604 reads as GOA: 6 for G, 0 for O, and 4 for A. For Goa Day, I put both on the oscilloscope.

In X–Y mode, one input controls the horizontal position of the trace and the other controls its vertical position. The two signals draw a trajectory across the screen, forming the numbers and letters.

A Rigol oscilloscope displaying 604 above GOA in yellow, with an audio interface and modular synthesizer rack below.

604 / GOA in X–Y mode.

Music: my October 2024 Goa set.