LSI 20160 User Manual
Page 53
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Copyright © 2001 by LSI Logic Corporation. All rights reserved.
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.
Parity Checking
A way to verify the accuracy of data transmitted over the SCSI bus. The
parity bit in the transfer is used to make the sum of all the 1 bits either
odd or even (for odd or even parity). If the sum is not correct, the
information may be retransmitted or an error message may appear.
Passive
Termination
The electrical connection required at each end of the SCSI bus,
composed of a set of resistors. It improves the integrity of bus signals.
PC99
A set of design standards that developers must comply with to be
Windows NT compatible.
PCI
Peripheral Component Interconnect. A local bus specification that allows
connection of peripherals directly to computer memory. It bypasses the
slower ISA and EISA buses.
Peripheral
Devices
A piece of hardware (such as a video monitor, disk drive, printer, or
CD-ROM) used with a computer and under the computer’s control. SCSI
peripherals are controlled through a SCSI host adapter.
Pin-1
Orientation
The alignment of pin 1 on a SCSI cable connector and the pin-1 position
on the SCSI connector into which it is inserted. External SCSI cables are
always keyed to insure proper alignment, but internal SCSI ribbon cables
sometimes are not keyed.
PIO
Programmed Input/Output. A way the CPU can transfer data to and from
memory using the computer’s I/O ports. PIO is usually faster than DMA,
but requires CPU time.
Port Address
Also Port Number. The address through which commands are sent to a
host adapter board. This address is assigned by the PCI bus.
Port Number
See Port Address.
Queue Tags
A way to keep track of multiple commands that allow for increased
throughput on the SCSI bus.