Here's how to do it. Reboot your notebook and go into BIOS setup. We want to configure this as the second serial port. Disable any serial ports that have the same IRQ and port settings to prevent hardware conflicts. Restart your computer and check dmesg to see that Linux detected your serial ports.
Most notebooks have dual serial-port capability, though there is usually just one serial connector.
The second is usually assigned by default to the Infrared port. Minicom is easiest and most Linux distributions load it as default. 8n1 with no error correction. Save the setting as dfl, aim the infrared ports of the two notebooks at each other and select Exit. At this point you should be in Minicom staring at a blank screen.