It is currently Wed Nov 22, 2017 8:02 am

All times are UTC - 7 hours





Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: Tue Jun 28, 2016 4:51 pm 
Offline

Joined: Sun Apr 13, 2008 11:12 am
Posts: 6448
Location: UK (temporarily)
zeroone wrote:
It looks like it positions sprite0 in the middle of the first scanline.
That's not what I'm seeing in Nintendulator (There sprite 0 is at Y=$EE on both black and white frames)


Top
 Profile  
 
PostPosted: Tue Jun 28, 2016 5:00 pm 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 729
Location: New York, NY
tepples wrote:
How well does your emulator handle Zap Ruder (which uses a normal D4/D3 Zapper, not the Vs. Zapper)? It also uses sprite 0 at the top and counts scanlines to determine. If I had a Zapper modified to also speak Vs. protocol, I might be able to help you by making a test ROM.


Zap Ruder appears to work perfectly. It's unfortunate there is no VS Zapper version of it.


Top
 Profile  
 
PostPosted: Tue Jun 28, 2016 5:07 pm 
Offline
User avatar

Joined: Mon Dec 29, 2014 1:46 pm
Posts: 729
Location: New York, NY
lidnariq wrote:
zeroone wrote:
It looks like it positions sprite0 in the middle of the first scanline.
That's not what I'm seeing in Nintendulator (There sprite 0 is at Y=$EE on both black and white frames)


I think you just revealed the issue. Apparently there is a flaw in my PPU implementation. It is reporting a sprite0 hit on the pre-render scanline (scanline -1). I put in a check to prevent that and now it detects it on scanline 239 ($EF). More importantly, the game works now!

It's really amazing that this flaw was not revealed in any other games. That's nuts. I'll study my code further to understand how this happened. Thanks so much everyone.

Edit: That solves the issue with VS Hogan's Alley also. And, it didn't break Battletoads or the Simpsons HUD, etc. Interesting.

Edit 2: The unlicensed game Lethal Weapon (Ch) [U][!].unf still does not work. But, it doesn't work correctly in Nestopia either. So, I can live with that.

Edit 3: Thanks again everyone. This change did not affect the test ROM results either. I'm still amazed that this issue wasn't detected until now.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 33 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 7 hours


Who is online

Users browsing this forum: No registered users and 3 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