I decided to write a driver and play around with this a bit. Timer can be run at 2048 hz rather than 256Hz. This gives a reasonable way to rapidly configure an audio driver.
toying around; if I get something that works in an interesting way I will post it. On Wed, Apr 6, 2022 at 5:43 PM Daryn Hanright <[email protected]> wrote: > That's pretty cool. > > The USA guys might not be familiar with the original Sinclair ZX Spectrum, > but that had a 1 voice beeper, but musicians/coders did some amazing things > with it. This guy does a detailed analysis on what they did > > > https://hackaday.com/2022/01/20/when-a-single-bit-was-enough-into-the-sound-of-the-zx-spectrum/?fbclid=IwAR2-g9QsikuuFz2eGhmPVT-p1KhYFZuXLaivcnafhtW__O9Sie1qU9a5YbM > > > > On Thu, Apr 7, 2022, 9:27 AM Stephen Adolph <[email protected]> wrote: > >> 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 >> >>
