1-20 Technical Information
Table 1-10 Serial Port 2 Addresses and Interrupts
Starting I/O Address
Interrupt Level
Port
3F8
IRQ04
COM1
2F8
IRQ03
COM2*
3E8
IRQ04
COM3
2E8
IRQ03
COM4
3F8
IRQ03
COM1
2F8
IRQ04
COM2
3E8
IRQ03
COM3
2E8
IRQ04
COM4
* Used for IrDA data transfer
See Section 2, “Setup and Operation,” for information on resetting the port through the
BIOS Setup utility.
Serial interface specifications include:
Baud rate up to 115.2 KB per second
Word length
5, 6, 7, or 8 bits
Stop bit
1, 1.5, or 2 bits
Start bit
1 bit
Parity bit
1 bit (odd parity or even parity).
Serial interface signals are output through the system board’s 9-pin, D-subconnectors. The
connectors are located at the rear of the system unit. Pin locations for the serial interface
connector are shown in Appendix A.
USB Interface
The Universal Serial Bus (USB) port allows new Plug and Play serial devices to be added
without having to open the system. One USB device may be plugged into the 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.
