AxibugEmuOnline/virtuanessrc097-master/NES/Mapper/Mapper067.cpp

101 lines
4.3 KiB
C++
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

//////////////////////////////////////////////////////////////////////////
// Mapper067 SunSoft Mapper 3 //
//////////////////////////////////////////////////////////////////////////
void Mapper067::Reset()
{
irq_enable = 0;
irq_toggle = 0;
irq_counter = 0;
irq_occur = 0;
SetPROM_32K_Bank( 0, 1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
SetVROM_4K_Bank( 0, 0 );
SetVROM_4K_Bank( 4, VROM_4K_SIZE-1 );
DWORD crc = nes->rom->GetPROM_CRC();
if( crc == 0x7f2a04bf ) { // For Fantasy Zone 2(J)
nes->SetRenderMethod( NES::PRE_ALL_RENDER );
}
}
void Mapper067::Write( WORD addr, BYTE data )
{
switch( addr & 0xF800 ) {
case 0x8800:
SetVROM_2K_Bank( 0, data );
break;
case 0x9800:
SetVROM_2K_Bank( 2, data );
break;
case 0xA800:
SetVROM_2K_Bank( 4, data );
break;
case 0xB800:
SetVROM_2K_Bank( 6, data );
break;
case 0xC800:
if( !irq_toggle ) {
irq_counter = (irq_counter&0x00FF)|((INT)data<<8);
} else {
irq_counter = (irq_counter&0xFF00)|((INT)data&0xFF);
}
irq_toggle ^= 1;
irq_occur = 0;
nes->cpu->ClrIRQ( IRQ_MAPPER );
break;
case 0xD800:
irq_enable = data & 0x10;
irq_toggle = 0;
irq_occur = 0;
nes->cpu->ClrIRQ( IRQ_MAPPER );
break;
case 0xE800:
data &= 0x03;
if( data == 0 ) SetVRAM_Mirror( VRAM_VMIRROR );
else if( data == 1 ) SetVRAM_Mirror( VRAM_HMIRROR );
else if( data == 2 ) SetVRAM_Mirror( VRAM_MIRROR4L );
else SetVRAM_Mirror( VRAM_MIRROR4H );
break;
case 0xF800:
SetPROM_16K_Bank( 4, data );
break;
}
}
void Mapper067::Clock( INT cycles )
{
if( irq_enable ) {
if( (irq_counter -= cycles) <= 0 ) {
irq_enable = 0;
irq_occur = 0xFF;
irq_counter = 0xFFFF;
nes->cpu->SetIRQ( IRQ_MAPPER );
}
}
// if( irq_occur ) {
// nes->cpu->IRQ_NotPending();
// }
}
void Mapper067::SaveState( LPBYTE p )
{
p[0] = irq_enable;
p[1] = irq_occur;
p[2] = irq_toggle;
*((INT*)&p[3]) = irq_counter;
}
void Mapper067::LoadState( LPBYTE p )
{
irq_enable = p[0];
irq_occur = p[1];
irq_toggle = p[2];
irq_counter = *((INT*)&p[3]);
}