Plug And Play; Isa Bus; Pci Local Bus - NEC POWERMATE PROFESSIONAL 9000 Service Manual

Plug and Play

The system comes with a Plug and Play BIOS in support of Plug and Play technology. Plug
and Play simplifies setup procedures for installing Plug and Play expansion boards. With
Plug and Play, adding a Plug and Play expansion board is done by turning off the system,
installing the board, and turning on the system. There are no jumpers to set and no system
resource conflicts to resolve. Plug and Play automatically configures the board. (Some Plug
and Play devices may need to be jumpered if used in a system running the Windows NT
operating system.)

ISA Bus

The system board uses the ISA bus for transferring data between the processor and some
I/O peripherals and expansion boards. The ISA bus supports 16-bit data transfers and
typically operates at 8 MHz. ISA expansion slot connector pin assignments are provided in
Appendix A.

PCI Local Bus

The 32-bit PCI bus is the primary I/O bus for the system. The PCI bus is a highly integrated
I/O interface that offers the highest performance local bus available for the Pentium
processor. The bus supports burst modes that send large chunks of data across the bus,
allowing fast displays of high-resolution images.
The PCI bus operates at half the Pentium processor's bus speed. The PCI bus supports
memory transfer rates of up to 105 MB per second for reads and up to 120 MB per second
for writes, depending on processor configuration.
The PCI bus eliminates the data bottleneck found in traditional systems, maintains maximum
performance at high clock speeds, and provides a clear upgrade path to future technologies.
PCI expansion slot connector pin assignments are provided in Appendix A.
NOTE: The PIIX4 can connect each PIRQ line
internally to one of the IRQ signals (3, 4, 5, 7, 9,
10, 11, 12, 14, or 15). Typically, a device that
does not share a PIRQ line will have a unique
interrupt. However, in certain interrupt-
constrained situations, it is possible for two or
more of the PIRQ lines to be connected to the
same IRQ signal. In the presence of an SMP
operating system, the IOAPIC is used instead of
the PIIX4 to distribute interrupts.
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