179 lines
3.1 KiB
C++
179 lines
3.1 KiB
C++
//////////////////////////////////////////////////////////////////////////
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// Mapper248 Bao Qing Tian //
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//////////////////////////////////////////////////////////////////////////
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void Mapper248::Reset()
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{
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for( INT i = 0; i < 8; i++ ) {
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reg[i] = 0x00;
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}
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prg0 = 0;
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prg1 = 1;
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SetBank_CPU();
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chr01 = 0;
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chr23 = 2;
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chr4 = 4;
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chr5 = 5;
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chr6 = 6;
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chr7 = 7;
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SetBank_PPU();
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we_sram = 0; // Disable
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irq_enable = 0; // Disable
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irq_counter = 0;
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irq_latch = 0;
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irq_request = 0;
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}
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void Mapper248::WriteLow( WORD addr, BYTE data )
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{
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SetPROM_32K_Bank( 2*data, 2*data+1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
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}
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void Mapper248::Write( WORD addr, BYTE data )
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{
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switch( addr & 0xE001 ) {
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case 0x8000:
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reg[0] = data;
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SetBank_CPU();
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SetBank_PPU();
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break;
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case 0x8001:
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reg[1] = data;
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switch( reg[0] & 0x07 ) {
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case 0x00:
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chr01 = data & 0xFE;
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SetBank_PPU();
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break;
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case 0x01:
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chr23 = data & 0xFE;
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SetBank_PPU();
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break;
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case 0x02:
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chr4 = data;
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SetBank_PPU();
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break;
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case 0x03:
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chr5 = data;
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SetBank_PPU();
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break;
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case 0x04:
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chr6 = data;
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SetBank_PPU();
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break;
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case 0x05:
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chr7 = data;
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SetBank_PPU();
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break;
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case 0x06:
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prg0 = data;
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SetBank_CPU();
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break;
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case 0x07:
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prg1 = data;
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SetBank_CPU();
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break;
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}
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break;
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case 0xA000:
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reg[2] = data;
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if( !nes->rom->Is4SCREEN() ) {
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if( data & 0x01 ) {
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SetVRAM_Mirror( VRAM_HMIRROR );
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} else {
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SetVRAM_Mirror( VRAM_VMIRROR );
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}
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}
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break;
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case 0xC000:
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irq_enable=0;
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irq_latch=0xBE;
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irq_counter =0xBE;
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nes->cpu->ClrIRQ( IRQ_MAPPER );
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break;
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case 0xC001:
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irq_enable=1;
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irq_latch=0xBE;
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irq_counter=0xBE;
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break;
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}
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}
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void Mapper248::HSync( INT scanline )
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{
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if( (scanline >= 0 && scanline <= 239) ) {
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if( nes->ppu->IsDispON() ) {
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if( irq_enable ) {
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if( !(irq_counter--) ) {
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irq_counter = irq_latch;
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// nes->cpu->IRQ_NotPending();
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nes->cpu->SetIRQ( IRQ_MAPPER );
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}
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}
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}
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}
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}
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void Mapper248::SetBank_CPU()
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{
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if( reg[0] & 0x40 ) {
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SetPROM_32K_Bank( PROM_8K_SIZE-2, prg1, prg0, PROM_8K_SIZE-1 );
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} else {
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SetPROM_32K_Bank( prg0, prg1, PROM_8K_SIZE-2, PROM_8K_SIZE-1 );
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}
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}
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void Mapper248::SetBank_PPU()
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{
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if( VROM_1K_SIZE ) {
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if( reg[0] & 0x80 ) {
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SetVROM_8K_Bank( chr4, chr5, chr6, chr7,
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chr01, chr01+1, chr23, chr23+1 );
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} else {
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SetVROM_8K_Bank( chr01, chr01+1, chr23, chr23+1,
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chr4, chr5, chr6, chr7 );
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}
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}
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}
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void Mapper248::SaveState( LPBYTE p )
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{
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for( INT i = 0; i < 8; i++ ) {
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p[i] = reg[i];
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}
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p[ 8] = prg0;
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p[ 9] = prg1;
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p[10] = chr01;
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p[11] = chr23;
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p[12] = chr4;
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p[13] = chr5;
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p[14] = chr6;
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p[15] = chr7;
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p[16] = irq_enable;
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p[17] = (BYTE)irq_counter;
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p[18] = irq_latch;
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p[19] = irq_request;
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}
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void Mapper248::LoadState( LPBYTE p )
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{
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for( INT i = 0; i < 8; i++ ) {
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reg[i] = p[i];
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}
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prg0 = p[ 8];
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prg1 = p[ 9];
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chr01 = p[10];
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chr23 = p[11];
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chr4 = p[12];
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chr5 = p[13];
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chr6 = p[14];
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chr7 = p[15];
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irq_enable = p[16];
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irq_counter = (INT)p[17];
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irq_latch = p[18];
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irq_request = p[19];
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}
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