76 lines
3.4 KiB
C++
76 lines
3.4 KiB
C++
//////////////////////////////////////////////////////////////////////////
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// Mapper142 SMB2j Pirate (KS 202) //
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//////////////////////////////////////////////////////////////////////////
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void Mapper142::Reset()
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{
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prg_sel = 0;
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irq_enable = 0;
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irq_counter = 0;
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SetPROM_8K_Bank( 3, 0 );
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SetPROM_8K_Bank( 7, 0x0F );
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if( VROM_1K_SIZE ) {
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SetVROM_8K_Bank( 0 );
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}
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}
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void Mapper142::Write( WORD addr, BYTE data )
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{
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switch( addr & 0xF000 ) {
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case 0x8000:
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irq_counter = (irq_counter & 0xFFF0) | ((data & 0x0F)<< 0);
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break;
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case 0x9000:
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irq_counter = (irq_counter & 0xFF0F) | ((data & 0x0F)<< 4);
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break;
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case 0xA000:
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irq_counter = (irq_counter & 0xF0FF) | ((data & 0x0F)<< 8);
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break;
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case 0xB000:
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irq_counter = (irq_counter & 0x0FFF) | ((data & 0x0F)<<12);
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break;
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case 0xC000:
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irq_enable = data & 0x0F;
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nes->cpu->ClrIRQ( IRQ_MAPPER );
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break;
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case 0xE000:
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prg_sel = data & 0x0F;
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break;
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case 0xF000:
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switch( prg_sel ) {
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case 1: SetPROM_8K_Bank( 4, data & 0x0F ); break;
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case 2: SetPROM_8K_Bank( 5, data & 0x0F ); break;
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case 3: SetPROM_8K_Bank( 6, data & 0x0F ); break;
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case 4: SetPROM_8K_Bank( 3, data & 0x0F ); break;
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}
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break;
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}
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}
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void Mapper142::HSync( INT scanline )
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{
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if( irq_enable ) {
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if( irq_counter > (0xFFFF - 113) ) {
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irq_counter = 0;
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nes->cpu->SetIRQ( IRQ_MAPPER );
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} else {
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irq_counter += 113;
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}
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}
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}
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void Mapper142::SaveState( LPBYTE p )
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{
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p[0] = prg_sel;
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p[0] = irq_enable;
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*(INT*)&p[2] = irq_counter;
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}
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void Mapper142::LoadState( LPBYTE p )
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{
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prg_sel = p[0];
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irq_enable = p[1];
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irq_counter = *(INT*)&p[2];
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}
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