From 52c51b525f09e939d06470a44841b6e4c2a8eeff Mon Sep 17 00:00:00 2001
From: Christian Speckner <christian.speckner@mayflower.de>
Date: Tue, 30 Jul 2024 08:22:48 +0200
Subject: [PATCH] Timing improvements.

---
 src/emucore/CartELF.cxx | 13 +++----------
 src/emucore/CartELF.hxx |  1 -
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/src/emucore/CartELF.cxx b/src/emucore/CartELF.cxx
index d6ec51b61..8613956ac 100644
--- a/src/emucore/CartELF.cxx
+++ b/src/emucore/CartELF.cxx
@@ -340,10 +340,11 @@ inline uInt64 CartridgeELF::getArmCycles() const
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 inline uInt8 CartridgeELF::driveBus(uInt16 address, uInt8 value)
 {
-  auto* nextTransaction = myTransactionQueue.getNextTransaction(address, getArmCycles());
+  auto* nextTransaction = myTransactionQueue.getNextTransaction(address,
+    mySystem->cycles() * myArmCyclesPer6502Cycle - myArmCyclesOffset);
   if (nextTransaction) {
     nextTransaction->setBusState(myIsBusDriven, myDriveBusValue);
-    syncClock(*nextTransaction);
+    myArmCyclesOffset = mySystem->cycles() * myArmCyclesPer6502Cycle - nextTransaction->timestamp;
   }
 
   if (myIsBusDriven) value |= myDriveBusValue;
@@ -355,14 +356,6 @@ inline uInt8 CartridgeELF::driveBus(uInt16 address, uInt8 value)
   return value;
 }
 
-inline void CartridgeELF::syncClock(const BusTransactionQueue::Transaction& transaction)
-{
-  const Int64 currentSystemArmCycles = mySystem->cycles() * myArmCyclesPer6502Cycle;
-  const Int64 transactionArmCycles = transaction.timestamp + myArmCyclesOffset;
-
-  myArmCyclesOffset += currentSystemArmCycles - transactionArmCycles;
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void CartridgeELF::parseAndLinkElf()
 {
diff --git a/src/emucore/CartELF.hxx b/src/emucore/CartELF.hxx
index 1ac58242b..91acd8021 100644
--- a/src/emucore/CartELF.hxx
+++ b/src/emucore/CartELF.hxx
@@ -79,7 +79,6 @@ class CartridgeELF: public Cartridge {
     uInt64 getArmCycles() const;
 
     uInt8 driveBus(uInt16 address, uInt8 value);
-    void syncClock(const BusTransactionQueue::Transaction& transaction);
 
     void parseAndLinkElf();
     void setupMemoryMap();