A Toast Question: MacOS & PC Hybrid CD format

[AHunter3]

Toast in the old "yellow screen" Adaptec days did not offer the format called "MacOS & PC Hybrid" (or its variant "MacOS Extended and PC Hybrid" either). That format is now offered under the newer "aqua screen / Titanium" Roxio version of Toast. That's the format I'm asking about.

The "Mac/PC Hybrid" format under the yellow-screen Adaptec-era Toast was a different thing. You used that when you wanted one set of files available to PC users and a different set (essentially a different CD) available to Mac users -- for example, platform-specific installers for your homegrown application. Under the new Roxio "aqua screen/Titanium" Toast, this option is available as "Custom Hybrid".

Meanwhile, if you wanted to create a CD with identical content available to both Mac users and PC users back in the yellow-screen Adaptec Toast days, you burned an ISO-9660 CD with Joliet extensions and told your MacOS 9 (or earlier) users to be sure and install the free Joliet system extension extension (http://www.tempel.org/joliet/) to enable the Mac to show long file names instead of DOS-shortened ISO names.

So now there is this convenient new format, "MacOS & PC Hybrid". It seems to work transparently on both platforms without having to burn your information twice. How does it work? What is it DOING behind the scenes? Is the same data referenced with two different catalogue systems, one (Desktop BF/Desktop DF for Mac HFS/HFS+) telling the Macintosh what files are present and one (FAT or whatever the heck ISO9660 + Joliet uses to catalogue disk contents and their location) for PCs? Can you make these suckers bootable on both platforms? (PS-How do you make a bootable Windows CD anyhow?)

The Roxio/aqua/Titanium version of Toast is a lot more dumbed down on the end-user level and isn't very informative about what is actually being done.



Just curious.

[Balthisar]

Originally posted by AHunter3
The "Mac/PC Hybrid" format under the yellow-screen Adaptec-era Toast was a different thing. You used that when you wanted one set of files available to PC users and a different set (essentially a different CD) available to Mac users -- for example, platform-specific installers for your homegrown application. Under the new Roxio "aqua screen/Titanium" Toast, this option is available as "Custom Hybrid".

I suspect it's doing the "custom hybrid" behind the scenes. Doing the Mac/PC hybrid didn't limit you to only different sets for Mac/PC formats, but allowed sharing across formats. For example, I'd use this format to burn MP3 CD's in Windows format for compatibility with my DVD player (only recognized 8.3 names), but do the custom hybrid so that the same disk in my Mac's would show the whole MP3 file name. It was the same data; different file directories pointed to the same data is all. The idea was you put all your data on the PC side, and then craft the Mac directory to point to the desired PC data. For example, if you don't want the Windows installer to show up on the Mac, you didn't create a directory entry for it. If you wanted a Mac installer, you could put that on the "Mac side" and it'd be invisible to Windows. This was a royal pain in the arse to do, since you had to create a Mac disk image of aliases and figure out how to burn the disk properly every time. The current hybrid is great for simple multi-platform disks, as it's effortless. I suspect, though, that the advanced functionality still exists, though.

[Some Guy]

It is probably doing the same thing as mkisofs under the hood (manpage (http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/man/mkisofs-2.0.html)).

If you don't want to read the whole thing, here's the important part::



If Joliet or HFS hybrid command line options are specified, mkisofs will create additional filesystem meta data for Joliet or HFS. The file content in this case refers to the same data blocks on the media. It will generate a pure ISO9660 filesystem unless the Joliet or HFS hybrid command line options are given.

mkisofs can generate a true (or shared) HFS hybrid filesystem. The same files are seen as HFS files whenaccessed from a Macintosh and as ISO9660 files when accessed from other machines. HFS stands for Hierarchical File System and is the native file system used on Macintosh computers.

As an alternative, mkisofs can generate the Apple Extensions to ISO9660 for each file. These extensions provideeach file with CREATOR, TYPE and certain Finder Flags when accessed from a Macintosh.

[AHunter3]

That sounds likely, thanks.

So it most likely is an ISO variant, as I suspected.

Balthisar, how did you do that?. A Custom Hybrid requires that for the ISO portion you select (or drag) a folder or various individual files, while for the Mac portion you drag a volume onto the Toast screen (most commonly one you make with Disk Copy). I suppose it would be possible to drag Folders A, B, and C from mounted volume V onto Toast to have them sent to the ISO partition, then drag Volume V itself onto toast and thereby have the same Folders A, B, and C end up in the Mac partition, but I figured Toast would still burn two copies of the identical files when you burn the CD. I'll have to experiment.

[AHunter3]

Balthisar is right. I hadn't noticed that. That is an improvement over the way Toast 4 did it!