Card Type	I/O controller
Chipset/Controller	National Semiconductor
I/O Options	Serial ports (2)
Maximum DRAM	N/A

CONNECTIONS
Purpose	Location	Purpose	Location
Serial port 1	J2	Serial port 2	J3

PRIMARY PORT I/O ADDRESS CONFIGURATION
Address		SW1/1	SW1/2	SW1/3	SW1/4	SW1/5	SW1/6	SW1/7	SW1/8
»	3F8h - 3FFh	Off	Off	Off	Off	Off	Off	Off	On
	2F8h - 2FFh	Off	Off	Off	Off	Off	On	Off	On
	3E8h - 3EFh	Off	On	Off	Off	Off	Off	Off	On
	2E8h - 2EFh	Off	On	Off	Off	Off	On	Off	On
	2F0h - 2FFh	On	Off	Off	Off	Off	On	Off	On
	3E0h - 3E7h	On	On	Off	Off	Off	Off	Off	On
	2EOh - 2E7h	On	On	Off	Off	Off	On	Off	On
	26Oh - 267h	On	On	Off	Off	On	On	Off	On
	Disabled	Off	Off	Off	Off	Off	Off	Off	Off

SECONDARY PORT I/O ADDRESS CONFIGURATION
Address	SW2/1	SW2/2	SW2/3	SW2/4	SW2/5	SW2/6	SW2/7	SW2/8
3F8h - 3FFh	Off	Off	Off	Off	Off	Off	Off	On
2F8h - 2FFh	Off	Off	Off	Off	Off	On	Off	On
3E8h - 3EFh	Off	On	Off	Off	Off	Off	Off	On
2E8h - 2EFh	Off	On	Off	Off	Off	On	Off	On
2F0h - 2FFh	On	Off	Off	Off	Off	On	Off	On
3E0h - 3E7h	On	On	Off	Off	Off	Off	Off	On
2EOh - 2E7h	On	On	Off	Off	Off	On	Off	On
26Oh - 267h	On	On	Off	Off	On	On	Off	On
Disabled	Off	Off	Off	Off	Off	Off	Off	Off

SERIAL PORT INTERRUPT SELECT
IRQ	Port 1 (JP3)	Port 2 (JP4)
IRQ2	Pins 1 & 2 closed	Pins 1 & 2 closed
IRQ3	Pins 3 & 4 closed	Pins 3 & 4 closed
IRQ4	Pins 5 & 6 closed	Pins 5 & 6 closed
IRQ5	Pins 7 & 8 closed	Pins 7 & 8 closed
IRQ10	Pins 9 & 10 closed	Pins 9 & 10 closed
IRQ11	Pins 11 & 12 closed	Pins 11 & 12 closed
IRQ12	Pins 13 & 14 closed	Pins 13 & 14 closed
IRQ15	Pins 15 & 16 closed	Pins 15 & 16 closed
Disabled	Open	Open
Note:The default interrupt setting for Port 1 is IRQ4, and for Port 2 it is IRQ3.

RS-422/RS-485 CONFIGURATION
Port	Setting	JP5
1	RTS controls output if RTS is Low	Pins 1 & 2 closed
1	Transmit output enabled	Pins 3 & 4 closed
1	DTR controls receive input if DTR is Low	Pins 5 & 6 closed
1	Receive input enabled	Pins 7 & 8 closed
2	RTS controls output if RTS is Low	Pins 9 & 10 closed
2	Transmit output enabled	Pins 11 & 12 closed
2	DTR controls receive input if DTR is Low	Pins 13 & 14 closed
2	Receive input enabled	Pins 15 & 16 closed

PRIMARY PORT SINGLE/MULTIPLE SOURCE INTERRUPT SELECT
Setting		JP1
»	Single source	Pins 2 & 3 closed
	Multiple source	Pins 1 & 2 closed
Note:Multiple source mode allows two or more ports to use the same IRQ setting, while Single source mode requires separate IRQ’s for each port.

SECONDARY PORT SINGLE/MULTIPLE SOURCE INTERRUPT SELECT
Setting		JP2
»	Single source	Pins 2 & 3 closed
	Multiple source	Pins 1 & 2 closed
Note:Multiple source mode allows two or more ports to use the same IRQ setting, while Single source mode requires separate IRQ’s for each port.

TERMINATING RESISTOR CONFIGURATION
Setting	JP6	JP7
Resistors enabled	Closed	Closed
Resistors disabled	Open	Open