Search found 203 matches

by Snake
Tue Apr 07, 2009 8:31 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 859
Views: 360417

This is probably an error copied over from some other document. A lot of the documentation was probably copied then edited where necessary, same is probably true of most of Yamaha documentation, given the huge similarities with a lot of their chips. But we know this stuff in the YM2612 works differe...
by Snake
Fri Apr 03, 2009 11:03 pm
Forum: Megadrive/Genesis
Topic: What are the 68K/Z80 clock spes for NTSC v PAL machines?
Replies: 9
Views: 3759

Ok - I think I'm going crazy. Extra lines or no extra lines 50hz is 50hz. So if a game ROM is for both NTSC and PAL, sample play back for PAL will be lower pitched unless the z80 code compensates for it. Nope - because the framerate has nothing to do with how fast the Z80 whacks out samples. Give i...
by Snake
Thu Apr 02, 2009 11:42 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 859
Views: 360417

Now, this is another PDF that requires translation :) Kind of awesome since thats the CMOS version of the 2612! I don't know if this document will tell us anything we didn't already know, but it does indeed appear to be hardware and software 100% identical to the YM2612. So this is a very nice thin...
by Snake
Sat Mar 28, 2009 6:54 pm
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

That looks like a very nice test ROM :) As I said earlier, I knew Kega would fail that one particular test, but... If you try and, for example, jump to sprite entry 65 under H32 mode, that sprite entry will not be processed and the sprite list will terminate, even if you jump to it directly from the...
by Snake
Sat Mar 28, 2009 4:16 am
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

I can confirm that the CD version (at least the EUR version) shows exactly the same: same code, same problem in Fusion, but works on real hardware. Ok, well that's a good start, means I'm not wasting my time ;) But I still don't think this is sprite masking. It'd be interesting to hack the ROM to m...
by Snake
Sat Mar 28, 2009 4:10 am
Forum: Video Display Processor
Topic: HBlank Timings
Replies: 163
Views: 35244

Yes, you may be right there. Even so, that would make the timing at least one cycle longer than a bunch of NOPs. Hell, what else are you going to fill that rom space with? ;)
by Snake
Fri Mar 27, 2009 8:31 pm
Forum: Video Display Processor
Topic: HBlank Timings
Replies: 163
Views: 35244

I thought to read hvcounter in a loop and write to ram only in interrupt routine, not each time you read it :) oh well, something like this ? Main: LEA $C00004,A6 Loop: MOVE.w (a6), D0 ;Get HVcounter BRA Loop; Hint: MOVE.w D0 $E01000 // DISPLAY STORED VALUE ON SCREEN RTE; I don't know if this is po...
by Snake
Fri Mar 27, 2009 8:10 pm
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

PS: using the simple rule "sprite masking occurs when a low priority sprite with xpos=0 is found" I think what Nemesis meant by 'high priority' was a sprite earlier in the list, i.e. high priority with respect to the current sprite - and not the background priority settings, which have no effect. B...
by Snake
Fri Mar 27, 2009 4:41 am
Forum: Megadrive/Genesis
Topic: Anyonw seen Virtual FighterII pattern A corruption before?
Replies: 4
Views: 1724

(Assuming BGB is lower pri than BGA).
The window basically replaces BGA, so if the window is transparent, you see BGB through it - regardless of priority.
by Snake
Fri Mar 27, 2009 2:25 am
Forum: Megadrive/Genesis
Topic: Anyonw seen Virtual FighterII pattern A corruption before?
Replies: 4
Views: 1724

Hey Steve,

It's almost certainly the window. Remember that BGA is masked wherever the window is.
by Snake
Thu Mar 26, 2009 11:39 pm
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

I can confirm what Nemesis says here is absolutely correct. Note point number 2. Nothing emulates that Indeed. In Fusion, this is mainly because I jump to the wrong place at the wrong time, and now that I've realised this it's something I plan to fix, when I actually get the chance. I actually think...
by Snake
Thu Mar 26, 2009 6:29 am
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

It's not as simple as the first sprite being ignored for sprite masking. I don't think any of the current implementations of sprite masking are fully emulating the behaviour of the hardware. Both incorrect :) This has nothing whatsoever to do with sprite masking, and everything to do with the fact ...
by Snake
Thu Mar 26, 2009 2:44 am
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 25378

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 a...
by Snake
Fri Feb 27, 2009 10:55 pm
Forum: Sound
Topic: New Documentation: An authoritative reference on the YM2612
Replies: 859
Views: 360417

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 th...
by Snake
Fri Feb 27, 2009 2:57 am
Forum: Regen
Topic: Regen - Camera shy?
Replies: 4
Views: 5465

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