NEC SP B-Series - Manual (Page 18)

Technical Information 1-7
System Memory Map
Memory Address Size Function
100000-18000000 383 MB Extended memory
E8000-FFFFF 96 KB System BIOS
E0000-E7FFF 32 KB System BIOS (available as
UMB)
C8000-DFFFF 96 KB Available high DOS memory
(open to ISA and PCI bus)
A0000-C7FFF 160 KB Video memory and BIOS
00000-9FFFF 640 KB Conventional memory
Plug and Play Support
The system comes with Plug and Play BIOS technology. Plug and Play
eliminates complicated setup procedures for installing Plug and Play expansion
boards.
To add a Plug and Play expansion board, simply power off the system, install
the board, and power on the system. There are no jumpers to set and no system
resource conflicts to resolve. Plug and Play automatically configures the board
for the system. The system also supports non-Plug and Play boards.
Plug and Play is controlled by the Plug and Play BIOS and the system’s
operating system. The Plug and Play BIOS is stored in the Flash EPROM on the
system board.
The Plug and Play BIOS adds several steps to the POST process. During POST,
the Plug and Play evaluates the configuration of installed boards and assigns
available system resources to the devices. On completion of Plug and Play
POST, the operating system checks to see if there are any additional resources
required, then assigns available resources to the devices.
CMOS Memory/Real-Time Clock Battery
The 82371EB PCI ISA IDE Xcelerator (PIIX4E) on the system board stores
system information in non-volatile CMOS memory. The chip also contains the
system’s real-time clock. Both are maintained by a 3-volt coin cell lithium
battery on the system board. The battery is replaceable.
DMA/IRQ Settings
The system automatically configures, with minimal user intervention, interrupt
requests (IRQ), direct memory access (DMA) channels, and other parameters
when adding PCI boards.
The following tables list system IRQ and DMA default settings.