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add B6 and C1 instructions
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parent
ee0b5fc58c
commit
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15
cpu6502.h
15
cpu6502.h
@ -456,6 +456,15 @@ struct CPU6502
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break;
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break;
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}
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}
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case 0xC1: { // CMP (ind, X)
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unsigned char zpg = (read_pc_inc() + x) & 0xFF;
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int addr = bus.read(zpg) + bus.read((zpg + 1) & 0xFF) * 256;
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m = bus.read(addr);
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flag_change(C, m <= a);
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set_flags(N | Z, m = a - m);
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break;
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}
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case 0xD9: { // CMP abs, Y
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case 0xD9: { // CMP abs, Y
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int addr = read_pc_inc() + read_pc_inc() * 256;
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int addr = read_pc_inc() + read_pc_inc() * 256;
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m = bus.read(addr + y);
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m = bus.read(addr + y);
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@ -1135,6 +1144,12 @@ struct CPU6502
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break;
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break;
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}
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}
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case 0xB6: { // LDX zpg, Y
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int zpg = (read_pc_inc() + y) & 0xFF;
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set_flags(N | Z, x = bus.read(zpg));
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break;
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}
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case 0xA4: { // LDY
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case 0xA4: { // LDY
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unsigned char zpg = read_pc_inc();
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unsigned char zpg = read_pc_inc();
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set_flags(N | Z, y = bus.read(zpg));
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set_flags(N | Z, y = bus.read(zpg));
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