diff --git a/bsnes/emulator/emulator.hpp b/bsnes/emulator/emulator.hpp
index ffea014d..3baae31d 100644
--- a/bsnes/emulator/emulator.hpp
+++ b/bsnes/emulator/emulator.hpp
@@ -31,13 +31,13 @@ using namespace nall;
 
 namespace Emulator {
   static const string Name    = "bsnes";
-  static const string Version = "108.1";
+  static const string Version = "108.2";
   static const string Author  = "byuu";
   static const string License = "GPLv3";
   static const string Website = "https://byuu.org";
 
   //incremented only when serialization format changes
-  static const string SerializerVersion = "108";
+  static const string SerializerVersion = "108.2";
 
   namespace Constants {
     namespace Colorburst {
diff --git a/bsnes/emulator/scheduler.hpp b/bsnes/emulator/scheduler.hpp
deleted file mode 100644
index da683a56..00000000
--- a/bsnes/emulator/scheduler.hpp
+++ /dev/null
@@ -1,98 +0,0 @@
-#pragma once
-#define uintmax uint64
-
-namespace Emulator {
-
-struct Scheduler {
-  enum class Mode : uint {
-    Run,
-    SynchronizeMaster,
-    SynchronizeSlave,
-  };
-
-  enum class Event : uint {
-    Step,
-    Frame,
-    Synchronize,
-  };
-
-  inline auto synchronizing() const -> bool { return _mode == Mode::SynchronizeSlave; }
-
-  auto reset() -> void {
-    _host = co_active();
-    _threads.reset();
-  }
-
-  auto primary(Thread& thread) -> void {
-    _master = _resume = thread.handle();
-    uintmax clock = 0;
-    for(auto& thread : _threads) {
-      thread->_clock = clock++;  //this bias prioritizes threads appended earlier first
-    }
-  }
-
-  auto append(Thread& thread) -> bool {
-    if(_threads.find(&thread)) return false;
-    thread._clock = _threads.size();
-    return _threads.append(&thread), true;
-  }
-
-  auto remove(Thread& thread) -> bool {
-    if(auto offset = _threads.find(&thread)) return _threads.remove(*offset), true;
-    return false;
-  }
-
-  auto enter(Mode mode = Mode::Run) -> Event {
-    _mode = mode;
-    _host = co_active();
-    co_switch(_resume);
-    return _event;
-  }
-
-  inline auto resume(Thread& thread) -> void {
-    if(_mode != Mode::SynchronizeSlave) co_switch(thread.handle());
-  }
-
-  auto exit(Event event) -> void {
-    uintmax minimum = -1;
-    for(auto thread : _threads) {
-      if(thread->_clock < minimum) minimum = thread->_clock;
-    }
-    for(auto thread : _threads) {
-      thread->_clock -= minimum;
-    }
-
-    _event = event;
-    _resume = co_active();
-    co_switch(_host);
-  }
-
-  inline auto synchronize(Thread& thread) -> void {
-    if(thread.handle() == _master) {
-      while(enter(Mode::SynchronizeMaster) != Event::Synchronize);
-    } else {
-      _resume = thread.handle();
-      while(enter(Mode::SynchronizeSlave) != Event::Synchronize);
-    }
-  }
-
-  inline auto synchronize() -> void {
-    if(co_active() == _master) {
-      if(_mode == Mode::SynchronizeMaster) return exit(Event::Synchronize);
-    } else {
-      if(_mode == Mode::SynchronizeSlave) return exit(Event::Synchronize);
-    }
-  }
-
-private:
-  cothread_t _host = nullptr;    //program thread (used to exit scheduler)
-  cothread_t _resume = nullptr;  //resume thread (used to enter scheduler)
-  cothread_t _master = nullptr;  //primary thread (used to synchronize components)
-  Mode _mode = Mode::Run;
-  Event _event = Event::Step;
-  vector<Thread*> _threads;
-};
-
-}
-
-#undef uintmax
diff --git a/bsnes/emulator/thread.hpp b/bsnes/emulator/thread.hpp
deleted file mode 100644
index 59711bf5..00000000
--- a/bsnes/emulator/thread.hpp
+++ /dev/null
@@ -1,64 +0,0 @@
-#pragma once
-#define uintmax uint64
-
-namespace Emulator {
-
-struct Thread {
-  enum : uintmax { Second = (uintmax)-1 >> 1 };
-
-  virtual ~Thread() {
-    if(_handle) co_delete(_handle);
-  }
-
-  inline auto active() const { return co_active() == _handle; }
-  inline auto handle() const { return _handle; }
-  inline auto frequency() const { return _frequency; }
-  inline auto scalar() const { return _scalar; }
-  inline auto clock() const { return _clock; }
-
-  auto setHandle(cothread_t handle) -> void {
-    _handle = handle;
-  }
-
-  auto setFrequency(double frequency) -> void {
-    _frequency = frequency + 0.5;
-    _scalar = Second / _frequency;
-  }
-
-  auto setScalar(uintmax scalar) -> void {
-    _scalar = scalar;
-  }
-
-  auto setClock(uintmax clock) -> void {
-    _clock = clock;
-  }
-
-  auto create(auto (*entrypoint)() -> void, double frequency) -> void {
-    if(_handle) co_delete(_handle);
-    _handle = co_create(64 * 1024 * sizeof(void*), entrypoint);
-    setFrequency(frequency);
-    setClock(0);
-  }
-
-  inline auto step(uint clocks) -> void {
-    _clock += _scalar * clocks;
-  }
-
-  auto serialize(serializer& s) -> void {
-    s.integer(_frequency);
-    s.integer(_scalar);
-    s.integer(_clock);
-  }
-
-protected:
-  cothread_t _handle = nullptr;
-  uintmax _frequency = 0;
-  uintmax _scalar = 0;
-  uintmax _clock = 0;
-
-  friend class Scheduler;
-};
-
-}
-
-#undef uintmax
diff --git a/bsnes/sfc/coprocessor/armdsp/armdsp.cpp b/bsnes/sfc/coprocessor/armdsp/armdsp.cpp
index efb4e2a6..2a2111e7 100644
--- a/bsnes/sfc/coprocessor/armdsp/armdsp.cpp
+++ b/bsnes/sfc/coprocessor/armdsp/armdsp.cpp
@@ -6,6 +6,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 ArmDSP armdsp;
 
+auto ArmDSP::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto ArmDSP::Enter() -> void {
   armdsp.boot();
   while(true) scheduler.synchronize(), armdsp.main();
@@ -32,8 +36,8 @@ auto ArmDSP::main() -> void {
 
 auto ArmDSP::step(uint clocks) -> void {
   if(bridge.timer && --bridge.timer == 0);
-  Thread::step(clocks);
-  synchronize(cpu);
+  clock += clocks * (uint64_t)cpu.frequency;
+  synchronizeCPU();
 }
 
 //MMIO: 00-3f,80-bf:3800-38ff
@@ -41,7 +45,7 @@ auto ArmDSP::step(uint clocks) -> void {
 //a0 ignored
 
 auto ArmDSP::read(uint addr, uint8) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
 
   uint8 data = 0x00;
   addr &= 0xff06;
@@ -65,7 +69,7 @@ auto ArmDSP::read(uint addr, uint8) -> uint8 {
 }
 
 auto ArmDSP::write(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
 
   addr &= 0xff06;
 
diff --git a/bsnes/sfc/coprocessor/armdsp/armdsp.hpp b/bsnes/sfc/coprocessor/armdsp/armdsp.hpp
index b500ef2f..732ee899 100644
--- a/bsnes/sfc/coprocessor/armdsp/armdsp.hpp
+++ b/bsnes/sfc/coprocessor/armdsp/armdsp.hpp
@@ -7,6 +7,7 @@
 struct ArmDSP : Processor::ARM7TDMI, Thread {
   #include "registers.hpp"
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto boot() -> void;
   auto main() -> void;
diff --git a/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.cpp b/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.cpp
index 33362678..4ddc20c9 100644
--- a/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.cpp
+++ b/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.cpp
@@ -7,6 +7,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 EpsonRTC epsonrtc;
 
+auto EpsonRTC::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto EpsonRTC::Enter() -> void {
   while(true) scheduler.synchronize(), epsonrtc.main();
 }
@@ -27,7 +31,11 @@ auto EpsonRTC::main() -> void {
   }
 
   step(1);
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto EpsonRTC::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto EpsonRTC::initialize() -> void {
@@ -127,7 +135,7 @@ auto EpsonRTC::synchronize(uint64 timestamp) -> void {
 }
 
 auto EpsonRTC::read(uint addr, uint8 data) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   addr &= 3;
 
   if(addr == 0) {
@@ -152,7 +160,7 @@ auto EpsonRTC::read(uint addr, uint8 data) -> uint8 {
 }
 
 auto EpsonRTC::write(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   addr &= 3, data &= 15;
 
   if(addr == 0) {
diff --git a/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.hpp b/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.hpp
index 991de3cb..62ff70ef 100644
--- a/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.hpp
+++ b/bsnes/sfc/coprocessor/epsonrtc/epsonrtc.hpp
@@ -1,10 +1,10 @@
 //Epson RTC-4513 Real-Time Clock
 
 struct EpsonRTC : Thread {
-  using Thread::synchronize;
-
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
 
   auto initialize() -> void;
   auto power() -> void;
diff --git a/bsnes/sfc/coprocessor/event/event.cpp b/bsnes/sfc/coprocessor/event/event.cpp
index 968ca1a7..b339defc 100644
--- a/bsnes/sfc/coprocessor/event/event.cpp
+++ b/bsnes/sfc/coprocessor/event/event.cpp
@@ -5,6 +5,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 Event event;
 
+auto Event::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto Event::Enter() -> void {
   while(true) scheduler.synchronize(), event.main();
 }
@@ -26,7 +30,11 @@ auto Event::main() -> void {
   }
 
   step(1);
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto Event::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto Event::unload() -> void {
diff --git a/bsnes/sfc/coprocessor/event/event.hpp b/bsnes/sfc/coprocessor/event/event.hpp
index 6161df1f..b2f0de4c 100644
--- a/bsnes/sfc/coprocessor/event/event.hpp
+++ b/bsnes/sfc/coprocessor/event/event.hpp
@@ -15,8 +15,10 @@
 
 struct Event : Thread {
   //event.cpp
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
   auto unload() -> void;
   auto power() -> void;
 
diff --git a/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.cpp b/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.cpp
index 8aa6b5e9..18cd3236 100644
--- a/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.cpp
+++ b/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.cpp
@@ -7,14 +7,18 @@ namespace SuperFamicom {
 #include "data-rom.cpp"
 HitachiDSP hitachidsp;
 
+auto HitachiDSP::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto HitachiDSP::Enter() -> void {
   while(true) scheduler.synchronize(), hitachidsp.main();
 }
 
 auto HitachiDSP::step(uint clocks) -> void {
   HG51B::step(clocks);
-  Thread::step(clocks);
-  synchronize(cpu);
+  clock += clocks * (uint64_t)cpu.frequency;
+  synchronizeCPU();
 }
 
 auto HitachiDSP::halt() -> void {
diff --git a/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.hpp b/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.hpp
index afc0475a..632aca3e 100644
--- a/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.hpp
+++ b/bsnes/sfc/coprocessor/hitachidsp/hitachidsp.hpp
@@ -3,6 +3,7 @@ struct HitachiDSP : Processor::HG51B, Thread {
   WritableMemory ram;
 
   //hitachidsp.cpp
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto step(uint clocks) -> void override;
   auto halt() -> void override;
diff --git a/bsnes/sfc/coprocessor/icd/icd.cpp b/bsnes/sfc/coprocessor/icd/icd.cpp
index f10cf859..0b95a86c 100644
--- a/bsnes/sfc/coprocessor/icd/icd.cpp
+++ b/bsnes/sfc/coprocessor/icd/icd.cpp
@@ -46,6 +46,10 @@ namespace SameBoy {
   }
 }
 
+auto ICD::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto ICD::Enter() -> void {
   while(true) {
     scheduler.synchronize();
@@ -61,7 +65,11 @@ auto ICD::main() -> void {
     stream->sample(float(0.0), float(0.0));
     step(128);
   }
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto ICD::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto ICD::load() -> bool {
diff --git a/bsnes/sfc/coprocessor/icd/icd.hpp b/bsnes/sfc/coprocessor/icd/icd.hpp
index 6e4840e8..b84c2b66 100644
--- a/bsnes/sfc/coprocessor/icd/icd.hpp
+++ b/bsnes/sfc/coprocessor/icd/icd.hpp
@@ -4,8 +4,10 @@ struct ICD : Emulator::Platform, Thread {
 
   inline auto pathID() const -> uint { return information.pathID; }
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
 
   auto load() -> bool;
   auto save() -> void;
diff --git a/bsnes/sfc/coprocessor/icd/io.cpp b/bsnes/sfc/coprocessor/icd/io.cpp
index 069b0fec..8a87257a 100644
--- a/bsnes/sfc/coprocessor/icd/io.cpp
+++ b/bsnes/sfc/coprocessor/icd/io.cpp
@@ -57,10 +57,10 @@ auto ICD::writeIO(uint addr, uint8 data) -> void {
     }
     auto frequency = system.cpuFrequency();
     switch(data & 3) {
-    case 0: setFrequency(frequency / 4); break;  //fast (glitchy, even on real hardware)
-    case 1: setFrequency(frequency / 5); break;  //normal
-    case 2: setFrequency(frequency / 7); break;  //slow
-    case 3: setFrequency(frequency / 9); break;  //very slow
+    case 0: this->frequency = frequency / 4; break;  //fast (glitchy, even on real hardware)
+    case 1: this->frequency = frequency / 5; break;  //normal
+    case 2: this->frequency = frequency / 7; break;  //slow
+    case 3: this->frequency = frequency / 9; break;  //very slow
     }
     r6003 = data;
     return;
diff --git a/bsnes/sfc/coprocessor/msu1/msu1.cpp b/bsnes/sfc/coprocessor/msu1/msu1.cpp
index 62875a04..804e7700 100644
--- a/bsnes/sfc/coprocessor/msu1/msu1.cpp
+++ b/bsnes/sfc/coprocessor/msu1/msu1.cpp
@@ -6,6 +6,11 @@ MSU1 msu1;
 
 #include "serialization.cpp"
 
+auto MSU1::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
+
 auto MSU1::Enter() -> void {
   while(true) scheduler.synchronize(), msu1.main();
 }
@@ -36,7 +41,11 @@ auto MSU1::main() -> void {
 
   stream->sample(float(left), float(right));
   step(1);
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto MSU1::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto MSU1::unload() -> void {
@@ -46,7 +55,7 @@ auto MSU1::unload() -> void {
 
 auto MSU1::power() -> void {
   create(MSU1::Enter, 44100);
-  stream = Emulator::audio.createStream(2, frequency());
+  stream = Emulator::audio.createStream(2, frequency);
 
   io.dataSeekOffset = 0;
   io.dataReadOffset = 0;
@@ -98,7 +107,7 @@ auto MSU1::audioOpen() -> void {
 }
 
 auto MSU1::readIO(uint addr, uint8) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
 
   switch(0x2000 | (addr & 7)) {
   case 0x2000:
@@ -128,7 +137,7 @@ auto MSU1::readIO(uint addr, uint8) -> uint8 {
 }
 
 auto MSU1::writeIO(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
 
   switch(0x2000 | (addr & 7)) {
   case 0x2000: bit8(io.dataSeekOffset,0) = data; break;
diff --git a/bsnes/sfc/coprocessor/msu1/msu1.hpp b/bsnes/sfc/coprocessor/msu1/msu1.hpp
index 3054fc68..3eb6d99b 100644
--- a/bsnes/sfc/coprocessor/msu1/msu1.hpp
+++ b/bsnes/sfc/coprocessor/msu1/msu1.hpp
@@ -1,8 +1,10 @@
 struct MSU1 : Thread {
   shared_pointer<Emulator::Stream> stream;
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
   auto unload() -> void;
   auto power() -> void;
 
diff --git a/bsnes/sfc/coprocessor/necdsp/necdsp.cpp b/bsnes/sfc/coprocessor/necdsp/necdsp.cpp
index 53925564..9db99df5 100644
--- a/bsnes/sfc/coprocessor/necdsp/necdsp.cpp
+++ b/bsnes/sfc/coprocessor/necdsp/necdsp.cpp
@@ -5,6 +5,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 NECDSP necdsp;
 
+auto NECDSP::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto NECDSP::Enter() -> void {
   while(true) scheduler.synchronize(), necdsp.main();
 }
@@ -12,11 +16,15 @@ auto NECDSP::Enter() -> void {
 auto NECDSP::main() -> void {
   exec();
   step(1);
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto NECDSP::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto NECDSP::read(uint addr, uint8) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   if(addr & 1) {
     return uPD96050::readSR();
   } else {
@@ -25,7 +33,7 @@ auto NECDSP::read(uint addr, uint8) -> uint8 {
 }
 
 auto NECDSP::write(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   if(addr & 1) {
     return uPD96050::writeSR(data);
   } else {
@@ -34,12 +42,12 @@ auto NECDSP::write(uint addr, uint8 data) -> void {
 }
 
 auto NECDSP::readRAM(uint addr, uint8) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   return uPD96050::readDP(addr);
 }
 
 auto NECDSP::writeRAM(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   return uPD96050::writeDP(addr, data);
 }
 
diff --git a/bsnes/sfc/coprocessor/necdsp/necdsp.hpp b/bsnes/sfc/coprocessor/necdsp/necdsp.hpp
index 94b935a5..dd29fbbd 100644
--- a/bsnes/sfc/coprocessor/necdsp/necdsp.hpp
+++ b/bsnes/sfc/coprocessor/necdsp/necdsp.hpp
@@ -1,6 +1,8 @@
 struct NECDSP : Processor::uPD96050, Thread {
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
 
   auto read(uint addr, uint8 data) -> uint8;
   auto write(uint addr, uint8 data) -> void;
diff --git a/bsnes/sfc/coprocessor/sa1/bwram.cpp b/bsnes/sfc/coprocessor/sa1/bwram.cpp
index 0213029f..5de8caf8 100644
--- a/bsnes/sfc/coprocessor/sa1/bwram.cpp
+++ b/bsnes/sfc/coprocessor/sa1/bwram.cpp
@@ -22,7 +22,7 @@ auto SA1::BWRAM::write(uint address, uint8 data) -> void {
 //00-3f,80-bf:6000-7fff size=0x2000 => 00:0000-1fff
 //40-4f:0000-ffff => untranslated
 auto SA1::BWRAM::readCPU(uint address, uint8 data) -> uint8 {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
 
   if(address < 0x2000) {  //$00-3f,80-bf:6000-7fff
     address = sa1.mmio.sbm * 0x2000 + (address & 0x1fff);
@@ -33,7 +33,7 @@ auto SA1::BWRAM::readCPU(uint address, uint8 data) -> uint8 {
 }
 
 auto SA1::BWRAM::writeCPU(uint address, uint8 data) -> void {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
 
   if(address < 0x2000) {  //$00-3f,80-bf:6000-7fff
     address = sa1.mmio.sbm * 0x2000 + (address & 0x1fff);
diff --git a/bsnes/sfc/coprocessor/sa1/io.cpp b/bsnes/sfc/coprocessor/sa1/io.cpp
index e1d56abb..43f520de 100644
--- a/bsnes/sfc/coprocessor/sa1/io.cpp
+++ b/bsnes/sfc/coprocessor/sa1/io.cpp
@@ -1,5 +1,5 @@
 auto SA1::readIOCPU(uint address, uint8 data) -> uint8 {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
 
   switch(0x2200 | address & 0x1ff) {
 
@@ -25,7 +25,7 @@ auto SA1::readIOCPU(uint address, uint8 data) -> uint8 {
 }
 
 auto SA1::readIOSA1(uint address, uint8) -> uint8 {
-  synchronize(cpu);
+  synchronizeCPU();
 
   switch(0x2200 | address & 0x1ff) {
 
@@ -101,7 +101,7 @@ auto SA1::readIOSA1(uint address, uint8) -> uint8 {
 }
 
 auto SA1::writeIOCPU(uint address, uint8 data) -> void {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
 
   switch(0x2200 | address & 0x1ff) {
 
@@ -236,7 +236,7 @@ auto SA1::writeIOCPU(uint address, uint8 data) -> void {
 }
 
 auto SA1::writeIOSA1(uint address, uint8 data) -> void {
-  synchronize(cpu);
+  synchronizeCPU();
 
   switch(0x2200 | address & 0x1ff) {
 
diff --git a/bsnes/sfc/coprocessor/sa1/iram.cpp b/bsnes/sfc/coprocessor/sa1/iram.cpp
index 9cd6ae81..9e489559 100644
--- a/bsnes/sfc/coprocessor/sa1/iram.cpp
+++ b/bsnes/sfc/coprocessor/sa1/iram.cpp
@@ -18,12 +18,12 @@ auto SA1::IRAM::write(uint address, uint8 data) -> void {
 }
 
 auto SA1::IRAM::readCPU(uint address, uint8 data) -> uint8 {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
   return read(address, data);
 }
 
 auto SA1::IRAM::writeCPU(uint address, uint8 data) -> void {
-  cpu.synchronize(sa1);
+  cpu.synchronizeCoprocessors();
   return write(address, data);
 }
 
diff --git a/bsnes/sfc/coprocessor/sa1/sa1.cpp b/bsnes/sfc/coprocessor/sa1/sa1.cpp
index fc46c8d9..535b7708 100644
--- a/bsnes/sfc/coprocessor/sa1/sa1.cpp
+++ b/bsnes/sfc/coprocessor/sa1/sa1.cpp
@@ -11,6 +11,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 SA1 sa1;
 
+auto SA1::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto SA1::Enter() -> void {
   while(true) scheduler.synchronize(), sa1.main();
 }
@@ -78,13 +82,9 @@ auto SA1::interruptPending() const -> bool {
   return status.interruptPending;
 }
 
-auto SA1::synchronizing() const -> bool {
-  return scheduler.synchronizing();
-}
-
 auto SA1::step() -> void {
-  Thread::step(2);
-  synchronize(cpu);
+  clock += (uint64_t)cpu.frequency << 1;
+  synchronizeCPU();
 
   //adjust counters:
   //note that internally, status counters are in clocks;
diff --git a/bsnes/sfc/coprocessor/sa1/sa1.hpp b/bsnes/sfc/coprocessor/sa1/sa1.hpp
index 14eef0aa..f4807c2a 100644
--- a/bsnes/sfc/coprocessor/sa1/sa1.hpp
+++ b/bsnes/sfc/coprocessor/sa1/sa1.hpp
@@ -1,7 +1,10 @@
 //Super Accelerator (SA-1)
 
 struct SA1 : Processor::WDC65816, Thread {
+  inline auto synchronizing() const -> bool override { return scheduler.mode == Scheduler::Mode::SynchronizeAll; }
+
   //sa1.cpp
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto step() -> void;
@@ -10,7 +13,6 @@ struct SA1 : Processor::WDC65816, Thread {
   alwaysinline auto triggerIRQ() -> void;
   alwaysinline auto lastCycle() -> void override;
   alwaysinline auto interruptPending() const -> bool override;
-  auto synchronizing() const -> bool override;
 
   auto unload() -> void;
   auto power() -> void;
diff --git a/bsnes/sfc/coprocessor/sharprtc/sharprtc.cpp b/bsnes/sfc/coprocessor/sharprtc/sharprtc.cpp
index fcea6dbc..ee8e0326 100644
--- a/bsnes/sfc/coprocessor/sharprtc/sharprtc.cpp
+++ b/bsnes/sfc/coprocessor/sharprtc/sharprtc.cpp
@@ -7,6 +7,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 SharpRTC sharprtc;
 
+auto SharpRTC::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto SharpRTC::Enter() -> void {
   while(true) scheduler.synchronize(), sharprtc.main();
 }
@@ -15,7 +19,11 @@ auto SharpRTC::main() -> void {
   tickSecond();
 
   step(1);
-  synchronize(cpu);
+  synchronizeCPU();
+}
+
+auto SharpRTC::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
 }
 
 auto SharpRTC::initialize() -> void {
diff --git a/bsnes/sfc/coprocessor/sharprtc/sharprtc.hpp b/bsnes/sfc/coprocessor/sharprtc/sharprtc.hpp
index 987de8cd..9ce97b78 100644
--- a/bsnes/sfc/coprocessor/sharprtc/sharprtc.hpp
+++ b/bsnes/sfc/coprocessor/sharprtc/sharprtc.hpp
@@ -1,8 +1,8 @@
 struct SharpRTC : Thread {
-  using Thread::synchronize;
-
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
 
   auto initialize() -> void;
   auto power() -> void;
diff --git a/bsnes/sfc/coprocessor/spc7110/spc7110.cpp b/bsnes/sfc/coprocessor/spc7110/spc7110.cpp
index aa57559b..fb253efb 100644
--- a/bsnes/sfc/coprocessor/spc7110/spc7110.cpp
+++ b/bsnes/sfc/coprocessor/spc7110/spc7110.cpp
@@ -16,6 +16,10 @@ SPC7110::~SPC7110() {
   delete decompressor;
 }
 
+auto SPC7110::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto SPC7110::Enter() -> void {
   while(true) scheduler.synchronize(), spc7110.main();
 }
@@ -27,9 +31,13 @@ auto SPC7110::main() -> void {
   addClocks(1);
 }
 
+auto SPC7110::step(uint clocks) -> void {
+  clock += clocks * (uint64_t)cpu.frequency;
+}
+
 auto SPC7110::addClocks(uint clocks) -> void {
   step(clocks);
-  synchronize(cpu);
+  synchronizeCPU();
 }
 
 auto SPC7110::unload() -> void {
@@ -96,7 +104,7 @@ auto SPC7110::power() -> void {
 }
 
 auto SPC7110::read(uint addr, uint8 data) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   if((addr & 0xff0000) == 0x500000) addr = 0x4800;  //$50:0000-ffff == $4800
   if((addr & 0xff0000) == 0x580000) addr = 0x4808;  //$58:0000-ffff == $4808
   addr = 0x4800 | (addr & 0x3f);  //$00-3f,80-bf:4800-483f
@@ -180,7 +188,7 @@ auto SPC7110::read(uint addr, uint8 data) -> uint8 {
 }
 
 auto SPC7110::write(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   if((addr & 0xff0000) == 0x500000) addr = 0x4800;  //$50:0000-ffff == $4800
   if((addr & 0xff0000) == 0x580000) addr = 0x4808;  //$58:0000-ffff == $4808
   addr = 0x4800 | (addr & 0x3f);  //$00-3f,80-bf:4800-483f
diff --git a/bsnes/sfc/coprocessor/spc7110/spc7110.hpp b/bsnes/sfc/coprocessor/spc7110/spc7110.hpp
index 29aca9a2..ab8d4561 100644
--- a/bsnes/sfc/coprocessor/spc7110/spc7110.hpp
+++ b/bsnes/sfc/coprocessor/spc7110/spc7110.hpp
@@ -4,8 +4,10 @@ struct SPC7110 : Thread {
   SPC7110();
   ~SPC7110();
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
+  auto step(uint clocks) -> void;
   auto unload() -> void;
   auto power() -> void;
 
diff --git a/bsnes/sfc/coprocessor/superfx/io.cpp b/bsnes/sfc/coprocessor/superfx/io.cpp
index 670ba6e6..8bdc40cc 100644
--- a/bsnes/sfc/coprocessor/superfx/io.cpp
+++ b/bsnes/sfc/coprocessor/superfx/io.cpp
@@ -1,5 +1,5 @@
 auto SuperFX::readIO(uint addr, uint8) -> uint8 {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   addr = 0x3000 | addr & 0x3ff;
 
   if(addr >= 0x3100 && addr <= 0x32ff) {
@@ -51,7 +51,7 @@ auto SuperFX::readIO(uint addr, uint8) -> uint8 {
 }
 
 auto SuperFX::writeIO(uint addr, uint8 data) -> void {
-  cpu.synchronize(*this);
+  cpu.synchronizeCoprocessors();
   addr = 0x3000 | addr & 0x3ff;
 
   if(addr >= 0x3100 && addr <= 0x32ff) {
diff --git a/bsnes/sfc/coprocessor/superfx/memory.cpp b/bsnes/sfc/coprocessor/superfx/memory.cpp
index e3c0463e..01a8c821 100644
--- a/bsnes/sfc/coprocessor/superfx/memory.cpp
+++ b/bsnes/sfc/coprocessor/superfx/memory.cpp
@@ -2,8 +2,8 @@ auto SuperFX::read(uint addr, uint8 data) -> uint8 {
   if((addr & 0xc00000) == 0x000000) {  //$00-3f:0000-7fff,:8000-ffff
     while(!regs.scmr.ron) {
       step(6);
-      synchronize(cpu);
-      if(scheduler.synchronizing()) break;
+      synchronizeCPU();
+      if(synchronizing()) break;
     }
     return rom.read((((addr & 0x3f0000) >> 1) | (addr & 0x7fff)) & romMask);
   }
@@ -11,8 +11,8 @@ auto SuperFX::read(uint addr, uint8 data) -> uint8 {
   if((addr & 0xe00000) == 0x400000) {  //$40-5f:0000-ffff
     while(!regs.scmr.ron) {
       step(6);
-      synchronize(cpu);
-      if(scheduler.synchronizing()) break;
+      synchronizeCPU();
+      if(synchronizing()) break;
     }
     return rom.read(addr & romMask);
   }
@@ -20,8 +20,8 @@ auto SuperFX::read(uint addr, uint8 data) -> uint8 {
   if((addr & 0xe00000) == 0x600000) {  //$60-7f:0000-ffff
     while(!regs.scmr.ran) {
       step(6);
-      synchronize(cpu);
-      if(scheduler.synchronizing()) break;
+      synchronizeCPU();
+      if(synchronizing()) break;
     }
     return ram.read(addr & ramMask);
   }
@@ -33,8 +33,8 @@ auto SuperFX::write(uint addr, uint8 data) -> void {
   if((addr & 0xe00000) == 0x600000) {  //$60-7f:0000-ffff
     while(!regs.scmr.ran) {
       step(6);
-      synchronize(cpu);
-      if(scheduler.synchronizing()) break;
+      synchronizeCPU();
+      if(synchronizing()) break;
     }
     return ram.write(addr & ramMask, data);
   }
diff --git a/bsnes/sfc/coprocessor/superfx/superfx.cpp b/bsnes/sfc/coprocessor/superfx/superfx.cpp
index 41f1f55b..c651cf9c 100644
--- a/bsnes/sfc/coprocessor/superfx/superfx.cpp
+++ b/bsnes/sfc/coprocessor/superfx/superfx.cpp
@@ -10,6 +10,10 @@ namespace SuperFamicom {
 #include "serialization.cpp"
 SuperFX superfx;
 
+auto SuperFX::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto SuperFX::Enter() -> void {
   while(true) scheduler.synchronize(), superfx.main();
 }
diff --git a/bsnes/sfc/coprocessor/superfx/superfx.hpp b/bsnes/sfc/coprocessor/superfx/superfx.hpp
index 99297753..0ef80292 100644
--- a/bsnes/sfc/coprocessor/superfx/superfx.hpp
+++ b/bsnes/sfc/coprocessor/superfx/superfx.hpp
@@ -2,7 +2,10 @@ struct SuperFX : Processor::GSU, Thread {
   ReadableMemory rom;
   WritableMemory ram;
 
+  inline auto synchronizing() const -> bool { return scheduler.mode == Scheduler::Mode::SynchronizeAll; }
+
   //superfx.cpp
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto unload() -> void;
diff --git a/bsnes/sfc/coprocessor/superfx/timing.cpp b/bsnes/sfc/coprocessor/superfx/timing.cpp
index 3a427b2b..0b4bf653 100644
--- a/bsnes/sfc/coprocessor/superfx/timing.cpp
+++ b/bsnes/sfc/coprocessor/superfx/timing.cpp
@@ -14,8 +14,8 @@ auto SuperFX::step(uint clocks) -> void {
     }
   }
 
-  Thread::step(clocks);
-  synchronize(cpu);
+  clock += clocks * (uint64_t)cpu.frequency;
+  synchronizeCPU();
 }
 
 auto SuperFX::syncROMBuffer() -> void {
diff --git a/bsnes/sfc/cpu/cpu.cpp b/bsnes/sfc/cpu/cpu.cpp
index 70d8e8f3..f198da93 100644
--- a/bsnes/sfc/cpu/cpu.cpp
+++ b/bsnes/sfc/cpu/cpu.cpp
@@ -10,8 +10,27 @@ CPU cpu;
 #include "irq.cpp"
 #include "serialization.cpp"
 
+auto CPU::synchronizeSMP() -> void {
+  if(smp.clock < 0) co_switch(smp.thread);
+}
+
+auto CPU::synchronizePPU() -> void {
+  if(ppu.clock < 0) co_switch(ppu.thread);
+}
+
+auto CPU::synchronizeCoprocessors() -> void {
+  for(auto coprocessor : coprocessors) {
+    if(coprocessor->clock < 0) co_switch(coprocessor->thread);
+  }
+}
+
 auto CPU::Enter() -> void {
-  while(true) scheduler.synchronize(), cpu.main();
+  while(true) {
+    if(scheduler.mode == Scheduler::Mode::SynchronizeCPU) {
+      scheduler.leave(Scheduler::Event::Synchronize);
+    }
+    cpu.main();
+  }
 }
 
 auto CPU::main() -> void {
diff --git a/bsnes/sfc/cpu/cpu.hpp b/bsnes/sfc/cpu/cpu.hpp
index a304fe1b..5c11202a 100644
--- a/bsnes/sfc/cpu/cpu.hpp
+++ b/bsnes/sfc/cpu/cpu.hpp
@@ -2,9 +2,12 @@ struct CPU : Processor::WDC65816, Thread, PPUcounter {
   inline auto interruptPending() const -> bool override { return status.interruptPending; }
   inline auto pio() const -> uint8 { return io.pio; }
   inline auto refresh() const -> bool { return status.dramRefresh == 1; }
-  inline auto synchronizing() const -> bool override { return scheduler.synchronizing(); }
+  inline auto synchronizing() const -> bool override { return scheduler.mode == Scheduler::Mode::SynchronizeCPU; }
 
   //cpu.cpp
+  auto synchronizeSMP() -> void;
+  auto synchronizePPU() -> void;
+  auto synchronizeCoprocessors() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto load() -> bool;
diff --git a/bsnes/sfc/cpu/io.cpp b/bsnes/sfc/cpu/io.cpp
index a6521946..4a4b758c 100644
--- a/bsnes/sfc/cpu/io.cpp
+++ b/bsnes/sfc/cpu/io.cpp
@@ -3,7 +3,7 @@ auto CPU::readRAM(uint addr, uint8 data) -> uint8 {
 }
 
 auto CPU::readAPU(uint addr, uint8 data) -> uint8 {
-  synchronize(smp);
+  synchronizeSMP();
   return smp.portRead(addr & 3);
 }
 
@@ -100,7 +100,7 @@ auto CPU::writeRAM(uint addr, uint8 data) -> void {
 }
 
 auto CPU::writeAPU(uint addr, uint8 data) -> void {
-  synchronize(smp);
+  synchronizeSMP();
   return smp.portWrite(addr & 3, data);
 }
 
diff --git a/bsnes/sfc/cpu/timing.cpp b/bsnes/sfc/cpu/timing.cpp
index 13852b1d..08dadd82 100644
--- a/bsnes/sfc/cpu/timing.cpp
+++ b/bsnes/sfc/cpu/timing.cpp
@@ -28,9 +28,19 @@ template<uint Clocks, bool Synchronize>
 auto CPU::step() -> void {
   static_assert(Clocks == 2 || Clocks == 4 || Clocks == 6 || Clocks == 8 || Clocks == 10 || Clocks == 12);
 
+  for(auto coprocessor : coprocessors) {
+    coprocessor->clock -= Clocks * (uint64_t)coprocessor->frequency;
+  }
+
   if(overclocking.target) {
     overclocking.counter += Clocks;
-    if(overclocking.counter < overclocking.target) return;
+    if(overclocking.counter < overclocking.target) {
+      if constexpr(Synchronize) {
+        if(configuration.hacks.coprocessors.delayedSync) return;
+        synchronizeCoprocessors();
+      }
+      return;
+    }
   }
 
   if constexpr(Clocks >=  2) stepOnce();
@@ -39,7 +49,9 @@ auto CPU::step() -> void {
   if constexpr(Clocks >=  8) stepOnce();
   if constexpr(Clocks >= 10) stepOnce();
   if constexpr(Clocks >= 12) stepOnce();
-  Thread::step(Clocks);
+
+  smp.clock -= Clocks * (uint64_t)smp.frequency;
+  ppu.clock -= Clocks;
 
   if(!status.dramRefresh && hcounter() >= status.dramRefreshPosition) {
     //note: pattern should technically be 5-3, 5-3, 5-3, 5-3, 5-3 per logic analyzer
@@ -53,7 +65,7 @@ auto CPU::step() -> void {
 
   if constexpr(Synchronize) {
     if(configuration.hacks.coprocessors.delayedSync) return;
-    for(auto coprocessor : coprocessors) synchronize(*coprocessor);
+    synchronizeCoprocessors();
   }
 }
 
@@ -73,9 +85,9 @@ auto CPU::scanline() -> void {
   status.lineClocks = lineclocks();
 
   //forcefully sync S-CPU to other processors, in case chips are not communicating
-  synchronize(smp);
-  synchronize(ppu);
-  for(auto coprocessor : coprocessors) synchronize(*coprocessor);
+  synchronizeSMP();
+  synchronizePPU();
+  synchronizeCoprocessors();
 
   if(vcounter() == 0) {
     //HDMA setup triggers once every frame
diff --git a/bsnes/sfc/ppu-fast/io.cpp b/bsnes/sfc/ppu-fast/io.cpp
index 23fc6bac..d497c184 100644
--- a/bsnes/sfc/ppu-fast/io.cpp
+++ b/bsnes/sfc/ppu-fast/io.cpp
@@ -90,7 +90,7 @@ auto PPU::writeCGRAM(uint8_t address, uint15 data) -> void {
 }
 
 auto PPU::readIO(uint address, uint8 data) -> uint8 {
-  cpu.synchronize(ppu);
+  cpu.synchronizePPU();
 
   switch(address & 0xffff) {
 
@@ -202,7 +202,7 @@ auto PPU::readIO(uint address, uint8 data) -> uint8 {
 }
 
 auto PPU::writeIO(uint address, uint8 data) -> void {
-  cpu.synchronize(ppu);
+  cpu.synchronizePPU();
 
   switch(address & 0xffff) {
 
diff --git a/bsnes/sfc/ppu-fast/ppu.cpp b/bsnes/sfc/ppu-fast/ppu.cpp
index 2ae2609f..88c426ed 100644
--- a/bsnes/sfc/ppu-fast/ppu.cpp
+++ b/bsnes/sfc/ppu-fast/ppu.cpp
@@ -60,14 +60,21 @@ PPU::~PPU() {
   delete[] tilecache[TileMode::BPP8];
 }
 
+auto PPU::synchronizeCPU() -> void {
+  if(ppubase.clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto PPU::Enter() -> void {
-  while(true) scheduler.synchronize(), ppu.main();
+  while(true) {
+    scheduler.synchronize();
+    ppu.main();
+  }
 }
 
 auto PPU::step(uint clocks) -> void {
   tick(clocks);
-  Thread::step(clocks);
-  synchronize(cpu);
+  ppubase.clock += clocks;
+  synchronizeCPU();
 }
 
 auto PPU::main() -> void {
@@ -116,7 +123,7 @@ auto PPU::scanline() -> void {
 
   if(vcounter() == 240) {
     Line::flush();
-    scheduler.exit(Scheduler::Event::Frame);
+    scheduler.leave(Scheduler::Event::Frame);
   }
 }
 
@@ -160,7 +167,6 @@ auto PPU::load() -> bool {
 }
 
 auto PPU::power(bool reset) -> void {
-  Thread::create(Enter, system.cpuFrequency());
   PPUcounter::reset();
   memory::fill<uint16>(output, 1024 * 960);
 
diff --git a/bsnes/sfc/ppu-fast/ppu.hpp b/bsnes/sfc/ppu-fast/ppu.hpp
index 4bfc376f..bb01afa8 100644
--- a/bsnes/sfc/ppu-fast/ppu.hpp
+++ b/bsnes/sfc/ppu-fast/ppu.hpp
@@ -7,7 +7,7 @@
 
 #define PPU PPUfast
 
-struct PPU : Thread, PPUcounter {
+struct PPU : PPUcounter {
   alwaysinline auto interlace() const -> bool;
   alwaysinline auto overscan() const -> bool;
   alwaysinline auto vdisp() const -> uint;
@@ -23,6 +23,7 @@ struct PPU : Thread, PPUcounter {
   PPU();
   ~PPU();
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   alwaysinline auto step(uint clocks) -> void;
   auto main() -> void;
diff --git a/bsnes/sfc/ppu-fast/serialization.cpp b/bsnes/sfc/ppu-fast/serialization.cpp
index 69500e87..b7525dd8 100644
--- a/bsnes/sfc/ppu-fast/serialization.cpp
+++ b/bsnes/sfc/ppu-fast/serialization.cpp
@@ -1,5 +1,5 @@
 auto PPU::serialize(serializer& s) -> void {
-  Thread::serialize(s);
+  ppubase.Thread::serialize(s);
   PPUcounter::serialize(s);
 
   latch.serialize(s);
diff --git a/bsnes/sfc/ppu/io.cpp b/bsnes/sfc/ppu/io.cpp
index cf161aa6..b4fc083d 100644
--- a/bsnes/sfc/ppu/io.cpp
+++ b/bsnes/sfc/ppu/io.cpp
@@ -13,7 +13,7 @@ auto PPU::latchCounters() -> void {
     return ppufast.latchCounters();
   }
 
-  cpu.synchronize(ppu);
+  cpu.synchronizePPU();
   io.hcounter = hdot();
   io.vcounter = vcounter();
   latch.counters = 1;
@@ -69,7 +69,7 @@ auto PPU::writeCGRAM(uint8 addr, uint15 data) -> void {
 }
 
 auto PPU::readIO(uint addr, uint8 data) -> uint8 {
-  cpu.synchronize(ppu);
+  cpu.synchronizePPU();
 
   switch(addr & 0xffff) {
 
@@ -193,7 +193,7 @@ auto PPU::readIO(uint addr, uint8 data) -> uint8 {
 }
 
 auto PPU::writeIO(uint addr, uint8 data) -> void {
-  cpu.synchronize(ppu);
+  cpu.synchronizePPU();
 
   switch(addr & 0xffff) {
 
diff --git a/bsnes/sfc/ppu/ppu.cpp b/bsnes/sfc/ppu/ppu.cpp
index 67b958ca..3f5b050a 100644
--- a/bsnes/sfc/ppu/ppu.cpp
+++ b/bsnes/sfc/ppu/ppu.cpp
@@ -36,22 +36,26 @@ bg4(Background::ID::BG4) {
 }
 
 PPU::~PPU() {
-  if(system.fastPPU()) {
-    setHandle(nullptr);
-  }
+}
+
+auto PPU::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
 }
 
 auto PPU::step(uint clocks) -> void {
   clocks >>= 1;
   while(clocks--) {
     tick(2);
-    Thread::step(2);
-    synchronize(cpu);
+    clock += 2;
+    synchronizeCPU();
   }
 }
 
 auto PPU::Enter() -> void {
-  while(true) scheduler.synchronize(), ppu.main();
+  while(true) {
+    scheduler.synchronize();
+    ppu.main();
+  }
 }
 
 auto PPU::main() -> void {
@@ -99,16 +103,17 @@ auto PPU::load() -> bool {
 
 auto PPU::power(bool reset) -> void {
   if(system.fastPPU()) {
+    create(PPUfast::Enter, system.cpuFrequency());
     ppufast.power(reset);
-    return setHandle(ppufast.handle());
+    return;
   }
 
   create(Enter, system.cpuFrequency());
   PPUcounter::reset();
   memory::fill<uint16>(output, 512 * 480);
 
-  function<auto (uint, uint8) -> uint8> reader{&PPU::readIO, this};
-  function<auto (uint, uint8) -> void> writer{&PPU::writeIO, this};
+  function<uint8 (uint, uint8)> reader{&PPU::readIO, this};
+  function<void  (uint, uint8)> writer{&PPU::writeIO, this};
   bus.map(reader, writer, "00-3f,80-bf:2100-213f");
 
   if(!reset) random.array((uint8*)vram.data, sizeof(vram.data));
@@ -232,7 +237,7 @@ auto PPU::scanline() -> void {
   }
 
   if(vcounter() == 240) {
-    scheduler.exit(Scheduler::Event::Frame);
+    scheduler.leave(Scheduler::Event::Frame);
   }
 }
 
diff --git a/bsnes/sfc/ppu/ppu.hpp b/bsnes/sfc/ppu/ppu.hpp
index 47b172bd..7a97e5f4 100644
--- a/bsnes/sfc/ppu/ppu.hpp
+++ b/bsnes/sfc/ppu/ppu.hpp
@@ -7,6 +7,7 @@ struct PPU : Thread, PPUcounter {
   PPU();
   ~PPU();
 
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto load() -> bool;
diff --git a/bsnes/sfc/sfc.hpp b/bsnes/sfc/sfc.hpp
index dc317ca6..8412ebae 100644
--- a/bsnes/sfc/sfc.hpp
+++ b/bsnes/sfc/sfc.hpp
@@ -4,8 +4,6 @@
 //started: 2004-10-14
 
 #include <emulator/emulator.hpp>
-#include <emulator/thread.hpp>
-#include <emulator/scheduler.hpp>
 #include <emulator/random.hpp>
 #include <emulator/cheat.hpp>
 
@@ -24,22 +22,55 @@ extern "C" {
 namespace SuperFamicom {
   #define platform Emulator::platform
   namespace File = Emulator::File;
-  using Scheduler = Emulator::Scheduler;
   using Random = Emulator::Random;
   using Cheat = Emulator::Cheat;
-  extern Scheduler scheduler;
   extern Random random;
   extern Cheat cheat;
 
-  struct Thread : Emulator::Thread {
-    auto create(auto (*entrypoint)() -> void, double frequency) -> void {
-      Emulator::Thread::create(entrypoint, frequency);
-      scheduler.append(*this);
+  struct Scheduler {
+    enum class Mode : uint { Run, SynchronizeCPU, SynchronizeAll } mode;
+    enum class Event : uint { Frame, Synchronize } event;
+
+    cothread_t host = nullptr;
+    cothread_t active = nullptr;
+
+    auto enter() -> void {
+      host = co_active();
+      co_switch(active);
     }
 
-    inline auto synchronize(Thread& thread) -> void {
-      if(clock() >= thread.clock()) scheduler.resume(thread);
+    auto leave(Event event_) -> void {
+      event = event_;
+      active = co_active();
+      co_switch(host);
     }
+
+    auto synchronize() -> void {
+      if(mode == Mode::SynchronizeAll) leave(Event::Synchronize);
+    }
+  };
+  extern Scheduler scheduler;
+
+  struct Thread {
+    auto create(auto (*entrypoint)() -> void, uint frequency_) -> void {
+      if(thread) co_delete(thread);
+      thread = co_create(65536 * sizeof(void*), entrypoint);
+      frequency = frequency_;
+      clock = 0;
+    }
+
+    auto active() const -> bool {
+      return thread == co_active();
+    }
+
+    auto serialize(serializer& s) -> void {
+      s.integer(frequency);
+      s.integer(clock);
+    }
+
+    cothread_t thread = nullptr;
+      uint32_t frequency = 0;
+       int64_t clock = 0;
   };
 
   struct Region {
diff --git a/bsnes/sfc/slot/bsmemory/bsmemory.cpp b/bsnes/sfc/slot/bsmemory/bsmemory.cpp
index 70c98d10..e02f63dd 100644
--- a/bsnes/sfc/slot/bsmemory/bsmemory.cpp
+++ b/bsnes/sfc/slot/bsmemory/bsmemory.cpp
@@ -12,6 +12,10 @@ BSMemory::BSMemory() {
   block.self = this;
 }
 
+auto BSMemory::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
 auto BSMemory::Enter() -> void {
   while(true) scheduler.synchronize(), bsmemory.main();
 }
@@ -30,8 +34,8 @@ auto BSMemory::main() -> void {
 }
 
 auto BSMemory::step(uint clocks) -> void {
-  Thread::step(clocks);
-  synchronize(cpu);
+  clock += clocks * (uint64_t)cpu.frequency;
+  synchronizeCPU();
 }
 
 auto BSMemory::load() -> bool {
diff --git a/bsnes/sfc/slot/bsmemory/bsmemory.hpp b/bsnes/sfc/slot/bsmemory/bsmemory.hpp
index 3442b65e..efa12731 100644
--- a/bsnes/sfc/slot/bsmemory/bsmemory.hpp
+++ b/bsnes/sfc/slot/bsmemory/bsmemory.hpp
@@ -24,6 +24,7 @@ struct BSMemory : Thread, Memory {
 
   //bsmemory.cpp
   BSMemory();
+  auto synchronizeCPU() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto step(uint clocks) -> void;
diff --git a/bsnes/sfc/smp/io.cpp b/bsnes/sfc/smp/io.cpp
index 36a60fa8..d672a51c 100644
--- a/bsnes/sfc/smp/io.cpp
+++ b/bsnes/sfc/smp/io.cpp
@@ -31,19 +31,19 @@ auto SMP::readIO(uint16 address) -> uint8 {
     return dsp.read(io.dspAddr & 0x7f);
 
   case 0xf4:  //CPUIO0
-    synchronize(cpu);
+    synchronizeCPU();
     return io.apu0;
 
   case 0xf5:  //CPUIO1
-    synchronize(cpu);
+    synchronizeCPU();
     return io.apu1;
 
   case 0xf6:  //CPUIO2
-    synchronize(cpu);
+    synchronizeCPU();
     return io.apu2;
 
   case 0xf7:  //CPUIO3
-    synchronize(cpu);
+    synchronizeCPU();
     return io.apu3;
 
   case 0xf8:  //AUXIO4
@@ -111,13 +111,13 @@ auto SMP::writeIO(uint16 address, uint8 data) -> void {
     }
 
     if(bit1(data,4)) {
-      synchronize(cpu);
+      synchronizeCPU();
       io.apu0 = 0x00;
       io.apu1 = 0x00;
     }
 
     if(bit1(data,5)) {
-      synchronize(cpu);
+      synchronizeCPU();
       io.apu2 = 0x00;
       io.apu3 = 0x00;
     }
@@ -135,22 +135,22 @@ auto SMP::writeIO(uint16 address, uint8 data) -> void {
     break;
 
   case 0xf4:  //CPUIO0
-    synchronize(cpu);
+    synchronizeCPU();
     io.cpu0 = data;
     break;
 
   case 0xf5:  //CPUIO1
-    synchronize(cpu);
+    synchronizeCPU();
     io.cpu1 = data;
     break;
 
   case 0xf6:  //CPUIO2
-    synchronize(cpu);
+    synchronizeCPU();
     io.cpu2 = data;
     break;
 
   case 0xf7:  //CPUIO3
-    synchronize(cpu);
+    synchronizeCPU();
     io.cpu3 = data;
     break;
 
diff --git a/bsnes/sfc/smp/smp.cpp b/bsnes/sfc/smp/smp.cpp
index 5ae391ac..abea3a58 100644
--- a/bsnes/sfc/smp/smp.cpp
+++ b/bsnes/sfc/smp/smp.cpp
@@ -8,8 +8,19 @@ SMP smp;
 #include "timing.cpp"
 #include "serialization.cpp"
 
+auto SMP::synchronizeCPU() -> void {
+  if(clock >= 0 && scheduler.mode != Scheduler::Mode::SynchronizeAll) co_switch(cpu.thread);
+}
+
+auto SMP::synchronizeDSP() -> void {
+  while(dsp.clock < 0) dsp.main();
+}
+
 auto SMP::Enter() -> void {
-  while(true) scheduler.synchronize(), smp.main();
+  while(true) {
+    scheduler.synchronize();
+    smp.main();
+  }
 }
 
 auto SMP::main() -> void {
diff --git a/bsnes/sfc/smp/smp.hpp b/bsnes/sfc/smp/smp.hpp
index 4e8168a3..ee2aaecf 100644
--- a/bsnes/sfc/smp/smp.hpp
+++ b/bsnes/sfc/smp/smp.hpp
@@ -1,13 +1,15 @@
 //Sony CXP1100Q-1
 
 struct SMP : Processor::SPC700, Thread {
-  inline auto synchronizing() const -> bool override { return scheduler.synchronizing(); }
+  inline auto synchronizing() const -> bool override { return scheduler.mode == Scheduler::Mode::SynchronizeAll; }
 
   //io.cpp
   auto portRead(uint2 port) const -> uint8;
   auto portWrite(uint2 port, uint8 data) -> void;
 
   //smp.cpp
+  auto synchronizeCPU() -> void;
+  auto synchronizeDSP() -> void;
   static auto Enter() -> void;
   auto main() -> void;
   auto load() -> bool;
diff --git a/bsnes/sfc/smp/timing.cpp b/bsnes/sfc/smp/timing.cpp
index 4aaad961..00b4f296 100644
--- a/bsnes/sfc/smp/timing.cpp
+++ b/bsnes/sfc/smp/timing.cpp
@@ -33,21 +33,21 @@ auto SMP::waitIdle(maybe<uint16> addr) -> void {
 }
 
 auto SMP::step(uint clocks) -> void {
-  Thread::step(clocks);
+  clock += clocks * (uint64_t)cpu.frequency;
   dsp.clock -= clocks;
-  while(dsp.clock < 0) dsp.main();
+  synchronizeDSP();
 
   #if defined(DEBUGGER)
-  synchronize(cpu);
+  synchronizeCPU();
   #else
   //forcefully sync S-SMP to S-CPU in case chips are not communicating
-  //sync if S-SMP is more than 1ms ahead of S-CPU
-  if(clock() - cpu.clock() > Thread::Second / 1'000) synchronize(cpu);
+  //sync if S-SMP is more than 24 samples ahead of S-CPU
+  if(clock > +(768 * 24 * (int64_t)24'000'000)) synchronizeCPU();
   #endif
 }
 
 auto SMP::stepIdle(uint clocks) -> void {
-  Thread::step(clocks);
+  clock += clocks * (uint64_t)cpu.frequency;
   dsp.clock -= clocks;
 }
 
diff --git a/bsnes/sfc/system/system.cpp b/bsnes/sfc/system/system.cpp
index 456e42ec..92f8a4a2 100644
--- a/bsnes/sfc/system/system.cpp
+++ b/bsnes/sfc/system/system.cpp
@@ -9,7 +9,9 @@ Cheat cheat;
 #include "serialization.cpp"
 
 auto System::run() -> void {
-  if(scheduler.enter() == Scheduler::Event::Frame) {
+  scheduler.mode = Scheduler::Mode::Run;
+  scheduler.enter();
+  if(scheduler.event == Scheduler::Event::Frame) {
     ppu.refresh();
 
     //refresh all cheat codes once per frame
@@ -24,10 +26,22 @@ auto System::run() -> void {
 }
 
 auto System::runToSave() -> void {
-  scheduler.synchronize(cpu);
-  scheduler.synchronize(smp);
-  scheduler.synchronize(ppu);
-  for(auto coprocessor : cpu.coprocessors) scheduler.synchronize(*coprocessor);
+  scheduler.mode = Scheduler::Mode::SynchronizeCPU;
+  while(true) { scheduler.enter(); if(scheduler.event == Scheduler::Event::Synchronize) break; }
+
+  scheduler.mode = Scheduler::Mode::SynchronizeAll;
+  scheduler.active = smp.thread;
+  while(true) { scheduler.enter(); if(scheduler.event == Scheduler::Event::Synchronize) break; }
+
+  scheduler.mode = Scheduler::Mode::SynchronizeAll;
+  scheduler.active = ppu.thread;
+  while(true) { scheduler.enter(); if(scheduler.event == Scheduler::Event::Synchronize) break; }
+
+  for(auto coprocessor : cpu.coprocessors) {
+    scheduler.mode = Scheduler::Mode::SynchronizeAll;
+    scheduler.active = coprocessor->thread;
+    while(true) { scheduler.enter(); if(scheduler.event == Scheduler::Event::Synchronize) break; }
+  }
 }
 
 auto System::load(Emulator::Interface* interface) -> bool {
@@ -97,7 +111,6 @@ auto System::power(bool reset) -> void {
 
   random.entropy(Random::Entropy::Low);
 
-  scheduler.reset();
   cpu.power(reset);
   smp.power(reset);
   dsp.power(reset);
@@ -140,7 +153,7 @@ auto System::power(bool reset) -> void {
   if(cartridge.has.MSU1) cpu.coprocessors.append(&msu1);
   if(cartridge.has.BSMemorySlot) cpu.coprocessors.append(&bsmemory);
 
-  scheduler.primary(cpu);
+  scheduler.active = cpu.thread;
 
   controllerPort1.power(ID::Port::Controller1);
   controllerPort2.power(ID::Port::Controller2);
diff --git a/bsnes/target-bsnes/input/input.hpp b/bsnes/target-bsnes/input/input.hpp
index 342c0810..d93d078f 100644
--- a/bsnes/target-bsnes/input/input.hpp
+++ b/bsnes/target-bsnes/input/input.hpp
@@ -1,4 +1,9 @@
+#if defined(PLATFORM_WINDOWS) || defined(PLATFORM_MACOS)
+//TODO: hiro support for TableView::activate(TableViewCell) is required for > 1 binding
+enum : uint { BindingLimit = 1 };
+#else
 enum : uint { BindingLimit = 4 };
+#endif
 
 struct InputMapping {
   auto bind() -> void;