leonardoliveira & Idc's clean decrypted roms

PCB problems and fixes
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Shou
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Re: leonardoliveira & Idc's clean decrypted roms

Post by Shou »

Also to note, Leo fixed Vampire Savior 970519 JP as it did not work.

Ones that I have found not to work are SF Zero 3 980904 JP and Battle Circuit JP.

Super Street Fighter II X 940223 JP seems to be based off of another region's build as certain bugs that exist in the Japanese build do not work in the decrypted set.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by Asayuki »

I had a talk with Leonard on IRC lately, and we went down into the nitty gritty of CPS2 security. It was a very interesting talk, and I think the work you guys are doing there is awesome. Keep it up dudes! :)
My 15kHz cabinet Peplos will never power up, with any item, and I am quite proud of that.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

Just mentioning, I am going through a process of (slowly) revisit all the existing decrypts at the site. This time I am documenting each decrypt and keeping track of decryption masks for each ROM.

Those decryption masks are actually more important than they look like as they can be used to encrypt the ROM to a different region. (hint hint) :lol:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by Bonky »

Wow ^^
Thanks for your effort, so rapidly :awe:

I Test them this week on hardware :)
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

New games I just added:

ssf2tbj - Super Street Fighter II: The Tournament Battle (Japan 931005) / Thanks Shou :awe:

ssf2tbjr1 - Super Street Fighter II: The Tournament Battle (Japan 930911)
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

Updated:

qndream - Quiz Nanairo dreams: Nijiirochou no kiseki (JAPAN 960826) - Decryption errors :oops:


Edit, also updated at the site:

smbomb SUPER MUSCLE BOMBER (JAPAN 940831) - Decryption errors, too... :oops:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by Shou »

Rockman 2 960708 JP fix appears to have quite a few issues:
- the game boots but has severe AI problems even with difficulty on the highest setting (enemies are just dumb and do very little)
- in the Save Roll mode, the game sometimes says you saved Roll after you only have beat 2 stages
- in the Save Roll mode, the game will crash before the Yellow Devil/Rock Monster fight and goes to some kind of debug emulator screen
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

New games I just added to the site:

dstlkur1dl - Darkstalkers: The Night Warriors (USA 940705)
vampjdl - Vampire: The Night Warriors (JAPAN 940705)
vampjr1dl - Vampire: The Night Warriors (JAPAN 940630)

Keep in mind that Vampire (940630) have a "odd behavior" regarding the kick harness and the pin 25 of the jamma header. Some people like to wire one of the kick inputs together with the pin 25 of the jamma connector for compatibility with the NEO GEO. if the harness is wired that way, the kick button which is connected to the pin 25 will not function properly. Version 940705 had that issue solved.

Rockman 2 960708 issues solved and file updated at the site. Megaman 2 games also required the same repair which was done. :awe: :awe: :awe:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by xodaraP »

I think this is the version of Darkstalkers I have here, nice I can get it going again :D

Thanks guys for your work on this
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

A big shout for Shoutime for pointing problems with Choko and Quiz Nanairo Dreams: Nijiirochou no kiseki.

The sets were updated at the site. :awe:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by xodaraP »

I assume the way it's verified is someone plays the game through in it's entirety without bugs.... the reason they're there in the first place? leo and idc probably don't have the time to 100% each game they decrypt...
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

xodaraP wrote:I assume the way it's verified is someone plays the game through in it's entirety without bugs.... the reason they're there in the first place? leo and idc probably don't have the time to 100% each game they decrypt...
Decryption is done by hand by manually analyzing code in IDA. Sometimes I am sleepy or tired and I deem data as code or code as data by mistake or miss a offset by a word or two. I'm human, not a machine and "IDA" means "Interactive Dis-Assembler" which implies it requires my input to know what/where to analyze. :awe:

So because the errors are of a totally random nature and cannot be easily traced back without a crash reference to begin with, I rely on user input to repair problems.

The very same reason why Razoola's fixes had a crash/exception handler program of it's own and it told users to report any problems to him so he could fix the mistakes on decryption. 8-)

The only difference here is that I actually enable Capcom's exception handler (using a flag toggle in the game) and use reports from it, Razoola uses his own, which he made and put on the phoenix menu code.
TV2016061323294800.jpg
TV2016061323382400.jpg
TV2016061323382900.jpg
This particular bug was caused by a wrong word at offset 0x00059BA4 which was loading the long value 0x0012EA47 instead of 0x00128646 at the register A0.
That was causing a word read at a odd address which was causing a address error exception, resetting the game when Gallon/J.Talbain move Beast Cannon was used in the dive direction (as shown on the crash picture).
MC68000 have no A0 pin so it can't read words or longs at odd addresses, for that it has a special instruction and two dedicated pins to indicate odd/even access at byte level. That's why it has a "address error" exception.


Offset 0 1 2 3 4 5 6 7 8 9 A B C D E F

00059B80 68 16 00 12 68 B6 00 12 74 72 00 12 75 12 00 12 h...h¶..tr..u...
00059B90 75 B2 00 12 76 52 00 12 84 66 00 12 85 06 00 12 u²..vR..„f..…...
00059BA0 85 A6 00 12 86 46 10 2E 00 05 32 3B 00 12 4E BB …¦..†F....2;..N»
00059BB0 10 0E 4E B9 00 00 52 F6 4E F9 00 00 55 B6 00 06 ..N¹..RöNù..U¶..
00059BC0 00 C8 00 F2 3D 6C 00 0C 00 0C 61 00 00 F0 66 00 .È.ò=l....a..ðf.
(blue is code/supposedly encrypted)

I actually hit "c" on the value "EA47" (EA47 is the value for that address under the encryption algorithm) and IDA interpreted it as a valid instruction, botching the tail of a address table. Decrypt a game is basically the act of discerning what should be considered encrypted and not encrypted. I misjudged that word as it being a encrypted word and it wasn't.

Hope that post is informative. :)

And FYI, the fixed ROM was uploaded to the avalaunch site.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

New games added to the Avalaunch site:

Dungeons and Dragons: Shadow Over Mystara (JAPAN 960619)
Dungeons and Dragons: Shadow Over Mystara (USA 960619)

Only a year late as they have been rotting on my harddrive (forgotten) for that long, might as well put them up.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

Released:
Dungeons and Dragons: Shadow Over Mystara (Brazil 960223)

Revised:
Dungeons and Dragons: Shadow Over Mystara (EURO 960619)

A couple of wrong bytes and a few mangled instructions after I am fairly confident this is final. :awe:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

Hyper Street Fighter 2 (JAPAN 031222) :awe: :awe: :awe: :awe:

P.S.: The 040202 set had the filenames inside the zip renamed to match MAME naming scheme. Because the file names I used were from 031222 set. File contents are absolutely the same as before.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by VectorGlow »

Wonderful work, you're on a roll. :D
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Re: leonardoliveira & Idc's clean decrypted roms

Post by Asayuki »

Don't forget to eat properly and to sleep, Leonard! :D
My 15kHz cabinet Peplos will never power up, with any item, and I am quite proud of that.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

Has anyone noticed that Hyper Street Fighter 2 AI is dumber on MAME than it is on the real board? :lol:
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Re: leonardoliveira & Idc's clean decrypted roms

Post by leonardoliveira »

New games at the Avalaunch site ! :awe:

Vampire Hunter: Darkstalkers Revenge JAPAN 950307 and 950316.
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Re: leonardoliveira & Idc's clean decrypted roms

Post by fluxcore »

Awesome work Leo :)
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