NEC POWERMATE 2000, Инструкция по обслуживанию и справочник

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4-12 System Board
PCI Local Bus
The 32-bit PCI local 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 III processor. The bus supports burst modes that send
large amounts of data across the bus, allowing fast displays of high-resolution
images.
The high-performance PCI local bus provides a processor-independent data path
between the CPU and high-speed peripherals. The PCI bus is a robust
interconnect mechanism designed specifically to accommodate multiple high
performance peripherals for graphics and full motion video.
The PCI local bus supports memory transfer rates of over 100 MB per second
for reads and over 120 MB per second for writes, depending on processor
configuration.
PCI/IDE Port
The system board supports a high-performance primary PCI/IDE two-channel
port on the system board. The PCI/IDE port has an enhanced IDE interface that
supports a PIO Mode 4 device with 16 MB per second 32-bit wide data transfers
on the high-performance PCI local bus. The port supports Ultra DMA/33/66.
The installed hard drive is connected as a master device on the primary port.
The installed CD-ROM drive is connected as a slave device on the primary port.
Each device is connected to the port with a signal and power interface cable.
Parallel Interface
The system has a 25-pin bidirectional parallel port on the system board. Port
specifications conform to the IBM-PC standards. The port supports Enhanced
Capabilities Port (ECP) and Enhanced Parallel Port (EPP) modes for devices
that require ECP or EPP protocols. The protocols allow high-speed
bi-directional transfer over a parallel port and increase parallel port functionality
by supporting more devices.
The BIOS has automatic ISA printer port sensing that works with most devices.
If the BIOS detects an ISA printer port mapped to the same address, the built-in
printer port is disabled. (Verify in the BIOS Setup that printer ports mapped to
the same address are enabled or disabled appropriately.) The BIOS also sets the
first parallel interface port it finds as LPT1 and the second port it finds as LPT2.
The interrupt is set at IRQ7 via the BIOS Setup utility. Software-selectable base
addresses are 228h, 378h, and 278h.
Sets of I/O addresses for the parallel port are given in the following table (see
Section 2, “System Configuration,” for interrupt levels). This is a list of all
possible configurations. The parallel port uses only one set.