I hope Topanga shows the links to the hacks/methods required to do this in "pre 1.6" versions, but the short answer is that you can't stop stuff from showing up in blog #1. Oh wait: any post that is posted as 'protected' will not show up in blog 1 unless a registered blogger who is a member of the specific blog happens to be visiting. That's an exception to the "blog 1 shows all" rule, but it's notable if you're using another blog for content intended for a limited audience.

But I want Blog 4 to be shown when I open it's url

Such is life eh? If all goes well Topanga will link to posts that show you how to hide stuff from blog 1 in versions prior to 1.6 OR show you how to do it in 1.6. Straight out of the box, ALL published posts in ALL blogs show up in blog #1. That is the nature of blog #1 - it aggregates all posts from all blogs.

Resolved!

in index.php, before
require( dirname(__FILE__).'/'.$core_subdir.'_blog_main.inc.php' );
I added:

global $force_blogs;
$force_blogs = array(2,3);

then in my _main.php file of my skin after:

while( $Item = $MainList->get_item())
{

I added

if (!in_array($Item->blog_ID,$force_blogs) && $blog == 1) continue;

where Blog #1 is the "global" blog showing posts for all blogs.
In this way it only shows posts from blogs #2 and #3 in the "global" Blog #1

:P

Lorenzo

Nice that you found the answer yourself!

Because 'my' solution was only to not show particular categories..

@EdB : I have no experience with 1.6 since I only have 1 site in 1.6 and it is not doing what I want ;)
I'm patience enough (yeah realy) to wait for the official next release ;)

FIX ALREADY!
:)

better change
if (!in_array($Item->blog_ID,$force_blogs) && $blog == 1) continue;
in
if (isset($blog) && isset($force_blogs))
if (!in_array($Item->blog_ID,$force_blogs) && ($blog == 1)) continue;

I'm using alfa version because I'm still working on my site... and it will take a some time before I finish working at it.