I have finally figured out how to convert the larger VT03 .WXN games into .BIN format, so that they can be used with EmuVT. There are two reasons why doing so is difficult:

• EmuVT expects PRG and CHR data in one single address space, i.e. in OneBus form. .WXN games always use separate PRG/CHR address spaces, even the VT03 ones. Combining them into one address space is difficult because ...
  • ... .WXN games' PRG and CHR bank register values each expect their data to start at offset zero in their respective address spaces. This means that either all bank register writes must be modified, or the OneBus registers that mask regular bank writes ("PS", $410B) and upper bank registers ("PQ2", $4109) must be written to. These writes would need to be added to the existing game code.
    
  • ... on the OneBus, the last 16 KiB PRG bank is always the last 32, 64, 128, 256 or 512 KiB bank of the .BIN file. Depending on the size of the CHR data, this may require rearranging the several PRG and CHR banks.
• .WXN shuffles the five CHR banking register numbers around: $2012,$2013,$2014,$2015,$2016,$2017 become $2013,$2012,$2017,$2016,$2015,$2014, and MMC3 registers 0,1,2,3,4,5 become 5,4,3,2,1,0. The only way to correct this for EmuVT is to manually patch all banking register numbers.

It's quite a laborious process, and I see no way of doing this automatically. These oddities of .WXN files undoubtedly exist for protection reasons.

Here are few larger .WXN VT03 games converted to .BIN format as a proof of concept. These particular games to my knowledge have not been available anywhere in VT03 .BIN format.

I'm certainly not wasting more time doing this for the other 112 VT03 .WXN ROMs in taizou's archive. Instead, I will try to add VT03 support to Nintendulator. I already managed to add VT02 support, including the additional sound channels that EmuVT does not emulate, and the ability to load .WXN files directly. At least all those Waixing .WXN RPG/strategy games now run perfectly (as far as what I can tell), including the SRAM functionality.[/s]

Because .WXN VT03 games can now be run directly in my Nintendulator build, I have removed the download to prevent the spread of more hacked ROM images.

The 9-in-1 King001 multicart has the games The Lion King, Earthworm Jim 2, Super Aladdin, Boogerman, Somari, T.M.N.T. Tournament Fighters, Mortal Kombat 3, Captain Tsubasa 2 Arabic (as Boy Soccer Team 2) and Taito Basketball on it. Its menu is depicted in the attached screenshot. If someone has this multicart in its original physical form, could that person please play The Lion King until the first boss is defeated and tell me if the game freezes at that point?

Background: Of the emulators that I have tried, only FCEUX and Nestopia Plus even run this ROM image at all (in .UNF format). FCEUX freezes after the "The Pridelands" screen because it decodes the CPU address too restrictively. Nestopia Plus runs the game until the first boss is defeated, then freezes. I can get as far as Nestopia Plus by implementing the board in Nintendulator as I described. After the first boss is defeated, the game basically hashes a section of PRG-ROM to check against hackers having modified the game (code executed in RAM at $0682). Since that checksum does not match the expected value in Nestopia Plus' and my emulation, the game freezes on purpose. While I cannot rule out that we both just still get the bankswitching slightly wrong (even though everything else works fine), I have a hunch that the game was modified for multicart inclusion without the expected checksum being adjusted, and the multicart manufacturer did not notice because one has to play the game a bit to notice it.

I have crossposted this topic from nesdev, as CaH4e3, who originally dumped the cartridge, says that he no longer has it, and this message board is on-topic enough to assume that somebody else here might physically possess this multicart.

Attachments:

• 9_in_1_King001__Unl___U____.png (2.47 KB)

Maybe I'm being Captain Obvious here, but is Gouder Ltd. (of Street Fighter IV fame) just the anglicized name of Ge De Industry (哥德有限公同), or are they supposed to be separate companies?

Here I plan to list ROM images that are found in the various collections that I have been unable to run, or that only run with implausible emulator behavior. Any information on them is appreciated.

ROM CRC32=032ae837, GoodNES 3.23b's "Street Fighter II - The World Warrior (Unl) [a3][!]". Starts with an unknown write to $6808, and has a bad NMI vector. If it weren't for the [!] tag, I would assume this was some kind of multicart rip.

ROM CRC32=193F3412, GoodNES 3.23b's "Mortal Kombat (JJ-01) (Ch) [!]". Seems MMC3-like (and is set to mapper 4), but at some point start executing data as code.

ROM CRC32=FFB3E74A, GoodNES 3.23b's "King of Fighters 97, The (AKA Colour 2001 Streetfighter II) (Unl) [!]". Seems to be an MMC3 hack of "King of Fighters 97, The (Rex Soft) (Unl) (U)[!]" (which emulators so far only support in UNIF format). Does not run in the current emulators I tried, but it does run in older ones. The difference seems to be whether the emulator assumes that the power-on value of register $4017 is $00 (which freezes the game due to non-stop firing of Frame IRQs), or $40 with allows the game to run. Given that it is documented that the default value is $00, I wonder how this could ever work on real hardware.

ROM CRC32=08F3544B, GoodNES 3.23b's "King of Fighters 99, The (Unl)". Same issue with this name hack.

The 1989 version of 3D Block is credited to Hwang Shinwei himself, not to RCM group. The game does not work correctly in emulators, as it expects some rather strange scanline IRQs. I would like to try my hand at getting the game to work, but lacking the actual cartridge, I would need at least a real-hardware (with real cartridge) video of that version in action to know what kind of scanline effects I should be getting. Can anyone provide, or guide me to, such a video?