Vs. DualSystem support

Discuss emulation of the Nintendo Entertainment System and Famicom.

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zeroone
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Vs. DualSystem support

Post by zeroone »

Do any emulators support Vs. DualSystem games? I imagine this would have to tie into netplay if supported.
lidnariq
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Re: Vs. DualSystem support

Post by lidnariq »

As far as I know, only MAME.
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zeroone
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Re: Vs. DualSystem support

Post by zeroone »

The wiki does not go into a lot of detail about the Vs. DualSystem. What makes it difficult to emulate?
lidnariq
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Re: Vs. DualSystem support

Post by lidnariq »

Nothing much? It's just two 2A03s and two RGB PPUs all running off the same clock. The shared memory and IRQ handshaking is the only weird thing, and that's probably only hard with emulators that use catch-up optimizations.

If I had to guess why it's so rarely emulated? There's only six Dualsystem-requiring games according to Nocash and Wrecking Crew is probably the only one that's compelling to western audiences...

In fact, since the two PPUs are running off the same clock, and /RESET for everything is tied together, and it's the RGB PPU, there's no missing pixel, so the two PPUs should stay genlocked forever, too.
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zeroone
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Re: Vs. DualSystem support

Post by zeroone »

Why does it use 2 CPUs and 2 PPUs? Does it show the games from 2 different perspectives (e.g. camera centered around player 1 on one screen and around player 2 on the other)?
lidnariq
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Re: Vs. DualSystem support

Post by lidnariq »

Two screens is what makes it a dual system? Two screens requires two PPUs. And two sets of controls.

DualSystem cabinets had two CRTs, and it would have been stupid to make the arcade manager not use one whole set when they wanted to rotate out games... so two CPUs running entirely separate code.

Vs. Balloon Fight does have one player on each screen. Vs. Wrecking Crew seems to have a 2v2 setup, one team on each screen.
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thefox
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Re: Vs. DualSystem support

Post by thefox »

lidnariq wrote:and it's the RGB PPU, there's no missing pixel
Speaking of this, it would be nice to get the frame timing confirmed for the RGB PPU. Likewise, would be nice to be able to fill in the missing information at http://wiki.nesdev.com/w/index.php/Clock_rate

Do we have anybody in here with a system with a 2C03/2C04/2C05 PPU that can run custom test ROMs?

(If the timings have been confirmed before: source?)
Download STREEMERZ for NES from fauxgame.com! — Some other stuff I've done: fo.aspekt.fi
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zeroone
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Re: Vs. DualSystem support

Post by zeroone »

How are 2 CPUs wired up to the same memory?
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Re: Vs. DualSystem support

Post by lidnariq »

What's unclear about the wiki?
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