I tried connecting an USB CD burner (there is Plextor written on it).
It was detected as an umass device - and nothing.
So I added some devices to umass as seen in other kerel config files
(wd, atapibus, scsibus).
Next time the kernel found an scsi cdrom on the umass device:

umass0 at uhub0 port 1 configuration 2 interface 0
umass0: Plextor Corp. USB Storage Adapter, rev 2.00/3.01, addr 2
umass0: using SCSI over Bulk-Only
scsibus0 at umass0: 2 targets, 1 lun per target
cd0 at scsibus0 target 0 lun 0: <PLEXTOR, CD-R   PX-S88T, 1.04> cdrom removable

So I tried to get some info. Cdrecord detected drive capabilities
and media type with -atip but I was unabe to get msinfo or burn an iso:

bash-2.05b# cdrecord -msinfo
cdrecord: Drive needs to reload the media to return to proper status.
Re-load disk and hit <CR>
cdrecord: Input/output error. read track info: scsi sendcmd: retryable error
CDB:  52 01 00 00 00 FF 00 00 1C 00
status: 0x0 (GOOD STATUS)
resid: 28
cmd finished after 0.018s timeout 240s
cdrecord: Cannot read first writable address

Kernel messages:
cd0(umass0:0:0:0):  Check Condition on CDB: 0x43 00 00 00 00 00 00 00 0c 40
    SENSE KEY:  Illegal Request
     ASC/ASCQ:  Illegal Field in CDB

cd0(umass0:0:0:0):  Check Condition on CDB: 0x28 00 00 00 00 00 00 00 01 00
    SENSE KEY:  Illegal Request
     ASC/ASCQ:  Logical Block Address Out of Range

cd0: dos partition I/O error
cd0(umass0:0:0:0):  Check Condition on CDB: 0x43 00 00 00 00 00 00 00 0c 40
    SENSE KEY:  Illegal Request
     ASC/ASCQ:  Illegal Field in CDB

# cdrecord -driveropts=burnfree -dao -data Mandrake92-updated-cd1.iso 
Cdrecord 2.00.3 (i386-unknown-netbsd1.6ZC) Copyright (C) 1995-2002 Jörg Schilling
scsidev: '0,0,0'
scsibus: 0 target: 0 lun: 0
Using libscg version 'schily-0.7'
cdrecord: Warning: using inofficial libscg transport code version (frueauf-scsi-bsd.c-1.41nb1 '@(#)scsi-bsd.c	1.41 02/10/19 Copyright 1997 J. Schilling').
Device type    : Removable CD-ROM
Version        : 0
Response Format: 1
Vendor_info    : 'PLEXTOR '
Identifikation : 'CD-R   PX-S88T  '
Revision       : '1.04'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
Driver flags   : MMC SWABAUDIO BURNFREE 
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
cdrecord: Drive needs to reload the media to return to proper status.
Re-load disk and hit <CR>
Starting to write CD/DVD at speed 8 in real SAO mode for single session.
Last chance to quit, starting real write    0 seconds. Operation starts.
Turning BURN-Free on
cdrecord: Input/output error. read track info: scsi sendcmd: retryable error
CDB:  52 01 00 00 00 FF 00 00 1C 00
status: 0x0 (GOOD STATUS)
resid: 28
cmd finished after 0.017s timeout 240s
cdrecord: WARNING: Drive returns wrong startsec (0) using -150
cdrecord: Input/output error. write_g1: scsi sendcmd: retryable error
CDB:  2A 00 FF FF FF 6A 00 00 1E 00
status: 0x0 (GOOD STATUS)
resid: 61440
cmd finished after 0.014s timeout 200s
write track pad data: error after 0 bytes
BFree: 1162 K BSize: 1162 K
cdrecord: Input/output error. write_g1: scsi sendcmd: retryable error
CDB:  2A 00 00 00 00 00 00 00 1E 00
status: 0x0 (GOOD STATUS)
resid: 61440
cmd finished after 0.017s timeout 200s
write track data: error after 0 bytes
Sense Bytes: 70 00 05 00 00 00 00 0A 00 00 00 00 27 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00


Rebuilding cdrecord did not help.
I can at least read CDs with the burner so it looks promising :)

-- 
Michal Suchanek
hramrach@centrum.cz