20-08-2024, 10:08 AM
(19-08-2024, 06:58 PM)RetroBee Wrote: Can you elaborate more on the sound capabilities of these new machines.
The only info I could find is that you are implementing "8 bit dual channel sound FIFOs"?
What's this comparable to on older systems?
Hey Retro.
With the sound FIFO's (First in first out buffers - these store 8k of sound wave data each) you will be able to play
wave files much like the Amiga / Atari ST etc. It's not CPU intensive as a chunk of sound data gets loaded in all at once,
then the CPU goes off to do other things until an 'Almost empty' interrupt occurs to let the CPU know that more data
is required by the FIFO's before they run out sending the sound data to the output digital to analogue converters.
The 8k of sound data (per channel) gets fed (at the sound sampling rate) out to D->A converters to produce the audio.
The sound voices / channels etc. that you refer to in other systems that usually use AY-3-8910 / YM2149's etc. use a
different method for generating sound. I have been looking at adding a compatible core (for the 8910) into the mix as
well, but I've not got there yet. The sound enhancements are probably the last on the list to tackle before release.
If I don't get the 8910 compatibility into the logic design (inside the FPGA) before release, I can still do an update
to include it later.