It is currently Sun Dec 10, 2017 9:01 pm

All times are UTC - 7 hours





Post new topic Reply to topic  [ 9 posts ] 
Author Message
 Post subject: Vs. DualSystem support
PostPosted: Tue Sep 06, 2016 1:08 pm 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 750
Location: New York, NY
Do any emulators support Vs. DualSystem games? I imagine this would have to tie into netplay if supported.


Top
 Profile  
 
PostPosted: Tue Sep 06, 2016 1:49 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6503
Location: Seattle
As far as I know, only MAME.


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 9:43 am 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 750
Location: New York, NY
The wiki does not go into a lot of detail about the Vs. DualSystem. What makes it difficult to emulate?


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 11:22 am 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6503
Location: Seattle
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.


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 12:13 pm 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 750
Location: New York, NY
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)?


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 12:20 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6503
Location: Seattle
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.


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 12:42 pm 
Offline
User avatar

Joined: Mon Jan 03, 2005 10:36 am
Posts: 2981
Location: Tampere, Finland
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: kkfos.aspekt.fi


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 12:48 pm 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 750
Location: New York, NY
How are 2 CPUs wired up to the same memory?


Top
 Profile  
 
PostPosted: Wed Sep 07, 2016 1:10 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6503
Location: Seattle
What's unclear about the wiki?


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: No registered users and 5 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group