From 7df8ed1f27bf9331b13505d57bb5d92eeb0ea280 Mon Sep 17 00:00:00 2001
From: alyosha-tas <alexei.f.k@gmail.com>
Date: Sat, 13 Jul 2019 18:33:54 -0400
Subject: [PATCH] A2600: Add HMCLR delay

---
 .../Consoles/Atari/2600/Tia/TIA.cs            | 27 ++++++++++++++-----
 .../Consoles/Atari/2600/Tia/Tia.SyncState.cs  |  2 ++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/TIA.cs b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/TIA.cs
index d7b2901d1e..225139911a 100644
--- a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/TIA.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/TIA.cs
@@ -104,6 +104,8 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 		private int _hmbDelay;
 		private byte _hmbVal;
 
+		private int _hmClrDelay;
+
 		private int _prg0Delay;
 		private int _prg1Delay;
 		private byte _prg0Val;
@@ -387,6 +389,21 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 				}
 			}
 
+			if (_hmClrDelay > 0)
+			{
+				_hmClrDelay++;
+				if (_hmClrDelay == 5)
+				{
+					_hmClrDelay = 0;
+
+					_player0.HM = 0;
+					_player0.Missile.Hm = 0;
+					_player1.HM = 0;
+					_player1.Missile.Hm = 0;
+					_ball.HM = 0;
+				}
+			}
+
 			// Reset the RDY flag when we reach hblank
 			if (_hsyncCnt <= 0)
 			{
@@ -799,7 +816,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 					_hmove.BallLatch = true;
 					_hmove.BallCnt = 0;
 
-					_hmove.LateHBlankReset = true;
+					if (_hsyncCnt < 67) { _hmove.LateHBlankReset = true; }			
 				}
 			}
 
@@ -1357,11 +1374,9 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			}
 			else if (maskedAddr == 0x2B) // HMCLR
 			{
-				_player0.HM = 0;
-				_player0.Missile.Hm = 0;
-				_player1.HM = 0;
-				_player1.Missile.Hm = 0;
-				_ball.HM = 0;
+				_hmClrDelay = 1;
+
+				
 			}
 			else if (maskedAddr == 0x2C) // CXCLR
 			{
diff --git a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/Tia.SyncState.cs b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/Tia.SyncState.cs
index 252f74e644..8881944917 100644
--- a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/Tia.SyncState.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/Tia.SyncState.cs
@@ -51,6 +51,8 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			ser.Sync("hmb_delay", ref _hmbDelay);
 			ser.Sync("hmb_val", ref _hmbVal);
 
+			ser.Sync("_hmClrDelay", ref _hmClrDelay);
+
 			ser.Sync("PRG0_delay", ref _prg0Delay);
 			ser.Sync("PRG1_delay", ref _prg1Delay);
 			ser.Sync("PRG0_val", ref _prg0Val);