It is becoming evident that there may be multiple version of the River City Ransom (NTSC-US) ROM that were released in the United States.
On my cartridge, the first gang encountered (outside of Cross Town High) is ¤always¤ The Frat Guys. However, if I use FCEUX with a ROM, the first gang encountered is ¤always¤ The Generic Dudes. Moreover, Darkwing_Duck_SDA's 7:40.35 run also starts with The Generic Dudes. Elipsis who is using either a PowerPak or EverDrive also always starts with The Generic Dudes. Again, this points to different ROM versions.
On my cartridge, the top of the label says, "NES-DN-USA MADE IN JAPAN". On the reverse, the numbers "1 1" are imprinted in the top-left corner of the label, and "REV-A" is printed on the top-right corner of the label in white text. I received this cartridge I believe in 1990, for my birthday.
If anyone has different cartridge labels than the above, please provide information so folks can identify cartridge versions. The differences between the runs likely do not provide any material advantage for speedruns, but in the event it is discovered that one particular version imparts some advantage, this information will be needed to provide separate categories.
Making another post here, so others can help.
I now have handled 5 different RCR carts. All of them, when put in my NES, give Frat Guys on the initial screen. They all have different imprinted numbers on the back, which are likely just lot/batch numbers. Feasel and Darkwing get Generic Dudes on the initial screen, even if they come from the same lot/batch. This made me think there were two ROM versions.
However... Feasel also has a "1 1" cart, but gets Generic Dudes instead of Frat Guys. Additionally the ROM provided by BestOfNES always starts with Generic Dudes on my computer in FCEUX 2.2.2, regardless of PPU. Toad22484 uses the same ROM in a PowerPak, and instead gets Frat Guys. Again, same ROM, different results. This points to there being a slight quirk in the RNG, instead of two ROM versions. I am desperately trying to find out what the actual reality is -- if there were multiple versions of the ROM released by Technos, or if there's just a timing bug. This matters because if there are two versions, I'm actually going to diff both of them and see what is different between the binary and other RCR assets.
How can you help? Well, if you have a River City Ransom ROM, regardless of where it's from, I would be eternally grateful if you can do two things for me:
- Tell me what gang spaws at the beginning of the game on Novice, Fast speed, choosing Ryan.
- The MD5 checksum of the ROM. You can do this with tools built into Windows 7.
To get the MD5 checksum of the ROM, enter the following command at the Windows command line (cmd.exe):
CertUtil -hashfile "C:\PathToRom\RomName.nes" MD5
With that said, I'm providing the first spawn/checksum.
Spawn: Generic Dudes MD5: 29 4e 4f a0 92 db 8e 29 d8 3f 71 e1 37 d1 f9 9f
If you have a different spawn/MD5 combination, please post it. If someone posts a result with a different checksum than the one here, it is immediately clear that multiple ROM versions exist.
CapnGoof,
I tried this with the ROM I've had for years (can't confirm where I got it from, Modify Date is 6/17/2000 if it helps)
My old ROM: Spawn: Generic Dudes MD5: 54 1d 55 26 e0 da 2b da 59 b8 a9 0e dc 58 24 65
I also tested the Big 20 ROM on my system, and got the same first spawn/checksum that you got.
Naturally, I'd much rather have a ROM that spawns Frat Guys, because chains.
Let me know if I can be of any assistance.
Edit: I tried a handful of different ROMs, but I only ever come up with the same two spawn/MD5 combos; the one you listed, and the one I listed. Always Dudes; never Frat. Bizarre.
This rom came from some pack of all the NES games on emuparadise
Nestopia 1.40: Frat Guys Fceux 2.2.2: Generic Dudes
29 4e 4f a0 92 db 8e 29 d8 3f 71 e1 37 d1 f9 9f
Made another test...Big20 ROM: Fceux 2.2.2 and 2.2.0: Generic Dudes Bizhawk: Frat Guys
Same numbers as Yogi..
Need to write up an explanation at some point, but subtle timing differences on different computers (and in different emulators) result in a boundary condition where it flips between Frat Guys and Generic Dudes.
I'll do a writeup on this in the future, complete with annotations of the original 6502 assembler and how it's possible to end up on different sides of the boundary due to clock drift.
MD5 hash of file River City Ransom.nes: 29 4e 4f a0 92 db 8e 29 d8 3f 71 e1 37 d1 f9 9f
Produces Generic Dudes on Everdrive.
