SpritesMind.Net

nice... this is Out Topic but do you plan to analyze the VDP also (or maybe did you already) ? I always wanted to know the exact timings of the different VDP events (interrupts and HV blanking periods) related to the main clocks as well as the exact video signal timings (VSYNC/HSYNC) and pixel cloc...

Also interesting. I remember this game giving me trouble back in the very early days of KGen. One thing it does is spam the living hell out of the YM2612, repeatedly writing registers that haven't changed. I don't remember if it checks the status to see if the chip is busy between writes - but mayb...

Aha. The document you found mentions there is only one operator. Incorrect. There are two, running in parallel. It simplifies the hardware design. This is the reason for the 'odd' operator numbering (1,3,2,4) in the registers. It also means that in most algorithms, an operator may need input from a...

Alrighty, I've just got everything back together, and I've got the same problem with this chainsaw sound effect in my emulator. The problem is related to the point at which SSG-EG mode triggers a "loop". I said that SSG-EG loops when attenuation hits max. The YM2608 documentation tells us that when ...

I'm in the middle of some pretty major changes, so I can't actually compile a build which works right now, but as soon as I've got everything back together (maybe a couple of days) I'll give it a try. The SSG-EG test rom I posted only tested SSG-EG with an attack rate set to 0x1F however. The attack...

Heh, so there is a game out there which uses SSG-EG with an attack rate less than 0x1F. At least it's only using 0x08. An SSG-EG setting of 0x08 or 0x09 would be consistent and reliable with an attack rate less than 0x1F, because the inverted output flag is not used by those SSG-EG patterns.

I dunno, I think Regen has it right and Gens has it wrong, and this game is one of my favorites, so it know it pretty well. I think it definitely needs to be tested on the hardware. In fact, I might make a recording this afternoon, since the splash sound in Ecco II seems to be one of those infamous ...

Well, looking at the YM3016 datasheet, the 10-bit mantissa actually includes the sign bit. Traditionally when taking about floating point formats, the sign bit would be counted separately from the mantissa, so maybe that's where that came from. If the embedded DAC in the YM2612 did use a different f...

Hi Snake, I was hoping you'd drop by at some point. Welcome to the forum. :) The CSM stuff is news to me, though. I haven't really looked at this since 1997, when I was talking to Tatsuyuki Satoh (original MAME core, and the one I think Stef based his on) - he has some japanese documents which sugge...

That's a region setting issue. It happens if you try and play the european Flashback rom on a US region machine. The european version of Flashback is tagged as a world-wide build with a JUE region code, even though it's actually a european-only build. The Japanese build has the same problem. The US ...

There are still some glitches in SSG-EG relating to the release phase. Check the release on the last few SSG-EG patterns and compare them to the reference recording. If you fix those, it looks like SSG-EG will be pretty solid.

I still need to do tests to determine when various register changes take effect. I think you'll find most of the decisions about SSG-EG are only made when changing between envelope generator states, but I think it's quite possible that toggling the SSG-EG enabled state during the release phase (or t...

Looking at the envelope generator update process in the MAME core, specifically in the advance_eg_channel function, I suspect you need to change this: if ( SLOT->volume >= SLOT->sl ) SLOT->state = EG_SUS; into something like this: if ( SLOT->volume >= SLOT->sl ) { SLOT->volume = SLOT->sl; SLOT->stat...

the only difficulty being that Enveloppe Counter is updated between each 2nd and 3rd samples (352/144) .... umm, yeah, about that..... :) When I was doing my tests on the envelope generator and calculating the update cycle, I had assumed the minimum output level was reached when the envelope genera...

The MAME operator unit gets a perfect result (mainly implemented through sin_tab and tl_tab), so there are no mistakes to fix there, although personally if it was my core, I'd rewrite some of it to make it simpler if nothing else (at the cost of a little extra overhead most likely). I know the detun...