It is currently Mon Jan 21, 2019 1:09 am

All times are UTC - 7 hours





Post new topic Reply to topic  [ 36 posts ]  Go to page Previous  1, 2, 3
Author Message
 Post subject: Re: Vs. DualSystem
PostPosted: Mon Jan 14, 2019 9:51 am 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 862
Location: New York, NY
NewRisingSun wrote:
Of course. Just look at the Vs. System's ROM files...


I started working with your VS DualSystem NES 2.0 files. I setup 2 CPUs bridged by the shared memory range. And I am alternating between executing one instruction each processor. The master CPU appears to be attempting to trigger interrupts on the slave processor and I see reads from the exact addresses listed in your stub-processor code snippet. But the slave processor appears to be stuck in an infinite loop. It's not interested in the interrupt requests.

I'm not sure what I'm missing here. Any suggestions or experiments I can try?


Top
 Profile  
 
 Post subject: Re: Vs. DualSystem
PostPosted: Mon Jan 14, 2019 10:11 am 
Offline

Joined: Thu May 19, 2005 11:30 am
Posts: 802
Well, you need to actually raise the IRQ pin, of course, and $4016 must return reads with D7 clear on the master and D7 set on the slave CPU, so that the code knows on which CPU it's running.


Top
 Profile  
 
 Post subject: Re: Vs. DualSystem
PostPosted: Mon Jan 14, 2019 10:37 am 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 862
Location: New York, NY
NewRisingSun wrote:
Well, you need to actually raise the IRQ pin, of course, and $4016 must return reads with D7 clear on the master and D7 set on the slave CPU, so that the code knows on which CPU it's running.


Yep. I'm doing all that (I think). I also split the NES 2.0 PRG ROM, giving each CPU a half.


Top
 Profile  
 
 Post subject: Re: Vs. DualSystem
PostPosted: Mon Jan 14, 2019 11:22 am 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 7974
Location: Seattle
Just so I can follow along, which specific game are you testing with right now?


Top
 Profile  
 
 Post subject: Re: Vs. DualSystem
PostPosted: Mon Jan 14, 2019 11:53 am 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 862
Location: New York, NY
lidnariq wrote:
Just so I can follow along, which specific game are you testing with right now?


I've primarily focused on Balloon Fight and Wrecking Crew. They both have the behavior that I described where only the Master CPU seems to be doing it's thing.

Is there one game in particular that's easier to get running?


Top
 Profile  
 
 Post subject: Re: Vs. DualSystem
PostPosted: Fri Jan 18, 2019 9:50 am 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 862
Location: New York, NY
I finally got most of the VS DualSystem games running. It turned out that I was failing to initialize the slave PPU properly, preventing it from receiving NMI's.

The only game that won't launch is Raid on Bungeling Bay. Supposedly, it has the same copy protection that Ice Climber has, but duplicating that has yet to get it going. I'm also testing with the padded NES 2.0 version; so, it's not an issue with PRG RAM locations.

Anyone have any hints for this one?

Edit: I got Raid on Bungeling Bay loaded. It just a typo on my end.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 36 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 7 hours


Who is online

Users browsing this forum: Google Adsense [Bot] and 4 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