Expansion Bus; Bios - NEC DIRECTION L Service Manual

1-6 Technical Information
The PCI bus contains two embedded PCI devices: the PCI local bus IDE interface and the
PCI video/graphics controller. The PCI bus also contains a connector for attaching the bus
expansion board.

Expansion Bus

The expansion bus contains one ISA slot, three PCI slots, one PCI/ISA slot, and one AGP
video slot. The PCI ISA IDE Xccelerator chip (PIIX4) provides the logic that enables the
ISA bus functions. With 24-bit memory addressing, a 16-bit data path, and an eight MHz
clock, the ISA bus is designed to support all peripherals compatible with the IBM AT
standard. For PCI functions, the Xcelerator chip provides 32-bit memory addressing, 32-bit
data path, and a 33-MHz clock speed.

BIOS

The BIOS (Basic Input Output System) is stored in the Intel PA28FB200BX Flash
EPROM. The Flash EPROM is reprogrammable and allows fast, economical BIOS
upgrades.
The system memory map in shown in Table 1-4.