For anyone with an oscilloscope, Vectrex or XYZ display, I decided to share my performance patch for a hybrid Rutt Etra type of video synthesizer.
Instead of dedicated hardware, the system uses computer with multichannel soundcard (3 channels minimum, although you can see something using built in stereo out as well) which connects to an analog oscilloscope. System is of much lower resolution than the original Rutt Etra, but it has some other interesting and unique capabilities, like arbitrary framerate and resolution (all the way from from low to none!).
Considering recent interest in computer/oscilloscope combo, I also added preset notes that help understand what's going on in the patch and mouseover hints for all parameters.