When I have looked at the buzzer circuit circuit in the past, I was always wondering - could you drive 2 audio signals into the buzzer?
There are 3 signals that drive the buzzer. Port BA pin 5 - direct drive Port BA pin 2 - on/off control for the "sound" tone Timer signal - tone generator So, you can make sound 3 ways 1) by enabling a single tone, enabling pin 2 and disabling pin 5 2) by enabling a single tone, and modulating pin 2, and disabling pin 5 3) by disabling single tone, disabling pin 2, and modulating pin 5. I ran a simple program to prove that you can generate extra sounds. 5 sound1000,1 10 out186,233 15 fori=1to1000:next 20 call30326:goto20 (hit reset to get back to normal!!) line 5 sets a tone line 10 turns on pin 2; you hear the tone line 15... some delay line 20 rapidly toggles the direct drive at pin 5. new sounds! you can distinctly hear the two separate sounds. In fact you can hear the timer interrupt as well, every second. you can also hear keyboard inputs so, this little test shows that you could separately set up a single tone, as well as driving modulated signal directly. that's 2 sounds A third sound could be mixed in by modulating pin 2 (turning the tone on and off). I don't know of any M100 software that has taken advantage of these extra ways to make sounds. Anyone else? Seems like an interesting area to explore. Some supporting machine code routines would be interesting to think about. need to think of a clever way to demonstrate 3 sounds mixed. Steve
