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small wip



which means I (almost) fixed the sprite limit flags.

since the changes are quite large, I will probably wait until 0.137 is out before commit, to avoid any last minute apocalypse


EDIT: further tests show that the new OAM code fixes also the missing Mario sprite at the upper-left corner of world map in SMW. the reported priority problems in TMNT and Chrono Trigger are not fixed though and a few glitches have been introduced in at least R-Type 3... more work is needed on the sprites

This makes the most sense to me.. you could do a random stress test (just throw random sequences at it, reporting if any fail) or just allow the test range to be subdivided so that anybody with a copier can run a range of it overnight if they want.

I don't know what the SNES community is like these days, but there might be enough people out there willing to run their SNES for a week to get some idea of if the 16-bit implementation is accurate.

I'd certainly be willing to.

LN

blargg made an extensive 16-bit adc/sbc test, which his algorithm and my 16-bit adaptation passes. He is 100% sure the implementation is perfect. I'll try and get a link to that when I can, need to get it e-mailed to me at home.

So, ADC/SBC out of the way. I'm tired of talking about the MUL/DIV delays, let's get that one resolved for good already.

blargg appears to have cracked the MUL algorithm already. I haven't personally confirmed it on hardware, but I trust his results. We need help with the DIV algorithm next.

Please join and discuss here if you can help:
http://board.byuu.org/viewtopic.php?f=16&t=569

And again I'll emphasize here, please don't provide baseless speculation and educated guesses. Nintendo hardware is not based on any semblance of logic or reasoning.

Answers and actual hardware research only, please.

blargg is crazy-insane, and I love it. blargg is awesome. There can be no doubt in this.

That is indeed awesome!

With the help of blargg's step-based multiplication algorithm:
if((WRMPYA >> shift) & 1) RDMPY += WRMPYB << shift;

I have successfully reverse engineered the ALU multiplication process. Details are posted here:
http://board.byuu.org/viewtopic.php?p=12235#p12235

Now I'm just hoping blargg or someone else can come up with the step-based division algorithm, and we can finally emulate this behavior correctly!

That's fantastic!

blargg figured out the DIV algorithm:
http://board.byuu.org/viewtopic.php?p=12251#p12251

It works exactly like the 8-step MUL, only this one is 15-step.

So yeah, congratulations everyone. We can finally trick d4s' code into thinking it is running on a real SNES

There is a caveat that the new mini-SNES acts a little different on how it computes. But the new SNES really is a substantial redesign of a lot of the hardware. Not as much as a clone RetroDuo, but still. I chose to go after 1/1/1 and 2/1/3. When those are perfected (hah), I can consider the mini-SNES more.

But differences aside, these algorithms do have the important property that the true results are available at the correct time now. And it means that anything that relies on them won't work on certain hardware revisions.

So this really is an important thing to have. Almost as important as not writing to VRAM during active display.

MESS SVN #7566 passes all 4 ADC/SBC test programs. Woot!