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/*===================================================================*/
/* */
/* Mapper 6 (FFE) */
/* */
/*===================================================================*/
BYTE Map6_IRQ_Enable;
DWORD Map6_IRQ_Cnt;
BYTE Map6_Chr_Ram[ 0x2000 * 4 ];
/*-------------------------------------------------------------------*/
/* Initialize Mapper 6 */
/*-------------------------------------------------------------------*/
void Map6_Init()
{
int nPage;
/* Initialize Mapper */
MapperInit = Map6_Init;
/* Write to Mapper */
MapperWrite = Map6_Write;
/* Write to SRAM */
MapperSram = Map0_Sram;
/* Write to APU */
MapperApu = Map6_Apu;
/* Read from APU */
MapperReadApu = Map0_ReadApu;
/* Callback at VSync */
MapperVSync = Map0_VSync;
/* Callback at HSync */
MapperHSync = Map6_HSync;
/* Callback at PPU */
MapperPPU = Map0_PPU;
/* Callback at Rendering Screen ( 1:BG, 0:Sprite ) */
MapperRenderScreen = Map0_RenderScreen;
/* Set SRAM Banks */
SRAMBANK = SRAM;
/* Set ROM Banks */
ROMBANK0 = ROMPAGE( 0 );
ROMBANK1 = ROMPAGE( 1 );
ROMBANK2 = ROMPAGE( 14 );
ROMBANK3 = ROMPAGE( 15 );
/* Set PPU Banks */
if ( NesHeader.byVRomSize > 0 )
{
for ( nPage = 0; nPage < 8; ++nPage )
{
PPUBANK[ nPage ] = VROMPAGE( nPage );
}
InfoNES_SetupChr();
}
else
{
for ( nPage = 0; nPage < 8; ++nPage )
{
PPUBANK[ nPage ] = Map6_VROMPAGE( nPage );
}
InfoNES_SetupChr();
}
/* Set up wiring of the interrupt pin */
K6502_Set_Int_Wiring( 1, 1 );
}
/*-------------------------------------------------------------------*/
/* Mapper 6 Write to APU Function */
/*-------------------------------------------------------------------*/
void Map6_Apu( WORD wAddr, BYTE byData )
{
switch ( wAddr )
{
/* Name Table Mirroring */
case 0x42fe:
if ( byData & 0x10 )
{
InfoNES_Mirroring( 2 );
} else {
InfoNES_Mirroring( 3 );
}
break;
case 0x42ff:
if ( byData & 0x10 )
{
InfoNES_Mirroring( 0 );
} else {
InfoNES_Mirroring( 1 );
}
break;
case 0x4501:
Map6_IRQ_Enable = 0;
break;
case 0x4502:
Map6_IRQ_Cnt = ( Map6_IRQ_Cnt & 0xff00 ) | (DWORD)byData;
break;
case 0x4503:
Map6_IRQ_Cnt = ( Map6_IRQ_Cnt & 0x00ff ) | ( (DWORD)byData << 8 );
Map6_IRQ_Enable = 1;
break;
}
}
/*-------------------------------------------------------------------*/
/* Mapper 6 Write Function */
/*-------------------------------------------------------------------*/
void Map6_Write( WORD wAddr, BYTE byData )
{
BYTE byPrgBank = ( byData & 0x3c ) >> 2;
BYTE byChrBank = byData & 0x03;
/* Set ROM Banks */
byPrgBank <<= 1;
byPrgBank %= ( NesHeader.byRomSize << 1 );
ROMBANK0 = ROMPAGE( byPrgBank );
ROMBANK1 = ROMPAGE( byPrgBank + 1 );
/* Set PPU Banks */
PPUBANK[ 0 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 0 * 0x400 ];
PPUBANK[ 1 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 1 * 0x400 ];
PPUBANK[ 2 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 2 * 0x400 ];
PPUBANK[ 3 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 3 * 0x400 ];
PPUBANK[ 4 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 4 * 0x400 ];
PPUBANK[ 5 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 5 * 0x400 ];
PPUBANK[ 6 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 6 * 0x400 ];
PPUBANK[ 7 ] = &Map6_Chr_Ram[ byChrBank * 0x2000 + 7 * 0x400 ];
InfoNES_SetupChr();
}
/*-------------------------------------------------------------------*/
/* Mapper 6 H-Sync Function */
/*-------------------------------------------------------------------*/
void Map6_HSync()
{
if ( Map6_IRQ_Enable )
{
Map6_IRQ_Cnt += 133;
if ( Map6_IRQ_Cnt >= 0xffff )
{
IRQ_REQ;
Map6_IRQ_Cnt = 0;
}
}
}
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