TYAN Thunder HEsl S2567 User Manual page 58

PM timers (Power Management timers): software timers that count down the number of seconds or min-
utes until the system times out and enters sleep, suspend, or doze mode.
PnP (Plug-n-Play): a design standard that has become ascendant in the industry. Plug-n-Play devices
require little set-up to use. Novice end users can simply plug them into a computer that is running on a
Plug-n-Play aware operating system (such as Windows 98), and go to work. Devices and operating sys-
tems that are not Plug-n-Play require you to reconfigure your system each time you add or change any
part of your hardware.
PXE (Preboot Execution Environment): one of four components that together make up the Wired for Man-
agement 2.0 baseline specification. PXE was designed to define a standard set of preboot protocol ser-
vices within a client, towards the goal of allowing networked-based booting to boot using industry
standard protocols.
Striping: see RAID.
RAID (Redundant Array of Independent Disks): a way for the same data to be stored in different places
on many hard drives. By using this method, the data is stored redundantly, also the multiple hard drives
willl appear as a single drive to the operating system. RAID level 0 is is known as striping, where data is
striped (or overlapped) across multiple hard drives, but offers no fault-tolerance. RAID level 1 is known as
mirroring, which stores the data within at least two hard drives, but does not stripe. RAID level 1 also
allows for faster access time and fault-tolerance, since either hard drive can be read at the same time.
RAID level 0+1 is both striping and mirroring, providing fault-tolerance, striping, and faster access all at
the same time.
RAM (Random Access Memory): technically refers to a type of memory where any byte can be accessed
without touching the adjacent data, is often used to refer to the system's main memory. This memory is
available to any program running on the computer.
ROM (Read-Only Memory): a storage chip which contains the BIOS; the basic instructions required to
boot the computer and start up the operating system.
SDRAM (Synchronous Dynamic RAM): called as such because it can keep two sets of memory
addresses open simultaneously. By transferring data alternately from one set of addresses and then the
other, SDRAM cuts down on the delays associated with non-synchronous RAM, which must close one
address bank before opening the next.
Serial port: called as such because it transmits the eight bits of a byte of data along one wire, and
receives data on another single wire (that is, the data is transmitted in serial form, one bit after another).
SIMM (Single In-line Memory Module): formerly the most common form of RAM for motherboards. They
must be installed in pairs, and do not have the carrying capacity or the speed of DIMMs.
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