OS3.1 comes with a CD filesystem. It's awful, but it's good enough for you to get a better CD filesystem onto your hard drive.
Look in SYS:Storage/DOSDrivers. Copy CD0 to Devs:DOSDrivers and modify the tooltypes to suit your setup.
(Personally, I think the phase 5 SCSI tools are awful and should never be used, but see what you think first.)
