INT 2F - DR-DOS 6.0 TaskMAX - DELETE TASK
        AX = 2708h
        DX = task index
Return: DX = FFFFh (task deleted)
Notes:  this call should only be used for abnormal task termination, after
          first checking for open files with AX=270Ch; should not be used
          with programs that allocate EMS or XMS memory
        switches to specified task first