32X mod to allow Sega Master System games

Discussion in 'Mega Everdrive / Everdrive MD' started by Fandangos, Sep 16, 2013.

  1. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    My friends, I remember Krikzz commenting modding the 32x to allow Sega Master System games to work with the Mega Everdrive would be possible.

    Any idea what this mod would be about? What would be need to pull this?

    Let's gather information here and I'll try it on my 32x here and post the results.
     
  2. superg

    superg Site Supporter 2013,2014,2015. Tape Drive Donor.

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    I would also be interested in such a modification.
     
  3. sonicdude10

    sonicdude10 So long AG and thanks for all the fish!

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    I know nothing despite having an extensive Sega hardware collection...

    I too am interested in this should someone come forth with the needed info.

    But now I need to buy Mega Everdrive and sell my old 2.0 revision Everdrive MD...
     
  4. superg

    superg Site Supporter 2013,2014,2015. Tape Drive Donor.

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    But it should be possible also for ordinary Everdrive, or I am missing something?
     
  5. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    I think it's also possible.

    I think this entire mod would be something like adding a fire point A to point B wires and it would work. I don't think it's complicated I just think the correct pins aren't being passed by the 32x.
    Keep in mind this is just speculation on my side.
     
  6. MottZilla

    MottZilla Champion of the Forum

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    http://wiki.megadrive.org/index.php?title=Connectors

    Pin B30 is a control signal for Master System mode. I've read the Genny Model 3, Nomad, and 32X have some issue with this signal making SMS mode impossible normally. I'm pretty sure the Model 3 and Nomad are just a matter of connecting a signal to the port. But I was unable to find a clear answer about the 32X.
     
  7. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    In other words just a wire from Genesis to the 32x on pin30 if that would be correct.
     
  8. MottZilla

    MottZilla Champion of the Forum

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    That's not necessarily true and I don't recommend doing that based on what I said. For one thing, the 32X could be driving that pin itself and not allowing the cartridge inserted into it to drive that pin. So if you added a wire from the 32X cart port to the Genesis edge connector on the 32X, you could cause a conflict where the 32X trys to drive that pin one way and the Cartridge inside it drives it the opposite and could fry something.

    I'm not an electrical engineer but I do know creating a short or adding wires shouldn't be done just by guess. You could permanently damage your hardware. Wait for someone TmEE to answer.
     
  9. APE

    APE Site Supporter 2015

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    I can't seem to find a 32x cartridge pinout to do any rudimentary checks and I don't terribly feel like stripping down my 32x. B30 seems to have a pair of traces (on the schematic I was looking at for a specific model 2) going off to enable SMS mode (obviously).

    I'd imagine there is more going on than simply needing a wire to insure that B30 is grounded enabling SMS mode otherwise someone would've dropped the Power Base Converter on their 32x and wired B30 to ground on the Genesis side. Or if they did they never bothered to tell anyone. And if I interpreted the PCB correctly the Power Base Converter has B30 and B32 wired together and connected to nothing else, this makes no sense as B32 has a pull up resistor wired to it (Genesis side) which would drive both B30 and B32 high leaving SMS mode off.

    Then again it's been a long day and I'm likely not reading this stuff correctly.
     
    Last edited: Sep 18, 2013
  10. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    To me they just did something to disable SMS mode on the 32x and that's it but again, that's just a guess.

    I think Sega didn't wanted people building a tower of devices: jap sega cd + genesis + 32x + sms adapter + cartridge would be insane.
    But now we have the everdrive and if this could be turned around it would add a whole library of games to be played on the system.

    On a further notice maybe even SG-1000 games could be played because of the lack of the bios protecting those games to be loaded.
     
  11. MottZilla

    MottZilla Champion of the Forum

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    B32 is the Cart Detect signal which has a pull-up on it, but the cartridge should connect it to ground. So B32 on the cartridge (or powerbase) should connect to Ground, as well as B30. But I've had a long day as well so I might not be looking at it right either.
     
  12. ApolloBoy

    ApolloBoy Gutsy Member

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    That's not possible as the Genesis/MD VDP lacks the video modes necessary to run those games. The Genesis/MD doesn't even have a BIOS so the BIOS thing is a total non-issue.
     
    Last edited: Sep 19, 2013
  13. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    The issue regarding the bios is related to the US SMS Bios that won't let SG-1000 games to work that's what I meant.
     
  14. APE

    APE Site Supporter 2015

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    I've known for many moons that a pin needed to be grounded to enable SMS mode - long before I could fully understand what that meant. Maybe I'll take apart my 32x later and go looking but I don't have a Power Base Converter to test anything out with nor do I really want to roll my own adapter.
     
  15. Fandangos

    Fandangos <B>Site Supporter 2013</B>

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    If you can give me directions I can try it here with the Mega Everdrive.
     
  16. MottZilla

    MottZilla Champion of the Forum

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    Your EverDrive cartridge by the way, will be driving this pin itself. Because the EverDrive has to start in MD mode, you choose to play a SMS game so it will likely use the Reset Signal on the Cartridge Port then as well as begin to drive the SMS Mode pin to come out of MD mode and into SMS mode. So whatever you do, needs to allow the EverDrive or any cartridge inserted to be able to drive the SMS mode pin however they like. One possibility would be a switch that switches between allowing the 32X to feed want it wants to the Genesis SMS pin and then when switched allows the inserted cartridge SMS pin to bypass the 32X hardware and go on to the Genesis port.

    It seems odd that no one has documented what exactly to do for the 32X.
     
  17. APE

    APE Site Supporter 2015

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    Since the Everdrive controls the necessary pins with software what I was thinking simply won't work.
     
  18. smoke monster

    smoke monster Rapidly Rising Member

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    Count me in as another interested party if this is actually possible.
     
  19. TriState294

    TriState294 Site supporter 2016

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    I hate to bump this thread back from the grave, but I'm really curious if anyone ever put any additional work into this idea.

    Space and connectivity is always at a premium, so if I could get away with playing Master System games on my Genesis/CD/32x rig, that would be great. I would probably always be using an Everdrive, so the cartridge pinout difference wouldn't even be a problem.
     
  20. IrishNinja

    IrishNinja Rising Member

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    forgive the bump here, but i'm most interested in this opportunity as well, if it yet exists! would krikzz/igor be a good person to hit up for ideas? I understand he's a big sega fan.
     

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