SNES Cx4 ROM

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Special T
Datter
Posts: 15
Joined: 16 Apr 2009 05:07

SNES Cx4 ROM

Post by Special T » 02 Aug 2011 03:16

I'm not sure if this is something that would be added to the SNES dat file but I figured I would post it here and let you all know about it.

Taken from byuu's homepage on 06/08/2011
Cx4 LLE2011-06-08

Thanks to the efforts of Jonas Quinn for discovering that the Cx4 program ROM is actually embedded inside the Mega Man X2/X3 mask ROMs themselves, Segher for reverse engineering a high level understanding of the instruction set, and Overload for exploiting these to dump the data ROM, we now have sufficient information to start on low-level emulation of the Cx4. Which means it's my turn.

I'd also like to thank Dr. Decapitator for the high-res scans of the Cx4, which allowed us to identify much information about the chip that will be invaluable in emulating it; and Lukasz for the donation that made this possible.

While we currently have high-level emulation (HLE) support for the Cx4, LLE will bring improved accuracy with actual timing support and bit-perfect math calculations. That is, assuming we are successful.

I am able to host the cx4.bin file this time, as the program ROM is separate and part of the MMX2/3 mask ROMs. The data ROM is nothing more than five math tables (inverse, square root, sin, cos, tan) which are not copyrightable. I do not plan on embedding it into bsnes, as I would like to allow for the possibility of using a custom data ROM ala the uPD7725/96050 emulation.
Cx4 Page

FST
Posts: 2
Joined: 29 Oct 2011 21:29

Re: SNES Cx4 ROM

Post by FST » 29 Oct 2011 23:03

I think it would make most sense to classify the Cx4 data ROM file "cx4.bin" as belonging to the "Mega Man X2" and "Mega Man X3" ROM sets.

PS Actually, similar thing goes for all the DSP program ROMs that to date have been dumped successfully (DSP-1/1A/1B, DSP-2, DSP-3, DSP-4, ST-0010 and ST-0011). Recent versions of bsnes already employ LLE of these ICs, which requires their program ROMs for the respective titles to work.

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