This is a little bit advanced, but useful.
1. Insert the DVD/CD into your drive.
2. Run the TERMINAL application (In your Appplications Utilities Folder)
You will get a little window with a prompt something this: Macintosh:~ wayne$
3.Type the following and then hit return:
It will give you some info like this:
Vendor Product Rev
SONY DVD RW DW-U21A AADB
Type: DVD-R Name: /dev/disk2
Cur Write: 4x DVD Sessions: 1
Max Write: 4x DVD Tracks: 1
This is information about your DVD/CD drive and the important thing to notice is the name, it will be /dev/disk1 or /dev/disk2
4. If it is disk1 type this: (If the name is different (eg disk2) then just replace all the disk1 references with disk2.)
diskutil unmountDisk /dev/disk1
This will make the DVD icon disappear from the desktop.
5. Type the following:
dd if=/dev/disk1 of=~/Desktop/file.iso bs=2048
6. Wait about 10 or 20 minutes while it now makes an image of the CD/DVD onto your desktop.
When it’s finished it will give a message like this:
2170784+0 records in
2170784+0 records out
4445765632 bytes transferred in 1335.111379 secs (3329884 bytes/sec)
7. Type this to make the DVD reappear on the desktop and you are done:
diskutil mountDisk /dev/disk1