Skull & Crossbones - Split Screen Shakes - Nestopia

Discuss emulation of the Nintendo Entertainment System and Famicom.

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trebor
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Skull & Crossbones - Split Screen Shakes - Nestopia

Post by trebor »

Under Nestopia (Undead) 1.45 (and older versions), as well as the (un)official releases (I.E. 1.40-1.42), when you split the screen by starting the second player in Skull & Crossbones in-game, the bottom portion shakes and there's some graphic corruption.

The ROM dump, per Nestopia's launcher shows it as a "Good" dump. Presuming then, it's an emulation issue (?)

Trying Nintendulator (Aug 10, 2014 beta), there's some minor graphic corruption (Just below 2nd player/"RED DOG" status info), but no shaking screen with the 2nd players enabled utilizing the same ROM.
lidnariq
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by lidnariq »

I don't think we understood exactly how the RAMBO-1's IRQ worked until James tested recently, which postdated the original author abdication. Rdanbrook has probably not had this pointed out to him yet?
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koitsu
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by koitsu »

Just opened this ticket for him. :-)

Also for lidnariq: check out the Discussion part of the RAMBO-1 Wiki page please. Zepper proposed a different methodology that may help with Hard Drivin' and no real follow-up to that discussion took place (at least on the Wiki). If it took place here on the forums, if you could find me the discussion that would be great.
zxbdragon
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by zxbdragon »

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

Post by *Spitfire_NES* »

Sorry to bring this back up but i think i found another bug with this mapper and shinobi on nestopia.

Everything is fine until you get to the last set of levels. The masked ninja set on the bamboo forest level the mirroring becomes screwed up on sideways scrolling. I opened this ticket on rdanbrook :

https://github.com/rdanbrook/nestopia/issues/181

Could these 2 games be related with the issues? They are both mapper 64, unless i am crazy here. Everything starts off fine in that level until you get about midway then the scrolling issues start and the next level seems to be screwed too.

I wonder if there's an easy fix for this or maybe its related to the database entry for shinobi.
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

I hope it helps. All the games work with no glitches.

-edited- Code removed.
Please, read the wiki discussion page!
Last edited by Zepper on Sat Jul 08, 2017 6:32 pm, edited 2 times in total.
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Thanks zepper, is this a patch for nestopia or code that you are using in your own emulator?
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

*Spitfire_NES* wrote:Thanks zepper, is this a patch for nestopia or code that you are using in your own emulator?
Nope. Just the info you'll need to the proper fix. The IRQ isn't triggered when the counter expires. It'll trigger after 4 CPU cycles.
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Im currently parsing through the nestopia source and I see the source file NstBoardTengenRambo1.cpp. Maybe I can get someone to help me a little bit, its very difficult to parse where to put a patch. And thanks again zepper for posting the code, guess its a matter of deciphering what goes where with what you posted.
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Sorry for the double post, im looking through nestopia undeads source to try to do this myself,

https://github.com/rdanbrook/nestopia/b ... Rambo1.cpp

if you scroll down to this part:

if (!count && enabled) {
/* wait one M2 cycle, then trigger IRQ */
return true;

do i just need to wait 3 more cycles or am i way off? I never claimed to be an expert but am trying my best here.

I believe this is dragon2snows experimental code, but im not seeing where i can actually change the cycle count to 4. This also might explain why part of the odometer is cut off in hard drivin.
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

Argh... fine. I'll take a look later... and make the necessary changes in the code. You should be able to do that, by the way. :x
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

ahh zepper. You rock man! 8-) And yes, im a noob but I am trying. :lol: :mrgreen:
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Hey zepper, do you know by chance if this might help fix the top of the odometer missing in hard drivin?
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*Spitfire_NES*
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by *Spitfire_NES* »

Hey Zepper, am I still lucky enough to get your help with this? If not, that's obviously ok. Just figured I would check. :D
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Zepper
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Re: Skull & Crossbones - Split Screen Shakes - Nestopia

Post by Zepper »

Sorry, I'm definitely unfamiliar with nestopia code style.
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