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The Smurfs 2

85A57E: LDA $002140
85A582: CMP #$bbaa
85A585: BNE 85a5b7 ($30) <- ???


Enables some intense DMA transfers then checks sound port 0x2140, if it isn't 0xbbaa then it goes to an alternative route instead of just recheck the sound port. Timing bug.

Man, SNES programming tools must've been very very very ... very dire --"

Another bug report, Final Fight (J) shows this at the Capcom logo, same issue as Super F1 Circus?



Sim City (garbage at the top of the title screen):



Super Tennis (U) / Super Tennis World Circuit (J) (mode 7 gfxs are offset when there's the change court animation):



Sim Earth has missing gfxs on gameplay (dunno why this was never reported before) and no sound



Pro Football (J) has flickering background, probably same issue of Daffy Duck and friends

Romancing SaGa (J) has misplaced gfxs just like Ardy Lightfoot:

Final Fight and Super Tennis have been like that since a long time (maybe since the beginning). I also thought I listed Super Tennis in the wiki bug page but I probably forgot about it

Sim City is otoh a regression happened after 0.137. I will try to find where it happened...

EDIT: Tin Star appears to have some glitch as well, appeared after 0.137. Give me a couple of days and I will have more time to find when these regressed and hopefully fix them.

btw, I finished going through Tafoid black screen. I will post the few new games which does not even reach title screen tomorrow (I still have to re-test a few of them)

Finally, one I can answer.

Sim Earth needs proper vertical mosaic support to work.

Here's how you do it: take two variables, mosaicY and mosaicCounter. At Vcounter=1, reset mosaicY to 1, and mosaicCounter to the size value in MOSAIC ($4106.d7-d4). At each scanline, if mosaicCounter == 0, set mosaicY to the current Vcounter position. Now decrement mosaicCounter. If it's <= 0, reload the counter from MOSAIC's size value again.

Do that for each background independently. Simply writing to MOSAIC again won't reload the internal decrement counter, it'll have to reach zero to fetch in the new value.

Lastly, use mosaicY instead of the Vcounter for all purposes when rendering.

Obviously, you special case when $2106.d3-d0 has mosaic disabled for that BG by using the actual scanline instead.

Super Famista (J) screen selection looks quite bogus:

MESS


BSNES


Guess it's some kind of subscreen issue.

That looks like color addition/subtraction, Kale.

As a "quick test", try the pilot selection in UN Squadron. I suspect it is similar.

Suspected cause: color addition or subtraction with halving is not working rcorrectly (possibly only with 0,0,0 blends)

That works fine, but yeah, that looks like a color addition / subtraction crap.

r7744 /src/mame/machine/snes.c: [SNES]: Basic implementation of the DMA master cycles steals

We started and here's the first results:

http://mamedev.emulab.it/kale/?p=1008

ETA: for some time, please don't report "minor" gfx glitches, just the black scren ones. I have to do many other tweaks to this thing hence it'll require some time. Please be patient.

Did the SNES get changed to a 21.whatever MHz clock?

If not, Kale, then you're stealing way too many cycles

8 master cycles is ~1 cycle at 2.68 MHz, or 1.33 cycles of what I thought MESS ran the CPU as (3.57 Mhz-ish)

ok I'll look into it, if Kale does not beat me. it's strange though, since we have some vertical mosaic support, but it seems to be not enough


the same color addition/subtraction seem to work fine with other games, though. it might be some edge case, I dunno, or a different reason

in general, if you want to test the various graphical modes and effects, you can simply recompile MESS with SNES_DEBUG_LAYER 1 in snes.h

then you can start to turn on/off modes and BGs (and isolate single priorities) and to enable/disable color math, horizontal mosaic effects and window masks.

of course, if the math/window/mosaic is enabled at the wrong time due to bogus read/write of the cpu, then these debug commands might not help much