Street Fighter 2 arcade bootleg m5 running on a CPS1

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Drakon
Posts: 46
Joined: Sat Dec 06, 2008 8:22 am

Street Fighter 2 arcade bootleg m5 running on a CPS1

Post by Drakon » Mon Mar 19, 2012 1:51 pm

Okay before I get into details let me explain what made this mod so darn complicated. The Street Fighter 2 M5 arcade hack is a brilliant hack, but this hack was only released on a bootleg pcb and it was never released on the capcom cps1 system which is what normal street fighter 2 ran on. The bootleg pcb hardware runs differently from a cps1 so it's AMAZING that this hack was even possible.

Since the M5 hack is brilliant so I decided to look into seeing just exactly how the rum dumps "tick".

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The top hex is from the regular sf2 champion edition rom, the second / third hex boxes are from the m5 hack dumps

I did some web searching and wound up on this site:

http://www.darkfader.net/toolbox/

I downloaded the "interleave.zip" tool. It's a dos command based program so I wrote a batch file for it that takes files named 1, 2, and combines them back together in the regular interleaved pattern. Doing so made the hex look just like the champion edition rom dump

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Then I split the file into the two 512 k separate files it needs. I split the roms at the proper spot and copied them into the sf2ce folder and it ran but unfortunately the sprite layer is flickering. The good news is that everything else works perfectly, audio is fine, controls are fine, even all the m5 hacks are running great even though the system is running it like it would be on a normal cps1. So I've managed to decrypt these roms on my own using tools I found on the net. I tested this M5 dump running as CE in multiple emulators and each emulator has the graphics flickering. I even did the same process on the m7 hack and got the same results, it ran but gave me flickering graphics in the emulator when loaded under the normal cps1 profile. Burning these cleaned up roms to eproms worked on my cps1 but the sprites rarely drew and when they appeared they were flickering. Also the controls weren't responding. I dug around in the cps1.c file from the mame source code and certainly enough the m5 bootleg pcb draws sprites in the opposite direction and has different controller inputs.

Since the champion edition rom dumps and the m5 cleaned up dump are very similar I tried copying data back and forth between the two rom sets and seeing what effect it would have. I did a LOT of trial and error and eventually found the programming that applies all the game hacks while keeping the cps1 compatible programming in tact. The M5 bootleg romset now runs 100% flawlessly on my official cps1 arcade pcb.

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Here's the rom zip:

http://www.mediafire.com/?7tkputeihk775e2

If you rename this zip sf2ce.zip winkawaks will run it fine and I assume other cps1 emulators will run it too. To upgrade your champion edition, turbo, or rainbow edition to this m5 hack just burn the 21, 22 and 23 roms and it should run fine on your regular cps1 arcade pcb. The 21 rom is just the regular champion edition rom and the 22 / 23 roms are the hacked up m5 roms.

Here's the video to prove it truly works:

http://www.youtube.com/watch?v=u0o7HeFb ... ature=plcp

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