debian:/home/chris# jack
This is jack 3.1.1 (C)2004 Arne Zellentin <zarne@users.sf.net>
 *warning* You have no standard location set, putting files into the current
           directory. Please consider setting base_dir in ~/.jack3rc.
 *error* Access of CD device /dev/cdrom resulted in error: Input/output error
debian:/home/chris#