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.

I have uploaded a video that shows the Bit Corp. version of the game glitching in Nestopia, and as one forum reader confirmed, on an AV Famicom.

GoodNES 3.23b has a ROM named "Duck Maze (HES) [!]" which has the same copyright-bearing title screen, but a different CRC32. The different bytes are as follows (left: GoodNES 3.23b ROM, right image: your ROM image:

Code:

 

00005705: B1 F8
00005706: C1 B1
00005707: 71 C1
00005708: B3 71
00005709: C9 B3
0000570A: 0A 91
0000570B: 90 B3
0000570C: 02 29
0000570D: E9 10
0000570E: 0A F0
0000570F: 91 04
00005710: B3 38
00005711: 88 4C
00005712: 30 05
00005713: 06 D7
00005714: A9 18
00005715: 00 B1
00005716: 71 B3
00005717: B3 29
00005718: 91 0F
00005719: B3 91
0000571A: C8 B3
0000571B: EA 88
0000571C: 88 10
0000571D: 10 E8
0000571E: E5 D8

---

Hm, that section is definitely 6502 code, and the byte at 5705 (F8h) is the "SED" opcode, which enters "decimal mode". The NES' 2A03 CPU has no decimal mode. I remember reading on some web site (I do not remember the address, unfortunately) that Bit Corp. developed for Famiclones that still had the decimal mode, and had to fix their games to work on the original Nintendo console that lacked decimal mode. In other words:

• Your ROM is basically Bit Corp's original version of the game and should only work on decimal-mode-having Famiclones, i.e. "Duck (rev0)".
  
• GoodNES 3.23b's "Duck Maze (HES) [!]" is the updated version for original Nintendo consoles, i.e. "Duck (rev1)".

This of course means that your ROM should fail at some point in NES emulators that accurately lack decimal mode, possibly in a rather subtle way. The code seems to be called when starting a stage, and seems to have something to do with the score.

I remember the same web site specifically mentioning a decimal-mode-using version of Bit Corp.'s Othello, the existence of which now has become more likely.

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?

"MLX"

 

Also it was recently discovered that CN-23 JP Ronny is a real thing. Features a NTDEC copyright on the title screen. I asked the owner if he wanted to get it dumped but he refused :/ So that would be your "original caltron version"[/quote]Can the owner be persuaded to take a picture of the title screen?