Why can't I connect to a parallel port target interface?
Failure to connect to parallel port target interfaces may be caused by the
following problems:
- The user does not have read permission for the parallel port device driver
(e.g. /dev/parport0). Linux typically does not grant all users access to the
parallel port device drivers by default. To permit a user to access to the
parallel port device drivers the user can either be added to the lp
group, or alternatively the read permissions of the parallel port device
driver can be changed to allow all users to have read access to it. Either
of these actions require super user level permissions.
- Another application or device driver already has exclusive control of the
parallel port device driver.
Why can't I connect the terminal emulator window to the serial port?
Failure to connect the terminal emulator window may be caused by the
following problems:
- You do not have permission to use the serial port device driver (e.g.
/dev/ttyS0). To permit a user to access the serial port either add the user
to the uucp group, or change the permissions of the serial port
device driver to enable all users to have access to it. Either of these
actions require super user level permissions.
- Another application already has the serial port open.