ICS Advent DUAL232/AT Series, Product Manual

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Manual Number: 00750-010-3 Page 5
Chapter 3: Option Selection
The board contains several jumper straps for each port which must be set for proper operation.
E1, E2: These headers select the interrupt request for each serial port. If COM1: is selected, this
jumper must be on the IRQ4 setting. If COM2: is selected, this jumper must be on IRQ3. E1 sets
the IRQ for Port 1 and E2 sets the IRQ for Port 2. Any two or more ports can share a common IRQ
by placing the jumpers on the same IRQ setting, and setting the appropriate selections at E3. Con-
sult your particular software for IRQ selection. If no interrupt is desired, remove the jumper.
Note : Most communications software applications default COM3: to IRQ4 and COM4: to IRQ3.
This requires the sharing of interrupts between COM1: and COM3:, and between COM2: and
COM4:. While this is the default, it is not always the preferred setting. Windows 3.1, OS/2 and
UNIX applications typically require a separate IRQ setting for each address. Check your software
configuration instructions to determine the most appropriate .
Figure 3-1: Header E1 & E2 (Factory Default)