magneto-optical devices, it's scope can (and should) be widened to
cover all removable type 0 (direct) devices as well, since this class
of devices is sharing the same principles. Things like suport for
media eject etc. will be supported later. (Shunsuke is also working
on the problems arising out of the use of media with physical block
size != 512 bytes (which is not uncommon for MODs).
Submitted by: akiyama@kme.mei.co.jp (Shunsuke Akiyama)