SpritesMind.Net

So, I highly doubt there exists a "mode 2".
No, there doesn't. It's much simpler than Charles describes.

Never seen this problem before - and looking at the shots, and the description of what it's doing/what's happening... I have no idea at all why this wouldn't work in Fusion already. It must be ...

Personally, the think that irks me the most is the behaviour when the effective attack rate is 62 or 63. If it was just a matter of forcing the attenuation directly to 0 when the attack phase is entered with these rate values, well, that's one thing, but the "stalling" behaviour when changing to ...

Err, no it isn't, most emulators have a 'fix checksums' option, you just need to turn it on.

Ahh, but remember that the attenuation isn't moving past 0x200 during a repeating SSG-EG wave.
Ah, this is what I meant, but I didn't explain it very well :)

I was assuming the attenuation starts at 0x3FF, and is decremented until it hits 0x200 - at which point it will immediately switch to decay ...

now it works, pretty nice, and quality is very good too :D

Thanks :D
Strangely the quality is better than my first driver which was using similar code at the same output rate :-/
:D

I often find I write something better the second time around ;) Probably some bug, typo, or timing error that was ...

The samples are averaging together, which is why you're being left with a regular sine wave at mid-level.
I did consider that, but since the sample rate is not divisible by the hardware output rate, I would have expected to see some clear distortion rather than an almost perfect wave - I can see ...

I have another question about DMA Timings.
Is it necessary to emulate dma transfert line per line or making all the transfert at start of dma and set the status flag to 0 after necessary cycles is sufficient?
For normal ROM to VRAM DMA, the CPU is locked while it happens anyway, so you could get ...

Care to share?
Absolutely, happy to.

It's to do with the inverting every cycle thing. I believe my tests were done with AR=0x0A, and one of the inverting patterns. I was looking at what I assume is an inverted attack, and it looks like a perfect sine wave at a constant volume. The samples you ...

I think you should use phonemes of syllables rather than letters. Then speech will be more clear. A long time ago I did the same thing for russian...
:D I've done this type of thing myself.

One thing I've always meant to do, but never seem to get around to it, is to attempt to extract samples ...

Hmm, that is strange. It looks like the one running at the higher frequency has some additional noise on the output signal. I'll take a look.
It's probably writing to the DAC at around the same time the chip is trying to read it.

I can't say I've done very thorough tests on this. I generally ran ...

What I did is to use the same increment values as when Rate is 0 (infinite rate)
Indeed, it makes perfect sense.

Can you confirm that output calculation also happen the same way with normal enveloppe ? Meaning that any change to internal attenuation level (for example on Key ON with AR=62,63 ...

That's a really good capture of the effect, better than I've seen so far. How did you capture that?

I noticed you are doing some sort of cache purge every scanline. Is this really needed? That's probably going to be slow.

Also, you're doing something with the palette every scanline too. Again, is this needed?

1/ attack rate is set to 62 or 63: you say that the attenuation level is set to 0 but is the next enveloppe update done with Attack or Decay parameters ?
Decay. Attack is skipped immediately in this case.

2/ SL is set to 0: does EG enter the susbtain phase once or does it directly jump to ...

Wow, huge post :) Kind of odd that you would post this right now. I have a ton of SSG-EG samples I did years ago, but I lost the test ROMs that created them, so I didn't know what I was looking at. This weekend I found them and spent most of it looking into this again. I'll read your post properly ...