From 8b187e761462ab1bd75bb20f3ba278b6b900d103 Mon Sep 17 00:00:00 2001
From: Adrian Conlon <Adrian.conlon@gmail.com>
Date: Wed, 9 Jan 2019 09:05:12 +0000
Subject: [PATCH] The clock still has to tick, even while held on RDY low,
 otherwise cycle timing won't work.

Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
---
 M6502/src/mos6502.cpp | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/M6502/src/mos6502.cpp b/M6502/src/mos6502.cpp
index ed6fe1a..d2eee0b 100644
--- a/M6502/src/mos6502.cpp
+++ b/M6502/src/mos6502.cpp
@@ -22,18 +22,21 @@ void EightBit::MOS6502::powerOn() {
 int EightBit::MOS6502::step() {
 	resetCycles();
 	ExecutingInstruction.fire(*this);
-	if (LIKELY(powered() && raised(RDY()))) {
+	if (LIKELY(powered())) {
+		addCycle();
 		if (UNLIKELY(lowered(SO())))
 			handleSO();
-		lower(SYNC());	// Instruction fetch beginning
-		opcode() = fetchByte();
-		if (UNLIKELY(lowered(RESET())))
-			handleRESET();
-		else if (UNLIKELY(lowered(NMI())))
-			handleNMI();
-		else if (UNLIKELY(lowered(IRQ()) && !interruptMasked()))
-			handleIRQ();
-		execute();
+		if (LIKELY(raised(RDY()))) {
+			lower(SYNC());	// Instruction fetch beginning
+			opcode() = BUS().read(PC()++);	// can't use fetchByte
+			if (UNLIKELY(lowered(RESET())))
+				handleRESET();
+			else if (UNLIKELY(lowered(NMI())))
+				handleNMI();
+			else if (UNLIKELY(lowered(IRQ()) && !interruptMasked()))
+				handleIRQ();
+			execute();
+		}
 	}
 	ExecutedInstruction.fire(*this);
 	return cycles();