Possible Bug with Expanded LoRoms?

[justin3009]

I'm not entirely sure if this post should be here but I've been working on a project and had to expand Mega Man X3, a LoRom, to be 32 Mbit instead of 16 Mbit, giving me quite a bit more room to mess with.

The graphics I had added load perfectly fine up in SNES9X which leads me to believe it's an emulator issue, but this is what happens in ZSNES 1.51 and any other verison for that matter.

- Those are graphics in bank 20, the start of huge chunk of empty space.

For what I've seen above and talked to a couple others, it seems to be an emulator issue but I'm not entirely sure. Any of the experts want to take a whack at this? Can I truly NOT expand the rom and load graphics from this bank? (I think I even had issues with code as well :/ ) I hope that isn't the case because that's really going to throw a huge project into the trash.

Edit: I used Lunar Expand in case that information is needed.

Edit 2: The Chksum is bad but that's most likely due to the rom expansion. But that shouldn't even effect it in this manner..

System Specs
=================
OS: Windows 7 Ultimate 32-Bit
Model: Inspiron 531
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor+ (2 CPUs), ~2.3ghz
Memory: 2048 RAM
Direct X 11

Video: NVIDIA GeForce 9500 GT

[badinsults]

It is entirely possible that zsnes is not interpreting the expanded rom properly. Your best bet is to modify the emulator to see if this is the case. It is possible that zsnes doesn't like you expanding a game that uses the CX-4 chip, check the specs of the chip to see what it expects.

[odditude]

i'd try it in bsnes and (if there are any copiers that support C4) on an actual console. i don't have a copier or flash cart, but there's likely someone here who does.

(posted in the project thread on rhdn, too, in case the op doesn't come back.)

[justin3009]

Yep, it bugs up on Bsnes as well Not as bad but it still bugs up to the point of graphics not even being readable.

The alternative method I have to "fix" this bug maybe is to bump all of the text to bank 20 (41) or more..but I think that'll cause errors with dialogue then. If it does, I'm really not sure what to do to fix this, if it's even fixable at all.

Edit: The information for the CX4 chips is on this site.

http://users.tpg.com.au/advlink/dsp/cx4.html

Edit 2: Strange. I can load text outside in those banks but graphics don't work.

[grinvader]

"Lorom" is oversimplified. C4 is not lorom. You cannot do what you want without creating a unique mapper.

[Rashidi]

is there any screenshot on how it look on snes9x?

[justin3009]

- That's what it looks like.

[grinvader]

Probably exploiting snes9x' way to handle c4 memmapping.

Zsnes only maps the stuff the pages needed by the 2 games, and i don't really know what bsnes does these days.


Basically, you may expand the rom, but the resulting stuff isn't accessible.

[justin3009]

It seems like expanding the rom works but only graphics are inaccessible. I bumped text out into those banks as a test and it was able to loaded perfectly fine. So it seems maybe a CX4 limitation?

Either way, as long as I'm able to bump extra stuff into the other banks then that should leave enough room to add in whatever graphics we may need.