SOLTEK SL-85DR User Manual page 92

Appendices
RIMM (Rambus Inline Memory Module)
RIMM is built with a 184-pin architecture module that supports
RDRAM memory technology. A RIMM memory module may contain
up to maximum of 16 RDRAM devices.
SDRAM (Synchronous DRAM)
SDRAM is one of the Dynamic Random Access Memory (DRAM)
technologies that allow DRAM to use the same clock as the CPU host
clock (EDO and FPM are asynchronous and do not have clock signal).
SDRAM comes in 64-bit 168-pin DIMM and operates at 3.3V.
SIMM (Single In Line Memory Module)
SIMM socket is only 72-pin, and is only single side. The golden fin-
ger signals on each side of PCB are identical. That is why it is called
Single In Line. SIMM is made of FPM or EDO DRAM and supports
32-bit data. SIMM is phased out in current mainboard design.
SPD (Serial Presence Detect)
SPD is a small ROM or EEPROM device resided on the DIMM or
RIMM. Memory module information such as DRAM timing and chip
parameters can be stored into SPD so that BIOS can access it and use
it to decide best timing for this DIMM or RIMM.
UART (Universal Asynchronous Receiver/transmitter)
UART is built in a chip that controls the data sent to and received
from a serial port. A 16550 UART is now standard in most PCs, and
supports modem speed up to 57,600 bps and beyond and direct con-
nect speed of 115,200 bps. Many UARTs have built-in errors in the
internal code and just do not work correctly with many external
modems. UART is also found as the serial interface on internal modem.
Ultra DMA
Ultra DMA (or, more accurately, Ultra DMA/33) is a protocol for trans-
ferring data at 33.3MB/s between a hard disk drive through the
computer's data path (or bus) to the computer's random access memory
(RAM). The transfer data is twice as fast as the previous Direct Ac-
cess Memory (DMA) interface. The latest Ultra DMA has advanced to
Ultra DMA/66 and Ultra DMA/100.
16.6MB/s x2 = 33MB/s
16.6MB/s x4 = 66MB/s
16.6MB/s x6 = 100MB/s
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