Advanced Setup
T4G Technical Reference
TRENTON Technology Inc.
4-18
Serial Port1 Address/Serial Port2 Address
Each of these options enables the specified serial port on the SBC and establishes the
base I/O address and the number of the interrupt request for the port.
The Setup screen displays the system option:
Serial Port1 Address
[3F8/IRQ4]
Serial Port2 Address
[2F8/IRQ3]
Available options are:
Disabled
3F8/IRQ4
3E8/IRQ4
2F8/IRQ3
2E8/IRQ3
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NOTE: The values available for each on-board serial port may vary, depending on the
setting previously selected for the other on-board serial port and any off-board serial
ports. If an I/O address is assigned to another serial port, AMIBIOS automatically omits
that address from the values available.
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If the system has off-board serial ports which are configured to specific starting I/O ports
via jumper settings, AMIBIOS configures the on-board serial ports to avoid conflicts.
AMIBIOS checks the ISA Bus for serial ports. Any off-board serial ports found on the
ISA Bus are left at their assigned addresses. Serial Port1, the first on-board serial port, is
configured with the first available address and Serial Port2, the second on-board serial
port, is configured with the next available address. The default address assignment
order is 3F8H, 2F8H, 3E8H, 2E8H. Note that this same assignment order is used by
AMIBIOS to place the active serial port addresses in lower memory (BIOS data area) for
configuration as logical COM devices.
For example, if there is one off-board serial port on the ISA Bus and its address is set to
2F8H, Serial Port1 is assigned address 3F8H and Serial Port2 is assigned address 3E8H.
Configuration is then as follows:
COM1 - Serial Port1 (at 3F8H)
COM2 - off-board serial port (at 2F8H)
COM3 - Serial Port2 (at 3E8H)
If Serial Port2 Address is set to Disabled, the Serial Port2 IRQ and Serial Port2
Mode options are not available.
Serial Port2 IRQ
If the Serial Port2 Address option is set to Disabled, this option is not available for
modification.
