It is referred to as non-volatile memory or Non-volatile random-access memory, NVRAM because, after the system loses power, it does retain state by virtue of the CMOS battery. When the battery fails, BIOS settings are reset to their defaults. The battery can also be used to power a real time clock (RTC) and the RTC, NVRAM and battery may be integrated into a single component. The name CMOS memory comes from the technology used to make the memory, which is easier to say than NVRAM. The CMOS RAM and the real-time clock have been integrated as a part of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addison-Wesley Publishing Company
Addison–Wesley is an American publisher of textbooks and computer literature. It is an imprint of Pearson plc, a global publishing and education company. In addition to publishing books, Addison–Wesley also distributes its technical titles through the O'Reilly Online Learning e-reference service. Addison–Wesley's majority of sales derive from the United States (55%) and Europe (22%). The Addison–Wesley Professional Imprint produces content including books, eBooks, and video for the professional IT worker including developers, programmers, managers, system administrators. Classic titles include ''The Art of Computer Programming'', '' The C++ Programming Language'', ''The Mythical Man-Month'', and ''Design Patterns''. History Lew Addison Cummings and Melbourne Wesley Cummings founded Addison–Wesley in 1942, with the first book published by Addison–Wesley being Massachusetts Institute of Technology professor Francis Weston Sears' ''Mechanics''. Its first computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Clock
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time. Although the term often refers to the devices in personal computers, server (computing), servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time of day. Terminology The term ''real-time clock'' is used to avoid confusion with ordinary clock signal, hardware clocks which are only signals that govern digital electronics, and do not count time in human units. RTC should not be confused with real-time computing, which shares its three-letter acronym but does not directly relate to time of day. Purpose Although keeping time can be done without an RTC, using one has benefits: * Reliably maintains and provides current time through disruptive system states such as Hang (computing), hangs, Sleep mode, sleep, reboots, or if given sufficient backup power, full Shutdown (computing), shutdown and hardwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PC DOS
PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * Production code number, a designation used to identify television episodes * ''Pretty Cure'', a Japanese anime franchise Business and finance * Percentage (pc) * Prime cost or variable cost * Principal Consultant, a management consulting position * Professional corporation, a type of corporate entity for licensed professionals (attorneys, architects, physicians, engineers, etc.) Organizations Businesses * Pearl-Continental Hotels & Resorts, a hotel chain in Pakistan * Pirelli & C. (stock symbol: PC) * President's Choice, a private label product brand of the Canadian supermarket chain Loblaw Companies ** PC Mobile, a Canadian mobile virtual network operator ** PC Optimum, a Canadian rewards program ** President's Choice Financial, a C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8237A
Intel 8237 is a direct memory access (DMA) controller, a part of the MCS 85 microprocessor family. It enables data transfer between memory and the I/O with reduced load on the system's main processor by providing the memory with control signals and memory address information during the DMA transfer. The 8237 is a four-channel device that can be expanded to include any number of DMA channel inputs. The 8237 is capable of DMA transfers at rates of up to per second. Each channel is capable of addressing a full 64k-byte section of memory and can transfer up to 64k bytes with a single programming. A single 8237 was used as the DMA controller in the original IBM PC and IBM XT. The IBM PC AT added another 8237 in master-slave configuration, increasing the number of DMA channels from four to seven. Later IBM-compatible personal computers may have chip sets that emulate the functions of the 8237 for backward compatibility. The Intel 8237 was actually designed by AMD (called Am9517). I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8259A
The Intel 8259 is a programmable interrupt controller (PIC) designed for the Intel 8085 and Intel 8086, 8086 microprocessors. The initial part was 8259, a later A suffix version was upward compatible and usable with the 8086 or Intel 8088, 8088 processor. The 8259 combines multiple interrupt input sources into a single interrupt output to the host microprocessor, extending the interrupt levels available in a system beyond the one or two levels found on the processor chip. The 8259A was the interrupt controller for the ISA bus in the original IBM PC and IBM PC AT. The 8259 was introduced as part of Intel's Intel 8085#MCS-85 family, MCS 85 family in 1976. The 8259A was included in the original PC introduced in 1981 and maintained by the PC/XT when introduced in 1983. A second 8259A was added with the introduction of the PC/AT. The 8259 has coexisted with the Intel APIC Architecture since its introduction in symmetric multiprocessor PCs. Modern PCs have begun to phase out the 8259A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Memory Access
Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system computer memory, memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed input/output, it is typically fully occupied for the entire duration of the read or write operation, and is thus unavailable to perform other work. With DMA, the CPU first initiates the transfer, then it does other operations while the transfer is in progress, and it finally receives an interrupt from the DMA controller (DMAC) when the operation is done. This feature is useful at any time that the CPU cannot keep up with the rate of data transfer, or when the CPU needs to perform work while waiting for a relatively slow I/O data transfer. Many hardware systems use DMA, including disk drive controllers, graphics cards, network cards and sound cards. DMA is also used for intra-chip data transfer in some multi-core processors. Computers that h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt Request (PC Architecture)
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card, key presses, or mouse movements. Interrupt lines are often identified by an index with the format of ''IRQ'' followed by a number. For example, on the Intel 8259 family of programmable interrupt controllers (PICs) there are eight interrupt inputs commonly referred to as ''IRQ0'' through ''IRQ7''. In x86 based computer systems that use two of these Programmable Interrupt Controller, PICs, the combined set of lines are referred to as ''IRQ0'' through ''IRQ15''. Technically these lines are named ''IR0'' through ''IR7'', and the lines on the Industry Standard Architecture, ISA bus to which they were historically attached are named ''IRQ0'' through ''IRQ15'' (although historically as the numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT Bus
Industry Standard Architecture (ISA) is the 16-bit internal bus of IBM PC/AT and similar computers based on the Intel 80286 and its immediate successors during the 1980s. The bus was (largely) backward compatible with the 8-bit bus of the 8088-based IBM PC, including the IBM PC/XT as well as IBM PC compatibles. Originally referred to as the PC bus (8-bit) or AT bus (16-bit), it was also termed ''I/O Channel'' by IBM. The ISA term was coined as a retronym by IBM PC clone manufacturers in the late 1980s or early 1990s as a reaction to IBM attempts to replace the AT bus with its new and incompatible Micro Channel architecture. The 16-bit ISA bus was also used with 32-bit processors for several years. An attempt to extend it to 32 bits, called Extended Industry Standard Architecture (EISA), was not very successful, however. Later buses such as VESA Local Bus and PCI were used instead, often along with ISA slots on the same mainboard. Derivatives of the AT bus structure were and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
