--- On Tue, 5/24/11, Austin Leeds <[email protected]> wrote:

> Bingo, finally found the issue! It
> was my version of StuffIt for
> windows messing stuff up. I'm going to try StuffIt 7, which
> preserved
> Mac-specific info in applications during stuffing and
> expanding operations.

If you un-stuff most Mac files on any non-Mac system, you'll break the file so 
it won't work on a Mac.

The reason is because Apple chose to use a two-fork file system where every 
file has a Resource Fork and a Data Fork.

To make it even weirder, a file *may* have one or the other fork with nothing 
at all in it, or for a particular file type the contents of one fork or the 
other may be non-critical if it's lost.

One example, Stuffit archives. The only thing their Resource Fork is used for 
is the Stuffit icon and the Type and Creator codes. Later versions of Stuffit 
programs can recognize Stuffit archives by the .sit file name extension and 
will create a Resource Fork for them when you doubleclick the archive. In older 
Stuffit versions the archives could be opened/extracted using the menu commands.

Many image, video and audio files can be opened on a Mac without a Resource 
Fork, but in general - formats that originated on a Mac have data in their 
Resource Forks that is critical. Quicktime videos are an odd case. They can be 
"flattened" where the Resource Fork is combined with the Data Fork. Then the 
video may be played on any other system with a Quicktime player app. The oddity 
is if you find and copy the Resource fork, give it the extension .qtr and place 
it in the same folder (on a PC) as the .mov Data Fork, Quicktime for Windows 
will play the video.

I know of no other dual fork Mac file that trick will work on. Any MOV file 
that plays on a non-Mac system and has only the .mov file has been flattened.

A special use of Apple Double is (or was) on server versions of Windows with 
Services For Macintosh installed. Macs could store dual fork files on the 
Windows Server without having them break. SFM also included a Forkize command 
to "reattach" the forks of a file. Search Windows help for Macintosh for 
information on how to utilize that if you have access to a Windows server with 
SFM installed. (The info is there in XP's help, I haven't looked for it in 
Vista or 7.)

If you want even more information on Apple's fondness for creating file systems 
incompatible with the rest of the computing world, look up AppleDouble and 
AppleSingle.

Aside from Stuffit archives and the few other formats/types that can survive 
losing their Resource Forks, you have to keep pre-OS X Mac files 'wrapped up' 
in Stuffit, MacBinary or BinHex when they're on a non-Mac system.

Apple *was* doing away with the dual fork system in OS X but it's been revived 
in 10.6 where the Data Forks of many system files have been compressed into the 
files' Resource Forks. Neat trick, gives the illusion that 10.6 is "smaller" 
than previous releases even though it's not.

It's also way late to the on-the-fly decompression game. Microsoft had that at 
least as far back as Windows NT4 - and almost nobody used it because it was 
totally pointless. If your system was that low on space it was far better to 
get more storage space. Windows still has it and still hardly anyone uses it. 
Apple forces it to be used, it's on by default and there's no way to turn it 
off - or at least nobody has bothered to dig in and figure out how to disable 
the "Wheee! Look what I can do!" pointless bit of frippery. :P

-- 
-----
You received this message because you are a member of the Vintage Macs group.
The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our 
netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml
To post to this group, send email to [email protected]
To leave this group, send email to [email protected]
For more options, visit this group at 
http://groups.google.com/group/vintage-macs

Support for older Macs: http://lowendmac.com/services/

Reply via email to