Romhacking => ROM Hacking Discussion => Topic started by: SPennLUE on June 14, 2022, 01:50:39 PM

Title: Oddity in a cheat in Brawl Brothers (SNES) that turns the game Japanese
Post by: SPennLUE on June 14, 2022, 01:50:39 PM
Many websites say you can access the Japanese version (called Rushing Beat) by pressing b a x y repeatedly on the first screen that appears.

QuoteTo play as the easier Japanese version, sequentially and repeatedly press B, A, X, Y at the white screen with the Jaleco logo until it disappears. If done right, you'll arrive at a glitched screen. Now, press Start, then Down three times and Start again. You'll be at the options screen and when you exit, you'll see the Japanese title screen. Now start your game and enjoy the original version of the game.
Contributed By: ReyVGM

But "repeatedly" isn't a very specific or satisfying answer.  I'm trying to find out the exact trigger for the cheat to work, and I noticed something weird.

Normally, you can wait to enter the code until the "Jaleco!" sound sample is finished.  If successful, the graphics will be glitched until you load a new screen.

My first test was to find the minimum number of button cycles (how many times I pressed b a x y in sequence) to activate the Japanese version, but I could not pin down an exact number.  The code worked less consistently with fewer cycles (which to me is more strange than a 0% or 100% success rate).  It seems you need to input about 10 cycles.

But get this: while the logo is first fading in and the sound sample is playing, you can activate the code with just 3 cycles!  Not only does the code work very consistently, but the graphics are not glitched at all!  This seems to work as often as the "repeatedly" method.

Without knowing how this cheat spread, I don't think we will ever know why the code was initially passed along in such a strange way.

If I ever make any progress on this I will come back with an update, but as of right now it's just food for thought.
Title: Re: Oddity in a cheat in Brawl Brothers (SNES) that turns the game Japanese
Post by: FAST6191 on June 15, 2022, 07:42:19 AM
Code like that is probably from testers that had to test things but maybe had the graphics of the debug screen disabled though not the underlying code/activations. Now curious what else might be on the glitch screen (what happens if you press down two times rather than three for instance).

The repeatedly press makes it sound like there is some period you don't know where the cheat input becomes viable, however to make it "easy" someone probably just said the equivalent of keep pressing until it works. I don't know why they did that rather than timing it (not like anybody playing such a game is not going to have fairly tight timing) but is what it is.

One day I will have to finish that guide to hidden cheat finding, though this might make a nice example so thanks for that if I use it. If you did want to go there though then I imagine this is fairly classic input storage.

You could possibly also convert it to a memory/action replay/gameshark cheat as well. Chances are this sets a flag somewhere in memory. An annoying search to do compared to potions but doable enough -- I would probably make a savestate after you get to the glitch screen, then* do the down three times and start thing, compare before and after for memory changes, then let the menu idle for a little while and see what remained the same, load the savestate and see what changed... repeat until you find it.

*theoretically you might be able to do it just before you press start, however I don't want to risk it being one of the games that sets a flag as soon as the menu option is hovered over rather than confirmed. If it is or you just want to fiddle with something for a bit then you could see what happens if you press up and down in the glitch screen and see what changes in memory. Try different numbers in the result of what you find here as well -- might be other languages or other interesting options as this sort of thing is how hidden characters, weapons, levels, settings and more are often found by cheat makers and how many of the force [language] cheats on the DS work (don't know if you saw the Advance Wars DS in Japanese and similar such cheats).
Title: Re: Oddity in a cheat in Brawl Brothers (SNES) that turns the game Japanese
Post by: SPennLUE on June 15, 2022, 08:20:45 PM
Good info, thanks!  I did try to mess with some memory address via bsnes-debugger, but I had trouble checking the hardware registers for controllers.  The documented memory location for controller input did not seem to change as I fiddled with the buttons, even as the surrounding addresses were updated

The "press start and down and start" thing is more obvious if you run the game.  The corrupted title screen is on the left, the proper Japanese one is on the right.

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Pressing start advances you past the "PUSH START BUTTON" prompt and onto the 1p/2p/vs/options screen. The cursor starts at 1PLAYER GAME.  Press down three times to highlight OPTION MODE, then press Start to choose it. 

The idea is just to unload the garbled title screen.  You can select any of those though, or just wait for the demo to start.

Incidentally, the Japanese title screen behaves a little differently. There is a "slash" sound effect and a fade to white as the title appears.  These are preserved in the glitch title screen.  This means the game is running different logic, not just combing through a different bank.

Could this be an offset error?  For argument's sake, let's say the US title screen is at bank 01.  Inputting the code once would decrement the bank number to 00, where the Japanese version is held.  Entering the code again might decrement the bank again, leaving us in bank FF (unintended territory for this screen) and causing the glitchy display.  This specific example seems very unlikely, since the game sticks with the Japanese display routine while rolling over to new graphics, but hopefully it illustrates the idea.