in theory its possible.
the Xbox hdd and probably also the Dvd discs has fatx filesystem.
However, the dvd / cd-rom drives read the normal formats.. something with blue and red or something.. there are color markings on cd`s dvd`s.
I forget how these things are called... but yes it is possible when your cd-rom drive has support for this disc format.
However, you can insert a normal dvd drive into a xbox, put the molux connecter to a normal pc power supply and connect the Ida cable from the xbox mainboard to the normal cd player.
This way you can read discs...
for more information... about the xbox fileformat you need to take a look at the fatx filesystem.
Differences between Xbox FATX and MS-DOS FAT - Xbox-Linux
However, to read the discs, you need .... what i think, a fatx driver or something.. and how manny people are trying this.. i have not seen a working copy.