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DOS Memory Management
In IBM PC compatible computing, DOS memory management refers to software and techniques employed to give applications access to more than 640 kibibytes (640*1024 bytes) (KiB) of "conventional memory". The 640 KiB limit was specific to the IBM PC and close compatibles; other machines running MS-DOS had different limits, for example the Apricot PC could have up to 768 KiB and the Sirius Victor 9000, 896 KiB. Memory management on the IBM family was made complex by the need to maintain backward compatibility to the original PC design and real-mode DOS, while allowing computer users to take advantage of large amounts of low-cost memory and new generations of processors. Since DOS has given way to Microsoft Windows and other 32-bit operating systems not restricted by the original arbitrary 640 KiB limit of the IBM PC, managing the memory of a personal computer no longer requires the user to manually manipulate internal settings and parameters of the system. The 640 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM PC Memory Areas
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is a publicly traded company and one of the 30 companies in the Dow Jones Industrial Average. IBM is the largest industrial research organization in the world, with 19 research facilities across a dozen countries; for 29 consecutive years, from 1993 to 2021, it held the record for most annual U.S. patents generated by a business. IBM was founded in 1911 as the Computing-Tabulating-Recording Company (CTR), a holding company of manufacturers of record-keeping and measuring systems. It was renamed "International Business Machines" in 1924 and soon became the leading manufacturer of Tabulating machine, punch-card tabulating systems. During the 1960s and 1970s, the IBM mainframe, exemplified by the IBM System/360, System/360 and its successors, wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus slot) on a computer's motherboard (see also backplane) to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most (or all) of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard. Expansion cards allow the capabilities and interfaces of a computer system to be extended or supplemented in a way appropriate to the tasks it will perform. For example, a high-speed multi-channel data acquisition system would be of no use in a personal computer used for bookkeeping, but might be a key part of a system used for in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keyboard Controller (computing)
In computing, a keyboard controller is a device that interfaces a keyboard (computing), keyboard to a computer. Its main function is to inform the computer when a computer keyboard keys, key is pressed or released. When data from the keyboard arrives, the controller raises an interrupt (a ''keyboard interrupt'') to allow the CPU to handle the input. If a keyboard is a separate computer peripheral, peripheral system unit (such as in most modern desktop computers), the keyboard controller is not directly attached to the keys, but receives scancodes from a microcontroller embedded in the keyboard via some kind of serial interface. In this case, the controller usually also controls the keyboard's LEDs by sending data back to keyboard through the wire. The IBM PC AT used an Intel 8042 chip to interface to the keyboard. This chip had two additional functions: it controlled access to the Intel 80286 CPU's A20 line in order to implement a workaround for a chip bug, and it was used to in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
