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Mega Key adapter without PAL setting?

Discussion in 'Technical Discussion' started by tokumaru, Nov 2, 2023.

  1. Hey, guys! I've recently been hunting some Genesis/MD games I always liked but never owned in physical form, and now that I'm actively looking for cartridges I noticed that the PAL versions of some games are much easier to find or simply cheaper than their NTSC counterparts.

    I lived in Brazil my entire life, so my consoles are either NTSC (1 Genesis and 1 Japanese Mega Drive) or PAL-M (1 Tec Toy Mega Drive, which AFAIK works exactly like an US Genesis as far as games are concerned), meaning that region-locked PAL games are gonna be a problem. Since I'm kind of a purist and don't really want to mod any consoles to add region/frequency switches, I decided to buy one of those Mega Key thingies, in hopes of having complete freedom to run any game I want on any of my consoles.

    What I failed to realize was that the Mega Key I bought doesn't specify a dip switch setting for PAL games on its label, presumably because it was sold in PAL territories, where most people would have no use for that setting. Anyway, since the thing has the same number of switches as the other Mega Key versions that are known to work with PAL games, I'm wondering if it can still do all the configurations, and they just didn't write that specific one on the label. Does anyone know if that's the case?

    I compared my Mega Key to other versions and it doesn't look like the dip switch configurations that are listed match those of any other version, so I don't think I can simply use the information printed on any of them as reference for the PAL setting on mine. It would be great if I knew what each switch actually does, so I could try different settings without being afraid of frying anything. Does anyone know how these devices work and what the switches actually do? Would it be safe for the hardware (console, game and the Mega Key itself) if I tried unlisted configurations one by one?

    I've attached a photo of the adapter I bought. Any information you guys can contribute will be greatly appreciated!

    mega-key.jpg

    BTW, I have no idea why these adapters have a setting for Brazil specifically... I was always under the impression that Brazilian consoles and games were just like the US ones, the only difference being that the Tec Toy consoles output PAL-M video (which is 60Hz just like NTSC).
     
  2. Chimes

    Chimes

    The One SSG-EG Maniac Member
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    Alright so forgive me if something goes terribly awry, but what I believe devices like the Mega Key do is directly hog the region commands the Mega Drive's hardware uses to identify the cartridge's origin. I haven't actually heard of any horror stories regarding region carts, but old manually settable devices like these might cause erroneous behavior if you set it to strange settings like "Japan PAL", but nothing happens on testing games with the Exodus emulator.

    The Mega Key was bundled with official releases of games at one point, though; Dragon Ball Z originally came bundled with one as it was just the Japanese cartridge.
     
  3. Thanks for the info. What I find confusing about this is that it looks like only 2 bits affect this region-lock thing, which's why the basic console mod only requires 2 switches, one for the region and one for the frequency, but for some reason, these Mega Key adapters have 4 switches...

    If these adapters work by monitoring memory accesses and tempering with the returned value whenever $A10001 is read, it looks to me like you'd only need to control the state of the 2 upper bits, but since these adapters have 4 switches, they must be doing something else I'm not aware of...

    The number of possible combinations with 4 switches is 16, which shouldn't take long to test, but some versions of the Mega Key have instructions involving flipping a switch only temporarily, so this might not be as simple as testing the 16 possible combinations one after the other.

    Does anyone know if there's a diagnostics ROM or something of the kind that I can run on my Everdrive that will report what's being returned by the version register?
     
  4. Chimes

    Chimes

    The One SSG-EG Maniac Member
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    Try Mickey Mania's Japanese ROM, that one's infamous for having a region check that verifies mid-game.
     
  5. "This machine has some how become an NTSC Mega Drive system" - That's awesome! hahahahaha

    How would I use this to debug the support for PAL/Europe in my adapter? It seems to me like the game will just let me know that the adapter is not set to Japan, but won't help me figure out what it's set to.

    It seems that making a ROM that displays the region settings from scratch is not particularly hard (according to this page), so I might give this a try at some point. It's just that this seems like one of those useful things that should already exist, so I decided to ask first.
     
  6. Failing to find more information about how the Mega Key adapters work, I plugged in my least favorite Mega Drive console and grabbed my least favorite region-locked European game and set out to try all 16 DIP switch combinations. To my surprise, the game worked right away on the first combination (all switches OFF)!

    I then proceeded to try the other region-locked games and they all ran just fine. The only real problem I ran into was with "Story of Thor" - when I bought this game I didn't realize it used the extended vertical resolution mode, so my TV couldn't sync to the signal and the image wouldn't stop rolling. I'll try this again with other TVs and video converters to see if I can find a combination that works.
     
  7. nineko

    nineko

    I am the Holy Cat Tech Member
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    This diagnostic ROM by MarkeyJester is designed to do something else, but it also displays the region settings, so you can focus on that and ignore everything else. There might be other, more suited, diagnostic ROMs out there, but this is the first one that comes to my mind.

    Also, sorry for the late reply, I just noticed the date. Is it that obvious that it's not the best of times for me, once again?