mapper073.c

一款游戏机的模拟器

#include	"..\DLL\d_iNES.h"

static	struct
{
	u8 IRQenabled;
	u16_n IRQcounter;
	u8 PRG;
}	Mapper;

static	void	Sync (void)
{
	MP->SetPRG_RAM8(0x6,0);
	MP->SetPRG_ROM16(0x8,Mapper.PRG);
	MP->SetPRG_ROM16(0xC,-1);
	MP->SetCHR_RAM8(0,0);
}

static	void	__cdecl	SaveMI (Ar128 MI)
{
	u8 x = 0;
	MI[x++] = Mapper.IRQcounter.b0;
	MI[x++] = Mapper.IRQcounter.b1;
	MI[x++] = Mapper.IRQenabled;
	MI[x++] = Mapper.PRG;
}

static	void	__cdecl	LoadMI (const Ar128 MI)
{
	u8 x = 0;
	Mapper.IRQcounter.b0	= MI[x++];
	Mapper.IRQcounter.b1	= MI[x++];
	Mapper.IRQenabled	= MI[x++];
	Mapper.PRG		= MI[x++];
	Sync();
}

static	void	__cdecl	HBlank (int Scanline, int Byte2001)
{
	if (Mapper.IRQenabled)
	{
		if (Mapper.IRQcounter.s0 >= (0xFFFF - 114))
		{
			Mapper.IRQenabled = 0;
			Mapper.IRQcounter.s0 = 0xFFFF;
			MP->IRQ();
		}
		else	Mapper.IRQcounter.s0 += 114;
	}
}

static	void	__cdecl	Write8 (int Bank, int Where, int What)
{
	Mapper.IRQcounter.n0 = What & 0xF;
}

static	void	__cdecl	Write9 (int Bank, int Where, int What)
{
	Mapper.IRQcounter.n1 = What & 0xF;
}

static	void	__cdecl	WriteA (int Bank, int Where, int What)
{
	Mapper.IRQcounter.n2 = What & 0xF;
}

static	void	__cdecl	WriteB (int Bank, int Where, int What)
{
	Mapper.IRQcounter.n3 = What & 0xF;
}

static	void	__cdecl	WriteC (int Bank, int Where, int What)
{
	Mapper.IRQenabled = What & 0x2;
}

static	void	__cdecl	WriteF (int Bank, int Where, int What)
{
	Mapper.PRG = What & 0xF;
	Sync();
}

static	void	__cdecl	UnloadMapper (void)
{
	iNES_UnloadROM();
}

static	void	__cdecl	InitMapper (const PMapperParam _MP, int IsHardReset)
{
	MP = _MP;
	iNES_InitROM();

	MP->SetWriteHandler(0x8,Write8);
	MP->SetWriteHandler(0x9,Write9);
	MP->SetWriteHandler(0xA,WriteA);
	MP->SetWriteHandler(0xB,WriteB);
	MP->SetWriteHandler(0xC,WriteC);
	MP->SetWriteHandler(0xF,WriteF);

	Mapper.IRQenabled = 0;
	Mapper.IRQcounter.s0 = 0;
	Mapper.PRG = 0;
	Sync();
}

CTMapperInfo	MapperInfo_073 =
{
	"Konami VRC3",
	73,
	MS_Full,
	16384,
	InitMapper,
	UnloadMapper,
	HBlank,
	NULL,
	SaveMI,
	LoadMI,
	NULL,
	NULL
};