Your best place to find 2017 past papers of computer science 11th class from bise sahiwal board. These old up to date papers can be downloaded or viewed online.
2017 Computer science Past Papers 9th Class BISE Sahiwal Board Analysis
Campus.pk gives you unique insight into each past paper about what are the top chapters and topics.
Computer-science Past Papers 9th Class BISE Sahiwal Board