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
B-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.
LVDlink
Low Voltage Differential Link allows greater Ultra2 SCSI device
connectability and longer SCSI cables. LVDlink lowers the amplitude of
noise reflections and allows higher transmission frequencies. Detailed
information may be found in
Section 1.5, “Benefits of LVDlink
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.
