OS2200
↑ Current Unisys documentation is available on the Unisys public support web site. For OS 2200 products, select one of the ClearPath Dorado platforms (e.g., Dorado 700 or Dorado 4000) and then the release level (usually the highest numbered one unless you are looking for something specific in an earlier release). That will take you to a search page where you can search by title or document content.
↑ More information is available on Unisys eCommunity. eCommunity requires a logon, but registration is free and open to the public. Within eCommunity a search for Information Repository leads to a site with searchable information about OS 2200 organized in tutorial form with drill downs.