Reminds me of the Timex Sinclair 1000 I picked up in the 80s. It has no audio functionality. But I found a program in a magazine which would mess with the video signal or something to generate very rough tones. I seem to recall the program was named "I love the sound of breaking glass."
aka Sinclair ZX81. There was such a program in Your Computer that would toggle between fast and slow mode to generate tones. It was a actually a trivial 8 or 16 step tracker, so you could even make beats...
