SAAsound SAA1099 support in Emulator

Matej · Post by **Matej** » Mon Oct 05, 2020 10:42 am

There is nice SAA1099 library called SAAsound:

https://github.com/stripwax/SAASound/

Its part of SAMcoupé emulator SIMCOUPE.

Also can You include save/record sound to *.WAV?

kelli217 · Post by **kelli217** » Mon Jan 04, 2021 7:46 am

As of now, the SAA1099 has been removed from the design in favor of the PSG on the VERA and the Yamaha YM2151.

Matej · Post by **Matej** » Thu Jan 14, 2021 12:18 pm

Why? SAA cost few USD. Like one cup of tea in restaurant. No emulation. True PSG. Saa+VERA for softer sounds will be perfect!

StephenHorn · Post by **StephenHorn** » Thu Jan 14, 2021 2:40 pm

~~The FAQ technically still says the SAA1099 is up for consideration~~, but I expect its value has been supplanted by the VERA's PSG. The VERA provides more channels and more waveforms, at the expense of not being able to specifically pan tones from left to right, though you could just set one channel to left-only, one channel to right-only, and adjust the volume of them independently to recreate a panning effect. Since the VERA has 16 fully independent channels, it can still do everything the SAA1099 could and then some. It's only drawback is being an FPGA solution instead of raw silicon.

Edit: Oops, I was wrong, the FAQ says the 1099 has been retired. My bad. The rest still stands, though.

Ender · Post by **Ender** » Thu Jan 14, 2021 3:31 pm

Kevin explained it in this video at around 8 minutes:

Basically, it's as @StephenHorn said, the VERA's PSG serves the same function as the SAA1099, and since the VERA is not replaceable in the X16, as it was originally intended to be, due to the design of the kernal being fairly dependent on it, there's not much point in keeping it.

Matej · Post by **Matej** » Thu Jan 14, 2021 3:39 pm

Will watch. But I have C64 3xSID upgrade also Atari Pokey 2xstereo upgrade. And FGPA versions sounds not same! They are perfect but real Asic is real Asic. But I am musician. For games, demos fpga is excellent.

m00dawg · Post by **m00dawg** » Thu Jan 14, 2021 4:01 pm

12 minutes ago, Matej said:

Will watch. But I have C64 3xSID upgrade also Atari Pokey 2xstereo upgrade. And FGPA versions sounds not same! They are perfect but real Asic is real Asic. But I am musician. For games, demos fpga is excellent.

I am a musician too but to be fair here - I don't think the VERA is trying to emulate any other sound chips. It'll be its own so at this point you can expect the VERA to sound like, well, the VERA. Also, I can counter "ASIC is real ASIC" by simply saying "gates are gates". This is how designs are able to go from an FPGA to a real ASIC (this is part of the reason to have FPGAs).

The internal arrangement of gates in an FPGA vs an ASIC is, of course, different, but they are logically equivalent. Which means to say, the VERA could, in theory, be made into a real ASIC, but in terms of its (digital) audio outputs, I don't think you'd notice any real differences here.

Where there could be differences is how the analog output stages may differ, but this too isn't an FPGA vs ASIC issue, but relate to what components were used for a given output stage (which op-amps, buffers, caps, etc.). And of note, this IS one reason real SIDs are still superior to FPGAs - they use analog filters and the FPGA SID solution emulate these. Here I would definitely agree that the analog circuity wins out here. But since the VERA is purely digital, the differences between an FPGA and an ASIC are immaterial.

Besides, 16 channels of sweet PSG sound is pretty worth at least seeing what VERAsound can do before passing judgement, I think anyway. We'll end up with 26 channels of built in audio (8 FM, 16 PSG, 2 DPCM). That's still quite a beast!

Matej · Post by **Matej** » Thu Jan 14, 2021 4:31 pm

100% agree. Maybe in future we can have even SID or SAA1099 soundcard interface.

m00dawg · Post by **m00dawg** » Thu Jan 14, 2021 4:35 pm

Indeed I'm rather excited about that. I do hope we end up getting an internal audio in header so soundcard(s) can be internally mixed with the X16's built-in audio. That will allow for some really great things I think! I'm looking at the X16 largely as a chiptune maker but having a GUS-style soundcard could be a really nice solve since, from what I understand, using the stereo DPCM off the Vera is CPU intensive. So having an external "hardware accelerated" PCM soundcard (with it's own RAM, ala GUS) could be really neat!

SlithyMatt · Post by **SlithyMatt** » Thu Jan 14, 2021 8:17 pm

3 hours ago, m00dawg said:

from what I understand, using the stereo DPCM off the Vera is CPU intensive

Not really, it's more memory intensive. Samples take up a huge amount of memory, relatively speaking, compared to PSG or FM settings. But once you have a sample in memory, you don't have to service the PCM FIFO very often, and even then it doesn't take very long. It actually requires less CPU intervention than PSG or FM.