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|
/*===================================================================*/
/* */
/* Mapper 249 : MMC3 */
/* */
/*===================================================================*/
BYTE Map249_Spdata;
BYTE Map249_Reg[8];
BYTE Map249_IRQ_Enable;
BYTE Map249_IRQ_Counter;
BYTE Map249_IRQ_Latch;
BYTE Map249_IRQ_Request;
/*-------------------------------------------------------------------*/
/* Initialize Mapper 249 */
/*-------------------------------------------------------------------*/
void Map249_Init()
{
/* Initialize Mapper */
MapperInit = Map249_Init;
/* Write to Mapper */
MapperWrite = Map249_Write;
/* Write to SRAM */
MapperSram = Map0_Sram;
/* Write to APU */
MapperApu = Map249_Apu;
/* Read from APU */
MapperReadApu = Map0_ReadApu;
/* Callback at VSync */
MapperVSync = Map0_VSync;
/* Callback at HSync */
MapperHSync = Map249_HSync;
/* Callback at PPU */
MapperPPU = Map0_PPU;
/* Callback at Rendering Screen ( 1:BG, 0:Sprite ) */
MapperRenderScreen = Map0_RenderScreen;
/* Set SRAM Banks */
SRAMBANK = SRAM;
/* Set Registers */
for( int i = 0; i < 8; i++ ) {
Map249_Reg[i] = 0x00;
}
/* Set ROM Banks */
ROMBANK0 = ROMPAGE( 0 );
ROMBANK1 = ROMPAGE( 1 );
ROMBANK2 = ROMLASTPAGE( 1 );
ROMBANK3 = ROMLASTPAGE( 0 );
/* Set PPU Banks */
if ( NesHeader.byVRomSize > 0 ) {
for ( int nPage = 0; nPage < 8; ++nPage )
PPUBANK[ nPage ] = VROMPAGE( nPage );
InfoNES_SetupChr();
}
/* Set Registers */
Map249_IRQ_Enable = 0; // Disable
Map249_IRQ_Counter = 0;
Map249_IRQ_Latch = 0;
Map249_IRQ_Request = 0;
Map249_Spdata = 0;
/* Set up wiring of the interrupt pin */
K6502_Set_Int_Wiring( 1, 1 );
}
/*-------------------------------------------------------------------*/
/* Mapper 249 Write Function */
/*-------------------------------------------------------------------*/
void Map249_Write( WORD wAddr, BYTE byData )
{
BYTE byM0,byM1,byM2,byM3,byM4,byM5,byM6,byM7;
switch( wAddr&0xFF01 ) {
case 0x8000:
case 0x8800:
Map249_Reg[0] = byData;
break;
case 0x8001:
case 0x8801:
switch( Map249_Reg[0] & 0x07 ) {
case 0x00:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 0 ] = VROMPAGE((byData&0xFE) % (NesHeader.byVRomSize<<3));
PPUBANK[ 1 ] = VROMPAGE((byData|0x01) % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x01:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 2 ] = VROMPAGE((byData&0xFE) % (NesHeader.byVRomSize<<3));
PPUBANK[ 3 ] = VROMPAGE((byData|0x01) % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x02:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 4 ] = VROMPAGE(byData % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x03:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 5 ] = VROMPAGE(byData % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x04:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 6 ] = VROMPAGE(byData % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x05:
if( Map249_Spdata == 1 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
PPUBANK[ 7 ] = VROMPAGE(byData % (NesHeader.byVRomSize<<3));
InfoNES_SetupChr();
break;
case 0x06:
if( Map249_Spdata == 1 ) {
if( byData < 0x20 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=0;
byM6=0;
byM7=0;
byData=(byM7<<7)|(byM6<<6)|(byM5<<5)|(byM2<<4)|(byM1<<3)|(byM3<<2)|(byM4<<1)|byM0;
} else {
byData=byData-0x20;
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
}
ROMBANK0 = ROMPAGE(byData % (NesHeader.byRomSize<<1));
break;
case 0x07:
if( Map249_Spdata == 1 ) {
if( byData < 0x20 ) {
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=0;
byM6=0;
byM7=0;
byData=(byM7<<7)|(byM6<<6)|(byM5<<5)|(byM2<<4)|(byM1<<3)|(byM3<<2)|(byM4<<1)|byM0;
} else {
byData=byData-0x20;
byM0=byData&0x1;
byM1=(byData&0x02)>>1;
byM2=(byData&0x04)>>2;
byM3=(byData&0x08)>>3;
byM4=(byData&0x10)>>4;
byM5=(byData&0x20)>>5;
byM6=(byData&0x40)>>6;
byM7=(byData&0x80)>>7;
byData=(byM5<<7)|(byM4<<6)|(byM2<<5)|(byM6<<4)|(byM7<<3)|(byM3<<2)|(byM1<<1)|byM0;
}
}
ROMBANK1 = ROMPAGE(byData % (NesHeader.byRomSize<<1));
break;
}
break;
case 0xA000:
case 0xA800:
Map249_Reg[2] = byData;
if( !ROM_FourScr ) {
if( byData & 0x01 ) InfoNES_Mirroring( 0 );
else InfoNES_Mirroring( 1 );
}
break;
case 0xA001:
case 0xA801:
Map249_Reg[3] = byData;
break;
case 0xC000:
case 0xC800:
Map249_Reg[4] = byData;
Map249_IRQ_Counter = byData;
Map249_IRQ_Request = 0;
break;
case 0xC001:
case 0xC801:
Map249_Reg[5] = byData;
Map249_IRQ_Latch = byData;
Map249_IRQ_Request = 0;
break;
case 0xE000:
case 0xE800:
Map249_Reg[6] = byData;
Map249_IRQ_Enable = 0;
Map249_IRQ_Request = 0;
break;
case 0xE001:
case 0xE801:
Map249_Reg[7] = byData;
Map249_IRQ_Enable = 1;
Map249_IRQ_Request = 0;
break;
}
}
/*-------------------------------------------------------------------*/
/* Mapper 249 Write to APU Function */
/*-------------------------------------------------------------------*/
void Map249_Apu( WORD wAddr, BYTE byData )
{
if( wAddr == 0x5000 ) {
switch( byData ) {
case 0x00:
Map249_Spdata = 0;
break;
case 0x02:
Map249_Spdata = 1;
break;
}
}
}
/*-------------------------------------------------------------------*/
/* Mapper 249 H-Sync Function */
/*-------------------------------------------------------------------*/
void Map249_HSync()
{
if( ( /* PPU_Scanline >= 0 && */ PPU_Scanline <= 239) ) {
if( PPU_R1 & R1_SHOW_SCR || PPU_R1 & R1_SHOW_SP ) {
if( Map249_IRQ_Enable && !Map249_IRQ_Request ) {
if( PPU_Scanline == 0 ) {
if( Map249_IRQ_Counter ) {
Map249_IRQ_Counter--;
}
}
if( !(Map249_IRQ_Counter--) ) {
Map249_IRQ_Request = 0xFF;
Map249_IRQ_Counter = Map249_IRQ_Latch;
}
}
}
}
if( Map249_IRQ_Request ) {
IRQ_REQ;
}
}
|
