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Messages - davidstech

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46
Famicom/NES dumps / VTxx Dumping Thread
« on: February 02, 2018, 03:51:29 PM »
I've attempted to take photos of the dice of some of these consoles underneath the glob tops, but unfortunately VRT never put the real part number on the die (the 555 palette one, for example, is marked "VRT VH3029-002"). The FC pocket one is just marked "K06", and is clearly a different totally different chip.

I have a suspicion the M320 chipset is the same as the 555 dancing cat one, just using a different feature set/config, but I haven't decapped it yet. The PCBs look similar, and they both use SQI flash whereas every other type of VRT chipset uses parallel flash.

So far I know at least the following unclassified chips exist, that may have some degree of Famicom compatibility:
 - VT09
 - VT16
 - VT18
 - VT32
 - VT33
 - VT368
 - VT369

47
Famicom/NES dumps / VTxx Dumping Thread
« on: February 02, 2018, 03:35:20 PM »
Interesting, clearly VRT cared more about wider game compatibility with their new chipset. I'll look at getting this implemented in MAME.

48
Famicom/NES / VTxx BIN to NES 2.0 Converter
« on: February 02, 2018, 03:00:28 PM »
I know a few people have wanted a BIN to NES converter, so I've finally got round to making a Python script for this. It allows mapper and submapper to be specified, defaulting to 256/0.

Script: https://gist.github.com/daveshah1/39faa3f85d492cba38ecf45e272f72de

Let me know if you have any issues with this.

49
Famicom/NES dumps / VTxx Dumping Thread
« on: February 02, 2018, 01:48:53 PM »
Here are the split ROMs in NES format, although it seems most of the 130-in-1 games still aren't working in Nintendulator? I seem to have them working OK in MAME now.

http://davidstech.net/games/multis/Family%20Pocket%20(split,%20NES%20format).7z

I think you're right about 412C bit0, but I need to check.
Underwater is broken in MAME too, seems odd. Pretty sure dump is OK as it was consistent over several reads and everything else works...

50
Famicom/NES dumps / VTxx Dumping Thread
« 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)

51
Famicom/NES dumps / VTxx Dumping Thread
« 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.

52
Famicom/NES dumps / VTxx Dumping Thread
« 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.

53
Famicom/NES dumps / VTxx Dumping Thread
« 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.

54
Famicom/NES dumps / VTxx Dumping Thread
« 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.

55
Famicom/NES dumps / VTxx Dumping Thread
« 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.

56
Famicom/NES dumps / VTxx Dumping Thread
« on: January 29, 2018, 01:25:06 PM »
Yeah, these low res NES-based consoles are pretty ugly - but what can you expect for a handheld with ~50 playable games (plus some crappy ones) for $7 or something?

57
Famicom/NES dumps / VTxx Dumping Thread
« on: January 29, 2018, 12:57:53 PM »
Thanks for the updated build! Yes, the menu is correct, see this review on Youtube - however it is supposed to fill the screen, presumably because the VTxx config is switched from scaling down to cropping? Not a big worry though. Everything else seems correct.

58
Famicom/NES dumps / VTxx Dumping Thread
« on: January 29, 2018, 08:44:18 AM »
New dump today, the SY-888B handheld. This is the same hardware as the SY-889, but a different set of games including several Nice Code VT02 games and some possibly new hacks (including "Where is Dad", a hack of Adventure Island II).

Download here: http://davidstech.net/games/multis/288%20in%201%20SY-888B%20(VTxx).7z

I will add this to MAME, it also runs in EmuVT in VT09 mode with incorrect colours. Currently it doesn't seem to run in Nintendulator.

59
Other dumps / Systema TV Boy II Dump
« on: January 25, 2018, 10:52:51 AM »
Something a bit different for a change. The TV Boy II, and its other variants, was a clone of the Atari 2600 with 126 built in games, widely distributed in Europe during the 90's. I've dumped it and also added support to MAME, which will hopefully be included in their next release.

ROM image here: http://davidstech.net/games/multis/tvboyii.zip

60
Famicom/NES dumps / VTxx Dumping Thread
« on: January 23, 2018, 04:35:45 PM »
I think you're right actually, for some reason I thought one of the games looked like VT03 but it is all VT02 - that said the chip may be a VT03, I think VRT may have discontinued some older chips.

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