From 4ec462e79ad18d138b782e2c4c1b179602018b82 Mon Sep 17 00:00:00 2001
From: Adrian Conlon <adrian.conlon@gmail.com>
Date: Sat, 2 Jan 2021 11:04:38 +0000
Subject: [PATCH] Z80: Tidy the M1 activation sequence a little (start moving
 towards ZX Spectrum memory contention model)

Signed-off-by: Adrian Conlon <adrian.conlon@gmail.com>
---
 Z80/src/Z80.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Z80/src/Z80.cpp b/Z80/src/Z80.cpp
index 5072c38..7716135 100644
--- a/Z80/src/Z80.cpp
+++ b/Z80/src/Z80.cpp
@@ -69,6 +69,8 @@ uint8_t EightBit::Z80::memoryRead() {
 	public:
 		_Reader(Z80& parent) : m_parent(parent) {
 			m_parent.ReadingMemory.fire(EventArgs::empty());
+			if (lowered(m_parent.M1()))
+				m_parent.tick();
 			m_parent.tick(2);
 			m_parent.lowerMREQ();
 		}
@@ -750,7 +752,6 @@ void EightBit::Z80::fetchDisplacement() {
 // CPU.The HALT acknowledge signal is active during this time indicating that the processor
 // is in the HALT state
 uint8_t EightBit::Z80::fetchOpCode() {
-	tick();
 	uint8_t returned;
 	{
 		_ActivateM1 m1(*this);