microcomputer(redirected from Microcomputers)
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A digital computer whose central processing unit consists of a microprocessor, a single semiconductor integrated circuit chip. Once less powerful than larger computers, microcomputers are now as powerful as the minicomputers and superminicomputers of just several years ago. This is due in part to the growing processing power of each successive generation of microprocessor, plus the addition of mainframe computer features to the chip, such as floating-point mathematics, computation hardware, memory management, and multiprocessing support. See Integrated circuits, Multiprocessing
Microcomputers are the driving technology behind the growth of personal computers and workstations. The capabilities of today's microprocessors in combination with reduced power consumption have created a new category of microcomputers: hand-held devices. Some of these devices are actually general-purpose microcomputers: They have a liquid-crystal-display (LCD) screen and use an operating system that runs several general-purpose applications. Many others serve a fixed purpose, such as telephones that provide a display for receiving text-based pager messages and automobile navigation systems that use satellite-positioning signals to plot the vehicle's position. See Mobile radio
The microprocessor acts as the microcomputer's central processing unit (CPU), performing all the operations necessary to execute a program (see illustration).
A memory subsystem uses semiconductor random-access memory (RAM) for the temporary storage of data or programs. The memory subsystem may also have a small secondary memory cache that improves the system's performance by storing frequently used data objects or sections of program code in special high-speed RAM.
The graphics subsystem consists of hardware that displays information on a color monitor or LCD screen: a graphics memory buffer stores the images shown on the screen, digital-to-analog convertors (DACs) generate the signals to create an image on an analog monitor, and possibly special hardware accelerates the drawing of two- or three-dimensional graphics. (Since LCD screens are digital devices, the graphics subsystem sends data to the screen directly rather than through the DACs.)
The storage subsystem uses an internal hard drive or removable media for the persistent storage of data.
The communications subsystem consists of a high-speed modem or the electronics necessary to connect the computer to a network.
Microcomputer software is the logic that makes microcomputers useful. Software consists of programs, which are sets of instructions that direct the microcomputer through a sequence of tasks. A startup program in the microcomputer's ROM initializes all of the devices, loads the operating system software, and starts it. All microcomputers use an operating system that provides basic services such as input, simple file operations, and the starting or termination of programs. While the operating system used to be one of the major distinctions between personal computers and workstations, today's personal computer operating systems also offer advanced services such as multitasking, networking, and virtual memory. All microcomputers exploit the use of bit-mapped graphics displays to support windowing operating systems. See Operating system, Software
microcomputerGenerally refers to a Windows PC or Mac, but it can refer to any kind of small computer. When the term was first introduced in the late 1970s, it meant a computer with a single microprocessor chip as its CPU, namely, the personal computer. Today, the CPU in every computer is a microprocessor, and the terms "desktop computer," "laptop computer" and "PC" have mostly replaced the word microcomputer.
|The Revolution Begins!|
|In 1977, the same year RadioShack introduced its first microcomputer, the handwriting was on the wall... a "revolution" was beginning.|