Re: Sparsed Mean 18 courses

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

In article <CB3r7u.86@freenet.carleton.ca> aa382@Freenet.carleton.ca (Marc Sira) writes:
> 
> Same here...also, I think P8 handles (and creates) sparse files anyway (so
> copying with an 8-bit program wouldn't buy you anything). Correct me if I'm
> mistaken, of course.

ProDOS-8 will correctly read sparse files, but it won't automatically
create them.  To set up a sparse file, you must do a SET_EOF call to
enlarge the file, then use SET_MARK to skip past the blocks which will
contain zeros.  If you then continue writing normally, the blocks you
skipped will not be allocated, resulting in a sparse file.

The GS/OS ProDOS FST does this for you automatically - it will "sparse
out" any block which would be written as all zeros.

> If you were really worried about sparsing, I imagine you could use an HFS
> partition...I believe HFS doesn't support sparse files.

Correct.  In fact, if you use the trick described above, you end up
with garbage in the skipped blocks.
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand