number of posts on category archives pages

Can anyone tell me how to modify the code below so I can display multiple posts on category pages? There doesn’t seem to be anyway to change this in the theme options.
elseif(is_category() && get_option('cb2_blog_inner_count')) $numberposts = get_option('cb2_blog_inner_count') ? get_option('cb2_blog_inner_count') : $numberposts;