miscellaNEouS files

[May_Morals]

Gameplay of the more notable games from the Zenex 135-in-1: https://youtube.com/playlist?list=PLGqmY_QVHIWDypPhoRFb1EpM1D1pAQWr2

thank you very much! are there any plans on if this console will be dumped to rom format?

[forgotusername]

Not currently, I wouldn't really be opposed to dumping it but don't have the means to do so (via shipping it to a dumping group or otherwise). I will add that there is another one for sale right now, if someone does want it for dumping purposes: https://www.ebay.com/itm/126287242337

[NewRisingSun]

It appears that the descrambling method of the dreamGEAR Wireless Video Game Station (dgun2572) was identified in MAME (https://github.com/mamedev/mame/commit/d9d53e4ed13d9da6b6c0c2b402c74e3d69a8c0f5); this console is based on the "upscaled" VT369 hardware with the doubled-resolution versions of the Cube Technology hacks. Would anyone be able to post a modified/unscrambled ROM under these specifications? I couldn't determine how to decode it myself.

MAME's code has become even less readable than usual ever since they fully embraced C++20 template shenanigans.

The ROM won't work because there is some kind protection feature that is unemulated right now.

[forgotusername]

The games do seem to be extractable (I just searched for common text strings such as "NAMCO" to find game data), though emulating them under the current VT369 specifications doesn't display anything. I'm questioning if this is an incomplete dump, as I do not see any of the VT02/03 games that (AFAIK) are included on this console.

If it's of any note, I was able to partially make out graphics data in YYCHR via the "2BPP MSX Screen2" setting (the downscaled versions work under 8BPP SNES Mode7). The graphics display at 8x scale horizontally in this mode, though the true pixel count does appear to be exactly double that of the original graphics (e.g. 32x32 pixels for Pac-Man's sprite).

I attached rips of the Pac-Man and Sqoon hacks below. The coding is similar enough to the lower-resolution versions to where I assume these are complete game extracts.

[NewRisingSun]

I was able to understand how the silly protection device works. The menu still doesn't work, but the Pac-Man and Sqoon extracts at least show high-resolution backgrounds. Now, to get the sprites to display.

[forgotusername]

Excited to see it (partly) working, best of luck getting the graphics visible.

[forgotusername]

There seemed to be some confusion as to if this hack was dumped, so I've attached an extract of it here (sourced from the "Game 500-in-1" ROM). It's a presumably Funtime-affiliated "Harry Potter" hack of Magic Carpet 1001, predating the common Inventor version. It's probably headered incorrectly here, I couldn't get it to bankswitch.

[bootlegbastard]

Apparently a version of JungleTac’s Frogger port is on a NJ Pocket system. Which I didn’t even know they made more NJ Pockets or even did the VT1682 system at all. It probably isn’t dumped, but I really want to know about this other NJ Pocket and this version of VT03 Frogger.

[forgotusername]

Here is an assortment of extracts from the Retro-Bit "Go Retro Portable". I mainly wanted to rip some of the more notable Nice Code variants that I couldn't previously restore by hand; though I've also ripped the Shiru Tetris port (which differs from the My Arcade release) and two unused games, Mega Man and Gargoyle's Quest II. There aren't many mapper hacks included on this console (from what I could tell), though Thunderbolt Fighting Plane is converted to mapper 256; so I've included that ROM as well.

[lancuster]

The game already runs as mapper 4 submapper 4. I made a small change to the IRQ code to run it as regular MMC3. I only checked the initial screens, however.

I didn't have time to press the A button after defeating the level 2 boss, and I had this situation. The music is still playing, the screen is twitching, and you cannot return to the game.

[SF-Human]

The original release of Thunderbolt II seems to use the NROM mode of Mapper 115 as some kind of copy protection: the game reads data from the last two 8KB PRG bank after switching to NROM mode, then immediately changes back to MMC3 mode. NOPing out the routine will not spawn any enemies. Does the VT02 hack from Retro-Bit patched out the routine?

[bootlegbastard]

Taizou dumped a lot of previously unknown versions/undumped versions of Waixing VT02 games today from this “R36 Ultra” thing’s SD card.

[forgotusername]

Surprised to see these dumped, especially given I had only just learned of the Waixing copyright variants from the Zenex console. A few things of note that might not be obvious:

*It appears that some of the games, despite sharing Waixing titles, were substituted with Nice Code/Power Joy versions; this includes Archery, Backstroke, Goal Keeper, Shudu, Slots Machines, Star, and Triple.
*Could be coincidental, but something about the (previously-undocumented) "Butterfly" and "Play To Shoot" hacks strongly remind me of two other Waixing-derived Nice Code variants, Parkinof and Ranchboy. I think it's the color palettes and overall shoddier-than-usual quality that indicate this to me...
*Close Quarters does appear to have been an alternate copyright revision, but it only reads off of seven characters that are blanked out in the CHR; I can't conclude what it was meant to credit.
*I had previously noticed a discrepancy with the colors of Hitting (Magic Egg hack) between the Play Vision version and the prior-dumped Waixing version. This console seems to use the unaltered Play Vision ROM; showing that, between both versions, they merely swap the CHR color values rather than altering the actual palette. As to why they did this, who knows.
*Plush Dog has the dog-hitting sprite slightly altered, and appears to be a different revision in code otherwise.

[forgotusername]

Here is an incomplete attempt of analyzing the encryption seen in recent VT32 systems, namely the My Arcade Tetris systems and the "Retro Racer" 30-in-1 by Orb. I'm at a loss as to what could be done further, so any assistance with interpreting the code and/or ripping the remaining games would be appreciated.

The .zip file below features the code analysis in its .txt file, as well as various extracted ROM examples. I have also separately attached three games which were not dumped previously, two of which were successfully decoded.

[NewRisingSun]

That's not an encryption; it's just that the games were binary-hacked to call a subroutine placed in PRG-RAM at $6000-$7FFF (usually at $6100) that checks the status of the volume button and adjust the main volume if pressed. Since it is the menu that places the respective subroutine into PRG-RAM, the extracts won't find it there, and therefore crash or exhibit other strange behaviors. This was present in many VT32 consoles before; I removed those subroutine calls from the extracted files in Project Plug-and-Play.

For example, in Speed Challenge, I would set a breakpoint on execution between 6000 and 7FFF to find that the JSR address is 6100. I therefore search for the instruction "JSR $6100" (20 00 61) and find it at file offset 20003, which is of course the PRG-ROM's footer. In the debugger, I see it is part of an added routine at FFF0 that consists of a JSR D01B, JSR 6100, and RTS. I therefore replace all instances of 20 F0 FF with 20 1B D0 and clean out the footer at 20000 with FF. Doing that, I arrive at what you called the "decrypted" ROM. So you already did everything correctly; you just attributed it to an incorrect causal explanation.