Cache size: refers to the physical size of the cache. This should not be confused with the cacheable area, which is the total amount of memory which can be scanned by the system in search of data to put into the cache. A typical setup would be a cache size of 512KB, and a cacheable area of 512MB. In this case, up to 512KB of system memory is capable of being cached. However, only 512KB of this memory will be in the cache at any given moment.
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
COM port: another name for the serial port, which is called 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): is 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 throughput.
DIMM (Dual
DIMM bank: sometimes called DIMM sockets, 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 that 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.
Doze mode: in this mode, only the CPU’s speed is slowed.
DRAM (Dynamic RAM): widely available, very affordable form of RAM which will lose data if it is not recharged regularly (every few milliseconds). This refresh requirement makes DRAM three to ten times slower than
ECC (Error Correction Code or Error Checking and Correcting): allows data to be checked for errors during
EEPROM (Electrically Erasable Programmable ROM): also called Flash BIOS, 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 replace the BIOS chip. TYAN’s BIOS updates can be found at http://www.TYAN.com.
ESCD (Extended System Configuration Data): a format for storing information about
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