I modified  scsiconf.c and cd.c a little and now the changer works
for me.
Here's the changes:

in cd.c:

was
#if  0
        {T_CDROM, T_REMOV, /* more luns */ 
         "PIONEER ", "CD-ROM DRM-600  ", ""}, 
#endif
to
/* CWW */
#if  1
        {T_CDROM, T_REMOV, /* more luns */ 
         "NRC     ", "CD-ROM MBR-7    ", ""}, 
        {T_CDROM, T_REMOV, /* more luns */ 
         "PIONEER ", "CD-ROM DRM-600  ", ""}, 
#endif

and over in scsiconf.c  I added the middle entry below:

        {T_CDROM, T_REMOV,
         "NEC     ", "CD-ROM DRIVE:841", "",     SDEV_NOLUNS},
         {T_CDROM, T_REMOV,
         "NRC     ", "CDROM  MBR-7    ", "",     SDEV_FORCELUNS},
         {T_CDROM, T_REMOV,
         "SONY    ", "CD-ROM CDU-541  ", "",     SDEV_NOLUNS},
These are for the -current sources.

-- 
Clarence Wilkerson      \ HomePage:     http://www.math.purdue.edu/~wilker 
Prof. of Math. (topology)\ Internet:    wilker@math.purdue.edu
Dept. of Mathematics      \ Messages:   (317) 494-1903, FAX 494-0548
Purdue University,         \ Office:    (317) 494-1955 (voice)
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