poor graphics (nes)

[maxer]

As far as the graphics go on roms - why do some roms work really well with LJP and others do not?

At first I thought it might be the rom itself, but trying several different reiterations of the same rom have yielded the same results - poor graphic display.

Is it something to do with the way LJP interacts and reads these particular roms?

[Tinnus]

Be more specific. What's the problem you're getting? Can you post a screenshot (photo)?

[needhelp]

I don't know if he means this, but I found out that with some roms, the left side of the screen is white(about 0.5cm or so). True, 0.5cm isn't a lot, but it still makes a difference when your screen is about 14cm long or so.

[beavis]

What game is it? Some are known to have graphical glitches, like Big Nose Freaks Out.

[_Em]

Also, is it a PAL or NTSC game (US, JP, or EU)?

[maxer]

to be more specific, yes, serious gliches in the graphics that are displayed. let me get a list of games together ... ill search the msg boards here for a list that may have already been started? but, the first nes games that come to mind are: joshua, knight rider, choplifter, and mike tyson's punch out ...

also (so sorry, newbie here) what are PAL games versus NTSC?

most of the above games are US releases i think.

[_Em]

US releases are all NTSC; EU releases are all PAL. PAL systems use a different framerate and image resolution than NTSC systems, which would account for strangely displayed graphics. In my opinion, the PAL standard is the better one

[Tinnus]

The emulator should display both correctly.

maxer, can you take a photo of one of these games running so I can SEE what exactly the problem is?

[_Em]

Just so you know, HRCaptDA can take screenshots; just set an appropriate length timer, trigger it, then launch LJP and launch the game. Tap the middle of the screen and wait for the flash It does cover things up with the screen buttons, but you can see everything in the background.

[maxer]

will take a few screen shots and report back. thanks for the tips ya'll!

edit: have taken a few screen shots, will post up next week!

[maxer]

it only took me a month, but here are screen shots of several games that have graphical "glitches" in them.

you can check them out by following the path below:

new.photos.yahoo.com/maxfield.janer/album/576460762391597235


ps - great job on the progress of LJX Tinnus!!

[Tinnus]

Hmm... seems to be a bug in the PPU (NES graphic chip) emulation. Something deep in the emulator that I'm probably not smart enough to tackle ;D Although yoyofr himself could try, I guess.

Funny that no one else had this problem before though... well, at least didn't mention it.

[astroraptor]

Hmm, funny indeed seeing as I also have a Treo 650 and I also have pre RC3. I tried Goonies before and it had the same garbage on screen. My guess is that those games are bad dumps or incompatible in some way. Also, if you have the emulator set to the lowest graphics with frame skipping, some games can start to look crappy, but honestly, this is on a smartphone so I don't really pay much attention to it.

[neko68k]

Even more odd... I've played through mike tysons punchout in it's entirety without any graphical glitches. This was with rc2. maybe something broke in rc3?

[needhelp]

Believe it or not, I played that game as well, yet, with RC2, I had glitches in the game, it ran fine during the matches, but sometimes for the pictures, it put in random characters
Anyways, it was still playable, although, I wanted to point that out.

[neko68k]

Ah I see. Maybe I just never paid attention. Anyway, the NES emulator in LJP is pretty old and in serious need of updating or outright replacement. Actually all of the emus are pretty much deprecated on other platforms. Pity I never got the hang of all that ARM wackyness on the palm, silly palm and their 68k abstraction layer

[Tinnus]

I don't see a problem with the NES core in LJP (except maybe that graphical glitch which is VERY rare considering the thousands of ROMs that run 100% well).

To be honest, it's the best, fastest and most compatible emulator I've seen to date.

The problems with LJP regard the implementation of some things between the emulators and the framework/interface/users, not that the emulators themselves are bad (well, most of them). Some of the modules are just badly implemented (SMS-crashes, NGP-speed, WS-sound) but those are problems that are in the list to be solved with LJX or whatever you call it these days

[needhelp]

ok, just wanted to point that out.

[maxer]

Thanks for everyones input. I agree, not a huge issue, but thought it important enough to bring attention to - just in case. By the way, hows progress going Tinnus?

[countbuggula]

I've seen similar things but didn't worry about them because I've seen the same kind of things on desktop emulation and figured it just was an issue with the emulator. Most of them aren't by any means bad enough to make a game unplayable so I haven't worried about it.

[neko68k]

Didn't mean to sound ungrateful
I was just saying, for example, snes9x is many versions out of date in ljp. the nes emu is missing several mappers, fds support and some other odds and ends.

[Tinnus]

I'll look into all of these when I implement the individual modules for LJX. Don't worry, the final thing will be VERY good. Unfortunately I've just had zero time this pasth month to work on it

[needhelp]

OH NO
Just joking
Keep up the good work

[Tinnus]

BTW, plese tell me any mappers you think are missing, and I'll try to implement them.

[_Em]

NEStopia has a pretty complete mapper list, if you want a reference.

[Tinnus]

Well, I meant ones that you actually MISS. Not just aren't imlemented for the sake of being there.

There's code for some mappers in therebut they're not being used for whatever reason; I think I could implement those with little work.

[countbuggula]

Do you know of a good place where I can reference games to mappers? I could list off several games that run poorly or with graphical glitches, but it would be simpler to just tell you which mappers need work.

[Tinnus]

I just mean unsopported mappers. Basically, if a mapper isn't supported, the game won't work at all. Also, a game having some kind of bug pr glitch doesn't necessarily mean it's a problem in the mapper code (might be related to another coincidence in the games).

[countbuggula]

Hmm...ok I get that, but why would certain games emulate fine on one emulator but have glitched graphics on another? If it's not mapper-related what's causing that?

[Tinnus]

Why, there's a bug in the emulator somewhere that causes the rendering to be incorrect. That would be most likely in the graphics code, but might be in the memory (cannot access the place where the graphics are, or causes corruption) or the CPU (wrong emulation of some opcode).

The mappers are just different ways to access memory. A trick the NES used to have more RAM in a reduced address space. It's nothing very complex or anything--the code for most mappers is just two small functions and such.