I'm not even sure where to start with this, so I'm starting here.
Many years ago before Neo flash carts existed, I discovered a sound glitch in Samurai Shodown V Special that presented in all bootlegs and when played in MAME but did NOT exist on original hardware.
To make a long story shorter, it was discovered that the V-Rom decryption in MAME for Samurai Shodown V Special ( and possibly all PCM2 games ) was incorrect. Razoola ended up comparing the decrypted/unscrambled voice sample between Samurai Shodown 5 and Samurai Shodown 5 Special and found the first 2 bytes of each V-Rom were being decrypted incorrectly and shared the corrected values.
So at this point you're probably asking yourself, "who cares? Bootlegs are crap and why use MAME when we have flashcarts!". Well boys and girls, all flashcart options and even MiSTer require the roms be decrypted prior to running.
On the NeoSD the V-Roms are patched in memory. I'm not sure if the Darksoft multi is doing the same, but the issue definitely exists on the MiSTer and I noticed the SMDB for the Darksoft flash cart that comes with the Hardware Target Game Database has the checksums of the BAD V-Roms.
So the question is, how do we fix this? How do we stop circulating this improperly decrypted rom? Do we start with the Hardware Target Game Database? Do we start with our pirate friends distributed the "roll-up packs"? Is there a tool for converting MAME roms to the format accepted by the Darksoft flashcart that could "correct" the rom after decryption?
Here is a sample of the audio glitch. Listen for the "pop" at the end of pronouncing "Basara". Or fire the game up on your MiSTer and select Basara to hear it in person.
Obviously the V-Roms are copyrighted so I cant just share them openly online. But here is a diff of the BAD vroma0 ( left ) and the CORRECT vroma0 ( right ). So feel free to patch it yourself, or shoot me a PM.
The ROMs affected by this are as follows ( Pretty much any version of Samurai Shodown 5 Special or Perfect ):
samsh5sp
smsh5sph
smsh5spo
samsh5pf
Many years ago before Neo flash carts existed, I discovered a sound glitch in Samurai Shodown V Special that presented in all bootlegs and when played in MAME but did NOT exist on original hardware.
To make a long story shorter, it was discovered that the V-Rom decryption in MAME for Samurai Shodown V Special ( and possibly all PCM2 games ) was incorrect. Razoola ended up comparing the decrypted/unscrambled voice sample between Samurai Shodown 5 and Samurai Shodown 5 Special and found the first 2 bytes of each V-Rom were being decrypted incorrectly and shared the corrected values.
So at this point you're probably asking yourself, "who cares? Bootlegs are crap and why use MAME when we have flashcarts!". Well boys and girls, all flashcart options and even MiSTer require the roms be decrypted prior to running.
On the NeoSD the V-Roms are patched in memory. I'm not sure if the Darksoft multi is doing the same, but the issue definitely exists on the MiSTer and I noticed the SMDB for the Darksoft flash cart that comes with the Hardware Target Game Database has the checksums of the BAD V-Roms.
So the question is, how do we fix this? How do we stop circulating this improperly decrypted rom? Do we start with the Hardware Target Game Database? Do we start with our pirate friends distributed the "roll-up packs"? Is there a tool for converting MAME roms to the format accepted by the Darksoft flashcart that could "correct" the rom after decryption?
Here is a sample of the audio glitch. Listen for the "pop" at the end of pronouncing "Basara". Or fire the game up on your MiSTer and select Basara to hear it in person.
Obviously the V-Roms are copyrighted so I cant just share them openly online. But here is a diff of the BAD vroma0 ( left ) and the CORRECT vroma0 ( right ). So feel free to patch it yourself, or shoot me a PM.
Code:
niko@Eva01:/media/niko/7911A70B74F7E10B/MISTER/temp$ diff -y --suppress-common-lines vroma0.old.hex vroma0.hex
00006bc0 ab 00 80 80 80 08 00 80 80 80 08 08 08 08 08 08 | | 00006bc0 08 00 80 80 80 08 00 80 80 80 08 08 08 08 08 08 |
0000ed40 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 08 | | 0000ed40 08 89 08 08 08 08 08 08 08 08 08 08 08 08 08 08 |
00016bc0 6e 35 42 21 82 00 8a c9 80 18 9a ca db ba e9 a8 | | 00016bc0 82 35 42 21 82 00 8a c9 80 18 9a ca db ba e9 a8 |
0001ed40 31 da 9b 21 23 8b b8 14 09 f9 33 51 9a 9b 01 36 | | 0001ed40 31 8f 9b 21 23 8b b8 14 09 f9 33 51 9a 9b 01 36 |The ROMs affected by this are as follows ( Pretty much any version of Samurai Shodown 5 Special or Perfect ):
samsh5sp
smsh5sph
smsh5spo
samsh5pf
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I remember reading posts from you about this a long time ago.. (not here).
.