241 lines
6.8 KiB
C#
241 lines
6.8 KiB
C#
using System;
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using System.Globalization;
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using System.IO;
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namespace BizHawk.Emulation.CPUs.M6502
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{
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public sealed partial class MOS6502
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{
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public MOS6502()
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{
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//InitTableNZ();
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Reset();
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}
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/*
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private byte[] TableNZ;
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private void InitTableNZ()
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{
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TableNZ = new byte[256];
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for (int i = 0; i < 256; i++)
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{
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byte b = 0;
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if (i == 0) b |= 0x02;
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if (i > 127) b |= 0x80;
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TableNZ[i] = b;
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}
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}*/
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public bool debug;
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public bool throw_unhandled;
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public void Reset()
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{
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A = 0;
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X = 0;
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Y = 0;
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P = 0;
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S = 0;
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PC = 0;
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PendingCycles = 0;
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TotalExecutedCycles = 0;
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}
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public string State()
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{
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int notused;
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string a = string.Format("{0:X4} {1:X2} {2} ", PC, ReadMemory(PC), Disassemble(PC, out notused)).PadRight(30);
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string b = string.Format("A:{0:X2} X:{1:X2} Y:{2:X2} P:{3:X2} SP:{4:X2} Cy:{5}", A, X, Y, P, S, TotalExecutedCycles);
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string val = a + b + " ";
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if (FlagN) val = val + "N";
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if (FlagV) val = val + "V";
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if (FlagT) val = val + "T";
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if (FlagB) val = val + "B";
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if (FlagD) val = val + "D";
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if (FlagI) val = val + "I";
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if (FlagZ) val = val + "Z";
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if (FlagC) val = val + "C";
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return val;
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}
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public const ushort NMIVector = 0xFFFA;
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public const ushort ResetVector = 0xFFFC;
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public const ushort BRKVector = 0xFFFE;
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public const ushort IRQVector = 0xFFFE;
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enum ExceptionType
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{
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BRK, NMI, IRQ
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}
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void TriggerException(ExceptionType type)
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{
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if (type == ExceptionType.BRK)
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PC++;
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WriteMemory((ushort)(S-- + 0x100), (byte)(PC >> 8));
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WriteMemory((ushort)(S-- + 0x100), (byte)PC);
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FlagB = type == ExceptionType.BRK;
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WriteMemory((ushort)(S-- + 0x100), P);
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FlagI = true;
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switch (type)
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{
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case ExceptionType.NMI:
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PC = ReadWord(NMIVector);
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break;
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case ExceptionType.IRQ:
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PC = ReadWord(IRQVector);
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break;
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case ExceptionType.BRK:
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PC = ReadWord(BRKVector);
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break;
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default: throw new Exception();
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}
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PendingCycles -= 7;
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}
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// ==== CPU State ====
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public byte A;
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public byte X;
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public byte Y;
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public byte P;
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public ushort PC;
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public byte S;
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public bool IRQ;
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public bool NMI;
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public bool CLI_Pending;
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public bool SEI_Pending;
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public void SyncState(Serializer ser)
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{
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ser.BeginSection("MOS6502");
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ser.Sync("A", ref A);
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ser.Sync("X", ref X);
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ser.Sync("Y", ref Y);
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ser.Sync("P", ref P);
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ser.Sync("PC", ref PC);
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ser.Sync("S", ref S);
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ser.Sync("NMI", ref NMI);
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ser.Sync("IRQ", ref IRQ);
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ser.Sync("CLI_Pending", ref CLI_Pending);
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ser.Sync("SEI_Pending", ref SEI_Pending);
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ser.Sync("TotalExecutedCycles", ref TotalExecutedCycles);
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ser.Sync("PendingCycles", ref PendingCycles);
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ser.EndSection();
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}
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public void SaveStateBinary(BinaryWriter writer) { SyncState(Serializer.CreateBinaryWriter(writer)); }
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public void LoadStateBinary(BinaryReader reader) { SyncState(Serializer.CreateBinaryReader(reader)); }
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// ==== End State ====
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/// <summary>Carry Flag</summary>
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private bool FlagC
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{
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get { return (P & 0x01) != 0; }
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set { P = (byte)((P & ~0x01) | (value ? 0x01 : 0x00)); }
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}
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/// <summary>Zero Flag</summary>
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private bool FlagZ
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{
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get { return (P & 0x02) != 0; }
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set { P = (byte)((P & ~0x02) | (value ? 0x02 : 0x00)); }
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}
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/// <summary>Interrupt Disable Flag</summary>
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public bool FlagI
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{
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get { return (P & 0x04) != 0; }
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set { P = (byte)((P & ~0x04) | (value ? 0x04 : 0x00)); }
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}
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/// <summary>Decimal Mode Flag</summary>
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private bool FlagD
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{
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get { return (P & 0x08) != 0; }
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set { P = (byte)((P & ~0x08) | (value ? 0x08 : 0x00)); }
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}
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/// <summary>Break Flag</summary>
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private bool FlagB
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{
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get { return (P & 0x10) != 0; }
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set { P = (byte)((P & ~0x10) | (value ? 0x10 : 0x00)); }
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}
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/// <summary>T... Flag</summary>
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private bool FlagT
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{
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get { return (P & 0x20) != 0; }
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set { P = (byte)((P & ~0x20) | (value ? 0x20 : 0x00)); }
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}
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/// <summary>Overflow Flag</summary>
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private bool FlagV
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{
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get { return (P & 0x40) != 0; }
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set { P = (byte)((P & ~0x40) | (value ? 0x40 : 0x00)); }
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}
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/// <summary>Negative Flag</summary>
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private bool FlagN
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{
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get { return (P & 0x80) != 0; }
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set { P = (byte)((P & ~0x80) | (value ? 0x80 : 0x00)); }
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}
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public int TotalExecutedCycles;
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public int PendingCycles;
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public Func<ushort, byte> ReadMemory;
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public Action<ushort, byte> WriteMemory;
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public void UnregisterMemoryMapper()
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{
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ReadMemory = null;
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WriteMemory = null;
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}
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public ushort ReadWord(ushort address)
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{
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byte l = ReadMemory(address);
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byte h = ReadMemory(++address);
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return (ushort)((h << 8) | l);
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}
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private void WriteWord(ushort address, ushort value)
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{
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byte l = (byte)(value & 0xFF);
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byte h = (byte)(value >> 8);
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WriteMemory(address, l);
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WriteMemory(++address, h);
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}
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private ushort ReadWordPageWrap(ushort address)
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{
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ushort highAddress = (ushort)((address & 0xFF00) + ((address + 1) & 0xFF));
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return (ushort)(ReadMemory(address) | (ReadMemory(highAddress) << 8));
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}
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private static readonly byte[] TableNZ =
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{
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0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
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0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80
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};
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}
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} |