Ampro Corporation 486E Serial Port, Parallel Port, Port Address, Selection Address Interrupt

Product Reference

Serial Port

Use SETUP to independently enable or disable either of the two onboard serial ports. When SETUP is used to enable or disable a port, the change does not take effect until the system is rebooted.

The I/O addresses and interrupt assignments (IRQs) for the serial ports cannot be changed. Table 2–54 lists the I/O addresses and IRQs of each port. These resources are freed for use by other peripherals installed on the PC/104 bus when their respective ports are disabled.

Table 2–54. Serial Port Resources

Port

Address

Serial 1	3F8h – 3FFh
Serial 2	2F8h – 2FFh
Serial 3	3E8h – 3EFh
Serial 4	2E8h – 2EFh

The BIOS normally logs Serial 1 and Serial 2 as COM1 and COM2. COM1 and COM2 are logical designations, not physical values. When the system boots, the BIOS scans the standard serial port addresses and installs the first port it finds as COM1. If it finds a second port, it installs that one as COM2, and so on. If you disable a serial port, the designations of all higher-numbered COM ports changes. See the Serial Port section of this Chapter for more information.

Parallel Port

The Little Board/486e parallel port SETUP allows it to be enabled as the primary or secondary port. The I/O ports and interrupt request channels are freed for use by other peripherals installed on the PC/104 bus when the parallel port is disabled. Table 2–55 summarizes the resources that can be used for the parallel port.

Table 2–55. Parallel Port Resources

Selection

I/O Address

Interrupt

Primary	0378h - 037Fh	IRQ7
Secondary	0278h - 027Fh	IRQ5
Disable	None	None

The BIOS normally logs the primary and secondary parallel ports as LPT1 and LPT2. LPT1 and LPT2 are logical designations, not physical values. When the system boots, the BIOS scans the standard parallel port addresses and installs the first port it finds as LPT1. If it finds a second port, it installs that one as LPT2, and so on. If a parallel port is disabled, the designation of all higher-numbered LPT ports change.

For further information about utilizing the parallel port, see the section on the bi-directional Parallel Port.

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