A program for outputting vector images to an oscilloscope through a stereo audio output has long surprised no one. But only in January 2018, they began to write this in JavaScript.
One of the scripts displays an image of the clock face on the oscilloscope displaying the system time of your device.
Another - animates, forcing to rotate and pulsate, the picture you draw. It is incompatible with devices with touch screens: even if you connect the mouse via a USB host, instead of drawing you will scroll the page.
And this video, filmed by the author of both scripts Neil Fraser - for those who do not have an oscilloscope, or is, but without the input X.
PS Sorry, we were unable to force both scripts to display a picture on this
oscilloscope emulator running in the adjacent tab. He does not perceive audio from the adjacent tab. And in general, nothing but his own set of audio files, does not perceive.