From 760f5d5aecebc5db75502eff1a22374deb73776c Mon Sep 17 00:00:00 2001 From: Adrian Conlon Date: Sun, 10 Oct 2021 21:35:26 +0100 Subject: [PATCH] Correct filler memoryRead accesses to use PC() rather than the last location read. Signed-off-by: Adrian Conlon --- M6502/src/mos6502.cpp | 174 +++++++++++++++++++++--------------------- 1 file changed, 87 insertions(+), 87 deletions(-) diff --git a/M6502/src/mos6502.cpp b/M6502/src/mos6502.cpp index 48d6cbd..534cce5 100644 --- a/M6502/src/mos6502.cpp +++ b/M6502/src/mos6502.cpp @@ -120,45 +120,45 @@ int EightBit::MOS6502::execute() { case 0x05: A() = orr(A(), AM_ZeroPage()); break; // ORA (zero page) case 0x06: memoryReadModifyWrite(asl(AM_ZeroPage())); break; // ASL (zero page) case 0x07: slo(AM_ZeroPage()); break; // *SLO (zero page) - case 0x08: memoryRead(); php(); break; // PHP (implied) + case 0x08: memoryRead(PC()); php(); break; // PHP (implied) case 0x09: A() = orr(A(), AM_Immediate()); break; // ORA (immediate) - case 0x0a: memoryRead(); A() = asl(A()); break; // ASL A (implied) - case 0x0b: anc(AM_Immediate()); break; // *ANC (immediate) + case 0x0a: memoryRead(PC()); A() = asl(A()); break; // ASL A (implied) + case 0x0b: anc(AM_Immediate()); break; // *ANC (immediate) case 0x0c: AM_Absolute(); break; // *NOP (absolute) case 0x0d: A() = orr(A(), AM_Absolute()); break; // ORA (absolute) case 0x0e: memoryReadModifyWrite(asl(AM_Absolute())); break; // ASL (absolute) case 0x0f: slo(AM_Absolute()); break; // *SLO (absolute) - case 0x10: branch(!negative()); break; // BPL (relative) + case 0x10: branch(!negative()); break; // BPL (relative) case 0x11: A() = orr(A(), AM_IndirectIndexedY()); break; // ORA (indirect indexed Y) case 0x12: break; case 0x13: slo(AM_IndirectIndexedY()); break; // *SLO (indirect indexed Y) case 0x14: AM_ZeroPageX(); break; // *NOP (zero page, X) case 0x15: A() = orr(A(), AM_ZeroPageX()); break; // ORA (zero page, X) case 0x16: memoryReadModifyWrite(asl(AM_ZeroPageX())); break; // ASL (zero page, X) - case 0x17: slo(AM_ZeroPageX()); break; // *SLO (zero page, X) - case 0x18: memoryRead(); P() = clearBit(P(), CF); break; // CLC (implied) + case 0x17: slo(AM_ZeroPageX()); break; // *SLO (zero page, X) + case 0x18: memoryRead(PC()); P() = clearBit(P(), CF); break; // CLC (implied) case 0x19: A() = orr(A(), AM_AbsoluteY()); break; // ORA (absolute, Y) - case 0x1a: memoryRead(); break; // *NOP (implied) - case 0x1b: slo(AM_AbsoluteY()); break; // *SLO (absolute, Y) + case 0x1a: memoryRead(PC()); break; // *NOP (implied) + case 0x1b: slo(AM_AbsoluteY()); break; // *SLO (absolute, Y) case 0x1c: AM_AbsoluteX(); break; // *NOP (absolute, X) case 0x1d: A() = orr(A(), AM_AbsoluteX()); break; // ORA (absolute, X) case 0x1e: memoryReadModifyWrite(asl(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // ASL (absolute, X) - case 0x1f: slo(AM_AbsoluteX()); break; // *SLO (absolute, X) + case 0x1f: slo(AM_AbsoluteX()); break; // *SLO (absolute, X) case 0x20: jsr(); break; // JSR (absolute) case 0x21: A() = andr(A(), AM_IndexedIndirectX()); break; // AND (indexed indirect X) case 0x22: break; case 0x23: rla(AM_IndexedIndirectX()); break; // *RLA (indexed indirect X) - case 0x24: bit(A(), AM_ZeroPage()); break; // BIT (zero page) + case 0x24: bit(A(), AM_ZeroPage()); break; // BIT (zero page) case 0x25: A() = andr(A(), AM_ZeroPage()); break; // AND (zero page) case 0x26: memoryReadModifyWrite(rol(AM_ZeroPage())); break; // ROL (zero page) case 0x27: rla(AM_ZeroPage()); break; // *RLA (zero page) - case 0x28: memoryRead(); getBytePaged(1, S()); plp(); break; // PLP (implied) - case 0x29: A() = andr(A(), AM_Immediate()); break; // AND (immediate) - case 0x2a: memoryRead(); A() = rol(A()); break; // ROL A (implied) - case 0x2b: anc(AM_Immediate()); break; // *ANC (immediate) - case 0x2c: bit(A(), AM_Absolute()); break; // BIT (absolute) + case 0x28: memoryRead(PC()); getBytePaged(1, S()); plp(); break; // PLP (implied) + case 0x29: A() = andr(A(), AM_Immediate()); break; // AND (immediate) + case 0x2a: memoryRead(PC()); A() = rol(A()); break; // ROL A (implied) + case 0x2b: anc(AM_Immediate()); break; // *ANC (immediate) + case 0x2c: bit(A(), AM_Absolute()); break; // BIT (absolute) case 0x2d: A() = andr(A(), AM_Absolute()); break; // AND (absolute) case 0x2e: memoryReadModifyWrite(rol(AM_Absolute())); break; // ROL (absolute) case 0x2f: rla(AM_Absolute()); break; // *RLA (absolute) @@ -168,19 +168,19 @@ int EightBit::MOS6502::execute() { case 0x32: break; case 0x33: rla(AM_IndirectIndexedY()); break; // *RLA (indirect indexed Y) case 0x34: AM_ZeroPageX(); break; // *NOP (zero page, X) - case 0x35: A() = andr(A(), AM_ZeroPageX()); break; // AND (zero page, X) + case 0x35: A() = andr(A(), AM_ZeroPageX()); break; // AND (zero page, X) case 0x36: memoryReadModifyWrite(rol(AM_ZeroPageX())); break; // ROL (zero page, X) - case 0x37: rla(AM_ZeroPageX()); break; // *RLA (zero page, X) - case 0x38: memoryRead(); P() = setBit(P(), CF); break; // SEC (implied) - case 0x39: A() = andr(A(), AM_AbsoluteY()); break; // AND (absolute, Y) - case 0x3a: memoryRead(); break; // *NOP (implied) - case 0x3b: rla(AM_AbsoluteY()); break; // *RLA (absolute, Y) + case 0x37: rla(AM_ZeroPageX()); break; // *RLA (zero page, X) + case 0x38: memoryRead(PC()); P() = setBit(P(), CF); break; // SEC (implied) + case 0x39: A() = andr(A(), AM_AbsoluteY()); break; // AND (absolute, Y) + case 0x3a: memoryRead(PC()); break; // *NOP (implied) + case 0x3b: rla(AM_AbsoluteY()); break; // *RLA (absolute, Y) case 0x3c: AM_AbsoluteX(); break; // *NOP (absolute, X) - case 0x3d: A() = andr(A(), AM_AbsoluteX()); break; // AND (absolute, X) + case 0x3d: A() = andr(A(), AM_AbsoluteX()); break; // AND (absolute, X) case 0x3e: memoryReadModifyWrite(rol(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // ROL (absolute, X) - case 0x3f: rla(AM_AbsoluteX()); break; // *RLA (absolute, X) + case 0x3f: rla(AM_AbsoluteX()); break; // *RLA (absolute, X) - case 0x40: memoryRead(); rti(); break; // RTI (implied) + case 0x40: memoryRead(PC()); rti(); break; // RTI (implied) case 0x41: A() = eorr(A(), AM_IndexedIndirectX()); break; // EOR (indexed indirect X) case 0x42: break; case 0x43: sre(AM_IndexedIndirectX()); break; // *SRE (indexed indirect X) @@ -188,33 +188,33 @@ int EightBit::MOS6502::execute() { case 0x45: A() = eorr(A(), AM_ZeroPage()); break; // EOR (zero page) case 0x46: memoryReadModifyWrite(lsr(AM_ZeroPage())); break; // LSR (zero page) case 0x47: sre(AM_ZeroPage()); break; // *SRE (zero page) - case 0x48: memoryRead(); push(A()); break; // PHA (implied) - case 0x49: A() = eorr(A(), AM_Immediate()); break; // EOR (immediate) - case 0x4a: memoryRead(); A() = lsr(A()); break; // LSR A (implied) - case 0x4b: asr(AM_Immediate()); break; // *ASR (immediate) + case 0x48: memoryRead(PC()); push(A()); break; // PHA (implied) + case 0x49: A() = eorr(A(), AM_Immediate()); break; // EOR (immediate) + case 0x4a: memoryRead(PC()); A() = lsr(A()); break; // LSR A (implied) + case 0x4b: asr(AM_Immediate()); break; // *ASR (immediate) case 0x4c: jump(Address_Absolute()); break; // JMP (absolute) case 0x4d: A() = eorr(A(), AM_Absolute()); break; // EOR (absolute) case 0x4e: memoryReadModifyWrite(lsr(AM_Absolute())); break; // LSR (absolute) case 0x4f: sre(AM_Absolute()); break; // *SRE (absolute) - case 0x50: branch(!overflow()); break; // BVC (relative) + case 0x50: branch(!overflow()); break; // BVC (relative) case 0x51: A() = eorr(A(), AM_IndirectIndexedY()); break; // EOR (indirect indexed Y) case 0x52: break; case 0x53: sre(AM_IndirectIndexedY()); break; // *SRE (indirect indexed Y) case 0x54: AM_ZeroPageX(); break; // *NOP (zero page, X) - case 0x55: A() = eorr(A(), AM_ZeroPageX()); break; // EOR (zero page, X) + case 0x55: A() = eorr(A(), AM_ZeroPageX()); break; // EOR (zero page, X) case 0x56: memoryReadModifyWrite(lsr(AM_ZeroPageX())); break; // LSR (zero page, X) - case 0x57: sre(AM_ZeroPageX()); break; // *SRE (zero page, X) - case 0x58: memoryRead(); P() = clearBit(P(), IF); break; // CLI (implied) - case 0x59: A() = eorr(A(), AM_AbsoluteY()); break; // EOR (absolute, Y) - case 0x5a: memoryRead(); break; // *NOP (implied) - case 0x5b: sre(AM_AbsoluteY()); break; // *SRE (absolute, Y) + case 0x57: sre(AM_ZeroPageX()); break; // *SRE (zero page, X) + case 0x58: memoryRead(PC()); P() = clearBit(P(), IF); break; // CLI (implied) + case 0x59: A() = eorr(A(), AM_AbsoluteY()); break; // EOR (absolute, Y) + case 0x5a: memoryRead(PC()); break; // *NOP (implied) + case 0x5b: sre(AM_AbsoluteY()); break; // *SRE (absolute, Y) case 0x5c: AM_AbsoluteX(); break; // *NOP (absolute, X) - case 0x5d: A() = eorr(A(), AM_AbsoluteX()); break; // EOR (absolute, X) + case 0x5d: A() = eorr(A(), AM_AbsoluteX()); break; // EOR (absolute, X) case 0x5e: memoryReadModifyWrite(lsr(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // LSR (absolute, X) - case 0x5f: sre(AM_AbsoluteX()); break; // *SRE (absolute, X) + case 0x5f: sre(AM_AbsoluteX()); break; // *SRE (absolute, X) - case 0x60: memoryRead(); rts(); break; // RTS (implied) + case 0x60: memoryRead(PC()); rts(); break; // RTS (implied) case 0x61: A() = adc(A(), AM_IndexedIndirectX()); break; // ADC (indexed indirect X) case 0x62: break; case 0x63: rra(AM_IndexedIndirectX()); break; // *RRA (indexed indirect X) @@ -222,10 +222,10 @@ int EightBit::MOS6502::execute() { case 0x65: A() = adc(A(), AM_ZeroPage()); break; // ADC (zero page) case 0x66: memoryReadModifyWrite(ror(AM_ZeroPage())); break; // ROR (zero page) case 0x67: rra(AM_ZeroPage()); break; // *RRA (zero page) - case 0x68: memoryRead(); getBytePaged(1, S()); A() = through(pop()); break; // PLA (implied) + case 0x68: memoryRead(PC()); getBytePaged(1, S()); A() = through(pop()); break; // PLA (implied) case 0x69: A() = adc(A(), AM_Immediate()); break; // ADC (immediate) - case 0x6a: memoryRead(); A() = ror(A()); break; // ROR A (implied) - case 0x6b: arr(AM_Immediate()); break; // *ARR (immediate) + case 0x6a: memoryRead(PC()); A() = ror(A()); break; // ROR A (implied) + case 0x6b: arr(AM_Immediate()); break; // *ARR (immediate) case 0x6c: jump(Address_Indirect()); break; // JMP (indirect) case 0x6d: A() = adc(A(), AM_Absolute()); break; // ADC (absolute) case 0x6e: memoryReadModifyWrite(ror(AM_Absolute())); break; // ROR (absolute) @@ -238,15 +238,15 @@ int EightBit::MOS6502::execute() { case 0x74: AM_ZeroPageX(); break; // *NOP (zero page, X) case 0x75: A() = adc(A(), AM_ZeroPageX()); break; // ADC (zero page, X) case 0x76: memoryReadModifyWrite(ror(AM_ZeroPageX())); break; // ROR (zero page, X) - case 0x77: rra(AM_ZeroPageX()); break; // *RRA (zero page, X) - case 0x78: memoryRead(); P() = setBit(P(), IF); break; // SEI (implied) + case 0x77: rra(AM_ZeroPageX()); break; // *RRA (zero page, X) + case 0x78: memoryRead(PC()); P() = setBit(P(), IF); break; // SEI (implied) case 0x79: A() = adc(A(), AM_AbsoluteY()); break; // ADC (absolute, Y) - case 0x7a: memoryRead(); break; // *NOP (implied) - case 0x7b: rra(AM_AbsoluteY()); break; // *RRA (absolute, Y) + case 0x7a: memoryRead(PC()); break; // *NOP (implied) + case 0x7b: rra(AM_AbsoluteY()); break; // *RRA (absolute, Y) case 0x7c: AM_AbsoluteX(); break; // *NOP (absolute, X) case 0x7d: A() = adc(A(), AM_AbsoluteX()); break; // ADC (absolute, X) case 0x7e: memoryReadModifyWrite(ror(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // ROR (absolute, X) - case 0x7f: rra(AM_AbsoluteX()); break; // *RRA (absolute, X) + case 0x7f: rra(AM_AbsoluteX()); break; // *RRA (absolute, X) case 0x80: AM_Immediate(); break; // *NOP (immediate) case 0x81: memoryWrite(Address_IndexedIndirectX(), A()); break; // STA (indexed indirect X) @@ -256,9 +256,9 @@ int EightBit::MOS6502::execute() { case 0x85: memoryWrite(Address_ZeroPage(), A()); break; // STA (zero page) case 0x86: memoryWrite(Address_ZeroPage(), X()); break; // STX (zero page) case 0x87: memoryWrite(Address_ZeroPage(), A() & X()); break; // *SAX (zero page) - case 0x88: memoryRead(); Y() = dec(Y()); break; // DEY (implied) + case 0x88: memoryRead(PC()); Y() = dec(Y()); break; // DEY (implied) case 0x89: AM_Immediate(); break; // *NOP (immediate) - case 0x8a: memoryRead(); A() = through(X()); break; // TXA (implied) + case 0x8a: memoryRead(PC()); A() = through(X()); break; // TXA (implied) case 0x8b: break; case 0x8c: memoryWrite(Address_Absolute(), Y()); break; // STY (absolute) case 0x8d: memoryWrite(Address_Absolute(), A()); break; // STA (absolute) @@ -266,19 +266,19 @@ int EightBit::MOS6502::execute() { case 0x8f: memoryWrite(Address_Absolute(), A() & X()); break; // *SAX (absolute) case 0x90: branch(!carry()); break; // BCC (relative) - case 0x91: AM_IndirectIndexedY(); memoryWrite(A()); break; // STA (indirect indexed Y) + case 0x91: AM_IndirectIndexedY(); memoryWrite(A()); break; // STA (indirect indexed Y) case 0x92: break; case 0x93: break; case 0x94: memoryWrite(Address_ZeroPageX(), Y()); break; // STY (zero page, X) case 0x95: memoryWrite(Address_ZeroPageX(), A()); break; // STA (zero page, X) case 0x96: memoryWrite(Address_ZeroPageY(), X()); break; // STX (zero page, Y) - case 0x97: memoryWrite(Address_ZeroPageY(), A() & X()); break; // *SAX (zero page, Y) - case 0x98: memoryRead(); A() = through(Y()); break; // TYA (implied) - case 0x99: sta_AbsoluteY(); break; // STA (absolute, Y) - case 0x9a: memoryRead(); S() = X(); break; // TXS (implied) + case 0x97: memoryWrite(Address_ZeroPageY(), A() & X()); break; // *SAX (zero page, Y) + case 0x98: memoryRead(PC()); A() = through(Y()); break; // TYA (implied) + case 0x99: sta_AbsoluteY(); break; // STA (absolute, Y) + case 0x9a: memoryRead(PC()); S() = X(); break; // TXS (implied) case 0x9b: break; case 0x9c: break; - case 0x9d: sta_AbsoluteX(); break; // STA (absolute, X) + case 0x9d: sta_AbsoluteX(); break; // STA (absolute, X) case 0x9e: break; case 0x9f: break; @@ -290,79 +290,79 @@ int EightBit::MOS6502::execute() { case 0xa5: A() = through(AM_ZeroPage()); break; // LDA (zero page) case 0xa6: X() = through(AM_ZeroPage()); break; // LDX (zero page) case 0xa7: A() = X() = through(AM_ZeroPage()); break; // *LAX (zero page) - case 0xa8: memoryRead(); Y() = through(A()); break; // TAY (implied) + case 0xa8: memoryRead(PC()); Y() = through(A()); break; // TAY (implied) case 0xa9: A() = through(AM_Immediate()); break; // LDA (immediate) - case 0xaa: memoryRead(); X() = through(A()); break; // TAX (implied) - case 0xab: A() = X() = through(AM_Immediate()); break; // *ATX (immediate) + case 0xaa: memoryRead(PC()); X() = through(A()); break; // TAX (implied) + case 0xab: A() = X() = through(AM_Immediate()); break; // *ATX (immediate) case 0xac: Y() = through(AM_Absolute()); break; // LDY (absolute) case 0xad: A() = through(AM_Absolute()); break; // LDA (absolute) case 0xae: X() = through(AM_Absolute()); break; // LDX (absolute) case 0xaf: A() = X() = through(AM_Absolute()); break; // *LAX (absolute) - case 0xb0: branch(carry()); break; // BCS (relative) + case 0xb0: branch(carry()); break; // BCS (relative) case 0xb1: A() = through(AM_IndirectIndexedY()); break; // LDA (indirect indexed Y) case 0xb2: break; case 0xb3: A() = X() = through(AM_IndirectIndexedY()); break; // *LAX (indirect indexed Y) case 0xb4: Y() = through(AM_ZeroPageX()); break; // LDY (zero page, X) case 0xb5: A() = through(AM_ZeroPageX()); break; // LDA (zero page, X) case 0xb6: X() = through(AM_ZeroPageY()); break; // LDX (zero page, Y) - case 0xb7: A() = X() = through(AM_ZeroPageY()); break; // *LAX (zero page, Y) - case 0xb8: memoryRead(); P() = clearBit(P(), VF); break; // CLV (implied) + case 0xb7: A() = X() = through(AM_ZeroPageY()); break; // *LAX (zero page, Y) + case 0xb8: memoryRead(PC()); P() = clearBit(P(), VF); break; // CLV (implied) case 0xb9: A() = through(AM_AbsoluteY()); break; // LDA (absolute, Y) - case 0xba: memoryRead(); X() = through(S()); break; // TSX (implied) + case 0xba: memoryRead(PC()); X() = through(S()); break; // TSX (implied) case 0xbb: break; case 0xbc: Y() = through(AM_AbsoluteX()); break; // LDY (absolute, X) case 0xbd: A() = through(AM_AbsoluteX()); break; // LDA (absolute, X) case 0xbe: X() = through(AM_AbsoluteY()); break; // LDX (absolute, Y) - case 0xbf: A() = X() = through(AM_AbsoluteY()); break; // *LAX (absolute, Y) + case 0xbf: A() = X() = through(AM_AbsoluteY()); break; // *LAX (absolute, Y) case 0xc0: cmp(Y(), AM_Immediate()); break; // CPY (immediate) - case 0xc1: cmp(A(), AM_IndexedIndirectX()); break; // CMP (indexed indirect X) + case 0xc1: cmp(A(), AM_IndexedIndirectX()); break; // CMP (indexed indirect X) case 0xc2: AM_Immediate(); break; // *NOP (immediate) case 0xc3: dcp(AM_IndexedIndirectX()); break; // *DCP (indexed indirect X) - case 0xc4: cmp(Y(), AM_ZeroPage()); break; // CPY (zero page) - case 0xc5: cmp(A(), AM_ZeroPage()); break; // CMP (zero page) + case 0xc4: cmp(Y(), AM_ZeroPage()); break; // CPY (zero page) + case 0xc5: cmp(A(), AM_ZeroPage()); break; // CMP (zero page) case 0xc6: memoryReadModifyWrite(dec(AM_ZeroPage())); break; // DEC (zero page) case 0xc7: dcp(AM_ZeroPage()); break; // *DCP (zero page) - case 0xc8: memoryRead(); Y() = inc(Y()); break; // INY (implied) + case 0xc8: memoryRead(PC()); Y() = inc(Y()); break; // INY (implied) case 0xc9: cmp(A(), AM_Immediate()); break; // CMP (immediate) - case 0xca: memoryRead(); X() = dec(X()); break; // DEX (implied) - case 0xcb: axs(AM_Immediate()); break; // *AXS (immediate) - case 0xcc: cmp(Y(), AM_Absolute()); break; // CPY (absolute) - case 0xcd: cmp(A(), AM_Absolute()); break; // CMP (absolute) + case 0xca: memoryRead(PC()); X() = dec(X()); break; // DEX (implied) + case 0xcb: axs(AM_Immediate()); break; // *AXS (immediate) + case 0xcc: cmp(Y(), AM_Absolute()); break; // CPY (absolute) + case 0xcd: cmp(A(), AM_Absolute()); break; // CMP (absolute) case 0xce: memoryReadModifyWrite(dec(AM_Absolute())); break; // DEC (absolute) case 0xcf: dcp(AM_Absolute()); break; // *DCP (absolute) - case 0xd0: branch(!zero()); break; // BNE (relative) - case 0xd1: cmp(A(), AM_IndirectIndexedY()); break; // CMP (indirect indexed Y) + case 0xd0: branch(!zero()); break; // BNE (relative) + case 0xd1: cmp(A(), AM_IndirectIndexedY()); break; // CMP (indirect indexed Y) case 0xd2: break; case 0xd3: dcp(AM_IndirectIndexedY()); break; // *DCP (indirect indexed Y) case 0xd4: AM_ZeroPageX(); break; // *NOP (zero page, X) case 0xd5: cmp(A(), AM_ZeroPageX()); break; // CMP (zero page, X) case 0xd6: memoryReadModifyWrite(dec(AM_ZeroPageX())); break; // DEC (zero page, X) - case 0xd7: dcp(AM_ZeroPageX()); break; // *DCP (zero page, X) - case 0xd8: memoryRead(); P() = clearBit(P(), DF); break; // CLD (implied) + case 0xd7: dcp(AM_ZeroPageX()); break; // *DCP (zero page, X) + case 0xd8: memoryRead(PC()); P() = clearBit(P(), DF); break; // CLD (implied) case 0xd9: cmp(A(), AM_AbsoluteY()); break; // CMP (absolute, Y) - case 0xda: memoryRead(); break; // *NOP (implied) - case 0xdb: dcp(AM_AbsoluteY()); break; // *DCP (absolute, Y) + case 0xda: memoryRead(PC()); break; // *NOP (implied) + case 0xdb: dcp(AM_AbsoluteY()); break; // *DCP (absolute, Y) case 0xdc: AM_AbsoluteX(); break; // *NOP (absolute, X) case 0xdd: cmp(A(), AM_AbsoluteX()); break; // CMP (absolute, X) case 0xde: memoryReadModifyWrite(dec(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // DEC (absolute, X) - case 0xdf: dcp(AM_AbsoluteX()); break; // *DCP (absolute, X) + case 0xdf: dcp(AM_AbsoluteX()); break; // *DCP (absolute, X) case 0xe0: cmp(X(), AM_Immediate()); break; // CPX (immediate) case 0xe1: A() = sbc(A(), AM_IndexedIndirectX()); break; // SBC (indexed indirect X) case 0xe2: AM_Immediate(); break; // *NOP (immediate) case 0xe3: isb(AM_IndexedIndirectX()); break; // *ISB (indexed indirect X) - case 0xe4: cmp(X(), AM_ZeroPage()); break; // CPX (zero page) + case 0xe4: cmp(X(), AM_ZeroPage()); break; // CPX (zero page) case 0xe5: A() = sbc(A(), AM_ZeroPage()); break; // SBC (zero page) case 0xe6: memoryReadModifyWrite(inc(AM_ZeroPage())); break; // INC (zero page) case 0xe7: isb(AM_ZeroPage()); break; // *ISB (zero page) - case 0xe8: memoryRead(); X() = inc(X()); break; // INX (implied) + case 0xe8: memoryRead(PC()); X() = inc(X()); break; // INX (implied) case 0xe9: A() = sbc(A(), AM_Immediate()); break; // SBC (immediate) - case 0xea: memoryRead(); break; // NOP (implied) + case 0xea: memoryRead(PC()); break; // NOP (implied) case 0xeb: A() = sbc(A(), AM_Immediate()); break; // *SBC (immediate) - case 0xec: cmp(X(), AM_Absolute()); break; // CPX (absolute) + case 0xec: cmp(X(), AM_Absolute()); break; // CPX (absolute) case 0xed: A() = sbc(A(), AM_Absolute()); break; // SBC (absolute) case 0xee: memoryReadModifyWrite(inc(AM_Absolute())); break; // INC (absolute) case 0xef: isb(AM_Absolute()); break; // *ISB (absolute) @@ -374,15 +374,15 @@ int EightBit::MOS6502::execute() { case 0xf4: AM_ZeroPageX(); break; // *NOP (zero page, X) case 0xf5: A() = sbc(A(), AM_ZeroPageX()); break; // SBC (zero page, X) case 0xf6: memoryReadModifyWrite(inc(AM_ZeroPageX())); break; // INC (zero page, X) - case 0xf7: isb(AM_ZeroPageX()); break; // *ISB (zero page, X) - case 0xf8: memoryRead(); P() = setBit(P(), DF); break; // SED (implied) + case 0xf7: isb(AM_ZeroPageX()); break; // *ISB (zero page, X) + case 0xf8: memoryRead(PC()); P() = setBit(P(), DF); break; // SED (implied) case 0xf9: A() = sbc(A(), AM_AbsoluteY()); break; // SBC (absolute, Y) - case 0xfa: memoryRead(); break; // *NOP (implied) - case 0xfb: isb(AM_AbsoluteY()); break; // *ISB (absolute, Y) + case 0xfa: memoryRead(PC()); break; // *NOP (implied) + case 0xfb: isb(AM_AbsoluteY()); break; // *ISB (absolute, Y) case 0xfc: AM_AbsoluteX(); break; // *NOP (absolute, X) case 0xfd: A() = sbc(A(), AM_AbsoluteX()); break; // SBC (absolute, X) case 0xfe: memoryReadModifyWrite(inc(AM_AbsoluteX(PageCrossingBehavior::AlwaysReadTwice))); break; // INC (absolute, X) - case 0xff: isb(AM_AbsoluteX()); break; // *ISB (absolute, X) + case 0xff: isb(AM_AbsoluteX()); break; // *ISB (absolute, X) } ASSUME(cycles() > 0); @@ -517,7 +517,7 @@ uint8_t EightBit::MOS6502::AM_IndirectIndexedY() { void EightBit::MOS6502::branch(const int condition) { const auto destination = Address_relative_byte(); if (condition) { - memoryRead(); + memoryRead(PC()); const auto page = PC().high; jump(destination); if (UNLIKELY(PC().high != page))