Recent post call (exclude category)

Hi I’m using

<?php get_archives('postbypost', '15'); ?>

To call the last 15 posts in my sidebar, can anyone tell me how to exclude a category, say the category with ID #1.

I can do it with wp_get_archive but not with get_achive.

Thanks in advance for any help or links to information I’ve missed. ?? Merry Xmas!