Re: How do I deal with forked files on an Apple IIc?

[dempson@actrix.gen.nz (David Empson)]

SlideRB <sliderb@hotmail.com.nospam> wrote:

> I've been downloading software on my Mac for my IIc.  I initally tried
> to get the files to my IIc by using File Exchange in MacOS 8.6 to copy
> them to a ProDOS disk.  However, any file copyied from the Mac ends up
> being preceived on the IIc as a forked file.

Actually an "extended file".  An extended file has a different storage
type in the directory and an extra "extended key block" which contains
additional information which cannot be stored in the ProDOS directory.

One of the features offerred by extended files is that they can contain
two forks - the extended key block points to two normally structured
files for the data and resource forks.  Either of these forks may be
missing, but the file cannot be handled by ProDOS-8 simply because it
has the extended key block.

The other feature of the extended key block is that it allows the
Macintosh directory information to be retained when a file is copied to
a ProDOS volume.  This includes the Macintosh file type and creator
codes, and some miscellaneous information maintained by the Finder on
the Mac, such as the icon position.

> I've tried a couple different utilities on the Mac end for stripping the
> resource fork, such as ForkZapper and ProType.  Even when using those
> utilities, I still ended up with forked files that the IIc cannot work
> with.

I haven't used ProType, but I would have expected it to work.  I've
never heard of ForkZapper.

Did you use these utilities _before_ copying the file to the ProDOS
volume?  They wouldn't achieve anything if you used them on a file which
was already on a ProDOS volume, since it would already be in the
extended storage format by then.

PC Exchange uses a simple rule for copying a file to a ProDOS volume:

- If the file has a creator of 'pdos' and a recognised ProDOS-compatible
file type (the old two digit hex number format, or the 'pXYZ' format,
with binary encoded ProDOS file type and creator) or the file type is
'TEXT' with any creator code, _and_ the has no resource fork, then it is
copied to the ProDOS volume as a standard file.  The ProDOS directory
entry will be set up with the appropriate file type and auxiliary type.

- In nearly all other cases, the file is copied to the ProDOS volume as
an extended file.  The ProDOS file/aux type will be set up if recognised
(as above), or both set to zero if there is no known mapping.

> I read that setting the file type and creater to TEXT/pdos would do the
> trick, but it didn't work for me.

That also should have worked, provided the original file has a zero
length resource fork on the Mac, and you changed the file type before
copying the file to a ProDOS volume.

I'm pretty sure I've used this method recently, and it behaved as
expected.  As long as it was within the last year or so, I would have
been running Mac OS 8.6 at the time.  If it was earlier, then it would
have been Mac OS 7.6.1.  In any case, I doubt that Apple would have
changed this behaviour.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand