ive been looking for scsi cdroms to use in my quadra, found a few on ebay but some weren't apple branded. has anyone tried using these on such an old machine? this one in particular has my attention: http://www.ebay.com/itm/PIONEER-DR-506S-INTERNAL-32x-SCSI-CD-ROM-READER-/181574758501?pt=US_CD_DVD_Blu_Ray_Drives&hash=item2a46b2f065 i have an ide version of that drive in my g3 and it works pretty good.
It's like using hard disk drives that are not Apple-branded: works fine, as long as you use a third-party driver. The CD extension that comes with MacOS won't accept non-branded drives and needs to be replaced. That's it. You can also hack the Apple CD extension to accept every drive. See here.
that is awesome thanks!