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tiff_lee

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Apart from the multi interest thread HERE and a random thread on the NG forum I haven't been able to find much info regarding conversions with the ZN1 board.

Is it possible to convert this board from one capcom game to another? the thread on NG forum suggests that as long as the game being converted is from the same developer (Capcom in this instance) then it's just a rom swap?

If so where would I find the information necessary as to what needs to be swapped? I guess this is something you can find from MAME, I often see people saying 'check the mame source' etc but tbh i've never used mame for this kind of stuff.

cheers
 
So looking here

http://www.arcaderestoration.com/games/8420/Star+Gladiator+Episode+I+Final+Crusade.aspx
http://www.arcaderestoration.com/games/8530/Street+Fighter+EX+Plus.aspx

and checking the ROMs used it appears 4 of them are common with both games 78081g503.ic655 , cp01.ic652, m534002c-13.ic353 and msm27c402zb.ic353.

So I can see all the different ROMs that would need to be burnt and their size but apart from actually looking at a board is their an easy way to determine what ROM chip they should be burnt to?
 
Thanks for that, at a glance some of it makes sense the board layout and list of components i'll have to give that a good going over.

While I obviously want to convert this board I just didn't want to be told yeah burn these ROMs and swap them out job done. I actually want to learn a bit more about the tools other people use when identifying stuff like this (i.e using MAME for more than just games which is only my experience)
 
Ok think I have identified all the eproms I need to do the conversion with the exception of the security chip.

While the Capcom ZN1 has the same security chip for every game on the main board CP01 (http://members.iinet.net.au/~lantra9jp1_nbn/gurudumps/ZNx/index.html) the security chip differs on each game rom board. So mine has CP03 for Star Gladiator and SFEXplus requires CP04.

The security chip is a CAT702(103090-00203) and searching google comes up with very little. Do I need a replacement to match with the game then?
 
I haven’t done it but you can convert EX to EX+, but only because they both run CP04 protection chips. Any other conversions would require the appropriate protection chip, or perhaps some kind of rom patching that I’ve never heard about.

The thing that is the same, manufacturer to manufacturer, is the bios. So you can swap rom boards within brands (eg all capcom zn2 rom plays on any other capcom zn2 main board).
 
You can't do zn conversions without also swapping the security chip. Currently there is no way to make a new security chip so until that happens no conversions are possible unless you're just doing a region swap ( or as Ekorz pointed out swapping from sfex to sfex+).

The security chip code has been reverse engineered in mame, but again there is no chip you could just dump that code to. You'd need to build a small sub board with an mcu programmable logic or something similar. It seems totally doable but no one has actually done it yet.
 
I patched a ZN1 game (don't remember the game) for @Mitsurugi-w just to see if it was possible to circumvent the security chip, and result is it is.
 
haha we all get there mate.

Ok well I guess this puts a stop to this conversion then.

How hard is ROM patching? never done it before, the closest thing I ever done to that is probably memory hacking on games or trying to reverse engineering an exe to find the serial key using ollydbg, neither are the same I know.
 
How hard is ROM patching? never done it before
for security patching in simple terms you do this:
1. look at MAME source to see if there are any points in memory or program code related to security
2. Run the game in MAME with the debugger, stopping at the points you identified in step 1
3. see if you can determine out how the code works and how it can be modified for your needs
4. use a hex editor to modify the points in the ROM you identified in step 3.

The security chip is well documented if you want to take a look: https://github.com/mamedev/mame/blob/master/src/mame/machine/cat702.cpp
 
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