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Graphics_Flags doesn't work the same on 32X #1

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Clownacy opened this issue Oct 1, 2016 · 3 comments
Open

Graphics_Flags doesn't work the same on 32X #1

Clownacy opened this issue Oct 1, 2016 · 3 comments
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@Clownacy
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Clownacy commented Oct 1, 2016

I need to strip out that dependency, anyway. Perhaps, I should add a 'CloneDriverInit' function, where the user provides a 'this is a PAL console' flag.

@Clownacy Clownacy added the bug label Mar 18, 2017
@Clownacy
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Actually, does it work different on the 32X, or was the emulator I was using at the time (probably Kega) just bugged?

@Clownacy
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I'm just now noticing that I never explained what the issue even is.

Graphics_Flags in the Sonic disassemblies is a copy of some random IO register thingy ($A10001). Some bit in it (bit 6) indicates whether the console is a PAL model or not. When testing 32X support with an emulator (probably Kega) I noticed that this bit no longer seemed to indicate PAL consoles - it was always indicating NTSC models.

My point is that bit 6 of $A10001 doesn't seem to work properly in 32X games, but I'm not sure whether this is the case on real hardware or if it's just a bug in Kega.

Another way to detect PAL consoles is to check bit 8 of the VDP control port. This is the method Sonic 2's sound driver uses (see the SoundDriverLoad function). It may be worth switching to this method instead, just in case.

@Brainulator9
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I wonder if 32X Technical Bulletin #24 has anything to do with this.

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