Thanks to Lennart and Ben for their quick responses...

> Well, I think 0x08 is a READ operation.  You device probably doesn't li=
ke
> the short version of the commands.  Try the quirk PQUIRK_ONLYBIG.

That certainly helped.  Now I can mount a CD and read it without any prob=
lem!

But if I use cdrecord (1.10 compiled from pkgsrc) to try to write a CD I
get the following:

| # cdrecord speed=3D4 dev=3D/dev/rcd1d xxx.cd =

| Cdrecord 1.10 (i386-unknown-netbsd1.5W) Copyright (C) 1995-2001 J=F6rg =
Schilling
| scsidev: '/dev/rcd1d'
| devname: '/dev/rcd1d'
| scsibus: -2 target: -2 lun: -2
| Using libscg version 'schily-0.5'
| cdrecord: Warning: using inofficial libscg transport code version
| (frueauf-scsi-bsd.c-1.40nb1 '@(#)scsi-bsd.c   1.40 01/03/18 Copyright 1=
997
| J. Schilling').
| cdrecord: Warning: controller creates hard SCSI failure when retrieving=
 CD
| capabilities page.
| Device type    : Removable CD-ROM
| Version        : 0
| Response Format: 1
| Vendor_info    : 'IOMEGA  '
| Identifikation : 'ZIPCD 650 USB   '
| Revision       : 'I1.1'
| Device seems to be: Generic mmc CD-RW.
| Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
| Driver flags   : SWABAUDIO
| cdrecord: Drive needs to reload the media to return to proper status.
| Starting to write CD/DVD at speed 4 in write mode for single session.
| Last chance to quit, starting real write in 0 seconds. Operation starts=
=2E
| cdrecord: Input/output error. read track info: scsi sendcmd: fatal erro=
r
| CDB:  52 01 00 00 00 FF 00 00 1C 00
| resid: 28
| cmd finished after 0.016s timeout 240s
| #

I also noticed some syslogged error messages repeated a few times, but I =
don't
know the timing of those compared to the above:

| umass0: Phase Error, residue =3D 0
| cd1(umass0:0:1:0): unknown error category 8 from adapter

I'd appreciate any suggestions on what I could try next...

Thanks,

Duncan