American Megatrends 43 Series User Manual page 57

ADVANCED CHIPSET SETUP Options,
On Board Serial Port 2
This option enables or disables serial port 2 on the SX CAT motherboard. The settings are I/O Ports 2F8h - 2FFh, I/O Ports 2E8h - 2EFh, or Disabled.
If the configuration data stored in CMOS RAM is corrupted when the system is powered on, the system BIOS automatically configures onboard serial port 2
according to the presence or absence of serial ports on any adapter cards in the system expansion slots (offboard serial ports).
Autoconfiguration only occurs when CMOS RAM data is corrupted. The result for serial port 2 is:
J14 is serial port 2 on the SX CAT motherboard. If disabled through Setup, do not attach any device to J14 or to any cable attached to J14. Serial Port 2 is
hardwired to interrupt request line 3 (IRQ3). If Serial Port 2 is disabled through ADVANCED CHIPSET SETUP then IRQ3 may be used by other adapter cards.
Continued
If the Offboard the Onboard Serial Port 2 is Autoconfigured as
Serial Port is
None 2F8h Can be disabled or changed to 2E8h via BIOS
ADVANCED CHIPSET SETUP.
2F8h 2E8h Can be disabled via BIOS ADVANCED CHIPSET
SETUP. If changed to 2F8h, an I/O port address
conflict occurs.
2E8h 2F8h Can be disabled via BIOS ADVANCED CHIPSET
SETUP. If changed to 2E8h, an I/O port address
conflict occurs.
2F8h, 2E8h Disabled If changed to 2F8h or 2E8h, an I/O port address
conflict occurs.