From: Terry Lambert <terry@lambert.org>
Message-Id: <199602242000.NAA27912@phaeton.artisoft.com>
Subject: Re: Multisession CD-R
To: julian@ref.tfs.com (JULIAN Elischer)
Date: Sat, 24 Feb 1996 13:00:23 -0700 (MST)
Cc: terry@lambert.org, joerg_wunsch@uriah.heep.sax.de, jerry@border.com,
        freebsd-hackers@FreeBSD.ORG, netbsd-help@NetBSD.ORG,
        bsdi-users@bsdi.com
In-Reply-To: <199602241942.LAA09471@ref.tfs.com> from "JULIAN Elischer" at Feb 24, 96 11:42:49 am
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> > One of the Japanese engineers on the list posted about getting this
> > to work about a year ago.
> > 
> > If I remember correctly, he also read audio format CD's as data, so
> > you could eliminate the DAAD conversion.
> > 
> > The full multisession spec, including their Unicode extensions, is
> > available on the Microsoft Windows95 DDK CD.  From what I remember,
> > multiple sessions are *required* for Unicode encoding.
> 
> Better of course to NOT use a uSoft version
> because they keep extending hte specs this way or that
> without always making it obvious that it's an extension.

In this case it was clearly labelled.  The file DDK\DOCS\JOLIET.DOC
is labelled:

===========================================================================
Extending ISO 9660 to Handle UNICODE
Rick DeWitt
Allrosoft Corporationon
===========================================================================

Table of contents include:

===========================================================================
3. Terminology and Notation
3.1 Decimal and Hexadecimal Notation
4. Joliet Recording Specification
4.2 Identifying an ISO 9660 SVD as Unicode (UCS-2)
4.2.1 SVD Escape Sequences Field
4.2.2 SVD Volume Flags Field
4.3 Resolution of ISO 9660 Ambiguities for Wide Characters
4.3.1 Wide Character Byte Ordering
4.3.2 Allowed Character Set
4.3.3 Special Directory Identifiers
4.3.4 Separator Characters
4.3.6 Relaxation of ISO 9660 Restrictions on UCS-2 Volumes
4.4 Extensions to Joliet
4.4.1 Joliet for Multisession Media
4.4.2 CD-XA Extensions to Joliet
4.4.3 Other Extensions to Joliet
===========================================================================

A small excerpt:
===========================================================================
The Joliet specification utilizes the supplementary volume descriptor
(SVD) feature of ISO 9660 to specify a set of files recorded within
the Unicode character set.

The ISO 10646 character set specification may be identified by an
ISO 2022 escape sequence.  By recording this escape sequence in an
ISO 9660 SVD, this technique for identifying the Unicode SVD is
compliant with the ISO 9660 specification.  It also retains
interchange by not disrupting the files referenced through the
primary volume descriptor (PVD).

All that remains is to resolve minor technical ambiguities within
ISO 9660 which arise as the result of the use of wide characters.
===========================================================================

I think at least their CDROM guys know what they are doing....


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.