Fujitsu Primepower200, User Manual

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CHAPTER 14 Glossary
Parity Checking
A method of checking the integrity of transmitted or stored data. The number of ones or zeroes in a
binary data segment is used to calculate a parity bit which is appended to that piece of data. If the
same calculation at a later time produces a parity bit that does not match the previously assigned
parity bit, we can know that the value of at least one of the bits has changed, and the data can be
rejected as corrupt. This works if only 1 (or other odd number) bit changes, but if 2 bits (or other
even number) bits change then the calculated parity bit will match the previously assigned parity bit,
meaning the errors will not be detected. This means that while parity can be used if errors are
infrequent (and hence the probability of two errors is minuscule), it should be avoided if errors are
rather more common.
PCI (Peripheral Component Interconnect)
A local (system) bus standard that provides (relatively) fast access to the CPU for a (relatively)
small number of (peripheral) devices.
PCI Bus
#
PCI slots listed as having the same PCI Bus number will share CPU access over the same PCI bus.
PPU (Power Processing Unit)
An internal (on-board component) type of power supply.
RCI (Remote Cabinet Interface)
A standard method of connecting multiple hosts to multiple I/O devices. The RCI provides power
on/off, system control, system monitoring, inter-host communication, and various other functions.
RCI Node Address
A logical address assigned to each node of a RCI network.
SCF (System Control Facility)
Dedicated circuitry (including an independent CPU, the Service Processor) on the systemboard that
provides unified monitoring and control of the status of cooling fans, power supplies, other system
components and peripheral devices.
SCSI (Small Computer Systems Interface)
A fast, 8-bit parallel, ANSI standard I/O bus that can be used to connect up to 8 peripheral devices
(hard disks, CR-ROM drives, MO drives, etc.) to a computer.
SCSI ID
#
A unique address (0-7) assigned to each device on the SCSI bus.
Service Processor
The independent CPU that monitors the system and supplies diagnostic functions, as part of the
SCF.
SMP (Symmetrical Multi-Processing)
A common method for using multiple processors together in a basically identical fashion.
Start and Stop Bits
In serial communications, special signals respectively mark the beginning and end of transmission
of a set of data.
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