From 412a44fafd7b483c954b97109b953f2ad3715bf3 Mon Sep 17 00:00:00 2001
From: Adrian Conlon <Adrian.conlon@gmail.com>
Date: Fri, 29 Dec 2017 14:49:53 +0000
Subject: [PATCH] Correct some page crossing conditions affecting 6502 cycle
 counts.

Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
---
 M6502/inc/mos6502.h       | 27 +++++++++++++++------------
 M6502/src/mos6502.cpp     |  2 +-
 Ricoh2A03/inc/Ricoh2A03.h |  2 ++
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/M6502/inc/mos6502.h b/M6502/inc/mos6502.h
index 628eb10..170ee35 100644
--- a/M6502/inc/mos6502.h
+++ b/M6502/inc/mos6502.h
@@ -113,14 +113,18 @@ namespace EightBit {
 			MEMPTR().low += Y();
 		}
 
-		void Address_AbsoluteX() {
+		bool Address_AbsoluteX() {
 			Address_Absolute();
+			const auto page = MEMPTR().high;
 			MEMPTR().word += X();
+			return MEMPTR().high != page;
 		}
 
-		void Address_AbsoluteY() {
+		bool Address_AbsoluteY() {
 			Address_Absolute();
+			const auto page = MEMPTR().high;
 			MEMPTR().word += Y();
+			return MEMPTR().high != page;
 		}
 
 		void Address_IndexedIndirectX() {
@@ -128,9 +132,11 @@ namespace EightBit {
 			getWord(0, MEMPTR().low, MEMPTR());
 		}
 
-		void Address_IndirectIndexedY() {
+		bool Address_IndirectIndexedY() {
 			Address_ZeroPageIndirect();
+			const auto page = MEMPTR().high;
 			MEMPTR().word += Y();
+			return MEMPTR().high != page;
 		}
 
 #pragma endregion Addresses
@@ -156,18 +162,16 @@ namespace EightBit {
 		}
 
 		uint8_t AM_AbsoluteX() {
-			Address_AbsoluteX();
-			BUS().ADDRESS() = MEMPTR();
-			if (BUS().ADDRESS().low == Mask8)
+			if (Address_AbsoluteX())
 				addCycle();
+			BUS().ADDRESS() = MEMPTR();
 			return getByte();
 		}
 
 		uint8_t AM_AbsoluteY() {
-			Address_AbsoluteY();
-			BUS().ADDRESS() = MEMPTR();
-			if (BUS().ADDRESS().low == Mask8)
+			if (Address_AbsoluteY())
 				addCycle();
+			BUS().ADDRESS() = MEMPTR();
 			return getByte();
 		}
 
@@ -187,10 +191,9 @@ namespace EightBit {
 		}
 
 		uint8_t AM_IndirectIndexedY() {
-			Address_IndirectIndexedY();
-			BUS().ADDRESS() = MEMPTR();
-			if (BUS().ADDRESS().low == Mask8)
+			if (Address_IndirectIndexedY())
 				addCycle();
+			BUS().ADDRESS() = MEMPTR();
 			return getByte();
 		}
 
diff --git a/M6502/src/mos6502.cpp b/M6502/src/mos6502.cpp
index 51f1220..c85be38 100644
--- a/M6502/src/mos6502.cpp
+++ b/M6502/src/mos6502.cpp
@@ -5,7 +5,7 @@ EightBit::MOS6502::MOS6502(Bus& bus)
 : Processor(bus) {
 	m_timings = {
 		////	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
-		/* 0 */	7, 6, 0, 0, 0, 4, 5, 0, 3, 2, 2, 0, 0, 4, 6, 0,
+		/* 0 */	7, 6, 0, 0, 0, 3, 5, 0, 3, 2, 2, 0, 0, 4, 6, 0,
 		/* 1 */	2, 5, 0, 0, 0, 4, 6, 0, 2, 4, 0, 0, 0, 4, 7, 0,
 		/* 2 */	6, 6, 0, 0, 3, 3, 5, 0, 4, 2, 2, 0, 4, 4, 6, 0,
 		/* 3 */	2, 5, 0, 0, 0, 4, 6, 0, 2, 4, 0, 0, 0, 4, 7, 0,
diff --git a/Ricoh2A03/inc/Ricoh2A03.h b/Ricoh2A03/inc/Ricoh2A03.h
index faddac2..9ad4efc 100644
--- a/Ricoh2A03/inc/Ricoh2A03.h
+++ b/Ricoh2A03/inc/Ricoh2A03.h
@@ -10,6 +10,8 @@ namespace EightBit {
 		Ricoh2A03(Bus& bus);
 		virtual ~Ricoh2A03() = default;
 
+		int clockCycles() const { return cycles();	}
+
 	protected:
 		virtual void SBC(uint8_t data) final;
 		virtual void ADC(uint8_t data) final;