Kieren Searle

When running Minicom for the first time you’re likely to be greeted with the following error message:

minicom: cannot open /dev/modem: No such file or directory

This is because Minicom is looking for your serial port in /dev/modem and in newer versions of Linux it’s located in /dev/ttyS0 or /dev/ttyS0. In the following example I will use /dev/ttyS0.

There are two ways to fix this problem. You can either create a shortcut of /dev/modem to point at /dev/ttyS0 or edit Minicom’s settings to use /dev/ttyS0.

To use the shortcut method use the following command:

ln -s /dev/ttyS0 /dev/modem

To edit Minicom’s settings start Minicom with the command:

minicom -s

This will open Minicom with the configuration menu. Use your direction key to scroll down to Serial port setup and press enter. Now press a to edit the Serial Device. Change this to be /dev/ttyS0. Press enter once you have finished editing. Now press escape to go back to the main menu. Finally select Save setup as dfl to make sure that the serial port is correct every time you run Minicom. You can now select Exit to start using Minicom or Exit from Minicom to close Minicom. In the future you can run Minicom without the -s flag