74 lines
1.5 KiB
C#
74 lines
1.5 KiB
C#
using BizHawk.Common;
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using BizHawk.Common.NumberExtensions;
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// http://wiki.nesdev.com/w/index.php/INES_Mapper_062
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namespace BizHawk.Emulation.Cores.Nintendo.NES
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{
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internal sealed class Mapper62 : NesBoardBase
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{
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bool prg_mode = false;
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int chr_reg;
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int prg_reg;
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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 "MAPPER062":
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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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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(prg_reg), ref prg_reg);
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ser.Sync(nameof(chr_reg), ref chr_reg);
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ser.Sync(nameof(prg_mode), ref prg_mode);
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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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prg_mode = addr.Bit(5);
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if (addr.Bit(7))
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{
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SetMirrorType(EMirrorType.Horizontal);
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}
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else
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{
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SetMirrorType(EMirrorType.Vertical);
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}
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prg_reg = (addr & 0x40) | ((addr >> 8) & 0x3F);
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chr_reg = ((addr & 0x1F) << 2) | (value & 0x03);
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}
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public override byte ReadPrg(int addr)
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{
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if (prg_mode == false)
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{
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return Rom[((prg_reg >> 1) * 0x8000) + addr];
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}
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else
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{
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return Rom[(prg_reg * 0x4000) + (addr & 0x3FFF)];
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}
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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[(chr_reg * 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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