Glossary

A

address A specific location in memory, designated either numerically or by a symbolic name.

Asynchronous Data Transfer

One of the ways data is transferred over the SCSI bus. It is slower than synchronous data transfer.

BIOS (Basic Input/Output System) Software that provides basic read/write capability. Usually kept as firmware (ROM based). The system BIOS on the main board of a computer is used to boot and control the system. The SCSI BIOS on the host adapter acts as an extension of the system BIOS.

bit A binary digit. The smallest unit of information a computer uses. The value of a bit (0 or 1) represents a two-way choice, such as on or off, true or false.

bus A collection of wires in a cable or copper traces on a circuit board used to transmit data, status, and control signals. EISA, PCI, and SCSI are examples of buses.

bus mastering A high-performance way to transfer data. The host adapter controls the transfer of data directly to and from system memory without bothering the computer’s

microprocessor. This is the fastest way for multi-tasking operating systems to transfer data.

byte A unit of information consisting of eight bits.

chain A topology in which every device is connected to two others, except for two-end devices that are connected to only one other.

CISPR (Committee, International and Special, for Protection in Radio) An international committee on radio frequency interference.

configuration Refers to the way a computer is set up; the combined hardware components (computer, monitor, key board, and peripheral devices) that make up a computer system; or the software settings that allow the hardware components to communicate with each other.

CPU (central processing unit)

The “brain” of the computer that performs the actual computations. The term Micro Processor Unit (MPU) is also used.

DMA (direct memory access) A method of moving data from a storage device directly to RAM, without using the CPU’s resources.

DMA bus master A feature that allows a peripheral to control the

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