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View topic - Are there patches for more games to swap player 1 and 2?

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  • Joined: 11 Jan 2019
  • Posts: 5
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Are there patches for more games to swap player 1 and 2?
Post Posted: Fri Jan 11, 2019 9:53 am
I have a Mcwill modded Game gear with an Everdrive and an adapter to connect a Sega Master system controller to the extension port however the extension port acts as port 2, but I need it to act as port 1.
I know there is a controller mod for the Game gear however I don't want the extension port to be port 1 for all games, so are there any patches for the games?
I'm looking for controller patches for Sega Master system and SG-1000 games.
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  • Joined: 05 Sep 2013
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Post Posted: Fri Jan 11, 2019 11:48 am
you can try coding them by your own - basically instead of simply reading from port $DC and take the lowest 6 bits from there, you should keep the two highest bits and take the 4 lowest bits from next port, $DD.

see: http://www.smspower.org/Development/PeripheralPorts#PortDCIOPortAAndB
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  • Joined: 14 Oct 2008
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Post Posted: Fri Jan 11, 2019 6:18 pm
That sounds like it would take a sizeable amount of code (to do the necessary reads and shifts).
Basically shift the high two bits of DC down to the lowest two bits,
the read the low 4 bits of DD, shift them left two and mix with the previous.
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  • Joined: 19 Oct 1999
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  • Location: London
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Post Posted: Fri Jan 11, 2019 7:20 pm
It's usually easy to find a few dozen bytes of unused space, then replace the existing code with a call to it.
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  • Joined: 11 Jan 2019
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I thought it was as simple as editing a few variables with the Hex editor
Post Posted: Fri Jan 11, 2019 10:04 pm
If I manage to swap player 1 and 2 will it be the same process for all games?
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Post Posted: Sat Jan 12, 2019 7:15 am
It's similar but definitely not identical, and not as simple as hex editing.
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