Author Topic: VTxx Dumping Thread  (Read 39677 times)

Y2K05

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VTxx Dumping Thread
« Reply #15 on: January 29, 2018, 07:26:14 PM »
Oh hey, you;'re right, NewRisingSun! It does run in the BuildBot  version of FCEUX! Excellent, thank you!

Has someone considered creating an executable that converts .bin to .nes? It surely has to be possible, right?
« Last Edit: January 29, 2018, 07:26:55 PM by Y2K05 »

forgotusername

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VTxx Dumping Thread
« Reply #16 on: January 30, 2018, 01:26:29 AM »
NewRisingSun2
Jan 29 2018, 04:04:02 PM
@forgotusername: I can offer to extract all of the individual games, as I did before.[/quote]There's not really a point in doing so, as on these new dumps there's only two completely unique games to my knowledge (one is a bad hack of Tetris and the other an Assart variant). May as well not bother.
Quote:
 
Here's TV Game 200-in-1, which davidstech converted for me. It sadly does not work in FCEUX. I wonder what it runs.[/quote]
Thanks. Oddly enough it worked perfectly in FCEUX for me. Got all the new ROMs extracted, which I'll post eventually.

davidstech

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VTxx Dumping Thread
« Reply #17 on: February 02, 2018, 07:39:20 AM »
Two new non-working dumps, I'll try and get these working at some point when I have the time. In the mean time if anyone wants to look at these they're here.

First of all, the MOGIS M320 246 in 1, which looks like similar hardware to the SY-88x handhelds, but doesn't emulate. I can't get this to work at all in Nintendulator or EmuVT, and currently in my branch of MAME I get a green screen and the intro music but don't get any further.

http://davidstech.net/games/multis/246%20in%201%20MOGIS%20M320%20(VTxx).7z

Secondly, the FC Pocket 600 in 1 handheld. This uses some kind of opcode scrambling, possibly involving XORing with 0xA1 but that doesn't always seem to work so I need to investigate a bit further. I think the problem may be down to working out how/when the scrambling is turned on, as I think the first few instructions aren't scrambled. Once that's figured out hopefully it won't be too hard to emulate. The same scrambling is seemingly used in the DreamGear DGUN-2573.

http://davidstech.net/games/multis/FC%20Pocket%20600%20in%201%20(VTxx).7z


I'm now making progress on emulation of the FC Pocket. There's more work to do, but it seems that what is happening with the CPU is that after the first jump (opcode 0x4C), all opcodes are scrambled by XORing with 0xA1. This is then turned off before NES games are loaded. I think register 0x411E might have something to do with this.
« Last Edit: February 02, 2018, 09:45:52 AM by davidstech »

NewRisingSun

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VTxx Dumping Thread
« Reply #18 on: February 02, 2018, 10:14:22 AM »
MOGIS M320 must use 8 KiB of internal RAM. Nintendulator emulates 2 KiB for normal NES and 4 KiB for VT09+. With 8 KiB, I also get intro music (that is too fast) and a garbled display.

Why is FC Pocket 128 MiB? The second half seems to be just zero bytes.

davidstech

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VTxx Dumping Thread
« Reply #19 on: February 02, 2018, 10:17:40 AM »
I don't know about the 128 MiB either - the flash ROM chip is a S29GL01GP which is definitely 1 Gbit/128Mbyte, so I kept the ROM size accurate. I can only presume that 128Mbyte chips were cheaper on the Shenzhen market the day that console was built.
I seem to have cracked the scrambling used in the FC pocket and DGUN-2573 as well now.

Writing 0x05 to $411e causes scrambling - XORing opcodes with 0xA1 - to be enabled after the next long jump operation (opcodes 0x4C, 0x6C or 0x00). Writing 0x00 to $411e disables scrambling after the next long jump.

Now I just need to sort out palette issues and both the DGUN-2573 and FC Pocket should be supported in MAME.
A few more things if you want to emulate the FC Pocket NewRisingSun2. There are some unknown opcodes at the start before scrambling is enabled. These can be ignored.

Also the high address bit of the ROM seems to be set by $412C but I need to investigate that myself.
« Last Edit: February 02, 2018, 10:29:32 AM by davidstech »

Y2K05

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VTxx Dumping Thread
« Reply #20 on: February 02, 2018, 10:46:11 AM »
Is VT09 supported in MAME yet? It doesn't seem to be marked off in the progress bar, davidstech.

And it's crazy to think if 220-in-1 would finally be emulatable in MAME.

davidstech

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VTxx Dumping Thread
« Reply #21 on: February 02, 2018, 11:37:22 AM »
The 220-in-1 is booting in my branch of MAME now, and all the games I tested work, but the palette is totally broken and there are other graphical issues.

Some VT09 ROMs work, like the VG Pocket series, but some other suspected VT09 don't like lexcyber, it's an bit mysterious.

NewRisingSun

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VTxx Dumping Thread
« Reply #22 on: February 02, 2018, 11:54:23 AM »
FC Pocket 600's palette is just four bits each of blue-green-red. Now for the PCM menu music...

davidstech

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VTxx Dumping Thread
« Reply #23 on: February 02, 2018, 12:02:17 PM »
Thanks for working that out. If you're curious how the "fake cartridge" switches between 472-in-1 and 128-in-1, it seems if $412d returns 0x06 then the 128-in-1 is used, otherwise it defaults to the 472-in-1.

NewRisingSun

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VTxx Dumping Thread
« Reply #24 on: February 02, 2018, 12:08:02 PM »
Here, In 220-in-1 (DGUN-2573), the preview image of Curly Monkey2 is still broken, while it's ok for Cut Fruit.

davidstech

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VTxx Dumping Thread
« Reply #25 on: February 02, 2018, 12:09:16 PM »
Same in MAME. I'm not sure why that is either though. Possibly DMA or nametable access related.

NewRisingSun

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VTxx Dumping Thread
« Reply #26 on: February 02, 2018, 12:11:38 PM »
And "Champion Boat" needs the normal VT03 palette. So there must be a switch between the normal VT03 hue/luma/saturation 4-4-4 and R-G-B 4-4-4 palette.
Edit: the only thing in terms of register writes is $411E. Value $05 has two bits set, so maybe one of them turns on encryption after the next jump, while the other switches 12-bit palette types?
Edit2: No, that doesn't work for Thunder Man either.
« Last Edit: February 02, 2018, 12:21:41 PM by NewRisingSun2 »

davidstech

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VTxx Dumping Thread
« Reply #27 on: February 02, 2018, 01:07:09 PM »
This is a dump of the Family Pocket 638 in 1. Despite seeming similar to the FC Pocket, it actually seems to use standard VT02/VT03 stuff as far as I can see and runs fine in Nintendulator. This one just has the "console" and "cartridge" after each other in the ROM, so I've also provided split files.

http://davidstech.net/games/multis/Family%20Pocket.7z
Actually, looks like a few games aren't working in Nintendulator for this. It seems bit 1 of $412C controls ROM A24 (and cartridge/console determines ROM A25)
« Last Edit: February 02, 2018, 01:12:22 PM by davidstech »

forgotusername

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VTxx Dumping Thread
« Reply #28 on: February 02, 2018, 01:17:05 PM »
You sure that 130-in-1 cartridge is working right? All the game names are wrong (one of which being a super-rare Bubble Bobble hack, which here just loads up Mario 9...)

NewRisingSun

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VTxx Dumping Thread
« Reply #29 on: February 02, 2018, 01:18:24 PM »
@davidstech: Add a NES header and set mapper to 270. The bankswitching must be similar to the Game Prince RS-16's. I need to add a "DIP Switch" menu for the non-split ROM to select ROM versus cartridge mode.

Edit: It seems that $412C bit 0 is ROM A25 also?
Edit2: Got everything working except console game #500 ("underwater", actually Little Mermaid), which has garbled CHR.
« Last Edit: February 02, 2018, 01:42:07 PM by NewRisingSun2 »