TYAN Thunder K8SR User Manual page 30

data should the system crash. Information 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 information is
stored in SRAM instead of slower 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.
Closed and open jumpers: jumpers and jumper pins are active when they are
"on" or "closed", and inactive when they are "off" or "open".
CMOS (Complementary Metal-Oxide Semiconductors): chips that hold the
basic startup information for the BIOS.
COM port: another name for the serial port, which is 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). Parallel ports transmit the bits of a byte on eight different wires at the
same time (that is, in parallel form, eight bits at the same time).
DDR (Double Data Rate): a technology designed to double the clock speed of
the memory. It activates output on both the rising and falling edge of the system
clock rather than on just the rising edge, potentially doubling output.
DIMM (Dual In-line Memory Module): faster and more capacious form of RAM
than SIMMs, and do not need to be installed in pairs.
DIMM bank: sometimes called DIMM socket because the physical slot and the
logical unit are the same. That is, one DIMM module fits into one DIMM socket,
which is capable of acting as a memory bank.
DMA (Direct Memory Access): channels are similar to IRQs. DMA channels
allow hardware devices (like soundcards or keyboards) to access the main
memory without involving the CPU. This frees up CPU resources for other tasks.
As with IRQs, it is vital that you do not double up devices on a single line. Plug-n-
Play devices will take care of this for you.
DRAM (Dynamic RAM): widely available, very affordable form of RAM which
looses data if it is not recharged regularly (every few milliseconds). This refresh
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requirement makes DRAM three to ten times slower than non-recharged RAM
such as SRAM.
ECC (Error Correction Code or Error Checking and Correcting): allows data
to be checked for errors during run-time. Errors can subsequently be corrected at
the same time that they're found.
EEPROM (Electrically Erasable Programmable ROM): also called Flash BIOS,
it is a ROM chip which can, unlike normal ROM, be updated. This allows you to
keep up with changes in the BIOS programs without having to buy a new chip.
TYAN's BIOS updates can be found at http://www.tyan.com
ESCD (Extended System Configuration Data): a format for storing information
about Plug-n-Play devices in the system BIOS. This information helps properly
configure the system each time it boots.
Firmware: low-level software that controls the system hardware.
Form factor: an industry term for the size, shape, power supply type, and
external connector type of the Personal Computer Board (PCB) or motherboard.
The standard form factors are the AT and ATX.
Global timer: onboard hardware timer, such as the Real-Time Clock (RTC).
HDD: stands for Hard Disk Drive, a type of fixed drive.
H-SYNC: controls the horizontal synchronization/properties of the monitor.
TM
HyperTransport : a high speed, low latency, scalable point-to-point link for
interconnecting ICs on boards. It can be significantly faster than a PCI bus for an
equivalent number of pins. It provides the bandwidth and flexibility critical for
today's networking and computing platforms while retaining the fundamental
programming model of PCI.
IC (Integrated Circuit): the formal name for the computer chip.
IDE (Integrated Device/Drive Electronics): a simple, self-contained HDD
interface. It can handle drives up to 8.4 GB in size. Almost all IDEs sold now are
in fact Enhanced IDEs (EIDEs), with maximum capacity determined by the
hardware controller.
IDE INT (IDE Interrupt): Hardware interrupt signal that goes to the IDE.
I/O (Input/Output): the connection between your computer and another piece of
hardware (mouse, keyboard, etc.)
IRQ (Interrupt Request): an electronic request that runs from a hardware device
to the CPU. The interrupt controller assigns priorities to incoming requests and
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