AxibugEmuOnline/virtuanessrc097-master/NES/Mapper/Mapper074.cpp

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//////////////////////////////////////////////////////////////////////////
// Mapper074 Nintendo MMC3 //
//////////////////////////////////////////////////////////////////////////
void Mapper074::Reset()
{
for( INT i = 0; i < 8; i++ ) {
reg[i] = 0x00;
}
prg0 = 0;
prg1 = 1;
SetBank_CPU();
chr01 = 0;
chr23 = 2;
chr4 = 4;
chr5 = 5;
chr6 = 6;
chr7 = 7;
SetBank_PPU();
we_sram = 0; // Disable
irq_enable = 0; // Disable
irq_counter = 0;
irq_latch = 0;
irq_request = 0;
DWORD crc = nes->rom->GetPROM_CRC();
patch = 0;
if( crc == 0x37ae04a8 ) {
patch = 1;
nes->SetRenderMethod( NES::TILE_RENDER );
}
}
void Mapper074::Write( WORD addr, BYTE data )
{
//DEBUGOUT( "MPRWR A=%04X D=%02X L=%3d CYC=%d\n", addr&0xFFFF, data&0xFF, nes->GetScanline(), nes->cpu->GetTotalCycles() );
switch( addr & 0xE001 ) {
case 0x8000:
reg[0] = data;
SetBank_CPU();
SetBank_PPU();
break;
case 0x8001:
reg[1] = data;
switch( reg[0] & 0x07 ) {
case 0x00:
chr01 = data & 0xFE;
SetBank_PPU();
break;
case 0x01:
chr23 = data & 0xFE;
SetBank_PPU();
break;
case 0x02:
chr4 = data;
SetBank_PPU();
break;
case 0x03:
chr5 = data;
SetBank_PPU();
break;
case 0x04:
chr6 = data;
SetBank_PPU();
break;
case 0x05:
chr7 = data;
SetBank_PPU();
break;
case 0x06:
prg0 = data;
SetBank_CPU();
break;
case 0x07:
prg1 = data;
SetBank_CPU();
break;
}
break;
case 0xA000:
reg[2] = data;
if( !nes->rom->Is4SCREEN() ) {
if( data & 0x01 ) SetVRAM_Mirror( VRAM_HMIRROR );
else SetVRAM_Mirror( VRAM_VMIRROR );
}
break;
case 0xA001:
reg[3] = data;
break;
case 0xC000:
reg[4] = data;
irq_counter = data;
irq_request = 0;
break;
case 0xC001:
reg[5] = data;
irq_latch = data;
irq_request = 0;
break;
case 0xE000:
reg[6] = data;
irq_enable = 0;
irq_request = 0;
nes->cpu->ClrIRQ( IRQ_MAPPER );
break;
case 0xE001:
reg[7] = data;
irq_enable = 1;
irq_request = 0;
break;
}
}
void Mapper074::HSync( INT scanline )
{
if( (scanline >= 0 && scanline <= 239) ) {
if( nes->ppu->IsDispON() ) {
if( irq_enable && !irq_request ) {
if( scanline == 0 ) {
if( irq_counter ) {
irq_counter--;
}
}
if( !(irq_counter--) ) {
irq_request = 0xFF;
irq_counter = irq_latch;
nes->cpu->SetIRQ( IRQ_MAPPER );
}
}
}
}
}
void Mapper074::SetBank_CPU()
{
if( reg[0] & 0x40 ) {
SetPROM_32K_Bank( PROM_8K_SIZE-2, prg1, prg0, PROM_8K_SIZE-1 );
} else {
SetPROM_32K_Bank( prg0, prg1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
}
}
void Mapper074::SetBank_PPU()
{
if( VROM_1K_SIZE ) {
if( reg[0] & 0x80 ) {
// SetVROM_8K_Bank( chr4, chr5, chr6, chr7,
// chr01, chr01+1, chr23, chr23+1 );
SetBank_PPUSUB( 4, chr01+0 );
SetBank_PPUSUB( 5, chr01+1 );
SetBank_PPUSUB( 6, chr23+0 );
SetBank_PPUSUB( 7, chr23+1 );
SetBank_PPUSUB( 0, chr4 );
SetBank_PPUSUB( 1, chr5 );
SetBank_PPUSUB( 2, chr6 );
SetBank_PPUSUB( 3, chr7 );
} else {
// SetVROM_8K_Bank( chr01, chr01+1, chr23, chr23+1,
// chr4, chr5, chr6, chr7 );
SetBank_PPUSUB( 0, chr01+0 );
SetBank_PPUSUB( 1, chr01+1 );
SetBank_PPUSUB( 2, chr23+0 );
SetBank_PPUSUB( 3, chr23+1 );
SetBank_PPUSUB( 4, chr4 );
SetBank_PPUSUB( 5, chr5 );
SetBank_PPUSUB( 6, chr6 );
SetBank_PPUSUB( 7, chr7 );
}
} else {
if( reg[0] & 0x80 ) {
SetCRAM_1K_Bank( 4, (chr01+0)&0x07 );
SetCRAM_1K_Bank( 5, (chr01+1)&0x07 );
SetCRAM_1K_Bank( 6, (chr23+0)&0x07 );
SetCRAM_1K_Bank( 7, (chr23+1)&0x07 );
SetCRAM_1K_Bank( 0, chr4&0x07 );
SetCRAM_1K_Bank( 1, chr5&0x07 );
SetCRAM_1K_Bank( 2, chr6&0x07 );
SetCRAM_1K_Bank( 3, chr7&0x07 );
} else {
SetCRAM_1K_Bank( 0, (chr01+0)&0x07 );
SetCRAM_1K_Bank( 1, (chr01+1)&0x07 );
SetCRAM_1K_Bank( 2, (chr23+0)&0x07 );
SetCRAM_1K_Bank( 3, (chr23+1)&0x07 );
SetCRAM_1K_Bank( 4, chr4&0x07 );
SetCRAM_1K_Bank( 5, chr5&0x07 );
SetCRAM_1K_Bank( 6, chr6&0x07 );
SetCRAM_1K_Bank( 7, chr7&0x07 );
}
}
}
void Mapper074::SetBank_PPUSUB( int bank, int page )
{
if( !patch && (page == 8 || page == 9) ) {
SetCRAM_1K_Bank( bank, page & 7 );
} else if( patch == 1 && page >= 128 ) {
SetCRAM_1K_Bank( bank, page & 7 );
} else {
SetVROM_1K_Bank( bank, page );
}
}
void Mapper074::SaveState( LPBYTE p )
{
for( INT i = 0; i < 8; i++ ) {
p[i] = reg[i];
}
p[ 8] = prg0;
p[ 9] = prg1;
p[10] = chr01;
p[11] = chr23;
p[12] = chr4;
p[13] = chr5;
p[14] = chr6;
p[15] = chr7;
p[16] = irq_enable;
p[17] = irq_counter;
p[18] = irq_latch;
p[19] = irq_request;
}
void Mapper074::LoadState( LPBYTE p )
{
for( INT i = 0; i < 8; i++ ) {
reg[i] = p[i];
}
prg0 = p[ 8];
prg1 = p[ 9];
chr01 = p[10];
chr23 = p[11];
chr4 = p[12];
chr5 = p[13];
chr6 = p[14];
chr7 = p[15];
irq_enable = p[16];
irq_counter = p[17];
irq_latch = p[18];
irq_request = p[19];
}