AxibugEmuOnline/References/virtuanessrc097-master/NES/Mapper/Mapper010.cpp
2024-08-05 17:58:53 +08:00

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//////////////////////////////////////////////////////////////////////////
// Mapper010 Nintendo MMC4 //
//////////////////////////////////////////////////////////////////////////
void Mapper010::Reset()
{
SetPROM_32K_Bank( 0, 1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
reg[0] = 0; reg[1] = 4;
reg[2] = 0; reg[3] = 0;
latch_a = 0xFE;
latch_b = 0xFE;
SetVROM_4K_Bank( 0, 4 );
SetVROM_4K_Bank( 4, 0 );
nes->ppu->SetChrLatchMode( TRUE );
}
void Mapper010::Write( WORD addr, BYTE data )
{
switch( addr & 0xF000 ) {
case 0xA000:
SetPROM_16K_Bank( 4, data );
break;
case 0xB000:
reg[0] = data;
if( latch_a == 0xFD ) {
SetVROM_4K_Bank( 0, reg[0] );
}
break;
case 0xC000:
reg[1] = data;
if( latch_a == 0xFE ) {
SetVROM_4K_Bank( 0, reg[1] );
}
break;
case 0xD000:
reg[2] = data;
if( latch_b == 0xFD ) {
SetVROM_4K_Bank( 4, reg[2] );
}
break;
case 0xE000:
reg[3] = data;
if( latch_b == 0xFE ) {
SetVROM_4K_Bank( 4, reg[3] );
}
break;
case 0xF000:
if( data & 0x01 ) SetVRAM_Mirror( VRAM_HMIRROR );
else SetVRAM_Mirror( VRAM_VMIRROR );
break;
}
}
void Mapper010::PPU_ChrLatch( WORD addr )
{
if( (addr&0x1FF0) == 0x0FD0 && latch_a != 0xFD ) {
latch_a = 0xFD;
SetVROM_4K_Bank( 0, reg[0] );
} else if( (addr&0x1FF0) == 0x0FE0 && latch_a != 0xFE ) {
latch_a = 0xFE;
SetVROM_4K_Bank( 0, reg[1] );
} else if( (addr&0x1FF0) == 0x1FD0 && latch_b != 0xFD ) {
latch_b = 0xFD;
SetVROM_4K_Bank( 4, reg[2] );
} else if( (addr&0x1FF0) == 0x1FE0 && latch_b != 0xFE ) {
latch_b = 0xFE;
SetVROM_4K_Bank( 4, reg[3] );
}
}
void Mapper010::SaveState( LPBYTE p )
{
p[0] = reg[0];
p[1] = reg[1];
p[2] = reg[2];
p[3] = reg[3];
p[4] = latch_a;
p[5] = latch_b;
}
void Mapper010::LoadState( LPBYTE p )
{
reg[0] = p[0];
reg[1] = p[1];
reg[2] = p[2];
reg[3] = p[3];
latch_a = p[4];
latch_b = p[5];
}