ok, i've got IM here now. look at ch.22-74ff the routine's name is 'SndPlayDoubleBuffer'. you specify another 'DoublebackProcedure' to refill those buffers -- and all is up & running in th ebackground. Also, look at IM IV, 22-90, but that's essentially the same. 22-74ff tells you all you need. -tobias.