135 lines
3.1 KiB
C++
135 lines
3.1 KiB
C++
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/////////////////////////////////////////////////////////////////////
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// Mapper 234
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void NES_mapper234::Reset()
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{
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regs[0] = regs[1] = regs[2] = 0;
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Sync();
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}
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void NES_mapper234::MemoryReadSaveRAM(uint32 addr)
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{
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NES_6502::Context context;
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parent_NES->cpu->GetContext(&context);
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uint8 data = context.mem_page[addr >> 13][addr & 0x1fff];
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switch(addr & 0xFFF8)
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{
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case 0xFF80:
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case 0xFF88:
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case 0xFF90:
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case 0xFF98:
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{
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if(!regs[0])
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{
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regs[0] = data;
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Sync();
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}
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}
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break;
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case 0xFFC0:
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case 0xFFC8:
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case 0xFFD0:
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case 0xFFD8:
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{
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if(!regs[2])
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{
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regs[2] = data;
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Sync();
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}
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}
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break;
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case 0xFFE8:
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case 0xFFF0:
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{
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regs[1] = data;
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}
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break;
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}
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}
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void NES_mapper234::MemoryWrite(uint32 addr, uint8 data)
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{
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switch(addr & 0xFFF8)
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{
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case 0xFF80:
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case 0xFF88:
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case 0xFF90:
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case 0xFF98:
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{
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if(!regs[0])
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{
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regs[0] = data;
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Sync();
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}
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}
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break;
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case 0xFFC0:
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case 0xFFC8:
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case 0xFFD0:
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case 0xFFD8:
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{
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if(!regs[2])
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{
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regs[2] = data;
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Sync();
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}
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}
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break;
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case 0xFFE8:
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case 0xFFF0:
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{
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regs[1] = data;
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}
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break;
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}
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}
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void NES_mapper234::Sync()
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{
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if(regs[0] & 0x80)
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{
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set_mirroring(NES_PPU::MIRROR_HORIZ);
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}
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else
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{
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set_mirroring(NES_PPU::MIRROR_VERT);
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}
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if (regs[0] & 0x40)
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{
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set_CPU_bank4(((regs[0] & 0x0E)|(regs[1] & 0x01))*4+0);
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set_CPU_bank5(((regs[0] & 0x0E)|(regs[1] & 0x01))*4+1);
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set_CPU_bank6(((regs[0] & 0x0E)|(regs[1] & 0x01))*4+2);
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set_CPU_bank7(((regs[0] & 0x0E)|(regs[1] & 0x01))*4+3);
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set_PPU_bank0((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+0);
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set_PPU_bank1((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+1);
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set_PPU_bank2((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+2);
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set_PPU_bank3((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+3);
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set_PPU_bank4((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+4);
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set_PPU_bank5((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+5);
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set_PPU_bank6((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+6);
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set_PPU_bank7((((regs[0] & 0x0E)<<2)|((regs[1] & 0x70)>>4))*8+7);
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}
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else
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{
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set_CPU_bank4((regs[0] & 0x0F)*4+0);
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set_CPU_bank5((regs[0] & 0x0F)*4+1);
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set_CPU_bank6((regs[0] & 0x0F)*4+2);
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set_CPU_bank7((regs[0] & 0x0F)*4+3);
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set_PPU_bank0((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+0);
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set_PPU_bank1((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+1);
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set_PPU_bank2((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+2);
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set_PPU_bank3((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+3);
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set_PPU_bank4((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+4);
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set_PPU_bank5((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+5);
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set_PPU_bank6((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+6);
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set_PPU_bank7((((regs[0] & 0x0F)<<2)|((regs[1] & 0x30)>>4))*8+7);
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}
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}
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/////////////////////////////////////////////////////////////////////
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