60 lines
1.2 KiB
C#
60 lines
1.2 KiB
C#
using BizHawk.Common;
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// https://wiki.nesdev.com/w/index.php/INES_Mapper_201
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namespace BizHawk.Emulation.Cores.Nintendo.NES
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{
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internal sealed class Mapper201 : NesBoardBase
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{
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public int reg;
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public int prg_bank_mask_32k;
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public int chr_bank_mask_8k;
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public override bool Configure(EDetectionOrigin origin)
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{
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switch (Cart.BoardType)
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{
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case "MAPPER201":
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break;
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default:
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return false;
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}
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SetMirrorType(EMirrorType.Vertical);
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prg_bank_mask_32k = Cart.PrgSize / 32 - 1;
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chr_bank_mask_8k = Cart.ChrSize / 8 - 1;
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return true;
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}
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public override void SyncState(Serializer ser)
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{
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ser.Sync(nameof(reg), ref reg);
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base.SyncState(ser);
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}
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public override void WritePrg(int addr, byte value)
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{
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if ((addr & 0x08) > 0)
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{
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reg = addr & 0x03;
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}
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else
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{
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reg = 0;
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}
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}
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public override byte ReadPrg(int addr)
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{
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return Rom[((reg & prg_bank_mask_32k) * 0x8000) + addr];
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}
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public override byte ReadPpu(int addr)
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{
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if (addr < 0x2000)
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{
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return Vrom[((reg & chr_bank_mask_8k) * 0x2000) + addr];
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}
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return base.ReadPpu(addr);
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}
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}
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}
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