(currently only CD-ROM drives on i386). The sys/dev/scsipi system provides 2
busses to which devices can attach (scsibus and atapibus). This needed to
change some include files and structure names in the low level scsi drivers.
influence from the old driver (written by Stefan Grefen) and from
an autochanger driver written by the Systems Programming Group at the
University of Utah Computer Science Department (currently residing
in src/sys/arch/hp300/dev/ac.c).