I just tried to get cups working and had the following problem:
I have a Lexmark Optra E+ parallel port printer and usually cups shows the parallel port as Device: on the second configuration screen. Only this time cups did not recognize the parallel port. lptest > /dev/lpt0 worked fine, just cups could not see the parallel port.
After about half an hour I finally found the solution:
# ls -l /dev/lpt0
crw——- 1 root wheel 0, 57 Mar 4 20:00 /dev/lpt0
The rights on /dev/lpt0 were not set correctly. After changing them, everything worked fine:
# chmod 666 /dev/lpt0
# ls -l /dev/lpt0
crw-rw-rw- 1 root wheel 0, 57 Mar 4 20:00 /dev/lpt0