List of all the NES emulators in development

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cpow
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Post by cpow » Fri May 28, 2010 6:45 pm

tokumaru wrote:A game that is notoriously hard to emulate is Super Cars. It uses $2004 reads for timing purposes, and very few emulators handle such reads correctly, AFAIK.
Wow. I just tried that one in NESICIDE and it looks great. I'm confused though because I also tried it in Nintendulator 0.965 and the bridges don't show up. Anyone have a video of playing track 1 on a real NES? =]

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tokumaru
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Post by tokumaru » Fri May 28, 2010 6:58 pm

I think Nestopia emulates it correctly. Nintendulator has some problems with the name tables (weird, huh?) and FCEUX has problems with the gray bar at the top of the screen.

EDIT: I just noticed that Nintendulator complains that an invalid opcode is used (LAX). Until now I wasn't aware of commercial games that use illegal opcodes.

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Post by cpow » Fri May 28, 2010 7:09 pm

tokumaru wrote: EDIT: I just noticed that Nintendulator complains that an invalid opcode is used (LAX). Until now I wasn't aware of commercial games that use illegal opcodes.
Yeah I saw some other discussion about that on here. I had to turn off the debug window to get the game to run...

Part of the reason why I decided to just allow execution of illegals and flag them with an icon in my code browser. I need a 22x22 PNG of a bomb for the KIL opcodes. =]

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Post by tepples » Sat May 29, 2010 4:30 am

NESICIDE wrote:I need a 22x22 PNG of a bomb for the KIL opcodes. =]
Why 22x22? If 16x16 is OK, you could just use the bomb from Concentration Room. Or, because the analogous opcode on 65C816 is STP, try the logo of STP (Scientifically Treated Petroleum).

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cpow
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Post by cpow » Sat May 29, 2010 5:50 am

tepples wrote:
NESICIDE wrote:I need a 22x22 PNG of a bomb for the KIL opcodes. =]
Why 22x22? If 16x16 is OK, you could just use the bomb from Concentration Room. Or, because the analogous opcode on 65C816 is STP, try the logo of STP (Scientifically Treated Petroleum).
Ahh that's a good idea...a STOP sign for KIL opcodes (but only when they're about to be executed though, otherwise there'd be stop-signs all over the data).

I couldn't find the 16x16 bomb... ?

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Post by koitsu » Sat May 29, 2010 8:34 am

tokumaru wrote:EDIT: I just noticed that Nintendulator complains that an invalid opcode is used (LAX). Until now I wasn't aware of commercial games that use illegal opcodes.
Are folks sure it isn't a bad dump or that there isn't a bug in the emulator that's causing it to somehow set PC to the wrong thing? (I can think of mapper emulation bugs that might cause the wrong PRG page to be switched in and thus wrong code getting executed)

Just sayin'.

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Post by Kasumi » Sat May 29, 2010 8:39 am

This bomb:

Image

I found it in the pattern data.

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Post by cpow » Sat May 29, 2010 3:43 pm

koitsu wrote:
tokumaru wrote:EDIT: I just noticed that Nintendulator complains that an invalid opcode is used (LAX). Until now I wasn't aware of commercial games that use illegal opcodes.
Are folks sure it isn't a bad dump or that there isn't a bug in the emulator that's causing it to somehow set PC to the wrong thing? (I can think of mapper emulation bugs that might cause the wrong PRG page to be switched in and thus wrong code getting executed)

Just sayin'.
Typically if the game didn't intentionally execute the undocumented opcode I would expect it to be completely inoperative -- especially if it was a bankswitch fault in the emulator! The game seems to work fine, but there's a few scanlines at the top that are a bit mangled looking. But, I can't say for sure because I never had it on a real NES. That's why I was wondering if anyone has a video of it being played on a real NES or even with a PowerPak [another thing I don't have].

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Post by tokumaru » Sat May 29, 2010 5:09 pm

I'm pretty sure I tried it on my PowerPak back when I was researching ways to hide vertical scrolling glitches, and I seem to remember it working just like in Nestopia. The gray "border" at the top is intentional, it's meant to hide vertical scrolling artifacts. It's supposed to be a steady (not shaky like in FCEUX), 20-scanlines tall border.

The problem is that in order to time the height of that border the game relies on $2004 reads to detect the start of the frame, and not many emulators have such writes implemented correctly.

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Post by James » Sun Jun 06, 2010 9:18 pm

koitsu wrote:I spent the past 3 hours this morning adding the following document to the Wiki:

http://wiki.nesdev.com/w/index.php/Emulators
I'm not sure where my emulator belongs... while I continue to develop it, on occasion, it's more or less complete and has been available for download for years now. I wouldn't say it's popular, though. Maybe there needs to be a third section to differentiate working emulators from those that are works-in-progress?

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Post by koitsu » Mon Jun 07, 2010 9:16 am

James wrote:
koitsu wrote:I spent the past 3 hours this morning adding the following document to the Wiki:

http://wiki.nesdev.com/w/index.php/Emulators
I'm not sure where my emulator belongs... while I continue to develop it, on occasion, it's more or less complete and has been available for download for years now. I wouldn't say it's popular, though. Maybe there needs to be a third section to differentiate working emulators from those that are works-in-progress?
It needs to go in the bottom portion of the page, along with all the other emulators. Popular/common ones are at the top.

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Post by albailey » Tue Jun 08, 2010 1:50 pm

Yeah mine would definitely not be considered working. (although it is entertaining)

Some NROM games look and run fine, while others (like Galaxian) look like a mess.


I saw a post earlier about Super Cars. Is there a link or list somewhere of the games that are tricky to emulate?


For example, I think Galaxian is tricky for a number of reasons, but at least one reason is that it uses a vertical scroll value of 255 (which I think acts like a negative scroll).

I like the idea of indicating NROM games that have quirks since that allows emulator writers to avoid mapper compliance until they are sure other important aspects are working.

Al

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Petruza
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Post by Petruza » Tue Jun 08, 2010 3:12 pm

Yes that would be great.
We should have a ROMs list on our wiki with as much relevant info for emulator developers as possible.
A good start is http://tuxnes.sourceforge.net/nesmapper.txt

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Post by tepples » Tue Jun 08, 2010 4:09 pm

albailey wrote:Is there a link or list somewhere of the games that are tricky to emulate?
There is such a list on the wiki, along with an incomplete list of glitches that should be there. Anyone who can help make these lists more complete is invited to do so.

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Petruza
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Post by Petruza » Tue Jun 08, 2010 4:59 pm

Is there a way to get a list of all the articles of the wiki, instead of having to find a link to one?

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