diff --git a/bsnes/nall/dsp/buffer.hpp b/bsnes/nall/dsp/buffer.hpp
index c1b85b8d..4386d0e9 100755
--- a/bsnes/nall/dsp/buffer.hpp
+++ b/bsnes/nall/dsp/buffer.hpp
@@ -1,35 +1,50 @@
 #ifdef NALL_DSP_INTERNAL_HPP
 
 struct Buffer {
-  double *sample[2];
+  double **sample;
   uint16_t rdoffset;
   uint16_t wroffset;
+  unsigned channels;
 
-  inline double& read(bool channel, signed offset = 0) {
+  void setChannels(unsigned channels) {
+    for(unsigned c = 0; c < this->channels; c++) {
+      if(sample[c]) delete[] sample[c];
+    }
+    if(sample) delete[] sample;
+
+    this->channels = channels;
+    if(channels == 0) return;
+
+    sample = new double*[channels];
+    for(unsigned c = 0; c < channels; c++) {
+      sample[c] = new double[65536]();
+    }
+  }
+
+  inline double& read(unsigned channel, signed offset = 0) {
     return sample[channel][(uint16_t)(rdoffset + offset)];
   }
 
-  inline double& write(bool channel, signed offset = 0) {
+  inline double& write(unsigned channel, signed offset = 0) {
     return sample[channel][(uint16_t)(wroffset + offset)];
   }
 
   inline void clear() {
-    for(unsigned n = 0; n < 65536; n++) {
-      sample[0][n] = 0;
-      sample[1][n] = 0;
+    for(unsigned c = 0; c < channels; c++) {
+      for(unsigned n = 0; n < 65536; n++) {
+        sample[c][n] = 0;
+      }
     }
     rdoffset = 0;
     wroffset = 0;
   }
 
   Buffer() {
-    sample[0] = new double[65536];
-    sample[1] = new double[65536];
+    channels = 0;
   }
 
   ~Buffer() {
-    delete[] sample[0];
-    delete[] sample[1];
+    setChannels(0);
   }
 };
 
diff --git a/bsnes/nall/dsp/core.hpp b/bsnes/nall/dsp/core.hpp
index bec46d93..3761cb2a 100755
--- a/bsnes/nall/dsp/core.hpp
+++ b/bsnes/nall/dsp/core.hpp
@@ -15,6 +15,7 @@ struct DSP {
     Average,
   };
 
+  inline void setChannels(unsigned channels);
   inline void setPrecision(unsigned precision);
   inline void setFrequency(double frequency);  //inputFrequency
   inline void setVolume(double volume);
@@ -23,9 +24,9 @@ struct DSP {
   inline void setResampler(Resampler resampler);
   inline void setResamplerFrequency(double frequency);  //outputFrequency
 
-  inline void sample(signed lchannel, signed rchannel);
+  inline void sample(signed channel[]);
   inline bool pending();
-  inline void read(signed &lchannel, signed &rchannel);
+  inline void read(signed channel[]);
 
   inline void clear();
   inline DSP();
@@ -33,6 +34,7 @@ struct DSP {
 
 protected:
   struct Settings {
+    unsigned channels;
     unsigned precision;
     double frequency;
     double volume;
@@ -50,7 +52,7 @@ protected:
   } resampler;
 
   inline void resamplerRun();
-  inline void resamplerWrite(double lchannel, double rchannel);
+  inline void resamplerWrite(double channel[]);
 
   inline void resamplePoint();
   inline void resampleLinear();
@@ -70,9 +72,10 @@ protected:
 
 #include "settings.hpp"
 
-void DSP::sample(signed lchannel, signed rchannel) {
-  buffer.write(0) = (double)lchannel / settings.intensity;
-  buffer.write(1) = (double)rchannel / settings.intensity;
+void DSP::sample(signed channel[]) {
+  for(unsigned c = 0; c < settings.channels; c++) {
+    buffer.write(c) = (double)channel[c] / settings.intensity;
+  }
   buffer.wroffset++;
   resamplerRun();
 }
@@ -81,12 +84,13 @@ bool DSP::pending() {
   return output.rdoffset != output.wroffset;
 }
 
-void DSP::read(signed &lchannel, signed &rchannel) {
+void DSP::read(signed channel[]) {
   adjustVolume();
   adjustBalance();
 
-  lchannel = clamp(settings.precision, output.read(0) * settings.intensity);
-  rchannel = clamp(settings.precision, output.read(1) * settings.intensity);
+  for(unsigned c = 0; c < settings.channels; c++) {
+    channel[c] = clamp(settings.precision, output.read(0) * settings.intensity);
+  }
   output.rdoffset++;
 }
 
@@ -101,9 +105,10 @@ void DSP::resamplerRun() {
   }
 }
 
-void DSP::resamplerWrite(double lchannel, double rchannel) {
-  output.write(0) = lchannel;
-  output.write(1) = rchannel;
+void DSP::resamplerWrite(double channel[]) {
+  for(unsigned c = 0; c < settings.channels; c++) {
+    output.write(c) = channel[c];
+  }
   output.wroffset++;
 }
 
@@ -115,11 +120,13 @@ void DSP::resamplerWrite(double lchannel, double rchannel) {
 #include "resample/average.hpp"
 
 void DSP::adjustVolume() {
-  output.read(0) *= settings.volume;
-  output.read(1) *= settings.volume;
+  for(unsigned c = 0; c < settings.channels; c++) {
+    output.read(c) *= settings.volume;
+  }
 }
 
 void DSP::adjustBalance() {
+  if(settings.channels != 2) return;  //TODO: support > 2 channels
   if(settings.balance < 0.0) output.read(1) *= 1.0 + settings.balance;
   if(settings.balance > 0.0) output.read(0) *= 1.0 - settings.balance;
 }
@@ -137,6 +144,7 @@ void DSP::clear() {
 }
 
 DSP::DSP() {
+  setChannels(2);
   setPrecision(16);
   setFrequency(44100.0);
   setVolume(1.0);
diff --git a/bsnes/nall/dsp/resample/average.hpp b/bsnes/nall/dsp/resample/average.hpp
index ca97050e..c5cdbca3 100755
--- a/bsnes/nall/dsp/resample/average.hpp
+++ b/bsnes/nall/dsp/resample/average.hpp
@@ -9,17 +9,20 @@ void DSP::resampleAverage() {
   double scalar = 1.0;
   if(resampler.fraction > resampler.step) scalar = 1.0 - (resampler.fraction - resampler.step);
 
-  output.write(0) += buffer.read(0) * scalar;
-  output.write(1) += buffer.read(1) * scalar;
+  for(unsigned c = 0; c < settings.channels; c++) {
+    output.write(c) += buffer.read(c) * scalar;
+  }
 
   if(resampler.fraction >= resampler.step) {
-    output.write(0) /= resampler.step;
-    output.write(1) /= resampler.step;
+    for(unsigned c = 0; c < settings.channels; c++) {
+      output.write(c) /= resampler.step;
+    }
     output.wroffset++;
 
     resampler.fraction -= resampler.step;
-    output.write(0) = buffer.read(0) * resampler.fraction;
-    output.write(1) = buffer.read(1) * resampler.fraction;
+    for(unsigned c = 0; c < settings.channels; c++) {
+      output.write(c) = buffer.read(c) * resampler.fraction;
+    }
   }
 
   buffer.rdoffset++;
diff --git a/bsnes/nall/dsp/resample/cosine.hpp b/bsnes/nall/dsp/resample/cosine.hpp
index 56fcf8fe..5405b7f3 100755
--- a/bsnes/nall/dsp/resample/cosine.hpp
+++ b/bsnes/nall/dsp/resample/cosine.hpp
@@ -2,9 +2,9 @@
 
 void DSP::resampleCosine() {
   while(resampler.fraction <= 1.0) {
-    double channel[2];
+    double channel[settings.channels];
 
-    for(unsigned n = 0; n < 2; n++) {
+    for(unsigned n = 0; n < settings.channels; n++) {
       double a = buffer.read(n, -1);
       double b = buffer.read(n, -0);
 
@@ -14,7 +14,7 @@ void DSP::resampleCosine() {
       channel[n] = a * (1.0 - mu) + b * mu;
     }
 
-    resamplerWrite(channel[0], channel[1]);
+    resamplerWrite(channel);
     resampler.fraction += resampler.step;
   }
 
diff --git a/bsnes/nall/dsp/resample/cubic.hpp b/bsnes/nall/dsp/resample/cubic.hpp
index f975f6aa..71e3766f 100755
--- a/bsnes/nall/dsp/resample/cubic.hpp
+++ b/bsnes/nall/dsp/resample/cubic.hpp
@@ -2,9 +2,9 @@
 
 void DSP::resampleCubic() {
   while(resampler.fraction <= 1.0) {
-    double channel[2];
+    double channel[settings.channels];
 
-    for(unsigned n = 0; n < 2; n++) {
+    for(unsigned n = 0; n < settings.channels; n++) {
       double a = buffer.read(n, -3);
       double b = buffer.read(n, -2);
       double c = buffer.read(n, -1);
@@ -20,7 +20,7 @@ void DSP::resampleCubic() {
       channel[n] = A * (mu * 3) + B * (mu * 2) + C * mu + D;
     }
 
-    resamplerWrite(channel[0], channel[1]);
+    resamplerWrite(channel);
     resampler.fraction += resampler.step;
   }
 
diff --git a/bsnes/nall/dsp/resample/hermite.hpp b/bsnes/nall/dsp/resample/hermite.hpp
index a042a55b..6eed087d 100755
--- a/bsnes/nall/dsp/resample/hermite.hpp
+++ b/bsnes/nall/dsp/resample/hermite.hpp
@@ -2,9 +2,9 @@
 
 void DSP::resampleHermite() {
   while(resampler.fraction <= 1.0) {
-    double channel[2];
+    double channel[settings.channels];
 
-    for(unsigned n = 0; n < 2; n++) {
+    for(unsigned n = 0; n < settings.channels; n++) {
       double a = buffer.read(n, -3);
       double b = buffer.read(n, -2);
       double c = buffer.read(n, -1);
@@ -32,7 +32,7 @@ void DSP::resampleHermite() {
       channel[n] = (a0 * b) + (a1 * m0) + (a2 * m1) + (a3 * c);
     }
 
-    resamplerWrite(channel[0], channel[1]);
+    resamplerWrite(channel);
     resampler.fraction += resampler.step;
   }
 
diff --git a/bsnes/nall/dsp/resample/linear.hpp b/bsnes/nall/dsp/resample/linear.hpp
index f4e48f57..3dbda6a0 100755
--- a/bsnes/nall/dsp/resample/linear.hpp
+++ b/bsnes/nall/dsp/resample/linear.hpp
@@ -2,9 +2,9 @@
 
 void DSP::resampleLinear() {
   while(resampler.fraction <= 1.0) {
-    double channel[2];
+    double channel[settings.channels];
 
-    for(unsigned n = 0; n < 2; n++) {
+    for(unsigned n = 0; n < settings.channels; n++) {
       double a = buffer.read(n, -1);
       double b = buffer.read(n, -0);
 
@@ -13,7 +13,7 @@ void DSP::resampleLinear() {
       channel[n] = a * (1.0 - mu) + b * mu;
     }
 
-    resamplerWrite(channel[0], channel[1]);
+    resamplerWrite(channel);
     resampler.fraction += resampler.step;
   }
 
diff --git a/bsnes/nall/dsp/resample/point.hpp b/bsnes/nall/dsp/resample/point.hpp
index 51d35935..b1cc7dae 100755
--- a/bsnes/nall/dsp/resample/point.hpp
+++ b/bsnes/nall/dsp/resample/point.hpp
@@ -2,9 +2,9 @@
 
 void DSP::resamplePoint() {
   while(resampler.fraction <= 1.0) {
-    double channel[2];
+    double channel[settings.channels];
 
-    for(unsigned n = 0; n < 2; n++) {
+    for(unsigned n = 0; n < settings.channels; n++) {
       double a = buffer.read(n, -1);
       double b = buffer.read(n, -0);
 
@@ -13,7 +13,7 @@ void DSP::resamplePoint() {
       channel[n] = mu < 0.5 ? a : b;
     }
 
-    resamplerWrite(channel[0], channel[1]);
+    resamplerWrite(channel);
     resampler.fraction += resampler.step;
   }
 
diff --git a/bsnes/nall/dsp/settings.hpp b/bsnes/nall/dsp/settings.hpp
index c7313d3d..dc422e39 100755
--- a/bsnes/nall/dsp/settings.hpp
+++ b/bsnes/nall/dsp/settings.hpp
@@ -1,5 +1,12 @@
 #ifdef NALL_DSP_INTERNAL_HPP
 
+void DSP::setChannels(unsigned channels) {
+  assert(channels > 0);
+  buffer.setChannels(channels);
+  output.setChannels(channels);
+  settings.channels = channels;
+}
+
 void DSP::setPrecision(unsigned precision) {
   settings.precision = precision;
   settings.intensity = 1 << (settings.precision - 1);
diff --git a/bsnes/nall/utility.hpp b/bsnes/nall/utility.hpp
index 1f5699e5..374b5469 100755
--- a/bsnes/nall/utility.hpp
+++ b/bsnes/nall/utility.hpp
@@ -27,6 +27,7 @@ namespace nall {
     inline operator bool() const { return valid; }
     inline const T& operator()() const { if(!valid) throw; return value; }
     inline optional<T>& operator=(const optional<T> &source) { valid = source.valid; value = source.value; return *this; }
+    inline optional() : valid(false) {}
     inline optional(bool valid, const T &value) : valid(valid), value(value) {}
   };
 
diff --git a/bsnes/nes/apu/apu.cpp b/bsnes/nes/apu/apu.cpp
index e3c7ab43..29932714 100755
--- a/bsnes/nes/apu/apu.cpp
+++ b/bsnes/nes/apu/apu.cpp
@@ -53,7 +53,21 @@ void APU::tick() {
   if(clock >= 0) co_switch(cpu.thread);
 }
 
+void APU::set_irq_line() {
+  cpu.set_irq_apu_line(frame.irq_pending || dmc.irq_pending);
+}
+
 void APU::power() {
+  for(unsigned n = 0; n < 2; n++) {
+    rectangle[n].sweep.shift = 0;
+    rectangle[n].sweep.decrement = 0;
+    rectangle[n].sweep.period = 0;
+    rectangle[n].sweep.counter = 1;
+    rectangle[n].sweep.enable = 0;
+    rectangle[n].sweep.reload = 0;
+    rectangle[n].sweep.rectangle_period = 0;
+  }
+
   reset();
 }
 
@@ -70,14 +84,6 @@ void APU::reset() {
     rectangle[n].envelope.decay_counter = 0;
     rectangle[n].envelope.decay_volume = 0;
 
-    rectangle[n].sweep.shift = 0;
-    rectangle[n].sweep.decrement = 0;
-    rectangle[n].sweep.period = 0;
-    rectangle[n].sweep.counter = 0;
-    rectangle[n].sweep.enable = 0;
-    rectangle[n].sweep.reload = 0;
-    rectangle[n].sweep.rectangle_period = 0;
-
     rectangle[n].duty = 0;
     rectangle[n].duty_counter = 0;
     rectangle[n].period = 0;
@@ -108,27 +114,44 @@ void APU::reset() {
   noise.short_mode = 0;
   noise.lfsr = 1;
 
-  dmc.irq = 0;
-  dmc.loop = 0;
+  dmc.length_counter = 0;
+  dmc.irq_pending = 0;
+
   dmc.period = 0;
-  dmc.counter = 0;
-  dmc.addr = 0xc000;
-  dmc.length = 1;
+  dmc.period_counter = ntsc_dmc_period_table[0];
+  dmc.irq_enable = 0;
+  dmc.loop_mode = 0;
+  dmc.dac_latch = 0;
+  dmc.addr_latch = 0;
+  dmc.length_latch = 0;
+  dmc.read_addr = 0;
+  dmc.dma_delay_counter = 0;
+  dmc.bit_counter = 0;
+  dmc.have_dma_buffer = 0;
+  dmc.dma_buffer = 0;
+  dmc.have_sample = 0;
+  dmc.sample = 0;
+
+  frame.irq_pending = 0;
 
   frame.mode = 0;
   frame.counter = 0;
   frame.divider = 1;
 
   enabled_channels = 0;
+//cpu.set_alu_irq_line(frame.irq_pending || dmc.irq_pending);
 }
 
 uint8 APU::read(uint16 addr) {
   if(addr == 0x4015) {
     uint8 result = 0x00;
-    result |= rectangle[0].length_counter ? 1 : 0;
-    result |= rectangle[1].length_counter ? 2 : 0;
-    result |=     triangle.length_counter ? 4 : 0;
-    result |=        noise.length_counter ? 8 : 0;
+    result |= rectangle[0].length_counter ? 0x01 : 0;
+    result |= rectangle[1].length_counter ? 0x02 : 0;
+    result |=     triangle.length_counter ? 0x04 : 0;
+    result |=        noise.length_counter ? 0x08 : 0;
+    result |=          dmc.length_counter ? 0x10 : 0;
+    result |=           frame.irq_pending ? 0x40 : 0;
+    result |=             dmc.irq_pending ? 0x80 : 0;
     return result;
   }
 
@@ -148,7 +171,7 @@ void APU::write(uint16 addr, uint8 data) {
 
   case 0x4001: case 0x4005:
     rectangle[r].sweep.enable = data & 0x80;
-    rectangle[r].sweep.period = (data >> 4) & 7;
+    rectangle[r].sweep.period = (data & 0x70) >> 4;
     rectangle[r].sweep.decrement = data & 0x08;
     rectangle[r].sweep.shift = data & 0x07;
     rectangle[r].sweep.reload = true;
@@ -216,20 +239,24 @@ void APU::write(uint16 addr, uint8 data) {
     break;
 
   case 0x4010:
-    dmc.irq = data & 0x80;
-    dmc.loop = data & 0x40;
-    dmc.period = ntsc_dmc_period_table[data & 0x0f];
+    dmc.irq_enable = data & 0x80;
+    dmc.loop_mode = data & 0x40;
+    dmc.period = data & 0x0f;
+
+    dmc.irq_pending = dmc.irq_pending && dmc.irq_enable && !dmc.loop_mode;
+    set_irq_line();
+    break;
 
   case 0x4011:
-    dmc.counter = data & 0x7f;
+    dmc.dac_latch = data & 0x7f;
     break;
 
   case 0x4012:
-    dmc.addr = 0xc000 | (data << 6);
+    dmc.addr_latch = data;
     break;
 
   case 0x4013:
-    dmc.length = (data << 4) | 1;
+    dmc.length_latch = data;
     break;
 
   case 0x4015:
@@ -237,6 +264,12 @@ void APU::write(uint16 addr, uint8 data) {
     if((data & 0x02) == 0) rectangle[1].length_counter = 0;
     if((data & 0x04) == 0)     triangle.length_counter = 0;
     if((data & 0x08) == 0)        noise.length_counter = 0;
+    if((data & 0x10) == 0)          dmc.length_counter = 0;
+
+    if((data & 0x10) && dmc.length_counter == 0) dmc.start();
+    dmc.irq_pending = false;
+    set_irq_line();
+
     enabled_channels = data & 0x1f;
     break;
 
@@ -245,20 +278,34 @@ void APU::write(uint16 addr, uint8 data) {
 
     frame.counter = 0;
     if(frame.mode & 2) clock_frame_counter();
-    frame.divider = 14915;
+    if(frame.mode & 1) {
+      frame.irq_pending = false;
+      set_irq_line();
+    }
+    frame.divider = FrameCounter::NtscPeriod;
     break;
   }
 }
 
-void APU::Sweep::clock() {
+bool APU::Sweep::check_period() {
+  if(rectangle_period > 0x7ff) return false;
+
+  if(decrement == 0) {
+    if((rectangle_period + (rectangle_period >> shift)) & 0x800) return false;
+  }
+
+  return true;
+}
+
+void APU::Sweep::clock(unsigned channel) {
   if(--counter == 0) {
     counter = period + 1;
-    if(enable & shift && rectangle_period > 8) {
+    if(enable && shift && rectangle_period > 8) {
       signed delta = rectangle_period >> shift;
 
       if(decrement) {
-        //first rectangle decrements by one extra
-        rectangle_period -= delta + (channel == 0);
+        rectangle_period -= delta;
+        if(channel == 0) rectangle_period--;
       } else if((rectangle_period + delta) < 0x800) {
         rectangle_period += delta;
       }
@@ -272,7 +319,7 @@ void APU::Sweep::clock() {
 }
 
 unsigned APU::Envelope::volume() const {
-  return use_speed_as_volume ? speed :decay_volume;
+  return use_speed_as_volume ? speed : decay_volume;
 }
 
 void APU::Envelope::clock() {
@@ -295,24 +342,13 @@ void APU::Rectangle::clock_length() {
   }
 }
 
-bool APU::Rectangle::check_period() {
-  const unsigned raw_period = sweep.rectangle_period;
-
-  if(raw_period < 0x008 || raw_period > 0x7ff) return false;
-
-  if(sweep.decrement == 0) {
-    if((raw_period + (raw_period >> sweep.shift)) & 0x800) return false;
-  }
-
-  return true;
-}
-
 uint8 APU::Rectangle::clock() {
-  if(check_period() == false) return 0;
+  if(sweep.check_period() == false) return 0;
   if(length_counter == 0) return 0;
 
   static const unsigned duty_table[] = { 1, 2, 4, 6 };
   uint8 result = (duty_counter < duty_table[duty]) ? envelope.volume() : 0;
+  if(sweep.rectangle_period < 0x008) result = 0;
 
   if(--period_counter == 0) {
     period_counter = (sweep.rectangle_period + 1) * 2;
@@ -340,11 +376,11 @@ void APU::Triangle::clock_linear_length() {
 
 uint8 APU::Triangle::clock() {
   uint8 result = step_counter & 0x0f;
-  if(step_counter & 0x10) result ^= 0x0f;
+  if((step_counter & 0x10) == 0) result ^= 0x0f;
   if(length_counter == 0 || linear_length_counter == 0) return result;
 
   if(--period_counter == 0) {
-    step_counter = (step_counter + 1) & 0x1f;
+    step_counter++;
     period_counter = period + 1;
   }
 
@@ -378,8 +414,63 @@ uint8 APU::Noise::clock() {
   return result;
 }
 
+void APU::DMC::start() {
+  read_addr = 0x4000 + (addr_latch << 6);
+  length_counter = (length_latch << 4) + 1;
+}
+
 uint8 APU::DMC::clock() {
-  uint8 result = counter;
+  uint8 result = dac_latch;
+
+  if(dma_delay_counter > 0) {
+    dma_delay_counter--;
+
+    if(dma_delay_counter == 1) {
+      cpu.set_rdy_addr({ true, uint16(0x8000 | read_addr) });
+    } else if(dma_delay_counter == 0) {
+      cpu.set_rdy_line(1);
+      cpu.set_rdy_addr({ false, 0u });
+
+      dma_buffer = cpu.mdr();
+      have_dma_buffer = true;
+      length_counter--;
+      read_addr++;
+
+      if(length_counter == 0) {
+        if(loop_mode) {
+          start();
+        } else if(irq_enable) {
+          irq_pending = true;
+          apu.set_irq_line();
+        }
+      }
+    }
+  }
+
+  if(--period_counter == 0) {
+    if(have_sample) {
+      signed delta = (((sample >> bit_counter) & 1) << 2) - 2;
+      unsigned data = dac_latch + delta;
+      if((data & 0x80) == 0) dac_latch = data;
+    }
+
+    if(++bit_counter == 0) {
+      if(have_dma_buffer) {
+        have_sample = true;
+        sample = dma_buffer;
+        have_dma_buffer = false;
+      } else {
+        have_sample = false;
+      }
+    }
+
+    period_counter = ntsc_dmc_period_table[period];
+  }
+
+  if(length_counter > 0 && have_dma_buffer == false && dma_delay_counter == 0) {
+    cpu.set_rdy_line(0);
+    dma_delay_counter = 4;
+  }
 
   return result;
 }
@@ -389,9 +480,9 @@ void APU::clock_frame_counter() {
 
   if(frame.counter & 1) {
     rectangle[0].clock_length();
-    rectangle[0].sweep.clock();
+    rectangle[0].sweep.clock(0);
     rectangle[1].clock_length();
-    rectangle[1].sweep.clock();
+    rectangle[1].sweep.clock(1);
     triangle.clock_length();
     noise.clock_length();
   }
@@ -402,7 +493,11 @@ void APU::clock_frame_counter() {
   noise.envelope.clock();
 
   if(frame.counter == 0) {
-    if(frame.mode & 2) frame.divider += 14195;
+    if(frame.mode & 2) frame.divider += FrameCounter::NtscPeriod;
+    if(frame.mode == 0) {
+      frame.irq_pending = true;
+      set_irq_line();
+    }
   }
 }
 
@@ -410,14 +505,11 @@ void APU::clock_frame_counter_divider() {
   frame.divider -= 2;
   if(frame.divider <= 0) {
     clock_frame_counter();
-    frame.divider += 14195;
+    frame.divider += FrameCounter::NtscPeriod;
   }
 }
 
 APU::APU() {
-  rectangle[0].sweep.channel = 0;
-  rectangle[1].sweep.channel = 1;
-
   for(unsigned amp = 0; amp < 32; amp++) {
     if(amp == 0) {
       rectangle_dac[amp] = 0;
diff --git a/bsnes/nes/apu/apu.hpp b/bsnes/nes/apu/apu.hpp
index 29ca723f..7e7cafd0 100755
--- a/bsnes/nes/apu/apu.hpp
+++ b/bsnes/nes/apu/apu.hpp
@@ -2,6 +2,7 @@ struct APU : Processor {
   static void Main();
   void main();
   void tick();
+  void set_irq_line();
 
   void power();
   void reset();
@@ -25,8 +26,6 @@ struct APU : Processor {
   };
 
   struct Sweep {
-    bool channel;
-
     uint8 shift;
     bool decrement;
     uint3 period;
@@ -35,7 +34,8 @@ struct APU : Processor {
     bool reload;
     unsigned rectangle_period;
 
-    void clock();
+    bool check_period();
+    void clock(unsigned channel);
   };
 
   struct Rectangle {
@@ -64,7 +64,7 @@ struct APU : Processor {
     uint11 period;
     unsigned period_counter;
 
-    uint8 step_counter;
+    uint5 step_counter;
     uint8 linear_length_counter;
     bool reload_linear;
 
@@ -89,18 +89,38 @@ struct APU : Processor {
   } noise;
 
   struct DMC {
-    bool irq;
-    bool loop;
-    unsigned period;
+    unsigned length_counter;
+    bool irq_pending;
 
-    uint8 counter;
-    uint16 addr;
-    uint16 length;
+    uint4 period;
+    unsigned period_counter;
 
+    bool irq_enable;
+    bool loop_mode;
+
+    uint8 dac_latch;
+    uint8 addr_latch;
+    uint8 length_latch;
+
+    uint15 read_addr;
+    unsigned dma_delay_counter;
+
+    uint3 bit_counter;
+    bool have_dma_buffer;
+    uint8 dma_buffer;
+
+    bool have_sample;
+    uint8 sample;
+
+    void start();
     uint8 clock();
   } dmc;
 
   struct FrameCounter {
+    enum : unsigned { NtscPeriod = 14915 };  //~(21.477MHz / 6 / 240hz)
+
+    bool irq_pending;
+
     uint2 mode;
     uint2 counter;
     signed divider;
diff --git a/bsnes/nes/cpu/core/core.hpp b/bsnes/nes/cpu/core/core.hpp
index d8f3527d..0a07d4c4 100755
--- a/bsnes/nes/cpu/core/core.hpp
+++ b/bsnes/nes/cpu/core/core.hpp
@@ -35,6 +35,7 @@ void interrupt();
 void interrupt_test();
 void set_nmi_line(bool);
 void set_irq_line(bool);
+void set_irq_apu_line(bool);
 
 //opcodes.cpp
 void opf_asl();
diff --git a/bsnes/nes/cpu/core/interrupt.cpp b/bsnes/nes/cpu/core/interrupt.cpp
index 0c094705..a3a76828 100755
--- a/bsnes/nes/cpu/core/interrupt.cpp
+++ b/bsnes/nes/cpu/core/interrupt.cpp
@@ -17,7 +17,7 @@ L abs.h = op_read(vector++);
 }
 
 void CPU::interrupt_test() {
-  status.interrupt_pending = (status.irq_line & ~regs.p.i) | status.nmi_pending;
+  status.interrupt_pending = ((status.irq_line | status.irq_apu_line) & ~regs.p.i) | status.nmi_pending;
 }
 
 void CPU::set_nmi_line(bool line) {
@@ -30,3 +30,8 @@ void CPU::set_irq_line(bool line) {
   //level-sensitive
   status.irq_line = line;
 }
+
+void CPU::set_irq_apu_line(bool line) {
+  //level-sensitive
+  status.irq_apu_line = line;
+}
diff --git a/bsnes/nes/cpu/cpu.cpp b/bsnes/nes/cpu/cpu.cpp
index df50108a..a5b4f390 100755
--- a/bsnes/nes/cpu/cpu.cpp
+++ b/bsnes/nes/cpu/cpu.cpp
@@ -70,6 +70,13 @@ void CPU::reset() {
   status.nmi_pending = false;
   status.nmi_line = 0;
   status.irq_line = 0;
+  status.irq_apu_line = 0;
+
+  status.rdy_line = 1;
+  status.rdy_addr = { false, 0x0000 };
+
+  status.oam_dma_pending = false;
+  status.oam_dma_page = 0x00;
 
   status.controller_latch = false;
   status.controller_port0 = 0;
@@ -80,6 +87,14 @@ uint8 CPU::mdr() const {
   return regs.mdr;
 }
 
+void CPU::set_rdy_line(bool line) {
+  status.rdy_line = line;
+}
+
+void CPU::set_rdy_addr(optional<uint16> addr) {
+  status.rdy_addr = addr;
+}
+
 uint8 CPU::ram_read(uint16 addr) {
   return ram[addr & 0x07ff];
 }
@@ -104,7 +119,8 @@ uint8 CPU::read(uint16 addr) {
 
 void CPU::write(uint16 addr, uint8 data) {
   if(addr == 0x4014) {
-    return oam_dma(data << 8);
+    status.oam_dma_page = data;
+    status.oam_dma_pending = true;
   }
 
   if(addr == 0x4016) {
@@ -118,10 +134,9 @@ void CPU::write(uint16 addr, uint8 data) {
   return apu.write(addr, data);
 }
 
-void CPU::oam_dma(uint16 addr) {
-  op_readpc();
+void CPU::oam_dma() {
   for(unsigned n = 0; n < 256; n++) {
-    uint8 data = op_read(addr + n);
+    uint8 data = op_read((status.oam_dma_page << 8) + n);
     op_write(0x2004, data);
   }
 }
diff --git a/bsnes/nes/cpu/cpu.hpp b/bsnes/nes/cpu/cpu.hpp
index 09973e85..6cab71c5 100755
--- a/bsnes/nes/cpu/cpu.hpp
+++ b/bsnes/nes/cpu/cpu.hpp
@@ -8,6 +8,13 @@ struct CPU : Processor {
     bool nmi_pending;
     bool nmi_line;
     bool irq_line;
+    bool irq_apu_line;
+
+    bool rdy_line;
+    optional<uint16> rdy_addr;
+
+    bool oam_dma_pending;
+    uint8 oam_dma_page;
 
     bool controller_latch;
     unsigned controller_port0;
@@ -22,6 +29,8 @@ struct CPU : Processor {
   void reset();
 
   uint8 mdr() const;
+  void set_rdy_line(bool);
+  void set_rdy_addr(optional<uint16>);
 
   uint8 ram_read(uint16 addr);
   void ram_write(uint16 addr, uint8 data);
@@ -29,7 +38,7 @@ struct CPU : Processor {
   uint8 read(uint16 addr);
   void write(uint16 addr, uint8 data);
 
-  void oam_dma(uint16 addr);
+  void oam_dma();
 
 bool trace;
 };
diff --git a/bsnes/nes/cpu/memory/memory.cpp b/bsnes/nes/cpu/memory/memory.cpp
index 38c26c51..1078e5ae 100755
--- a/bsnes/nes/cpu/memory/memory.cpp
+++ b/bsnes/nes/cpu/memory/memory.cpp
@@ -1,4 +1,15 @@
 uint8 CPU::op_read(uint16 addr) {
+  if(status.oam_dma_pending) {
+    status.oam_dma_pending = false;
+    op_read(addr);
+    oam_dma();
+  }
+
+  while(status.rdy_line == 0) {
+    regs.mdr = bus.read(status.rdy_addr ? status.rdy_addr() : addr);
+    add_clocks(12);
+  }
+
   regs.mdr = bus.read(addr);
   add_clocks(12);
   return regs.mdr;
diff --git a/bsnes/nes/nes.hpp b/bsnes/nes/nes.hpp
index 07148dc7..c8e81349 100755
--- a/bsnes/nes/nes.hpp
+++ b/bsnes/nes/nes.hpp
@@ -4,7 +4,7 @@
 namespace NES {
   namespace Info {
     static const char Name[] = "bnes";
-    static const char Version[] = "000.09";
+    static const char Version[] = "000.10";
   }
 }
 
diff --git a/bsnes/snes/audio/audio.cpp b/bsnes/snes/audio/audio.cpp
index 1e0d9886..6ad5f2c8 100755
--- a/bsnes/snes/audio/audio.cpp
+++ b/bsnes/snes/audio/audio.cpp
@@ -28,13 +28,13 @@ void Audio::sample(int16 left, int16 right) {
   }
 }
 
-void Audio::coprocessor_sample(int16 left, int16 right) {
-  dspaudio.sample(left, right);
+void Audio::coprocessor_sample(int16 lsample, int16 rsample) {
+  signed samples[] = { lsample, rsample };
+  dspaudio.sample(samples);
   while(dspaudio.pending()) {
-    signed left, right;
-    dspaudio.read(left, right);
+    dspaudio.read(samples);
 
-    cop_buffer[cop_wroffset] = ((uint16)left << 0) + ((uint16)right << 16);
+    cop_buffer[cop_wroffset] = ((uint16)samples[0] << 0) + ((uint16)samples[1] << 16);
     cop_wroffset = (cop_wroffset + 1) & buffer_mask;
     cop_length = (cop_length + 1) & buffer_mask;
     flush();
diff --git a/bsnes/snes/cheat/cheat.cpp b/bsnes/snes/cheat/cheat.cpp
index 06e79d08..70942017 100755
--- a/bsnes/snes/cheat/cheat.cpp
+++ b/bsnes/snes/cheat/cheat.cpp
@@ -65,51 +65,31 @@ Cheat::~Cheat() {
   delete[] override;
 }
 
-//===============
-//encode / decode
-//===============
-
-bool Cheat::decode(const char *s, unsigned &addr, unsigned &data, Type &type) {
-  string t = s;
+bool Cheat::decode(const string &code, unsigned &addr, unsigned &data) {
+  string t = code;
   t.lower();
 
   #define ischr(n) ((n >= '0' && n <= '9') || (n >= 'a' && n <= 'f'))
 
   if(strlen(t) == 8 || (strlen(t) == 9 && t[6] == ':')) {
-    //strip ':'
-    if(strlen(t) == 9 && t[6] == ':') t = { substr(t, 0, 6), substr(t, 7) };
-    //validate input
-    for(unsigned i = 0; i < 8; i++) if(!ischr(t[i])) return false;
+    //Pro Action Replay
+    if(strlen(t) == 9 && t[6] == ':') t = { substr(t, 0, 6), substr(t, 7) };  //strip ':'
+    for(unsigned i = 0; i < 8; i++) if(!ischr(t[i])) return false;  //validate input
+    unsigned r = hex(t);
 
-    type = Type::ProActionReplay;
-    unsigned r = hex((const char*)t);
     addr = r >> 8;
     data = r & 0xff;
     return true;
   } else if(strlen(t) == 9 && t[4] == '-') {
-    //strip '-'
-    t = { substr(t, 0, 4), substr(t, 5) };
-    //validate input
-    for(unsigned i = 0; i < 8; i++) if(!ischr(t[i])) return false;
-
-    type = Type::GameGenie;
+    //Game Genie
+    t = { substr(t, 0, 4), substr(t, 5) };  //strip '-'
+    for(unsigned i = 0; i < 8; i++) if(!ischr(t[i])) return false;  //validate input
     t.transform("df4709156bc8a23e", "0123456789abcdef");
-    unsigned r = hex((const char*)t);
-    //8421 8421 8421 8421 8421 8421
-    //abcd efgh ijkl mnop qrst uvwx
-    //ijkl qrst opab cduv wxef ghmn
-    addr = (!!(r & 0x002000) << 23) | (!!(r & 0x001000) << 22)
-         | (!!(r & 0x000800) << 21) | (!!(r & 0x000400) << 20)
-         | (!!(r & 0x000020) << 19) | (!!(r & 0x000010) << 18)
-         | (!!(r & 0x000008) << 17) | (!!(r & 0x000004) << 16)
-         | (!!(r & 0x800000) << 15) | (!!(r & 0x400000) << 14)
-         | (!!(r & 0x200000) << 13) | (!!(r & 0x100000) << 12)
-         | (!!(r & 0x000002) << 11) | (!!(r & 0x000001) << 10)
-         | (!!(r & 0x008000) <<  9) | (!!(r & 0x004000) <<  8)
-         | (!!(r & 0x080000) <<  7) | (!!(r & 0x040000) <<  6)
-         | (!!(r & 0x020000) <<  5) | (!!(r & 0x010000) <<  4)
-         | (!!(r & 0x000200) <<  3) | (!!(r & 0x000100) <<  2)
-         | (!!(r & 0x000080) <<  1) | (!!(r & 0x000040) <<  0);
+    unsigned r = hex(t);
+    static unsigned bits[] = { 13, 12, 11, 10, 5, 4, 3, 2, 23, 22, 21, 20, 1, 0, 15, 14, 19, 18, 17, 16, 9, 8, 7, 6 };
+
+    addr = 0;
+    for(unsigned n = 0; n < 24; n++) addr |= r & (1 << bits[n]) ? 0x800000 >> n : 0;
     data = r >> 24;
     return true;
   } else {
@@ -119,38 +99,6 @@ bool Cheat::decode(const char *s, unsigned &addr, unsigned &data, Type &type) {
   #undef ischr
 }
 
-bool Cheat::encode(string &s, unsigned addr, unsigned data, Type type) {
-  char t[16];
-
-  if(type == Type::ProActionReplay) {
-    s = string(hex<6>(addr), hex<2>(data));
-    return true;
-  } else if(type == Type::GameGenie) {
-    unsigned r = addr;
-    addr = (!!(r & 0x008000) << 23) | (!!(r & 0x004000) << 22)
-         | (!!(r & 0x002000) << 21) | (!!(r & 0x001000) << 20)
-         | (!!(r & 0x000080) << 19) | (!!(r & 0x000040) << 18)
-         | (!!(r & 0x000020) << 17) | (!!(r & 0x000010) << 16)
-         | (!!(r & 0x000200) << 15) | (!!(r & 0x000100) << 14)
-         | (!!(r & 0x800000) << 13) | (!!(r & 0x400000) << 12)
-         | (!!(r & 0x200000) << 11) | (!!(r & 0x100000) << 10)
-         | (!!(r & 0x000008) <<  9) | (!!(r & 0x000004) <<  8)
-         | (!!(r & 0x000002) <<  7) | (!!(r & 0x000001) <<  6)
-         | (!!(r & 0x080000) <<  5) | (!!(r & 0x040000) <<  4)
-         | (!!(r & 0x020000) <<  3) | (!!(r & 0x010000) <<  2)
-         | (!!(r & 0x000800) <<  1) | (!!(r & 0x000400) <<  0);
-    s = string(hex<2>(data), hex<2>(addr >> 16), "-", hex<4>(addr & 0xffff));
-    s.transform("0123456789abcdef", "df4709156bc8a23e");
-    return true;
-  } else {
-    return false;
-  }
-}
-
-//========
-//internal
-//========
-
 unsigned Cheat::mirror(unsigned addr) const {
   //$00-3f|80-bf:0000-1fff -> $7e:0000-1fff
   if((addr & 0x40e000) == 0x000000) return (0x7e0000 + (addr & 0x1fff));  
diff --git a/bsnes/snes/cheat/cheat.hpp b/bsnes/snes/cheat/cheat.hpp
index d2c2c17a..458c484c 100755
--- a/bsnes/snes/cheat/cheat.hpp
+++ b/bsnes/snes/cheat/cheat.hpp
@@ -5,7 +5,6 @@ struct CheatCode {
 
 class Cheat : public linear_vector<CheatCode> {
 public:
-  enum class Type : unsigned { ProActionReplay, GameGenie };
   uint8 *override;
 
   bool enabled() const;
@@ -17,8 +16,7 @@ public:
   Cheat();
   ~Cheat();
 
-  static bool decode(const char*, unsigned&, unsigned&, Type&);
-  static bool encode(string&, unsigned, unsigned, Type);
+  static bool decode(const string&, unsigned&, unsigned&);
 
 private:
   bool system_enabled;
diff --git a/bsnes/snes/interface/interface.cpp b/bsnes/snes/interface/interface.cpp
index b120a5c9..be109f0a 100755
--- a/bsnes/snes/interface/interface.cpp
+++ b/bsnes/snes/interface/interface.cpp
@@ -61,8 +61,7 @@ void Interface::setCheats(const lstring &list) {
     codelist.split("+", code);
     foreach(part, codelist) {
       unsigned addr, data;
-      Cheat::Type type;
-      if(Cheat::decode(part, addr, data, type)) {
+      if(Cheat::decode(part, addr, data)) {
         cheat.append({ addr, data });
       }
     }
diff --git a/bsnes/snes/snes.hpp b/bsnes/snes/snes.hpp
index 24f4e2ac..7e87c37a 100755
--- a/bsnes/snes/snes.hpp
+++ b/bsnes/snes/snes.hpp
@@ -4,7 +4,7 @@
 namespace SNES {
   namespace Info {
     static const char Name[] = "bsnes";
-    static const char Version[] = "082.13";
+    static const char Version[] = "082.14";
     static const unsigned SerializerVersion = 22;
   }
 }
diff --git a/bsnes/ui/Makefile b/bsnes/ui/Makefile
index cbaa3fac..f9354534 100755
--- a/bsnes/ui/Makefile
+++ b/bsnes/ui/Makefile
@@ -4,7 +4,7 @@ include $(gameboy)/Makefile
 name := batch
 
 ui_objects := ui-main ui-config ui-interface ui-utility
-ui_objects += ui-general ui-tools
+ui_objects += ui-general ui-settings ui-tools
 ui_objects += phoenix ruby
 ui_objects += $(if $(call streq,$(platform),win),resource)
 
@@ -72,6 +72,7 @@ obj/ui-config.o: $(ui)/config/config.cpp $(call rwildcard,$(ui)/)
 obj/ui-interface.o: $(ui)/interface/interface.cpp $(call rwildcard,$(ui)/)
 obj/ui-utility.o: $(ui)/utility/utility.cpp $(call rwildcard,$(ui)/)
 obj/ui-general.o: $(ui)/general/general.cpp $(call rwildcard,$(ui)/)
+obj/ui-settings.o: $(ui)/settings/settings.cpp $(call rwildcard,$(ui)/)
 obj/ui-tools.o: $(ui)/tools/tools.cpp $(call rwildcard,$(ui)/)
 
 obj/ruby.o: ruby/ruby.cpp $(call rwildcard,ruby/*)
diff --git a/bsnes/ui/base.hpp b/bsnes/ui/base.hpp
index a0a7e652..64dca409 100755
--- a/bsnes/ui/base.hpp
+++ b/bsnes/ui/base.hpp
@@ -23,6 +23,7 @@ using namespace ruby;
 #include "interface/interface.hpp"
 #include "utility/utility.hpp"
 #include "general/general.hpp"
+#include "settings/settings.hpp"
 #include "tools/tools.hpp"
 
 struct Application {
diff --git a/bsnes/ui/general/main-window.cpp b/bsnes/ui/general/main-window.cpp
index 7ebf1759..853ceb99 100755
--- a/bsnes/ui/general/main-window.cpp
+++ b/bsnes/ui/general/main-window.cpp
@@ -30,6 +30,7 @@ MainWindow::MainWindow() {
     settingsSynchronizeAudio.setText("Synchronize Audio");
     settingsSynchronizeAudio.setChecked();
     settingsMuteAudio.setText("Mute Audio");
+    settingsConfiguration.setText("Configuration ...");
 
   toolsMenu.setText("Tools");
     toolsStateSave.setText("Save State");
@@ -78,6 +79,8 @@ MainWindow::MainWindow() {
     settingsMenu.append(settingsSynchronizeVideo);
     settingsMenu.append(settingsSynchronizeAudio);
     settingsMenu.append(settingsMuteAudio);
+    settingsMenu.append(settingsSeparator);
+    settingsMenu.append(settingsConfiguration);
 
   append(toolsMenu);
     toolsMenu.append(toolsStateSave);
@@ -155,6 +158,8 @@ MainWindow::MainWindow() {
     dspaudio.setVolume(settingsMuteAudio.checked() ? 0.0 : 1.0);
   };
 
+  settingsConfiguration.onTick = [&] { settingsWindow->setVisible(); };
+
   toolsStateSave1.onTick = [&] { interface->saveState({ interface->baseName, "-1.bst" }); };
   toolsStateSave2.onTick = [&] { interface->saveState({ interface->baseName, "-2.bst" }); };
   toolsStateSave3.onTick = [&] { interface->saveState({ interface->baseName, "-3.bst" }); };
diff --git a/bsnes/ui/general/main-window.hpp b/bsnes/ui/general/main-window.hpp
index 7c13432e..aae23f66 100755
--- a/bsnes/ui/general/main-window.hpp
+++ b/bsnes/ui/general/main-window.hpp
@@ -28,6 +28,8 @@ struct MainWindow : Window {
     CheckItem settingsSynchronizeVideo;
     CheckItem settingsSynchronizeAudio;
     CheckItem settingsMuteAudio;
+    Separator settingsSeparator;
+    Item settingsConfiguration;
 
   Menu toolsMenu;
     Menu toolsStateSave;
diff --git a/bsnes/ui/interface/gameboy.cpp b/bsnes/ui/interface/gameboy.cpp
index b18bf2c8..e51872fa 100755
--- a/bsnes/ui/interface/gameboy.cpp
+++ b/bsnes/ui/interface/gameboy.cpp
@@ -53,11 +53,11 @@ void InterfaceGameBoy::videoRefresh(const uint8_t *data) {
 }
 
 void InterfaceGameBoy::audioSample(int16_t csample, int16_t lsample, int16_t rsample) {
-  dspaudio.sample(lsample, rsample);
+  signed samples[] = { lsample, rsample };
+  dspaudio.sample(samples);
   while(dspaudio.pending()) {
-    signed lsample, rsample;
-    dspaudio.read(lsample, rsample);
-    audio.sample(lsample, rsample);
+    dspaudio.read(samples);
+    audio.sample(samples[0], samples[1]);
   }
 }
 
diff --git a/bsnes/ui/interface/nes.cpp b/bsnes/ui/interface/nes.cpp
index 8971655c..27f7489e 100755
--- a/bsnes/ui/interface/nes.cpp
+++ b/bsnes/ui/interface/nes.cpp
@@ -36,11 +36,11 @@ void InterfaceNES::videoRefresh(const uint16_t *data) {
 }
 
 void InterfaceNES::audioSample(int16_t sample) {
-  dspaudio.sample(sample, sample);
+  signed samples[] = { sample };
+  dspaudio.sample(samples);
   while(dspaudio.pending()) {
-    signed lsample, rsample;
-    dspaudio.read(lsample, rsample);
-    audio.sample(lsample, rsample);
+    dspaudio.read(samples);
+    audio.sample(samples[0], samples[0]);  //NES audio output is monaural; ruby only takes stereo audio
   }
 }
 
diff --git a/bsnes/ui/interface/snes.cpp b/bsnes/ui/interface/snes.cpp
index 85732a35..16958553 100755
--- a/bsnes/ui/interface/snes.cpp
+++ b/bsnes/ui/interface/snes.cpp
@@ -69,11 +69,11 @@ void InterfaceSNES::videoRefresh(const uint16_t *data, bool hires, bool interlac
 }
 
 void InterfaceSNES::audioSample(int16_t lsample, int16_t rsample) {
-  dspaudio.sample(lsample, rsample);
+  signed samples[] = { lsample, rsample };
+  dspaudio.sample(samples);
   while(dspaudio.pending()) {
-    signed lsample, rsample;
-    dspaudio.read(lsample, rsample);
-    audio.sample(lsample, rsample);
+    dspaudio.read(samples);
+    audio.sample(samples[0], samples[1]);
   }
 }
 
diff --git a/bsnes/ui/main.cpp b/bsnes/ui/main.cpp
index f5c380b8..a8dd6ebd 100755
--- a/bsnes/ui/main.cpp
+++ b/bsnes/ui/main.cpp
@@ -41,6 +41,7 @@ Application::Application(int argc, char **argv) : quit(false) {
 
   mainWindow = new MainWindow;
   fileBrowser = new FileBrowser;
+  settingsWindow = new SettingsWindow;
   cheatEditor = new CheatEditor;
   stateManager = new StateManager;
   utility->setMode(Interface::Mode::None);
@@ -82,6 +83,7 @@ Application::Application(int argc, char **argv) : quit(false) {
 Application::~Application() {
   delete stateManager;
   delete cheatEditor;
+  delete settingsWindow;
   delete fileBrowser;
   delete mainWindow;
   delete utility;
diff --git a/bsnes/ui/settings/settings.cpp b/bsnes/ui/settings/settings.cpp
new file mode 100755
index 00000000..ffd8b535
--- /dev/null
+++ b/bsnes/ui/settings/settings.cpp
@@ -0,0 +1,7 @@
+#include "../base.hpp"
+SettingsWindow *settingsWindow = 0;
+
+SettingsWindow::SettingsWindow() {
+  setTitle("Configuration Settings");
+  setGeometry({ 128, 128, 640, 360 });
+}
diff --git a/bsnes/ui/settings/settings.hpp b/bsnes/ui/settings/settings.hpp
new file mode 100755
index 00000000..0ed081f8
--- /dev/null
+++ b/bsnes/ui/settings/settings.hpp
@@ -0,0 +1,5 @@
+struct SettingsWindow : Window {
+  SettingsWindow();
+};
+
+extern SettingsWindow *settingsWindow;
diff --git a/bsnes/ui/utility/utility.cpp b/bsnes/ui/utility/utility.cpp
index 402860d2..e5733bd0 100755
--- a/bsnes/ui/utility/utility.cpp
+++ b/bsnes/ui/utility/utility.cpp
@@ -18,18 +18,21 @@ void Utility::setMode(Interface::Mode mode) {
   else if(mode == Interface::Mode::NES) {
     mainWindow->setTitle({ notdir(interface->baseName), " - ", NES::Info::Name, " v", NES::Info::Version });
     mainWindow->nesMenu.setVisible(true);
+    dspaudio.setChannels(1);
     dspaudio.setFrequency(315.0 / 88.8 * 6000000.0 / 12.0);
   }
 
   else if(mode == Interface::Mode::SNES) {
     mainWindow->setTitle({ notdir(interface->baseName), " - ", SNES::Info::Name, " v", SNES::Info::Version });
     mainWindow->snesMenu.setVisible(true);
+    dspaudio.setChannels(2);
     dspaudio.setFrequency(32040.0);
   }
 
   else if(mode == Interface::Mode::GameBoy) {
     mainWindow->setTitle({ notdir(interface->baseName), " - ", GameBoy::Info::Name, " v", GameBoy::Info::Version });
     mainWindow->gameBoyMenu.setVisible(true);
+    dspaudio.setChannels(2);
     dspaudio.setFrequency(4194304.0);
   }