143 lines
3.0 KiB
C#
143 lines
3.0 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_228
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namespace BizHawk.Emulation.Cores.Nintendo.NES
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{
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public sealed class MLT_ACTION52 : NES.NESBoardBase
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{
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[MapperProp]
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public bool prg_mode = false;
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[MapperProp]
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public int prg_reg = 0;
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public int chr_reg;
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public int chip_offset;
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public bool cheetahmen = false;
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byte[] eRAM = new byte[4];
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int chr_bank_mask_8k, prg_bank_mask_16k, prg_bank_mask_32k;
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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 "MAPPER228":
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case "MLT-ACTION52":
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break;
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default:
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return false;
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}
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AssertPrg(256, 1536);
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chr_bank_mask_8k = Cart.chr_size / 8 - 1;
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prg_bank_mask_16k = Cart.prg_size / 16 - 1;
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prg_bank_mask_32k = Cart.prg_size / 32 - 1;
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if (Cart.prg_size == 256)
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{
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cheetahmen = true;
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}
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else
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{
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prg_bank_mask_16k = 0x1F;
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prg_bank_mask_32k = 0xF;
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}
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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(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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ser.Sync("chip", ref chip_offset);
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ser.Sync(nameof(eRAM), ref eRAM, false);
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base.SyncState(ser);
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}
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public override void WriteEXP(int addr, byte value)
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{
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if (addr >= 0x1800)
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{
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eRAM[(addr & 0x07)] = (byte)(value & 0x0F);
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}
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}
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public override byte ReadEXP(int addr)
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{
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if (addr >= 0x1800)
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{
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return eRAM[(addr & 0x07)];
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}
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else
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{
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return base.ReadEXP(addr);
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}
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}
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public override void WritePRG(int addr, byte value)
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{
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//$8000-FFFF: [.... ..CC] Low 2 bits of CHR
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//A~[..MH HPPP PPO. CCCC]
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addr += 0x8000;
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if (addr.Bit(13))
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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_mode = addr.Bit(5);
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prg_reg = (addr >> 6) & 0x1F;
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chr_reg = ((addr & 0x0F) << 2) | (value & 0x03);
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if (!cheetahmen)
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{
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int chip = ((addr >> 11) & 0x03);
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switch (chip)
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{
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case 0:
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chip_offset = 0x0;
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break;
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case 1:
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chip_offset = 0x80000;
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break;
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case 2:
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break; //TODO: this chip doesn't exist and should access open bus
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case 3:
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chip_offset = 0x100000;
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break;
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}
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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 & 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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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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int bank = (prg_reg >> 1) & prg_bank_mask_32k;
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return ROM[(bank * 0x8000) + addr + chip_offset];
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}
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else
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{
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return ROM[((prg_reg & prg_bank_mask_16k) * 0x4000) + (addr & 0x3FFF) + chip_offset];
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}
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}
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}
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}
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