From d39f3e2e61ee6c9be40c52e9f1d8d8fde3bdde84 Mon Sep 17 00:00:00 2001
From: SaxxonPike <saxxonpike@gmail.com>
Date: Sat, 13 Jul 2019 12:31:09 -0500
Subject: [PATCH] 6502X: pending IRQs are not delayed when !RDY is asserted

---
 BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs | 15 +++++++++------
 .../Computers/Commodore64/MOS/Chip6510.cs         |  3 ---
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs b/BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs
index 2d57892446..d0cd3cab16 100644
--- a/BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs	
+++ b/BizHawk.Emulation.Cores/CPUs/MOS 6502X/Execute.cs	
@@ -803,18 +803,24 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 		}
 		void Imp_SEI()
 		{
+			// not affected by RDY
+			iflag_pending = true;
+
 			rdy_freeze = !RDY;
 			if (RDY)
 			{
-				FetchDummy(); iflag_pending = true;
+				FetchDummy();
 			}
 		}
 		void Imp_CLI()
 		{
+			// not affected by RDY
+			iflag_pending = false;
+
 			rdy_freeze = !RDY;
 			if (RDY)
 			{
-				FetchDummy(); iflag_pending = false;
+				FetchDummy();
 			}
 		}
 		void Imp_SEC()
@@ -2970,10 +2976,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 		{
 			// total cycles now increments every time a cycle is called to accurately count during RDY
 			TotalExecutedCycles++;
-			if (!rdy_freeze)
-			{
-				interrupt_pending |= Interrupted;
-			}
+			interrupt_pending |= Interrupted;
 			rdy_freeze = false;
 
 			//i tried making ExecuteOneRetry not re-entrant by having it set a flag instead, then exit from the call below, check the flag, and GOTO if it was flagged, but it wasnt faster
diff --git a/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs b/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs
index 5d01e5edcf..9d4954a2cb 100644
--- a/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs
+++ b/BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs
@@ -89,9 +89,6 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
 		public void ExecutePhase()
 		{
 			_cpu.RDY = ReadRdy();
-
-//			if (!ReadAec()) 
-//				return;
 			_cpu.IRQ = !ReadIrq();
 			_pinNmiLast = _thisNmi;
 			_thisNmi = ReadNmi();