procedure determine_tasker;     {determine what multi-tasker is active, if any}
procedure give_up_time;         {give up unused time under doubledos}
const
   tasker:  (taskview,                  {taskview/omniview/topview/desqview}
             doubledos,                 {doubledos}
             notasker,                  {single task}
             unknown) = unknown;        {before first call}