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/*===================================================================*/
/* */
/* Mapper 40 (SMB2J) */
/* */
/*===================================================================*/
BYTE Map40_IRQ_Enable;
DWORD Map40_Line_To_IRQ;
/*-------------------------------------------------------------------*/
/* Initialize Mapper 40 */
/*-------------------------------------------------------------------*/
void Map40_Init()
{
int nPage;
/* Initialize Mapper */
MapperInit = Map40_Init;
/* Write to Mapper */
MapperWrite = Map40_Write;
/* Write to SRAM */
MapperSram = Map0_Sram;
/* Write to APU */
MapperApu = Map0_Apu;
/* Read from APU */
MapperReadApu = Map0_ReadApu;
/* Callback at VSync */
MapperVSync = Map0_VSync;
/* Callback at HSync */
MapperHSync = Map40_HSync;
/* Callback at PPU */
MapperPPU = Map0_PPU;
/* Callback at Rendering Screen ( 1:BG, 0:Sprite ) */
MapperRenderScreen = Map0_RenderScreen;
/* Set SRAM Banks */
SRAMBANK = ROMPAGE( 6 );
/* Initialize IRQ Registers */
Map40_IRQ_Enable = 0;
Map40_Line_To_IRQ = 0;
/* Set ROM Banks */
ROMBANK0 = ROMPAGE( 4 );
ROMBANK1 = ROMPAGE( 5 );
ROMBANK2 = ROMPAGE( 0 );
ROMBANK3 = ROMPAGE( 7 );
/* Set PPU Banks */
if ( NesHeader.byVRomSize > 0 )
{
for ( nPage = 0; nPage < 8; ++nPage )
PPUBANK[ nPage ] = VROMPAGE( nPage );
InfoNES_SetupChr();
}
/* Set up wiring of the interrupt pin */
K6502_Set_Int_Wiring( 1, 1 );
}
/*-------------------------------------------------------------------*/
/* Mapper 40 Write Function */
/*-------------------------------------------------------------------*/
void Map40_Write( WORD wAddr, BYTE byData )
{
switch ( wAddr & 0xe000 )
{
case 0x8000:
Map40_IRQ_Enable = 0;
break;
case 0xa000:
Map40_IRQ_Enable = 1;
Map40_Line_To_IRQ = 37;
break;
case 0xc000:
break;
case 0xe000:
/* Set ROM Banks */
ROMBANK2 = ROMPAGE ( ( byData & 0x07 ) % ( NesHeader.byRomSize << 1 ) );
break;
}
}
/*-------------------------------------------------------------------*/
/* Mapper 40 H-Sync Function */
/*-------------------------------------------------------------------*/
void Map40_HSync()
{
/*
* Callback at HSync
*
*/
if ( Map40_IRQ_Enable )
{
if ( ( --Map40_Line_To_IRQ ) <= 0 )
{
IRQ_REQ;
}
}
}
/* End of InfoNES_Mapper_40.cpp */
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