Author Topic: VTxx Dumping Thread  (Read 50280 times)

Y2K05

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VTxx Dumping Thread
« Reply #120 on: February 05, 2018, 08:31:19 PM »
i had no idea MAME and RetroArch could be combined?

davidstech

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VTxx Dumping Thread
« Reply #121 on: February 06, 2018, 05:31:37 AM »
Yes, there's a MAME core for RetroArch (in fact several, from around 2010 to the latest 0.194). I just need to get it working with the VTxx stuff.

woodexe

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VTxx Dumping Thread
« Reply #122 on: February 06, 2018, 10:52:28 AM »
Hello,Can you upload the neighborhood?
« Last Edit: February 06, 2018, 10:53:31 AM by woodexe »

forgotusername

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VTxx Dumping Thread
« Reply #123 on: February 06, 2018, 02:24:27 PM »
Looking through the 220-in-1 in Tile Layer Pro, I found graphics for a handful of games not on the menu. From what I can make out there's:
* The Hacker (Felix the Cat 3 hack)
* Sunken Ship (Titanic hack)
* some Mahjong game, Nice Code-esqe graphics
Any possibility the game coding is buried in the ROM somewhere? Wouldn't be the first time - I found several games buried in a 30-in-1 multicart as well, when I first started Project Plug 'n Play.

UPDATE: Yep they're in there. Got Sunken Ship ripped already. Might be able to get Hacker out too using the same method (but probably not Mahjong).
« Last Edit: February 06, 2018, 02:29:01 PM by forgotusername »

NewRisingSun

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VTxx Dumping Thread
« Reply #124 on: February 06, 2018, 02:39:12 PM »
Stop where you are and let me at it. ;)

Edit: Ugh. The menu puts some code into $6100 and has about half of all games (not just VT03) modified to call it before reading input. These will all need to have that JSR $6100 removed before they work extracted.

Edit 2: @forgotusername: Are you sure that The Hacker is not just a CHR bank within "Super Hero"?

Edit 3: @davidstech: Something's really strange. Now Champion Boat and King also use the 4-4-4 RGB palette instead of the legacy VT03 palette! I'm not quite sure what I changed to make this happen, but it tells me that the hardware probably only supports that palette, and these individual games can write CGRAM data for either palette type, and for some reason, my previous emulation attempt made the game choose the wrong palette.
« Last Edit: February 06, 2018, 04:18:04 PM by NewRisingSun2 »

davidstech

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VTxx Dumping Thread
« Reply #125 on: February 06, 2018, 04:36:13 PM »
This is starting to make sense, I thought the colours didn't look wrong enough. That also explains why I wasn't seeing CGRAM DMA accesses, clearly they were being disabled also as part of this weird auto-detection for however MAME was emulating it.

forgotusername

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VTxx Dumping Thread
« Reply #126 on: February 06, 2018, 04:45:37 PM »
NewRisingSun2
Feb 6 2018, 02:39:12 PM
Edit 2: @forgotusername: Are you sure that The Hacker is not just a CHR bank within "Super Hero"?[/quote]No its in there too, directly below the Super Hero data. Oddly enough I was able to rip Hacker, but not Super Hero (I'm guessing it runs on a weird mapper).

NewRisingSun

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VTxx Dumping Thread
« Reply #127 on: February 06, 2018, 04:50:49 PM »
No, no weird mapper, just the $6100 issue I described above.

@davidstech: I now know how the game detects palettes --- by reading from $4119. On the VT03, $4119 returns $00 on NTSC and $18 on PAL consoles. On NTSC consoles, a game needs to compensate for the CGRAM DMA error if it uses DMA. Champion Boat on the other hand uses the 4-4-4 RGB palette if $4119 returns anything other than $18, and the old VT03 palette if $4119 returns $18. I don't think that's the way one is supposed to do it, but the lesson is: for this hardware, $4119 needs to return $00 and not NTSC/PAL like an original VT03.

It's still good that I made the modification yesterday. Basically, before I just had Nintendulator always return $18 so games would not try to compensate for the CGRAM DMA bug, because I did not want to emulate it. I had tried to emulate it, but ran into the problem that VT09 games assumed that the bug did not exist (because it may have been fixed by that time) and had no easy way to tell whether the bug should be emulated or not. I am now emulating it if a CGRAM DMA transfer starts at 3F01 and not emulating it if a CGRAM DMA transfer starts at 3F00, and I accurately make $4119 return the TV system except for mapper 296, under which $4119 always returns $00. That should work with any game in any TV mode setting.
Here is my extract of DGUN-2573. Only includes games accessible from the menu. Download today's updated Nintendulator build for the aforementioned palette correction.
Edit: Please redownload the multicart extracts; made a correction fixing uninitialized RAM in the PCM music-using games.
« Last Edit: February 06, 2018, 06:36:47 PM by NewRisingSun2 »

Y2K05

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VTxx Dumping Thread
« Reply #128 on: February 06, 2018, 06:45:58 PM »
Do you guys have dgun-2561 yet? I remember that also got dumped on Bannister.org, and i'm willing to post it right here

davidstech

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VTxx Dumping Thread
« Reply #129 on: February 06, 2018, 07:13:27 PM »
No, more reverse engineering is needed for that one before it will work in anything. I think it is VT36x based and has various enhanced features - more banking modes, more palette nemory, more PPU modes and possibly a multiply/divide ALU.

Y2K05

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VTxx Dumping Thread
« Reply #130 on: February 06, 2018, 07:16:59 PM »
That's strange--I thought less reverse engineering was required for the 220-in-1's predecessor. You know what I mean? Kinda feels backward.

forgotusername

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VTxx Dumping Thread
« Reply #131 on: February 06, 2018, 08:56:08 PM »
NewRisingSun2
Feb 6 2018, 04:50:49 PM
Here is my extract of DGUN-2573. Only includes games accessible from the menu.[/quote]Thanks. Just wondering, for Project BLEB compiling, is one format of these games preferable compared to the other (as in mapper 256 over 296)? And are the games with all the fancy extra features (Guard Radish, Cut Fruit, etc.) still VT03 or are they something else?

NewRisingSun

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VTxx Dumping Thread
« Reply #132 on: February 07, 2018, 03:44:52 AM »
Don't think that mapper 256 is preferable over 296, especially with Nintendulator-NRS supporting both and nobody else supporting either. The games you mentioned are not strictly VT03 in terms of palette and sound; maybe davidstech will eventually determine the actual hardware name.
« Last Edit: February 07, 2018, 03:46:57 AM by NewRisingSun2 »

davidstech

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VTxx Dumping Thread
« Reply #133 on: February 07, 2018, 06:01:42 AM »
At the moment my best speculation for this chipset is VT33, which is an unknown new chipset from VRT (seen on the PCB of a NES clone I saw online, and one or two other places). But I'm hesitant to call it that without further investigation, I know there's been a few places in the past where guessed chipset names turned out to be wrong. I think calling it VT3x might be safe though?

@Y2K05 yeah it's odd, the 2561 is more advanced (albeit possibly older) hardware than the 2573 as far as I can tell. I don't think it's in any way impossible to emulate, and will probably be my next challenge, but it might take a while.
« Last Edit: February 07, 2018, 06:07:07 AM by davidstech »

Y2K05

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VTxx Dumping Thread
« Reply #134 on: February 07, 2018, 07:58:39 AM »
Yeah, davidstech. It reminds me of when those ambitious Oplayer MGS33501's were replaced with this crappy Oplayer MGS2401A VT02's in European airports (rebranded by MiTone, aka mitone.eu). It was strange.