This is helpful if you have 4 CD .isos (like an operating system distribution of CD 1 of 4, 2 of 4, 3 of 4, and 4 of 4 and you want just one .iso file on a single DVD disc for convenience purposes.

Put all .iso files into 1 temporary directory by using:

dd if=/dev/cdrom of=filename.iso

check creation is okay with sum -r /dev/cdrom and sum -r <filename.iso> copy make.dvdiso.sh into that directory, and call like this: ./make.dvdiso /dir/path filename.iso that creates the file, now burn with roxio!