JAVA FC模拟器源代码

// Decompiled by Jad v1.5.7g. Copyright 2000 Pavel Kouznetsov. // Jad home page: http://www.geocities.com/SiliconValley/Bridge/8617/jad.html // Decompiler options: packimports(3) fieldsfirst ansi // Source File Name: M6502.java import java.io.PrintStream; public class M6502 { private static final int FLAG_C = 1; private static final int FLAG_Z = 2; private static final int FLAG_I = 4; private static final int FLAG_D = 8; private static final int FLAG_B = 16; private static final int FLAG_NOTUSED = 32; private static final int FLAG_V = 64; private static final int FLAG_N = 128; public static final int INT_NONE = 0; public static final int INT_NMI = 1; public static final int INT_RESET = 2; public static final int INT_IRQBRK = 3; private int A; private int X; private int Y; private int P; private int S; private int PC; private int iPeriod; private int iCount; CPUMemory memory; PPU ppu; private int cycles[] = { 7, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 4, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7, 6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 4, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7, 6, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 3, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7, 6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 5, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7, 2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4, 2, 6, 2, 6, 4, 4, 4, 4, 2, 5, 2, 5, 5, 5, 5, 5, 2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4, 2, 5, 2, 5, 4, 4, 4, 4, 2, 4, 2, 5, 4, 4, 4, 4, 2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7, 2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6, 2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 5, 5, 7, 7 }; private int znTable[] = { 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }; public M6502() { iPeriod = 115; } public void init(NESSystem nessystem) { memory = nessystem.mainMemory; ppu = nessystem.ppu; } private final int read(int i) { return memory.read(i); } private final int readWord(int i) { return memory.readWord(i); } private final int readCode(int i) { return memory.read(i); } private final int readCodeWord(int i) { return memory.readWord(i); } private final void write(int i, int j) { memory.write(i, j); } private final void writeWord(int i, int j) { memory.writeWord(i, j); } private final int byImmediate() { return readCode(PC++); } private final int byAbsolute() { int i = readCodeWord(PC); PC += 2; return i; } private final int byAbsoluteX() { return byAbsolute() + X; } private final int byAbsoluteY() { return byAbsolute() + Y; } private final int byZeroPage() { return readCode(PC++); } private final int byZeroPageX() { return byZeroPage() + X & 0xff; } private final int byZeroPageY() { return byZeroPage() + Y & 0xff; } private final int byIndirectX() { return readWord(byZeroPageX()); } private final int byIndirectY() { return readWord(byZeroPage()) + Y; } private final void checkPageBoundaryCrossing(int i, int j) { if(((j ^ i) & 0x100) != 0) iCount--; } private final int byAbsoluteX2() { int i = byAbsolute(); int j = i + X; checkPageBoundaryCrossing(i, j); return j; } private final int byAbsoluteY2() { int i = byAbsolute(); int j = i + Y; checkPageBoundaryCrossing(i, j); return j; } private final int byIndirectY2() { int i = readWord(byZeroPage()); int j = i + Y; checkPageBoundaryCrossing(i, j); return j; } private final void evalZNFlag(int i) { P &= 0xffffff7d; P |= znTable[i]; } private final int shiftLeft(int i) { P &= 0xffffff7c; P |= i >> 7; i <<= 1; i &= 0xff; P |= znTable[i]; return i; } private final int shiftRight(int i) { P &= 0xffffff7c; P |= i & 0x1; i >>= 1; P |= znTable[i]; return i; } private final int rotateLeft(int i) { i <<= 1; i |= P & 0x1; P &= 0xffffff7c; P |= i >> 8; i &= 0xff; P |= znTable[i]; return i; } private final int rotateRight(int i) { int j = P & 0x1; P &= 0xffffff7c; P |= i & 0x1; i >>= 1; i |= j << 7; P |= znTable[i]; return i; } private final void branch(int i, boolean flag) { byte byte0 = (byte)readCode(PC++); if(((P & i) != 0) == flag) { int j = PC + byte0; checkPageBoundaryCrossing(PC, j); PC = j; iCount--; } } private final void push(int i) { write(S + 256, i); S--; S &= 0xff; } private final int pop() { S++; S &= 0xff; return read(S + 256); } private final void pushWord(int i) { push(i / 256); push(i & 0xff); } private final int popWord() { return pop() + pop() * 256; } private final int increment(int i) { i = ++i & 0xff; P &= 0xffffff7d; P |= znTable[i]; return i; } private final int decrement(int i) { i = --i & 0xff; P &= 0xffffff7d; P |= znTable[i]; return i; } private final void operateAdd(int i) { int j = P & 0x1; int k = A + i + j; P &= 0xffffff3c; P |= (~(A & i) & (k & i) & 0x80) != 0 ? 0x40 : 0; P |= k > 255 ? 1 : 0; A = k & 0xff; P |= znTable[A]; } private final void operateSub(int i) { int j = ~P & 0x1; int k = A - i - j; P &= 0xffffff3c; P |= (~(A & i) & (k & i) & 0x80)