The following is an excerpt from
http://www.macintouch.com/panreader28.html
It says to me that the DVD-ROM was probably missing
Microsoft Joliet file extension, and was therefore UDF
1.50 or 2.01 only.
UDF means Universal Disk Format, which is ironic
seeing as its not that universal.
UDF CDs
Thomas Tempelmann
There seems to be a lot of confusion and
misinformation about UDF. Let me makes these things
clear:
1. Adaptec/Roxio sold a software called DirectCD
for Macintosh. I was the author of this software
(along with someone else who did the low level driver,
which is not relevant here, though), so I know quite
well about this.
2. While DCD is not maintained by Roxio any more,
there is still a free "driver" to read DirectCD
formatted disks, called "Adaptec UDF Volume Access".
This software only works with old Mac OS 8 and 9, not
with OS X, though. You can download it here: Update
Toast 4.0 Deluxe or later to version 4.1.2
3. Apple's own UDF support is limited to the
original UDF format (rev. 1.02), which does not
support DirectCD formatted disks. Later, UDF was
extended to version 1.50 and 2.0, both of which
support writing to CD-R and CD-RW in ways that
DirectCD, WriteUDF!, PacketCD and other packet writing
tools use.
4. When you "close" a CD-R using DirectCD on a PC,
another format, ISO 9660 with Joliet, is added to the
disk, and only then you can read such a CD on a plain
OS X system, because OS supports the Joliet format. If
the disk is not closed, you might be able to read such
a CD using a CD recorder and the UDF software from
Software Architects (
www.softarch.com), but I can not
promise that as I've not tried this software myself.
For more information look here, for which I also wrote
some parts myself: "Universal Disk Format"
Jeremy Reichman
I recently had a customer come by with problems
reading CDs that were burned with software on Windows
XP. The discs the customer was having problems with
were apparently multi-session, and may have been
packet written. I'm not sure if any of the problematic
CDs were "closed" or not. We didn't get a sample of
the offending CDs to try out. Roxio software may also
have been involved in writing the discs on the Windows
XP side, and if so, it was probably pre-installed by
the vendor for her PC (Gateway).
One CD that I witnessed first-hand had a single
partition that was readable in Mac OS X. However, the
customer said that there was more data that could not
be seen, and that data had been written under Windows
XP.
I know suspect that the disc was a packet-written UDF
CD. Based on some information from Microsoft, I don't
think the built-in software on Windows XP does packet
writing, but that could be wrong: "Transcript: Chat
About Burning CDs in Windows XP", "Universal Disk
Format"
It appears that Mac OS X does not fully support these
discs, or at least certain versions of UDF on CDs. It
may be more liberal in support for UDF on DVD. (I'd be
happy if someone with more expert knowledge jumps in.)
For example: "Mac OS X 10.2, 10.3: Sony Mavica CDs
Don't Appear on Desktop"
Dale Hartlieb
In response to Kimo B. Yap, Markus Hänchen, and Mark
Bolick: The long since discontinued Mac software that
burned packet written UDF discs under OS 9 was the
Adaptec DirectCD control panel. Unfinished UDF discs
could be read in the CD burner and finished UDF discs
could be read in any OS 9 CD-ROM drive with Adaptec
UDF Volume Access extension installed. This was very
useful with another source of packet written UDF
discs; the mini CD digital still cameras (like Sony’s
MVC-CD1000, etc.). Along comes OS X. No support for
reading unfinished OR finished UDF discs either in a
burner or plain CD-ROM drive. This forces MVC-CD1000
users to cable the camera to the USB port and use
Virtual PC with the Windows-only software that comes
with the camera to read the disc while it’s still in
the camera. So, there are consumer appliance sources
of packet written UDF discs that OS X can’t read where
OS 9 could.
Harold Payson
Here is an interesting test / work around for those
who have UDF CDs that they can't read: Try reading
them from Virtual PC.
I regularly receive CDs from coworkers written in UDF
format and all that Mac OS X sees is the CD and
folders, but no files. Very frustrating. However I
found that Virtual PC (with Windows 2000 at least) can
read them without a problem and then all I need to do
is drag them back into Mac OS X.
It would really be nice if MacOSX could read them as
well. A side note to this is that these CDs hang 'Disk
Utility' most (all?) of the time.
I hope this can prove useful.
