Yes, you need a CD0 file along with CD0.info.
Here is the contents of the original CD0 file from WB 3.1:
/* $VER: CD0 40.6 (31.8.93)
*
* CD-ROM file system entry
*
* This file enables the CD-ROM file system which allows you to read standard
* ISO-9660 CD-ROM disks from an Amiga with a SCSI or IDE controller.
*
* The "Unit" line defines the SCSI address of the CD-ROM drive. Drives
* often come configured as unit 2, which is the default. Check the
* documentation for your CD-ROM drive to find the exact SCSI address.
* Note that most drives let you change this number using jumpers.
*/
FileSystem = L:CDFileSystem
Flags = 0
Surfaces = 1
SectorsPerTrack = 1
SectorSize = 2048
Mask = 0x7ffffffe
MaxTransfer = 0x100000
Reserved = 0
Interleave = 0
LowCyl = 0
HighCyl = 0
Buffers = 5
BufMemType = 0
StackSize = 1000
Priority = 10
GlobVec = -1
DosType = 0x43443031
/* The Device and Unit fields are controlled by tooltypes in the CD0 icon.
*
* Device = scsi.device
* Unit = 2
*/
(you can leave out the comments which start with /* and end with */. You can also leave out repeated space characters and empty lines.)
Make sure that CDFileSystem is present in the L directory.
