POST (Power On Self Test). When you turn ON the computer, it will first run through the POST, a series of software-controlled diagnostic tests. The POST checks system memory, the motherboard circuitry, the display, the keyboard, the diskette drive, and other I/O devices.

PS/2 Port. PS/2 ports are based on IBM Micro Channel Architecture. This type of architecture transfers data through a 16-bit or 32-bit bus. A PS/2 mouse and/or keyboard may be used on ATX motherboards.

RAM (Random Access Memory). The computer’s primary storage area used to write, store, and retrieve information and program instructions which are passed to the CPU for processing. The information in RAM can be repeatedly re-written with new data. Compared to other storage media like magnetic tape, floppy disk, and hard disk, RAM has an extraordinarily fast access rate. RAM, however, is volatile, which means that the data stored in it are lost when the system power is turned off, or if power glitches occur. See also DRAM and SDRAM.

ROM (Read Only Memory). An integrated circuit chip containing program and data that can be accessed and read but not modified.

SCSI (Small Computer System Interface). High speed multi-threaded I/ O interface defined by the X3T9.2 committee of the American National Standards Institute (ANSI) for connecting many peripheral devices. The standard covers 10MBytes/sec to 160MBytes/sec data rates.

SDRAM (Synchronous DRAM). A type of DRAM with access signals that are synchronized with the CPU clock, eliminating the delay associated with data transfers between the CPU and memory. SDRAM takes memory access away from the CPU control; internal registers in the memory accept the request, and lets the CPU do something else while the data requested is assembled for the next time the CPU talks to the memory.

SIR (Serial IrDA). A SIR specification defines a short-range infrared asynchronous serial transmission mode with one stat bit, eight data bits and one stop bit. The maximum data rate is 115.2Kbps.

SPD for SDRAM module. Serial Presence Detect (SPD) is most like an ID detect for SDRAM module, it uses an EEPROM component on a DIMM for storing module configuration information inside. The Serial Presence Detect function is implemented using a 2048 bit EEPROM component. This nonvolatile storage device contains data programmed by the DIMM manufacturer that identifies the module type and various SDRAM organization and timing parameters.

ASUS P4B266-C motherboard user guide

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