Appendix I: Glossary - TYAN TOMCAT I7221 User Manual

Tomcat i7221 S5150

Appendix I: Glossary

Appendix I: Glossary
ACPI (Advanced Configuration and Power Interface): a power management specification
that allows the operating system to control the amount of power distributed to the computer's
devices. Devices not in use can be turned off, reducing unnecessary power expenditure.
AGP (Accelerated Graphics Port): a PCI-based interface which was designed specifically for
demands of 3D graphics applications. The 32-bit AGP channel directly links the graphics
controller to the main memory. While the channel runs at only 66 MHz, it supports data
transmission during both the rising and falling ends of the clock cycle, yielding an effective
speed of 133 MHz.
ATAPI (AT Attachment Packet Interface): also known as IDE or ATA; a drive
implementation that includes the disk controller on the device itself. It allows CD-ROMs and
tape drives to be configured as master or slave devices, just like HDDs.
ATX: the form factor designed to replace the AT form factor. It improves on the AT design by
rotating the board 90 degrees, so that the IDE connectors are closer to the drive bays, and the
CPU is closer to the power supply and cooling fan. The keyboard, mouse, USB, serial, and
parallel ports are built-in.
Bandwidth: refers to carrying capacity. The greater the bandwidth, the more data the bus,
phone line, or other electrical path, can carry. Greater bandwidth, then, also results in greater
speed.
BBS (BIOS Boot Specification): is a feature within the BIOS that creates, prioritizes, and
maintains a list of all Initial Program Load (IPL) devices, and then stores that list in NVRAM.
IPL devices have the ability to load and execute an OS, as well as provide the ability to return
to the BIOS if the OS load process fails for some reason. At that point, the next IPL device is
called upon to attempt loading of the OS.
BIOS (Basic Input/Output System): the program that resides in the ROM chip, and provides
the basic instructions for controlling your computer's hardware. Both the operating system and
application software use BIOS routines to ensure compatibility.
Buffer: a portion of RAM which is used to temporarily store data, usually from an application,
though it is also used when printing, and in most keyboard drivers. The CPU can manipulate
data in a buffer before copying it, all at once, to a disk drive. While this improves system
performance --- reading to or writing from a disk drive a single time is much faster than doing
so repeatedly --- there is also the possibility of losing your data should the system crash.
Information stored in a buffer is temporarily stored, not permanently saved.
Bus: a data pathway. The term is used especially to refer to the connection between the
processor and system memory, and between the processor and PCI or ISA local buses.
Bus mastering: allows peripheral devices and IDEs to access the system memory without
going through the CPU (similar to DMA channels).
Cache: a temporary storage area for data that will be needed often by an application. Using a
cache lowers data access times, since the needed information is stored in the SRAM instead
of in the slow DRAM. Note that the cache is also much smaller than your regular memory: a
typical cache size is 512KB, while you may have as much as 4GB of regular memory.
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