Megaman X2 on Rockman X3 PCB

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Bool
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Joined: Mon Oct 07, 2013 1:50 am

Megaman X2 on Rockman X3 PCB

Post by Bool »

Hello everyone,

Firstable, sorry for my english, i'm french,

So, this week end i tried to convert a JAP RockMan X3 to a Megaman X2...

But it failed...

How i proceeded :

-Downloaded a Rom U of Megaman X2 (16Mb).
-Checked Header presence => Ok.
-Removed Protection with ucon64 => Ok.
-Burn the rom in a 27C160 with my GQ4X => Ok no error.
-And then soldered a socket following a GSU2 pinout on my Rockman X3 PCB.

But, the problem is here :

My game is booting, i can see the three blue lines intro... then Capcom Logo... And then i've got blackscreen. I can not access to the title screen...

So i tried with a Megaman X3 Rom in a c160, putted in my socket, and it worked !

But why isn't it working with Megaman X2?

Can someome help me ? have you ever tried this mod ? Is this a pinout problem with this X2? a Rom problem (Tried with U and E Rom, same thing...).

Thanks in advance,

Br,

Bool.
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MottZilla
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Re: Megaman X2 on Rockman X3 PCB

Post by MottZilla »

Mega Man X2 sets the Cx4 configuration differently than Mega Man X3. I don't recall the details. It's related to ROM configuration. I think X2 might use two MaskROMs. To use just one, you'd probably need to alter the ROM image to set the register for a single ROM chip.
qwertymodo
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Re: Megaman X2 on Rockman X3 PCB

Post by qwertymodo »

RMX2/MMX2 uses 2x8Mbit ROM chips, RMX3/MMX3 uses 1x16Mbit ROM. Here's what byuu told me about running RMX2 on an RMX3 board
byuu wrote:And by the way, if you do attempt to flash in RMX2, it will need one tiny code patch. Somewhere in the game it writes #$01 to $7f52. That needs to be commented out or set to #$00. (I may have the bit flipped in my head again.) The register toggles whether banks 20-3f go to the second ROM chip or not. Which obviously there will only be one.
Last edited by qwertymodo on Mon Oct 21, 2013 11:43 am, edited 1 time in total.
Bool
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Re: Megaman X2 on Rockman X3 PCB

Post by Bool »

Hi,

Thanks for your answer, unfortunately i don't know how to edit rom or to patch roms,

So I bought a RMX2 Cart, i'll use it to do my MMX2.

Thanks again
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Bregalad
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Re: Megaman X2 on Rockman X3 PCB

Post by Bregalad »

In other words, you're just wanting to make lots of profits by selling a MMX2 cart very expensive by buying MMX2/3 carts for very cheap.

You're free to do this, but don't count on other people's "kind" help.
qwertymodo
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Re: Megaman X2 on Rockman X3 PCB

Post by qwertymodo »

Bregalad wrote:In other words, you're just wanting to make lots of profits by selling a MMX2 cart very expensive by buying MMX2/3 carts for very cheap.

You're free to do this, but don't count on other people's "kind" help.
If that was the goal, then there would be no point in putting MMX2 on an RMX3 board, because RMX2 is consistantly cheaper, and no patching is needed. MMX3 on an RMX2 board? Then you might have a point.
Bool
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Re: Megaman X2 on Rockman X3 PCB

Post by Bool »

Hello, thanks for your answers,
Bregalad wrote:In other words, you're just wanting to make lots of profits by selling a MMX2 cart very expensive by buying MMX2/3 carts for very cheap.

You're free to do this, but don't count on other people's "kind" help.
Why do you say that while you don't know what i wanted to do?

Thanks qwertymodo, you answered before me.

I wanted to do that cause i bought 2 rmx3 carts, i thought i would be able to do both mmx2 and mmx3 because of the cx4 presence and also because rmx3 has 1 maskrom (avoiding 70+ wires and 2 27c801).

I have now bought a rmx2 cart (cause i'm not good enought to edit rom, work with hex etc...) and a friend of mine found a way to do a mmx2 with only one eprom.

That's it.
qwertymodo
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Re: Megaman X2 on Rockman X3 PCB

Post by qwertymodo »

I really wish the MMX3 Zero hack worked on hardware so there was a legitimate reason for CX4 repros... but really, a straight JAP->USA conversion? Just bite the bullet and buy the real deal... :(

Oh well, if you really want to run RMX2 on an RMX3 board without patching the ROM, you can probably just AND the CX4's two /CE outputs into the ROM's /CE and it should work with a single ROM.
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Drakon
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Re: Megaman X2 on Rockman X3 PCB

Post by Drakon »

Thank god I'm not a fan of x2/3, sounds like a pain.
qwertymodo
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Re: Megaman X2 on Rockman X3 PCB

Post by qwertymodo »

Drakon wrote:Thank god I'm not a fan of x2/3, sounds like a pain.
Meh, it's not really any worse than any other repro, other than the SMD soldering. I just wish the USA versions of MMX2/3 weren't so frakking expensive, they're pretty much the only 2 retail titles still on my wish list to collect, but I have no interest in a repro, even with the $100 price difference.

I'm a bit torn on the subject of repros. I've built a few myself for my own personal collection (Zelda: PW, Metroid Super Zero Mission, and a couple other ROM hacks), and I'm usually happy to help out, but usually I'd draw the line at reproing a commercially available game... (Earthbound, anyone?), but when you're talking a 5x price difference between regions... dunno. If you want to make your own personal repro, go for it. On the other hand, I may not be as jaded as some of the other users here, but if I start seeing MMX2/3 repros on Ebay...
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Drakon
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Re: Megaman X2 on Rockman X3 PCB

Post by Drakon »

qwertymodo wrote:
Drakon wrote:Thank god I'm not a fan of x2/3, sounds like a pain.
Meh, it's not really any worse than any other repro, other than the SMD soldering. I just wish the USA versions of MMX2/3 weren't so frakking expensive, they're pretty much the only 2 retail titles still on my wish list to collect, but I have no interest in a repro, even with the $100 price difference.

I'm a bit torn on the subject of repros. I've built a few myself for my own personal collection (Zelda: PW, Metroid Super Zero Mission, and a couple other ROM hacks), and I'm usually happy to help out, but usually I'd draw the line at reproing a commercially available game... (Earthbound, anyone?), but when you're talking a 5x price difference between regions... dunno. If you want to make your own personal repro, go for it. On the other hand, I may not be as jaded as some of the other users here, but if I start seeing MMX2/3 repros on Ebay...
Haha I just watched that the other day. I agree I get annoyed when people want to learn something about modding just to make money and they don't really take interest in how or why it works.
twitch
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Re: Megaman X2 on Rockman X3 PCB

Post by twitch »

Im sorry to dig out this thread - but i tried to put an X2 Rom on a X3 PCB....

I cant find the position in the rom .. @ 0x007f50 there is only FFFF FFFF ....

has someone successfully patched the rom?


rgds dario
lidnariq
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Re: Megaman X2 on Rockman X3 PCB

Post by lidnariq »

What byuu meant was:
  • Somewhere in the ROM
  • there is a series of 65816 instructions
  • That writes a specific value (1 or 0)
  • To the CX4's function register at $7F52
To figure out how to patch this, you'll need to load the game in a debugging emulator and set a breakpoint on that write, and then patch the corresponding bit of code in the ROM. Assuming it only happens once.
twitch
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Re: Megaman X2 on Rockman X3 PCB

Post by twitch »

Thank you for your respond but i dont think im capable of doing this - so then there will be no x3/x2 switching on my module if not someone already made a patch...

rgds dario
Markfrizb
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Re: Megaman X2 on Rockman X3 PCB

Post by Markfrizb »

qwertymodo wrote:I really wish the MMX3 Zero hack worked on hardware so there was a legitimate reason for CX4 repros...
I didn't realize this thread was so old..... but since it's been revived, I'll add to it.

Time index 4:33, fully playable zero on real hardware.
https://youtu.be/UlMQPt2F4SQ

And a YouTube review of it:
https://youtu.be/fOD_3UIdYmc Time index 18:15
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