NEC PowerMate 2000 Series, Инструкция по обслуживанию и справочник, Страница: 104 / 175

4-12 System Board
Serial Interface
The system has one 16C550 UART compatible serial port (COM1) integrated
on the I/O controller. The serial port supports the standard RS-232C interface.
The buffered high-speed serial port supports transfer rates up to 115.2 KB. The
port allows the installation of high-speed serial devices for faster data transfer
rates.
The I/O addresses for the channel is given in the following table (see Section 2,
“System Configuration,” for interrupt levels). Soft-selectable base addresses are
3F8h, 2F8h, 3E8h, and 2E8h.
Serial Port I/O Addresses
Starting I/O Address Port
3F8 COM1
2F8 COM2
3E8 COM3
2E8 COM4
See Section 2, “System Configuration,” for information on resetting the port
through the BIOS Setup utility. See Section 9, “Specifications,” for the serial
interface specifications.
Serial interface signals are output through the system board’s 9-pin,
D-subconnector. The connector is located at the back of the system unit.
USB Interface
The Universal Serial Bus (USB) ports allow new Plug and Play serial devices to
be added without having to open the system. One USB device may be plugged
into each USB port for direct system connection. With a hub and the proper
cabling, up to 127 USB devices can be addressed by the system. The USB
determines system resources for each peripheral and assigns them without user
intervention. Boot support for a USB keyboard is present so the system can be
booted with a USB keyboard instead of a standard keyboard.
Accelerated Graphics Port
The system board contains a direct integrated accelerated graphics port (Direct
AGP) that supports graphics-intensive, 3D applications. The Direct AGP
operates independently of the PCI bus and supports 133-MHz data transfer rates,
allowing 500 MB of data to be transmitted per second.
Attach an optional display monitor to the system board’s VGA-compatible
connector on the rear panel.