Firmware that cancontrol much of a computer’s input/outputfunctions, such as communication with the floppydrive and the monitor.
A small circuit board inserted in anexpansion slot and used to communicate betweenthe system bus and a peripheral device. Also called an interface card.
binary number system
The number system used bycomputers; it has only two numbers, 0 and 1,called binary digits, or bits.
The paths, or lines, on the motherboard onwhich data, instructions, and electrical powermove from component to component.
A collection of eight bits that can represent asingle character.
Adapter boards or interface cards placed intoexpansion slots to expand the functions of acomputer, allowing it to communicate withexternal devices such as monitors or speakers.
central processing unit (CPU)
Also called amicroprocessor or processor. The heart and brainof the computer, which receives data input,processes information, and executes instructions.
DIMM (dual inline memorymodule)
A miniaturecircuit board installed on a motherboard to holdmemory. DIMMs can hold up to 4 GB of RAM ona single module.
A circuit board inserted into a sloton the motherboard to enhance the capability ofthe computer.
Software that is permanently stored in achip. The BIOS on a motherboard is an example offirmware.
parallel ATA (PATA)
An older IDE cabling method thatuses a 40-pin flat or round data cable or an 80-conductor cable and a 40-pin IDE connector. See alsoserial ATA.
A female 25-pin port on a computerthat can transmit data in parallel, 8 bits at a time,and is usually used with a printer. The names forparallel ports are LPT1 and LPT2.
(1) As applied to services running on a computer, a number assigned to a process on a computer so that the process can be found by TCP/IP. Also called a port address or port number. (2) Another name foran I/O address. See also I/O address. (3) A physical connector, usually at the back of a computer, that allows a cable from a peripheral device, such as a printer, mouse, or modem, to be attached.
A box inside the computer case thatsupplies power to the motherboard and otherinstalled devices. Power supplies provide 3.3, 5, and12 volts DC. Also called a power supply unit (PSU).
Temporary storage on themotherboard used by the CPU to process data andinstructions. Memory is considered primary storage.
A set of step-by-step instructions to acomputer. Some are burned directly into chips, whileothers are stored as program files. Programs arewritten in languages such as Visual Basic and C++.
A set of rules and standards that two entitiesuse for communication.
S/PDIF (Sony-Philips DigitalInterface) sound port
A sound port that connects to an external hometheater audio system, providing digital output and the best signal quality.
Storage that is remote to the CPUand permanently holds data, even when the PC isturned off, such as a hard drive.
serial ATA (SATA)
An ATAPI cabling method thatuses a narrower and more reliable cable than the80-conductor cable. See also parallel ATA.
A male 9-pin or 25-pin port on a computer system used by slower I/O devices suchas a mouse or modem. Data travels serially, one bit at a time, through the port. Serial ports aresometimes configured as COM1, COM2, COM3,or COM4.
Part of system BIOS that is responsiblefor controlling the PC when it is first turned on.Startup BIOS gives control over to the OS once itis loaded.
The bus between the CPU and memoryon the motherboard. The bus frequency indocumentation is called the system speed, such as400 MHz. Also called the memory bus, front-sidebus, local bus, or host bus.
A wire on a circuit board that connects twocomponents or devices.
universal serial bus (USB) port
A type of port designed to make installation and configuration of I/O devices easy, providing room for as many as 127 devices daisy-chained together.