NES Emulator Woes

[triplesycs]

Hello,

I am attempting to play Adventure Island on a NES emulator. However, I keep running into this weird bug/error/something. Some of the characters/enemies in the game flicker. I have attached a .gif to show the problem.

I have tried three different ROMs and MULTIPLE (lots) emulators. When I watch videos of the game on YouTube, the real system does not exhibit these errors.

Please, any help would be appreciated. :)

http://img227.imageshack.us/img227/9689/adventureisland.gif

[Lillymon]

Which NES emulators in particular? Have you given Nestopia a go?

Also, which ROMs in particular? If they were from a GoodNES set, did any have a

[!]

somewhere in the filename?

[triplesycs]

It turns out this problem was caused by sprite flicker (which, from what I've read, NES does normally... this is not an emulation error). However, Nestopia has a feature that took it away! :bigthumbup:

Just to answer your questions: I am using Nestopia and it did have a [!] in the filename.


Thanks for the help!

[Reaper man]

yeah, the NES cannot have more than 8 sprites per scanline... the flicker isn't very noticable on older CRTs though, so they were able to get away with it.

[Diego Mendez]

However, Nestopia has a feature that took it away! :bigthumbup:

Just to answer your questions: I am using Nestopia and it did have a [!] in the filename.

For the Mac OS X version of Nestopia, the same flickering rarely happens
(and I noticed that the most, in Super Mario Bros : The Lost
Levels, not the pirate one, the real Famicom one).
I don't remember if it had an [!] or not, but I'm going to know it.
EDIT: I downloaded it from some site a long time ago, but
it didn't had a [!]. Only (Japan), and nothing else.

In the attachment, notice that between a Goomba and a Koopa, there's
one Koopa, the right side of it is flickering, so in the attachment you can't
see it's head or the right side of it's shell.

The reason why I chose the Lost Levels, is because in the first level,
there are a line of Koopas, their totals makes their sprites' flickers.

Sorry if I didn't talk about your game, but that's the one I noticed in the
Mac OS X version of Nestopia.

[InVerse]

Are you using an .NES ROM or a .FDS disc image? If it's a ROM, it isn't going to be official. The Japanese version of Super Mario Bros 2 was only released on the Famicom Disc System, never on cart. There are several FDS to NES conversions in existence but several of the ones I've looked at tended to be slightly buggy.

[Diego Mendez]

Are you using an .NES ROM or a .FDS disc image? If it's a ROM, it isn't going to be official. The Japanese version of Super Mario Bros 2 was only released on the Famicom Disc System, never on cart. There are several FDS to NES conversions in existence but several of the ones I've looked at tended to be slightly buggy.

If you read my post above, I said the real Famicom SMB2,
mean's it's the FDS disc... But I've downloaded it from somewhere,
and didn't get the one from the floppy (or disc, as the console name
suggests). Not lying, after getting the Famicom to work on my
Nestopia (took tedious time for the lack of more instructions :mad:),
this was the first FDS disc image to use.

[InVerse]

Famicom and Famicom Disk System aren't the same thing, which is why I asked for the clarification. I loaded SMB2 up in FCEUX and got to the part in your screen shot and there wasn't any flickering at all, so perhaps Nestopia just sucks. I assume that it's possible to get the Linux version of FCEUX working in MacOS but I have no clue how.

Edit: Nevermind, I went a bit further and got a couple of additional enemies on the screen and experienced the same flickering with FCEUX. I suppose I'm just so used to it from the real NES that I don't notice it in the emulator unless I'm actively looking for it.

[Diego Mendez]

Famicom and Famicom Disk System aren't the same thing, which is why I asked for the clarification. I loaded SMB2 up in FCEUX and got to the part in your screen shot and there wasn't any flickering at all, so perhaps Nestopia just sucks. I assume that it's possible to get the Linux version of FCEUX working in MacOS but I have no clue how.

Edit: Nevermind, I went a bit further and got a couple of additional enemies on the screen and experienced the same flickering with FCEUX. I suppose I'm just so used to it from the real NES that I don't notice it in the emulator unless I'm actively looking for it.

You mean "FCE Ultra X"? The only NES emulator on my Mac OS X
is Nestopia. It does happen in other games (and maybe, all the games),
and the reason is that the emulator has very accurate emulation to
the NES, which the flickering also happens on a real NES, so it
does the flickering.

Damn, I'm searching for a Windows emulator for the Mac OS X the whole
day, not seeing a great result to my PowerPC G4, and your saying
Linux? It's my luck, yes, the Mac is more stable than the PC, but
the programs and such are the least on it.

[InVerse]

The official name is FCEUX but yes. I don't know much about OS X but I do know that it runs on a base of FreeBSD and that FreeBSD has built in Linux emulation, so I thought perhaps it was possible to compile Linux software on OS X but, again, I'm completely theorizing here. (Although I just Googled "Can you run Linux Software on OS X?" and the first hit was a complete walkthrough on how to do so, so apparently you can.)

[Deadly-Dreamer-X]

I am suffering the same problems. Almost always flickery images. Good thing that I got this nice clean shot for display.

http://i27.tinypic.com/4fy62e.jpg

Isn't there a way where Emulators bypass this problem? Oh, I mostly use Nestopia, FakeNes(for its GUI mostly), Fceu and VirtuaNes. I have 10 other emulators, but I tend to use the aforementioned emulators.

Also, may someone please explain to me the "8 Pixels per scanline(or something)" thing. Any help is appreciated, thanks.

[Lillymon]

I am suffering the same problems. Almost always flickery images. Good thing that I got this nice clean shot for display.

http://i27.tinypic.com/4fy62e.jpg

Isn't there a way where Emulators bypass this problem? Oh, I mostly use Nestopia, FakeNes(for its GUI mostly), Fceu and VirtuaNes. I have 10 other emulators, but I tend to use the aforementioned emulators.
Most can. It'll be an option labelled 'Disable sprite limit' or similar.

Also, may someone please explain to me the "8 Pixels per scanline(or something)" thing. Any help is appreciated, thanks.
It's a hardware limitation the original Famicom/NES had. You can only have eight sprites on any horizontal line at a time. If you try to have more, they flicker as alternate sprites disappear and then come back. Since the emulators are not bound by Famicom/NES hardware limitations, they can disable this and display all sprites all the time.

The reason the sprite limit isn't disabled by default is partly because then the emulators aren't actually emulating a Famicom/NES when the sprite limit is disabled (they're emulating some hypothetical piece of hardware that is like the Famicom/NES, but with no sprite limit) but mostly because some games actually rely on the limitation for certain graphical effects, since game developers knew about this hardware limitation and would sometimes design their games to take advantage of it.

I believe probably the best way to actually deal with the sprite limit would be to blend alternate frames together, so sprites that would usually seem to flicker would appear translucent instead. This is most likely how it worked on the older television sets that the Famicom/NES was designed for, which is why the sprite limit was less of an issue at the time. I haven't used any NES emulators lately though, so I don't recall which can do this, though I'm pretty confident at least one must be able to.

[Deadly-Dreamer-X]

Most can. It'll be an option labelled 'Disable sprite limit' or similar.

It's a hardware limitation the original Famicom/NES had. You can only have eight sprites on any horizontal line at a time. ...........I haven't used any NES emulators lately though, so I don't recall which can do this, though I'm pretty confident at least one must be able to.

Oh, thanks a lot. So that's how it works. Yes, I didn't notice that 'Disable Sprite Limit', almost all of them had it. Now, I do not need to worry about that.

Anyway, a new whole subject(since the title of this thread is superb): What is VSync(Virtual Synchronization(it is the only thing I understood after google-ing it)), and what does it have to do with my refresh rate(60 Hz), and how does double/triple buffering helps(actually, what are they?)?

I sometimes notice some horizontal line dropping down as I move in-game, they kind of distort the line they are taking(on higher resolution). What does this have to do with the previous settings?

Any explanation is, of course, deeply appreciated.

[Lillymon]

Anyway, a new whole subject(since the title of this thread is superb): What is VSync(Virtual Synchronization(it is the only thing I understood after google-ing it)),
I actually don't know exactly what VSync is. The phrase 'sync during VBlank' comes to mind, but I don't really know what that means either. From what little I can recall, I think it means the emulators doesn't attempt to update the screen while an image is being written to it. I know it's supposed to stop 'tearing' and make the output look better, but at the cost of increasing system requirements, since your system needs to write everything pretty fast so that the emulator and screen never get out of sync.

and what does it have to do with my refresh rate(60 Hz),
I'm pretty sure VSync works best when your refresh rate matches that of the original console. For NTSC games, 60Hz is about as good as it gets for PC monitors.

and how does double/triple buffering helps(actually, what are they?)?
Double buffering means the computer is writing the information to one frame as it displays the one it just finished. Triple buffering means it displays one, is writing to a second, and has a third waiting to be written to screen. All of this is supposed to also make things smoother, but I think I heard that it increases input latency as well.

I think if VSync works well for you, just use that rather than double or triple buffering.

I sometimes notice some horizontal line dropping down as I move in-game, they kind of distort the line they are taking(on higher resolution). What does this have to do with the previous settings?
I think that's the 'tearing' effect I mentioned above. Give VSync a go.

[Deadly-Dreamer-X]

I actually don't know exactly what VSync is. The phrase 'sync during VBlank' comes to mind, but I don't really know what that means either. .....................
I think that's the 'tearing' effect I mentioned above. Give VSync a go.

Man, you are awesome. Thanks again. Wow, a lot of things I wasn't aware of.

But that "tear" effects happened to a lot of other emulators of different consoles; namely SNES, Gameboy, PSX.

I will try to Screenshot next time I get the chance. So, until then. :bigthumbup:

[The 9th Sage]

I actually don't know exactly what VSync is. The phrase 'sync during VBlank' comes to mind, but I don't really know what that means either. From what little I can recall, I think it means the emulators doesn't attempt to update the screen while an image is being written to it. I know it's supposed to stop 'tearing' and make the output look better, but at the cost of increasing system requirements, since your system needs to write everything pretty fast so that the emulator and screen never get out of sync.

From my understanding, it limits the frame rate to the refresh rate of your monitor (at most) and tries to make it so that the emulator doesn't try to draw an image to the screen while one is already being drawn (that would cause the tearing since you've got part of one frame and part of another very similar frame being drawn at once).

Triple Buffering remedies this as well...if your emulator supports that, you may want to use it instead (at the very least if Vsync doesn't help it might help you). It's not a big deal for emulators since most of them aren't going to reach a super high framerate anyway, but it's definitely better for 3D gaming since it doesn't have the FPS limitation like Vsync does.

[Rosswante]

Hello,

I am attempting to play Adventure Island on a NES emulator. However, I keep running into this weird bug/error/something. Some of the characters/enemies in the game flicker. I have attached a .gif to show the problem.

I have tried three different ROMs and MULTIPLE (lots) emulators. When I watch videos of the game on YouTube, the real system does not exhibit these errors.

Please, any help would be appreciated. :)

http://img227.imageshack.us/img227/9689/adventureisland.gif

yes I have tried about every emulator(nestopia, nester, jnes, fceux, nesticle ......) But getting same problem, background images flicker causing eye stress and headache.

[InVerse]

yes I have tried about every emulator(nestopia, nester, jnes, fceux, nesticle ......) But getting same problem, background images flicker causing eye stress and headache.

My suggestion would be to read the rest of the fucking thread.