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LSI 21003 User Manual

Page 58

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3.75 pc

10.25 pc

11.25 pc

38.25 pc

4.333 pc

48.583 pc

52.5 pc

34.5 pc

44.25 pc

A-4

Glossary of Terms and Abbreviations

IRQ

Interrupt Request Channel. A path through which a device can get the
immediate attention of the computer’s CPU. The PCI bus assigns an IRQ
path for each SCSI host adapter.

ISA

Industry Standard Architecture. A type of computer bus used in most
PCs. It allows devices to send and receive data up to 16 bits at a time.

Kbyte

Kilobyte. A measure of computer storage equal to 1024 bytes.

Local Bus

A way to connect peripherals directly to computer memory. It bypasses
the slower ISA and EISA buses. PCI is a local bus standard.

Logical Unit

A subdivision, either logical or physical, of a SCSI device (actually the
place for the device on the SCSI bus). Most devices have only one logical
unit, but up to eight are allowed for each of the eight possible devices on
a SCSI bus.

LUN

Logical Unit Number. An identifier, zero to seven, for a logical unit.

Mainboard

A large circuit board that holds RAM, ROM, the microprocessor, custom
integrated circuits, and other components that make a computer work. It
also has expansion slots for host adapters and other expansion boards.

Main Memory

The part of a computer’s memory which is directly accessible by the CPU
(usually synonymous with RAM).

Mbyte

Megabyte. A measure of computer storage equal to 1024 kilobytes.

Motherboard

See Mainboard. In some countries, the term Motherboard is not
appropriate.

Multitasking

The executing of more than one command at the same time. This allows
programs to operate in parallel.

Multithreading

The simultaneous accessing of data by more than one SCSI device. This
increases the data throughput.

NVRAM

NonVolatile Random Access Memory. Actually an EEPROM
(Electronically Erasable Read Only Memory chip) used to store
configuration information. See EEPROM.

Operating
System

A program that organizes the internal activities of the computer and its
peripheral devices. An operating system performs basic tasks such as
moving data to and from devices, and managing information in memory.
It also provides the user interface.