From: blob@Apple.COM (Brian Bechtel)
Newsgroups: alt.cd-rom
Subject: Re: Version Number in ISO Formatted CDROM (sorry, long)
Date: 28 Sep 92 15:25:54 GMT
Organization: Apple Computer Inc., Cupertino, CA

Chuck Wegrzyn (wegrzyn@nic.cerf.net) wrote:

> I have this question that I need to ask, and am hoping that someone out
> there has the answer.  I was told by NEC that a disk I had didn't conform
> to the ISO standard since it didn't have a "version number" on the disk.
> The same disk was able to be read by a "cheapo" CD reader.  Can some one
> tell me what the "version number" is -- I have an idea -- and is it
> necessary to have one.  This sounds bogus to me.

First of all, there are several "version numbers" on the disk.  If the
NEC driver is dumb enough, it will be looking for the volume descriptor
version in the primary volume descriptor.  I've seen a lot of ISO9660
format CDs that don't strictly conform to the ISO9660 standard because
the volume descriptor version is not 1 (typically zero.)  And I've even
seen drivers that reject ISO 9660 volumes due to this reason.

VanOver@atc.boeing.com writes:
>warnock.717264460@Hypatia> warnock@Hypatia.gsfc.nasa.gov (Archie Warnock) writes:
>>rjn@FC.HP.COM (Bob Niland) writes:
>>>There is disagreement over whether the file version is optional.  Even if
>>>present, some systems don't report it (or only report the same-named file
>>>with the largest fv).  HP routinely makes CD-ROMs WITHOUT fv's, but they
>>>aren't generally intended for use on non-HP systems.
>>
>>Yet another hole in the standard...
>>
>The hole in the standard is that the last section of it, "Requirements
>for systems" describes a very incomplete implementation.

>I've got the standard in front of me and in Section 3 (Requirements for
>systems) Part 12, Requirements for an originating system, it says "The
>implementation shall allow the data preparer to supply the information
>that is to be recorded in each of the descriptor fields listed below,
>and shall supply the information for a field if the data preparer does
>not supply it"  The list DOES include "File Version Number of a File
>Identifier."

>However, the following section, Part 13, Requirements for a receiving
>system, it says "The implementation shall make available to the user the
>information that is recorded in each of the descriptor fields listed
>below"  and the list that follows DOES NOT include "File Version
>number."

When I was writing the ISO 9660 file system translator for the Mac, I
followed Part 12 instead of Part 13 when deciding to pass version
numbers to the MacOS.  In retrospect, I think that was a mistake,
primarily because MS-DOS's MSCDEX doesn't handle version numbers.  This
makes Mac <-> DOS file name translation messy.


warnock@hypatia.gsfc.nasa.gov writes:
>In article <83644@bcsaic.boeing.com>, vanover@bcsaic.boeing.com (Jann VanOver) writes:
>|> Does anyone know WHY Section 3 (Requirements for systems) is so
>|> inadequate?

>I don't know why, but it _does_ point up the need to refer to practical
>experience within the industry, rather than just relying on what the
>standard document says.  

Amen to that.

>When our systems guy called HP to ask about the file versions, the
>person he talked to (who I believe wrote part/all of the CD-ROM driver)
>basically told him "The standard says I can do that".  

Be nice to him.  Reading the ISO 9660 spec warps your mind...

>Bottom line?  It ain't nearly as portable as we're led to believe...

Yep.  Sort of a VMS file system with minimum extensions to get other
operating systems to accept it...

bwilliam@iat.holonet.net (Bill Williams) writes:

>the version suffix when mastered on the disk *IS OPTIONAL* according to
>Apple's second edition of the CD ROM SC CD Developers handbook.

Could you cite a page?  I'm unable to find that reference.  I know of
people who have not put version numbers on an otherwise compliant
ISO 9660 CD, but it isn't optional according to section 12.3.1 of ISO
9660.

--Brian Bechtel     blob@apple.com     "My opinion, not Apple's"
Newsgroups: alt.cd-rom