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CPU socket. A 478-pin surface mount, Zero Insertion Force (ZIF) socket called mPGA478 B. This socket accommodates the Intel® Pentium® 4 478/Northwood Processor with 400MHz system bus.

North bridge controller. This controller called the Intel Memory Controller Hub (MCH) is one of the two major components of the Intel 845 (Brookdale) chipset. The MCH and the south bridge Intel I/O Controller Hub 2 (ICH2) are interconnected through the Intel proprietary Hub interface. The MCH provides the processor interface, memory interface, AGP interface, and Hub Interface.

SDRAM DIMM sockets. These three 168-pin DIMM sockets support up to 3GB using unbuffered ECC or non-ECC PC100/133 SDRAM DIMMs.

ATX power connector. This 20-pin connector connects to an ATX 12V power supply. The power supply must have at least 1A on the +5V standby lead (+5VSB).

Floppy disk connector. This connector connects the provided ribbon cable for the floppy disk drive. One side of the connector is slotted to prevent incorrect insertion of the floppy disk cable.

ASUS EZ Plug™ Auxilliary +12V connector. This ASUS patented auxilliary power connector is used if you don’t have an ATX +12V power supply. Connect a 4-pin device connector from a standard power supply to this connector to provide sufficient power to the CPU.

IDE connectors. These dual-channel bus master IDE connectors support up to four Ultra DMA/100/66, PIO Modes 3 & 4 IDE devices. Both the primary (blue) and secondary (black) connectors are slotted to prevent incorrect insertion of the IDE ribbon cable.

AGP warning LED. Serving as a smart burn-out protection for the motherboard, this red LED lights up if you plug in any 3.3V AGP card into the AGP slot. When this LED is lit, there is no way you can turn on the system power even if you press the power button. (The AGP LED feature is present on PCB R1.05 or later versions.)

South bridge controller. Referred to as the Intel I/O Controller Hub 2 (ICH2) of the Intel 845 chipset, this controller provides the I/O subsystem that allows access to the rest of the system. The ICH2 integrates I/O functions such as system bus interface, Ultra ATA/100, Low Pin Count (LPC) interface, Universal Serial Bus (USB) 1.1 interface, PCI interface, and CNR interface.

ASUS P4B motherboard user guide

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