102 lines
2.0 KiB
C#
102 lines
2.0 KiB
C#
using BizHawk.Common;
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using BizHawk.Common.NumberExtensions;
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namespace BizHawk.Emulation.Cores.Nintendo.NES
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{
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public sealed class Mapper057 : NES.NESBoardBase
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{
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// http://wiki.nesdev.com/w/index.php/INES_Mapper_057
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bool prg_mode = false;
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int chr_reg_low_0, chr_reg_low_1, chr_reg;
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int prg_reg;
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[MapperProp]
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public int Mapper57_DipSwitch = 0;
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public override bool Configure(NES.EDetectionOrigin origin)
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{
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switch (Cart.board_type)
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{
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case "MAPPER057":
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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.Horizontal);
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AutoMapperProps.Apply(this);
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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("prg_reg", ref prg_reg);
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ser.Sync("chr_reg", ref chr_reg);
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ser.Sync("chr_reg_low_0", ref chr_reg);
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ser.Sync("chr_reg_low_1", ref chr_reg);
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ser.Sync("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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addr &= 0x8800;
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if (addr == 0)
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{
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chr_reg_low_0 = value & 0x07;
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chr_reg &= 0x08;
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chr_reg |= (value & 0x40) >> 3;
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}
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else if(addr == 0x800)
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{
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prg_reg = (value >> 5) & 0x07;
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prg_mode = value.Bit(4);
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chr_reg_low_1 = (value & 0x07);
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if (value.Bit(3))
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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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}
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chr_reg &= ~0x07;
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chr_reg |= (chr_reg_low_0 | chr_reg_low_1);
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//Console.WriteLine("chr page = {0}", chr_reg);
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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)
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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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public override byte ReadWRAM(int addr)
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{
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return (byte)(Mapper57_DipSwitch & 3);
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}
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}
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}
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