mapper245.cpp

著名的任天堂FC游戏机模拟器VirtuaNes 085版的源码!

//////////////////////////////////////////////////////////////////////////
// Mapper245  Yong Zhe Dou E Long                                       //
//////////////////////////////////////////////////////////////////////////

void	Mapper245::Reset()
{
	for( INT i = 0; i < 8; i++ ) {
		reg[i] = 0x00;
	}

	prg0 = 0;
	prg1 = 1;

	SetPROM_32K_Bank( 0, 1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );

	if( VROM_1K_SIZE ) {
		SetVROM_8K_Bank( 0 );
	}

	we_sram  = 0;	// Disable
	irq_enable = 0;	// Disable
	irq_counter = 0;
	irq_latch = 0;
	irq_request = 0;

	nes->SetIrqType( NES::IRQ_CLOCK );
}

void	Mapper245::Write( WORD addr, BYTE data )
{
	switch( addr&0xF7FF ) {
		case	0x8000:
			reg[0] = data;
			break;
		case	0x8001:
			reg[1] = data;
			switch( reg[0] ) {
				case	0x00:
					reg[3]=(data & 2 )<<5;
					SetPROM_8K_Bank(6,0x3E | reg[3]);
					SetPROM_8K_Bank(7,0x3F | reg[3]);
					break;
				case	0x06:
					prg0=data;
					break;
				case	0x07:
					prg1=data;
					break;
			}
			SetPROM_8K_Bank( 4, prg0|reg[3] );
			SetPROM_8K_Bank( 5, prg1|reg[3] );
			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:
		    
			break;
		case	0xC000:
			reg[4] = data;
			irq_counter = data;
			irq_request = 0;
			nes->cpu->ClrIRQ( IRQ_MAPPER );
			break;
		case	0xC001:
			reg[5] = data;
			irq_latch = data;
			irq_request = 0;
			nes->cpu->ClrIRQ( IRQ_MAPPER );
			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;
			nes->cpu->ClrIRQ( IRQ_MAPPER );
			break;
	}
}

void	Mapper245::Clock( INT cycles )
{
//	if( irq_request && (nes->GetIrqType() == NES::IRQ_CLOCK) ) {
//		nes->cpu->IRQ_NotPending();
//	}
}

void	Mapper245::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 );
				}
			}
		}
	}
//	if( irq_request && (nes->GetIrqType() == NES::IRQ_HSYNC) ) {
//		nes->cpu->IRQ_NotPending();
//	}
}

void	Mapper245::SetBank_CPU()
{
	SetPROM_32K_Bank( prg0, prg1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
}

void	Mapper245::SetBank_PPU()
{
	if( VROM_1K_SIZE ) {
		if( reg[0] & 0x80 ) {
			SetVROM_8K_Bank( chr4, chr5, chr6, chr7,
					 chr23+1, chr23, chr01+1, chr01 );
		} else {
			SetVROM_8K_Bank( chr01, chr01+1, chr23, chr23+1,
					 chr4, chr5, chr6, 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	Mapper245::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] = (BYTE)irq_counter;
	p[18] = irq_latch;
	p[19] = irq_request;
}

void	Mapper245::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 = (INT)p[17];
	irq_latch   = p[18];
	irq_request = p[19];
}