SpritesMind.Net

If they're simply being added, yeah. That might not be the case however. I personally suspect the 13-bit output is being shifted up by 1 to make each operator a 14-bit output (or the operator unit actually does use 14-bit resolution internally. I'll be testing for that), and then they are simply bei...

I'm aware of the multiplexed output for the channels themselves. The clipping I was referring to was in relation to the operators. Depending on the algorithm selected for the channel, there may be multiple operators being combined into a single channel, eg, in the case of algorithm 7, you've got 4 1...

I'm partway through that process now. The key to getting the levels right lies in the accumulator. The accumulator takes an (almost certainly) 13-bit input from the operator unit, and definitely produces a 16-bit output for the embedded YM3015/YM3016 DAC for each channel. When the "DAC Enable" flag ...

Nice! I'll have to give the new core a spin. :D BTW, I notice that CSM support wasn't implemented in the official source, and you note in your development copy that it wasn't working correctly. Is that an implementation issue, or have you found cases where my description doesn't match the expected b...

For the record, I haven't finished working on this chip. Not by a long shot. Since I last posted I've written my own YM2612 core from scratch, and I'm using that as a testing ground to verify my model of the YM2612 internal structure, based on tests and observed behaviour on the hardware. The next i...

For the record, the MAME core resets the shift & increment values immediately after that: 1) the register values for the according rates (AR,DR,SR,RR) are modified 2)Rks is modified (either KSR register is modified or frequency/block is modified) I think the introduction of Batman&Robin is pretty s...

So, according to you, as the env rates are calculated at the start of each phase, would this mean that register values are also latched at the same time and not all together on Key ON as mentionned above ? Hmmm. To be honest, I didn't thoroughly test this particular aspect. I meant to double-check ...

I don't have access to any equipment right now, but I did my own measurements of the output with an oscilloscope during this process, and the numbers I got back matched this calculation as I recall. I didn't record any of the results though. I'll be able to test this again in a day or two, so I'll m...

Several things first up: 1. This is going to be a VERY long post 2. All this information relates specifically to tests I have performed on the YM2612. Although I may not always name the YM2612 specifically, it is implied that all this information has only been tested and verified on the YM2612. I'm ...

....since it uses SSG-EG I think that made a bit of difference.... Doh! That was the first thing I looked for, but it turns out the SSG-EG registers weren't being displayed correctly in my emulator's debugger, so I thought SSG-EG wasn't being used. Yes, it is just bad SSG-EG support which is respon...

I'm a fair way along in my testing of SSG-EG mode. Gens, Kega Fusion, and MAME all have attempted support for SSG-EG, but all of the implementations are broken in different ways. I know Steve Snake mentioned once that SSG-EG "doesn't always behave like it should" in the YM2612, but I haven't found a...

Don't tell me that. =P I was hoping to get away with a single standard core for either the Sega integrated or Yamaha discrete YM2612. I've had a brief look, and you're right of course, the music is clearly running at half the rate on the MD2. Personally, I doubt it will turn out to be a difference i...

Hmmm. On first impressions it could be something to do with the LFO, but I'll need to do a lot more testing to narrow it down. I'll definitely look into it.

There would definitely be a slight difference in the timing between an NTSC and PAL system, as the master clock for the system as a whole is slightly different (53.203MHz for PAL, 53.6931 for NTSC), and every operation any of these chips perform, including tracking the YM2612 timers, is ultimately b...