Using a synthesizer to generate sounds that will render shapes and pictures on an oscilloscope in X-Y mode...
Here is how I did it.
1. Set 5A48 (in left bay) to 1 volt per division. Display on, channel one output to AC, mode to channel 1. Plug 10x scope into channel 1
2. Set 5A48 (in middle bay) to 1 volt per division. Display off, channel one output to AC, mode to channel 1. Plug 10x scope into channel 1
3. Set 5B31 (in right bay) sec/div to AMPL. Auto trigger
4. Attach probe connector 1 into the left stereo channel, probe connector 2 into the right stereo channel. Attach the probe ends with alligator clips to the individual segmented ends of a 1/4 in stereo jack cable. The other end of the audio cable would be plugged into the headphone jack of the amplifier unit or mixer. The synthesizer is plugged into the mixer like any musical instrument.
5. Next, adjust the focus and intensity so that the image generated by the soundwave is to taste. Use the position knobs to move the center of the image. Adjust the headphone volume to make the image larger or smaller on the oscilloscope.
The hard part is generating "interesting" soundwaves that will render as patterns and not just a diagonal line. Use this video to test your equipment and then you can start experimenting with your own sounds. HINT: A regular piano makes a nice oval/circle shape naturally!