procedure sort( n, unit, direction : integer );
	var	i, r : integer;

	begin
	if n=0 then	{*** Mark as dummy entry ***}
		FilStat[unit] := '-'
	else if n=1 then
		ReadOneRun( unit, direction )

	else  for i:=1 to T-2 do begin
		r := n div (T-i-1);
		n := n-r;
		sort( r, (unit+i-2) mod T + 2, -direction );
		MergeOneRunInto( unit, -direction )
		end
	end;