Skull & Crossbones - Split Screen Shakes - Nestopia

Discuss emulation of the Nintendo Entertainment System and Famicom.

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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Zepper wrote:Sorry, I'm definitely unfamiliar with nestopia code style.
Thanks zepper, no worries. Just to clarify I did not mean the odometer from hard drivin, it was about the shinobi patch. :D
zxbdragon
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by zxbdragon »

Who can provide the real machine video for skull & crossbones.
or provide real machine video for all mapper 64 game;

I try fix.......
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

is this your video dragon? Have you been able to successfully fix this or something? This is obviously one of your builds (nestopia plus) so can you share your fix?
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

I've updated my mapper 64 IRQ code. It was broken, so Hard Drivin' now works as it should be.
The wiki has been updated with this information.
NewRisingSun
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by NewRisingSun »

I'm having trouble understanding that code. In particular, when is irq_rambo1 called? Every M2 cycle, with ppuflag set when at the end of a scanline? Then why is the //IRQ reset part in there, when according to the updated wiki, the IRQ reload business should be happening at the end of a scanline, not every M2 cycle.

As far as a glitch-free performance is concerned, here are a few things to look out for in Skull & Crossbones:

Correct (according to these real-machine-captured videos: 1, 2):
Image
Wrong:
Image

Look for a rogue scanline above the status bar in the left picture, a garbled "CONTINUES" lettering in the middle picture, and the level selection rectangle being one scanline off in the right picture. I have never seen an emulator that could get all three right AND run Hard Drivin' glitch-free (This video shows that at least during Hard Drivin's title screen, the top scanline of the lower part of the screen should be cut off.) Does your emulator manage to do that?

Here is a real-machine-captured video of the two-player mode, and what glitches should be expected (none, except some jitter at the far right side of the screen in the scanline directly below the status bar).
Great Hierophant
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Great Hierophant »

FWIW, for S&C there is a garbage scanline in both of the flash carts, but the item and level selection screens are correct. Hard Drivin is a glitchy mess below the driving portion of the screen in both.
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

NewRisingSun wrote:In particular, when is irq_rambo1 called?
At every CPU cycle, or 3 PPU cycles (NTSC), like you do with any other PPU IRQs, such as MMC3.
Every M2 cycle, with ppuflag set when at the end of a scanline? Then why is the //IRQ reset part in there, when according to the updated wiki, the IRQ reload business should be happening at the end of a scanline, not every M2 cycle.
Correct, read it again. Once the IRQ counter is zero, wait for 4 CPU cycles, then trigger an IRQ. This isn't an hack, as it was already confirmed.
(...)during Hard Drivin's title screen, the top scanline of the lower part of the screen should be cut off.) Does your emulator manage to do that?
The current public version has broken IRQs for mapper 64. The unreleased version has fixed such issue.
Great Hierophant
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Great Hierophant »

I believe Shinobi may have similar corruption on the last line of the in-game status bar

Is there any emulator available today that can demonstrate the accurate RAMBO-1 IRQ behavior?
NewRisingSun
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by NewRisingSun »

Not to my knowledge. As I mentioned before, no current emulator gets all screens of Skulls and Crossbones right. We'll see how that revised RockNES code actually performs once it is released.
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

Here's a pre-release of my emulator.
Download it.
NewRisingSun
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by NewRisingSun »

Thank-you. Using that pre-release build of RockNES, while Hard Driving works, as you described, Skull & Crossbones still has some glitches:

Corrupt "CONTINUES" in item screen, background one scanline off against selection:
Image

Background off by one scanline against selection on level select screen:
Image

Refer to the videos I linked to in my earlier post for proof that the actual cartridge does not produce these errors.
zxbdragon
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by zxbdragon »

And why do you think that is?IRQ?
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

I couldn't suit both games in a standard IRQ operation. If I fix Skull & Crossbones, then Hard Drivin' is glitched, and so on.

EDIT: it seems they do NOT use a same board..!?
S&C requires the IRQ to clock only after reset, next clock ($C001 write).
HD' requires the IRQ to clock immediately after reset ($C001 write).
Great Hierophant
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Great Hierophant »

Zepper wrote:I couldn't suit both games in a standard IRQ operation. If I fix Skull & Crossbones, then Hard Drivin' is glitched, and so on.

EDIT: it seems they do NOT use a same board..!?
S&C requires the IRQ to clock only after reset, next clock ($C001 write).
HD' requires the IRQ to clock immediately after reset ($C001 write).
You may want to ask Frank Cifaldi/TheRedEye over at LostLevels.org for a board shot.
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