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Irem M-92 Major Title 2 Conversion to R-Type Leo

ShootTheCore

ShootTheCore

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I have an Irem M-92 Major Title 2 board in the mail purchased specifically with the intention of converting it over to R-Type Leo. The two boards are similar, but the sound code is encrypted on both. Two years ago, a guy going by VxC worked out a way to decrypt the R-Type Leo sound code and re-encrypt it to match up to Major Title 2, as documented here:

http://www.jammaplus.co.uk/forum/fo...rem-m92-major-title-2-to-rtype-leo-conversion

The problem now is that VxC's site with the sound ROMs is down, and Google hasn't helped me in finding it. Does someone here have the same conversion, and if so, would you be willing to dump the sound ROMs for me? Golf is cool and all, but I really prefer shooting aliens...

Another note: I read that Darksoft once considered taking on an Irem M92 conversion aid tool. It's a pity that it never happened - the M92 doesn't have a lot of games, but the games it does have are very high-quality. Another guy in the thread I linked above was able to get conversions for Undercover Cops and In The Hunt mostly functional, but he pulled the links. I may tackle it myself at some point - I'm a coder by trade, but I haven't tackled encryption or MAME debugging before, so there'd definitely be a learning curve.
 
My friend has the conversion ROMs, I'll bug him about getting them up/hosted again.
I don't have the tools to dump my board (which is a conversion).

Also I'm told the conversion set for Undercover Cops Alpha never worked correctly.
I'm not sure about In the Hunt (my board for that game is original/real).

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jassin000 said:
My friend has the conversion ROMs, I'll bug him about getting them up/hosted again.
I don't have the tools to dump my board (which is a conversion).

Also I'm told the conversion set for Undercover Cops Alpha never worked correctly.
I'm not sure about In the Hunt (my board for that game is original/real).
Click to expand...
That would be wonderful if your friend could provide or host the ROMs.

I've been reading up on the process another guy named Apocalypse did to recreate the conversion process here:
https://translate.google.com/transl...w.neo-arcadia.com/forum/viewtopic.php?t=56664

His approach looks straightforward to reproduce, so I might take a stab at it myself in the next few weeks. The hard work of determining the decryption tables for the different Irem M92 boards has already been done by the MAME Team. A conversion tool would just need to know what M92 ROMs you're providing it with for conversion and what your target donor board is. The tool would then run the sound code through the appropriate decryption and re-encryption tables appropriate to the game and the target board.

That said - I'd still like a copy of the converted ROMs anyway - partly so I can verify that my own code produces the correct output, and partly because I'd like to start blasting aliens ASAP!
 
This thread is relevant to my interests, I too have a Major Title 2 I'd like to convert, bought some EPROMs to make it happen and the link for the patches is dead :(

I tried using the wayback machine but neither it nor Google had a cached version of the file and no one seems to have mirrored it :(
 
I've been deep-digging the 'Net everywhere for those conversion patches and have yet to turn them up. As I understand it, the original patch creator pulled it down because he was unhappy with all the board conversions selling for big $$$ on EBay. I'm crossing my fingers that Jassin's buddy will save the day for us.
 
I would love to do and play some conversions. I for one would like to learn more on this topic. But, I also ask that any conversion roms have some kind of identifying marker, lets say at bootup, to say its a conversion. Way too many people trying to pass off bootlegs as originals.
 
lets leave that like the neogeo, board scans and learning. as for intros and water marks, dont even try someone will remove it
 
Just saying in case this thread steers into other conversions, M92 boards are difficult enough to get. I think Darksoft creating an m92 multi would be the best solution :D
 
M92 conversions are easy to spot though-an authentic board will have a mix of mask ROM chips and EEPROMs, while a conversion will be all EEPROMs. Also, there's an embossed metal badge of authenticity with the game's title in the corner of the board.
 
As for board rarity, it's easy to swap the original ROMs back in to restore a conversion back to an original. The encryption is baked into the hardware so there's no special restore process like there is with CPS2.
 
What's up guys!
I downloaded the patches for a rainy day. I've never tried using them, but I did download the archive. Keep us posted if you're able to do the conversion successfully ShootTheCore. I'd love to be able to play Undercover Cops or Gunforce 2, so a tool to convert would be awesome.

http://s000.tinyupload.com/?file_id=40519762961017944884
 
Nice! I'll put these in my Dropbox as well for future potential need.

I understand the original creator getting annoyed with people selling conversions for big $$ off his work. But no matter what there will always be people who will profit off bootlegging and stealing other people's work, especially in this hobby due to the huge prices things can sell for :(
 
OMG - jepjepjep you are a saint! I am beyond thrilled right now - seriously. If you're ever in my neighborhood, let me know and I'll buy you dinner.

My Major Title 2 board arrived in the mail today - now I just have to wait for the right EEPROMs to arrive. The original conversion instructions say to repurpose the chips already on the board, but I want to preserve them in case I ever want to switch the board back to being authentic. I'll definitely update this thread after the conversion is done.

I still plan on proceeding with developing and eventually releasing my own tool for decrypting and reencrypting the sound code for these boards - hopefully it'll enable other M92 conversions as well. Having these files in hand will allow me to validate that my tool works correctly. Thank you, thank you, thank you!
 
You still need to have several 27C801 on hand due to the sound ROMs for R-Type LEO being different, that's also why you have to modify the jumpers.

The other ROMs can all be repurposed but I like you have separate EPROMs so I can keep the original ones original :)
 
ShootTheCore said:
OMG - jepjepjep you are a saint! I am beyond thrilled right now - seriously. If you're ever in my neighborhood, let me know and I'll buy you dinner.

My Major Title 2 board arrived in the mail today - now I just have to wait for the right EEPROMs to arrive. The original conversion instructions say to repurpose the chips already on the board, but I want to preserve them in case I ever want to switch the board back to being authentic. I'll definitely update this thread after the conversion is done.

I still plan on proceeding with developing and eventually releasing my own tool for decrypting and reencrypting the sound code for these boards - hopefully it'll enable other M92 conversions as well. Having these files in hand will allow me to validate that my tool works correctly. Thank you, thank you, thank you!
Click to expand...
It would be awesome to meet up someday. Either in Utah or if you come down to southern CA. I'm glad to be able to help. Best of luck on your tool development, that would be incredible!
 
jassin000 or jepjepjep, did you run into any sound problems at all with your R-Type Leo conversions, or did it work 100% first time? I'm having sound problems with mine as documented here.
 
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