getting Oscilloscope kind of lines

Hey Everyone

well I want to get something like oscilloscope lines as you can see them in winamp for example (or on your stereo or whereever)
can that be done? can it be done in DirectSound? (I would prefer DX7 over 8 because my app already uses DX7)
does anyone know how to do that?

Thank in advance
Misanthrop

I forgot to mention that the planet sourcecode samples did not work for me, maybe because of my sound chip (AC'97)
I would prefer a DSound solution...