Update to v082r22 release.

byuu says:

Mappers are now optionally threaded.
Fixed up MMC3 emulation, SMB3 and MM3-6 are all fully playable. However,
many unusual variants of this chip are not supported still.
Added UNROM+UOROM for Contra and MM1, allowing all six MM games to play
now.
Added VRC6 with sound emulation, because I wanted to get audio mixing in
place.

Chose VRC6 because it has Esper Dream 2, which is an absolutely amazing
game that everyone should play :D
The game didn't use sawtooth, and I didn't test any other VRC6 games, so
hopefully that is emulated passably well enough.

bsnes/nes/apu/apu.cpp

@@ -47,7 +47,7 @@ void APU::main() {
     clock_frame_counter_divider();
 
     signed output = rectangle_dac[rectangle_output] + dmc_triangle_noise_dac[dmc_output][triangle_output][noise_output];
-    interface->audioSample(output);
+    interface->audioSample(output + cartridge_sample);
 
     tick();
   }
@@ -62,6 +62,10 @@ void APU::set_irq_line() {
   cpu.set_irq_apu_line(frame.irq_pending || dmc.irq_pending);
 }
 
+void APU::set_sample(int16 sample) {
+  cartridge_sample = sample;
+}
+
 void APU::power() {
   for(unsigned n = 0; n < 2; n++) {
     rectangle[n].sweep.shift = 0;
@@ -144,6 +148,8 @@ void APU::reset() {
   frame.divider = 1;
 
   enabled_channels = 0;
+  cartridge_sample = 0;
+
   set_irq_line();
 }
 

bsnes/nes/apu/apu.hpp

@@ -3,6 +3,7 @@ struct APU : Processor {
   void main();
   void tick();
   void set_irq_line();
+  void set_sample(int16 sample);
 
   void power();
   void reset();
@@ -139,6 +140,7 @@ struct APU : Processor {
   void clock_frame_counter_divider();
 
   uint8 enabled_channels;
+  int16 cartridge_sample;
 
   int16 rectangle_dac[32];
   int16 dmc_triangle_noise_dac[128][16][16];

bsnes/nes/apu/serialization.cpp

@@ -8,6 +8,7 @@ void APU::serialize(serializer &s) {
   frame.serialize(s);
 
   s.integer(enabled_channels);
+  s.integer(cartridge_sample);
 }
 
 void APU::Envelope::serialize(serializer &s) {

bsnes/nes/cartridge/cartridge.cpp

@@ -4,6 +4,14 @@ namespace NES {
 
 Cartridge cartridge;
 
+void Cartridge::Main() {
+  cartridge.main();
+}
+
+void Cartridge::main() {
+  mapper->main();
+}
+
 void Cartridge::load(const string &xml, const uint8_t *data, unsigned size) {
   rom_size = size - 16;
   rom_data = new uint8[rom_size];
@@ -31,10 +39,13 @@ void Cartridge::load(const string &xml, const uint8_t *data, unsigned size) {
   switch(mapperNumber) {
   default : mapper = &Mapper::none; break;
   case   1: mapper = &Mapper::mmc1; break;
+  case   2: mapper = &Mapper::uorom; break;
   case   3: mapper = &Mapper::cnrom; break;
   case   4: mapper = &Mapper::mmc3; break;
   case   7: mapper = &Mapper::aorom; break;
   case  16: mapper = &Mapper::bandaiFCG; break;
+  case  24: mapper = &Mapper::vrc6; Mapper::vrc6.abus_swap = 0; break;
+  case  26: mapper = &Mapper::vrc6; Mapper::vrc6.abus_swap = 1; break;
   }
 
   system.load();
@@ -61,10 +72,12 @@ uint8* Cartridge::ram_data() {
 }
 
 void Cartridge::power() {
+  create(Cartridge::Main, 21477272);
   mapper->power();
 }
 
 void Cartridge::reset() {
+  create(Cartridge::Main, 21477272);
   mapper->reset();
 }
 

bsnes/nes/cartridge/cartridge.hpp

@@ -1,4 +1,7 @@
-struct Cartridge : property<Cartridge> {
+struct Cartridge : Processor, property<Cartridge> {
+  static void Main();
+  void main();
+
   void load(const string &xml, const uint8_t *data, unsigned size);
   void unload();
 

bsnes/nes/cpu/cpu.cpp

@@ -40,6 +40,9 @@ void CPU::add_clocks(unsigned clocks) {
 
   ppu.clock -= clocks;
   if(ppu.clock < 0 && scheduler.sync != Scheduler::SynchronizeMode::All) co_switch(ppu.thread);
+
+  cartridge.clock -= clocks;
+  if(cartridge.clock < 0 && scheduler.sync != Scheduler::SynchronizeMode::All) co_switch(cartridge.thread);
 }
 
 void CPU::power() {

bsnes/nes/mapper/bandai-fcg/bandai-fcg.cpp

@@ -1,8 +1,23 @@
 BandaiFCG bandaiFCG;
 
-uint8 BandaiFCG::prg_read(uint16 addr) {
-  clock();
+void BandaiFCG::main() {
+  while(true) {
+    if(scheduler.sync == Scheduler::SynchronizeMode::All) {
+      scheduler.exit(Scheduler::ExitReason::SynchronizeEvent);
+    }
 
+    if(irq_counter_enable) {
+      if(--irq_counter == 0xffff) {
+        cpu.set_irq_line(1);
+        irq_counter_enable = false;
+      }
+    }
+
+    tick();
+  }
+}
+
+uint8 BandaiFCG::prg_read(uint16 addr) {
   if(addr >= 0x8000 && addr <= 0xbfff) {
     unsigned rom_addr = (prg_bank << 14) | (addr & 0x3fff);
     return cartridge.prg_data[mirror(rom_addr, cartridge.prg_size)];
@@ -17,8 +32,6 @@ uint8 BandaiFCG::prg_read(uint16 addr) {
 }
 
 void BandaiFCG::prg_write(uint16 addr, uint8 data) {
-  clock();
-
   if(addr >= 0x6000) {
     addr &= 0x0f;
     switch(addr) {
@@ -95,15 +108,6 @@ unsigned BandaiFCG::ciram_addr(unsigned addr) const {
   throw;
 }
 
-void BandaiFCG::clock() {
-  if(irq_counter_enable) {
-    if(--irq_counter == 0xffff) {
-      cpu.set_irq_line(1);
-      irq_counter_enable = false;
-    }
-  }
-}
-
 //
 
 void BandaiFCG::serialize(serializer &s) {

bsnes/nes/mapper/bandai-fcg/bandai-fcg.hpp

@@ -1,4 +1,6 @@
 struct BandaiFCG : Mapper {
+  void main();
+
   uint8 prg_read(uint16 addr);
   void prg_write(uint16 addr, uint8 data);
 
@@ -15,7 +17,6 @@ struct BandaiFCG : Mapper {
 
 private:
   unsigned ciram_addr(unsigned addr) const;
-  void clock();
 
   uint8 chr_bank[8];
   uint8 prg_bank;

bsnes/nes/mapper/mapper.cpp

@@ -1,48 +1,66 @@
 #include <nes/nes.hpp>
 
 namespace NES {
-
 namespace Mapper {
-  unsigned Mapper::mirror(unsigned addr, unsigned size) const {
-    unsigned base = 0;
-    if(size) {
-      unsigned mask = 1 << 23;
-      while(addr >= size) {
-        while(!(addr & mask)) mask >>= 1;
-        addr -= mask;
-        if(size > mask) {
-          size -= mask;
-          base += mask;
-        }
-        mask >>= 1;
-      }
-      base += addr;
+
+void Mapper::main() {
+  while(true) {
+    if(scheduler.sync == Scheduler::SynchronizeMode::All) {
+      scheduler.exit(Scheduler::ExitReason::SynchronizeEvent);
     }
-    return base;
-  }
 
-  uint8& Mapper::prg_data(unsigned addr) {
-    return cartridge.prg_data[mirror(addr, cartridge.prg_size)];
+    cartridge.clock += 12 * 4095;
+    tick();
   }
-
-  uint8& Mapper::chr_data(unsigned addr) {
-    return cartridge.chr_data[mirror(addr, cartridge.chr_size)];
-  }
-
-  unsigned Mapper::ram_size() {
-    return 0u;
-  }
-
-  uint8* Mapper::ram_data() {
-    return 0;
-  }
-
-  #include "none/none.cpp"
-  #include "aorom/aorom.cpp"
-  #include "bandai-fcg/bandai-fcg.cpp"
-  #include "cnrom/cnrom.cpp"
-  #include "mmc1/mmc1.cpp"
-  #include "mmc3/mmc3.cpp"
 }
 
+void Mapper::tick() {
+  cartridge.clock += 12;
+  if(cartridge.clock >= 0 && scheduler.sync != Scheduler::SynchronizeMode::All) co_switch(cpu.thread);
+}
+
+unsigned Mapper::mirror(unsigned addr, unsigned size) const {
+  unsigned base = 0;
+  if(size) {
+    unsigned mask = 1 << 23;
+    while(addr >= size) {
+      while(!(addr & mask)) mask >>= 1;
+      addr -= mask;
+      if(size > mask) {
+        size -= mask;
+        base += mask;
+      }
+      mask >>= 1;
+    }
+    base += addr;
+  }
+  return base;
+}
+
+uint8& Mapper::prg_data(unsigned addr) {
+  return cartridge.prg_data[mirror(addr, cartridge.prg_size)];
+}
+
+uint8& Mapper::chr_data(unsigned addr) {
+  return cartridge.chr_data[mirror(addr, cartridge.chr_size)];
+}
+
+unsigned Mapper::ram_size() {
+  return 0u;
+}
+
+uint8* Mapper::ram_data() {
+  return 0;
+}
+
+#include "none/none.cpp"
+#include "aorom/aorom.cpp"
+#include "bandai-fcg/bandai-fcg.cpp"
+#include "cnrom/cnrom.cpp"
+#include "mmc1/mmc1.cpp"
+#include "mmc3/mmc3.cpp"
+#include "uorom/uorom.cpp"
+#include "vrc6/vrc6.cpp"
+
+}
 }

bsnes/nes/mapper/mapper.hpp

@@ -1,5 +1,8 @@
 namespace Mapper {
   struct Mapper {
+    virtual void main();
+    virtual void tick();
+
     unsigned mirror(unsigned addr, unsigned size) const;
     uint8& prg_data(unsigned addr);
     uint8& chr_data(unsigned addr);
@@ -28,4 +31,6 @@ namespace Mapper {
   #include "cnrom/cnrom.hpp"
   #include "mmc1/mmc1.hpp"
   #include "mmc3/mmc3.hpp"
+  #include "uorom/uorom.hpp"
+  #include "vrc6/vrc6.hpp"
 }

bsnes/nes/mapper/mmc1/mmc1.hpp

@@ -9,7 +9,7 @@ struct MMC1 : Mapper {
   void ciram_write(uint13 addr, uint8 data);
 
   unsigned ram_size();
-  uint8 *ram_data();
+  uint8* ram_data();
 
   void power();
   void reset();

bsnes/nes/mapper/mmc3/mmc3.cpp

@@ -1,24 +1,34 @@
 MMC3 mmc3;
 
-void MMC3::clock_irq_test(uint16 addr) {
-  if(!(last_chr_addr & 0x1000) && (addr & 0x1000)) {
+void MMC3::main() {
+  while(true) {
+    if(scheduler.sync == Scheduler::SynchronizeMode::All) {
+      scheduler.exit(Scheduler::ExitReason::SynchronizeEvent);
+    }
+
+    if(irq_delay) irq_delay--;
+    cpu.set_irq_line(irq_line);
+    tick();
+  }
+}
+
+void MMC3::irq_test(uint16 addr) {
+  if(!(chr_abus & 0x1000) && (addr & 0x1000)) {
     if(irq_delay == 0) {
       if(irq_counter == 0) {
         irq_counter = irq_latch;
-        irq_line = irq_enable;
-        cpu.set_irq_line(irq_line);
+      } else if(--irq_counter == 0) {
+        if(irq_enable) irq_line = 1;
       }
-      irq_counter--;
     }
-    irq_delay = 5;
+    irq_delay = 6;
   }
-
-  last_chr_addr = addr;
+  chr_abus = addr;
 }
 
 unsigned MMC3::prg_addr(uint16 addr) {
   if((addr & 0xe000) == 0x8000) {
-    if((bank_select & 0x40) == 1) return (0x3e << 13) | (addr & 0x1fff);
+    if((bank_select & 0x40) != 0) return (0x3e << 13) | (addr & 0x1fff);
     return (prg_bank[0] << 13) | (addr & 0x1fff);
   }
 
@@ -39,8 +49,6 @@ unsigned MMC3::prg_addr(uint16 addr) {
 }
 
 uint8 MMC3::prg_read(uint16 addr) {
-  if(irq_delay) irq_delay--;
-
   if((addr & 0xe000) == 0x6000) {  //$6000-7fff
     if(prg_ram_enable) {
       return prg_ram[addr & 0x1fff];
@@ -55,8 +63,6 @@ uint8 MMC3::prg_read(uint16 addr) {
 }
 
 void MMC3::prg_write(uint16 addr, uint8 data) {
-  if(irq_delay) irq_delay--;
-
   if((addr & 0xe000) == 0x6000) {  //$6000-7fff
     if(prg_ram_enable && prg_ram_write_protect == false) {
       prg_ram[addr & 0x1fff] = data;
@@ -133,26 +139,25 @@ unsigned MMC3::chr_addr(uint16 addr) {
 }
 
 uint8 MMC3::chr_read(uint16 addr) {
-  clock_irq_test(addr);
+  irq_test(addr);
   return chr_data(chr_addr(addr));
 }
 
 void MMC3::chr_write(uint16 addr, uint8 data) {
-  clock_irq_test(addr);
-  last_chr_addr = addr;
+  irq_test(addr);
   if(cartridge.chr_ram == false) return;
   chr_data(chr_addr(addr)) = data;
 }
 
 unsigned MMC3::ciram_addr(uint13 addr) {
-  clock_irq_test(0x2000 | addr);
+  irq_test(0x2000 | addr);
   if(mirror_select == 0) return ((addr & 0x0400) >> 0) | (addr & 0x03ff);
   if(mirror_select == 1) return ((addr & 0x0800) >> 1) | (addr & 0x03ff);
   throw;
 }
 
 uint8 MMC3::ciram_read(uint13 addr) {
-  clock_irq_test(0x2000 | addr);
+  irq_test(0x2000 | addr);
   return ppu.ciram_read(ciram_addr(addr));
 }
 
@@ -194,7 +199,24 @@ void MMC3::reset() {
   irq_enable = false;
   irq_delay = 0;
   irq_line = 0;
+
+  chr_abus = 0;
 }
 
 void MMC3::serialize(serializer &s) {
+  s.array(prg_ram);
+
+  s.integer(bank_select);
+  s.array(prg_bank);
+  s.array(chr_bank);
+  s.integer(mirror_select);
+  s.integer(prg_ram_enable);
+  s.integer(prg_ram_write_protect);
+  s.integer(irq_latch);
+  s.integer(irq_counter);
+  s.integer(irq_enable);
+  s.integer(irq_delay);
+  s.integer(irq_line);
+
+  s.integer(chr_abus);
 }

bsnes/nes/mapper/mmc3/mmc3.hpp

@@ -1,4 +1,6 @@
 struct MMC3 : Mapper {
+  void main();
+
   uint8 prg_read(uint16 addr);
   void prg_write(uint16 addr, uint8 data);
 
@@ -31,12 +33,12 @@ private:
   unsigned irq_delay;
   bool irq_line;
 
-  uint16 last_chr_addr;
+  uint16 chr_abus;
 
+  void irq_test(uint16 addr);
   unsigned prg_addr(uint16 addr);
   unsigned chr_addr(uint16 addr);
   unsigned ciram_addr(uint13 addr);
-  void clock_irq_test(uint16 addr);
 };
 
 extern MMC3 mmc3;

bsnes/nes/mapper/uorom/uorom.cpp

@@ -0,0 +1,46 @@
+UOROM uorom;
+
+uint8 UOROM::prg_read(uint16 addr) {
+  if((addr & 0xc000) == 0x8000) {
+    return prg_data((prg_bank << 14) | (addr & 0x3fff));
+  }
+
+  if((addr & 0xc000) == 0xc000) {
+    return prg_data((0x0f << 14) | (addr & 0x3fff));
+  }
+}
+
+void UOROM::prg_write(uint16 addr, uint8 data) {
+  if(addr & 0x8000) prg_bank = data & 0x0f;
+}
+
+uint8 UOROM::chr_read(uint16 addr) {
+  return chr_data(addr);
+}
+
+void UOROM::chr_write(uint16 addr, uint8 data) {
+  if(cartridge.chr_ram == false) return;
+  chr_data(addr) = data;
+}
+
+uint8 UOROM::ciram_read(uint13 addr) {
+  if(cartridge.mirroring == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff);
+  return ppu.ciram_read(addr);
+}
+
+void UOROM::ciram_write(uint13 addr, uint8 data) {
+  if(cartridge.mirroring == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff);
+  return ppu.ciram_write(addr, data);
+}
+
+void UOROM::power() {
+  reset();
+}
+
+void UOROM::reset() {
+  prg_bank = 0;
+}
+
+void UOROM::serialize(serializer &s) {
+  s.integer(prg_bank);
+}

bsnes/nes/mapper/uorom/uorom.hpp

@@ -0,0 +1,20 @@
+struct UOROM : Mapper {
+  uint8 prg_read(uint16 addr);
+  void prg_write(uint16 addr, uint8 data);
+
+  uint8 chr_read(uint16 addr);
+  void chr_write(uint16 addr, uint8 data);
+
+  uint8 ciram_read(uint13 addr);
+  void ciram_write(uint13 addr, uint8 data);
+
+  void power();
+  void reset();
+
+  void serialize(serializer&);
+
+private:
+  uint4 prg_bank;
+};
+
+extern UOROM uorom;

bsnes/nes/mapper/vrc6/vrc6.cpp

@@ -0,0 +1,342 @@
+VRC6 vrc6;
+
+//
+
+void VRC6::Pulse::clock() {
+  if(--divider == 0) {
+    divider = frequency;
+    cycle++;
+    output = (mode == 1 || cycle < duty) ? volume : (uint4)0;
+  }
+
+  if(enable == false) output = 0;
+}
+
+void VRC6::Pulse::serialize(serializer &s) {
+  s.integer(mode);
+  s.integer(duty);
+  s.integer(volume);
+  s.integer(enable);
+  s.integer(frequency);
+
+  s.integer(divider);
+  s.integer(cycle);
+  s.integer(output);
+}
+
+VRC6::Pulse::Pulse() {
+  for(unsigned n = 0; n < 16; n++) {
+    dac[n] = -15360 + (n * 2048);
+  }
+}
+
+//
+
+void VRC6::Sawtooth::clock() {
+  if(--divider == 0) {
+    divider = frequency;
+    if(phase == 0) {
+      phase = 0;
+      accumulator = 0;
+    } else if((phase & 1) == 0) {
+      accumulator += rate;
+    }
+  }
+
+  output = accumulator >> 3;
+  if(enable == false) output = 0;
+}
+
+void VRC6::Sawtooth::serialize(serializer &s) {
+  s.integer(rate);
+  s.integer(enable);
+  s.integer(frequency);
+
+  s.integer(divider);
+  s.integer(phase);
+  s.integer(accumulator);
+  s.integer(output);
+}
+
+VRC6::Sawtooth::Sawtooth() {
+  for(unsigned n = 0; n < 32; n++) {
+    dac[n] = -15872 + (n * 1024);
+  }
+}
+
+//
+
+void VRC6::main() {
+  while(true) {
+    if(scheduler.sync == Scheduler::SynchronizeMode::All) {
+      scheduler.exit(Scheduler::ExitReason::SynchronizeEvent);
+    }
+
+    if(irq_enable) {
+      if(irq_mode == 0) {
+        irq_scalar -= 3;
+        if(irq_scalar <= 0) {
+          irq_scalar += 341;
+          if(irq_counter == 0xff) {
+            irq_counter = irq_latch;
+            irq_line = 1;
+          } else {
+            irq_counter++;
+          }
+        }
+      }
+
+      if(irq_mode == 1) {
+        if(irq_counter == 0xff) {
+          irq_counter = irq_latch;
+          irq_line = 1;
+        } else {
+          irq_counter++;
+        }
+      }
+    }
+
+    pulse1.clock();
+    pulse2.clock();
+    sawtooth.clock();
+
+    signed output = 0;
+    output +=   pulse1.dac[  pulse1.output];
+    output +=   pulse2.dac[  pulse2.output];
+    output += sawtooth.dac[sawtooth.output];
+    output /= 6;  //div by 3 for channel count; div that by 2 to match NES volume intensity
+    output = sclamp<16>(output);
+
+    apu.set_sample(output);
+    cpu.set_irq_line(irq_line);
+    tick();
+  }
+}
+
+uint8 VRC6::prg_read(uint16 addr) {
+  if((addr & 0xe000) == 0x6000) {
+    return prg_ram[addr & 0x1fff];
+  }
+
+  if((addr & 0xc000) == 0x8000) {
+    return prg_data((prg_bank[0] << 14) | (addr & 0x3fff));
+  }
+
+  if((addr & 0xe000) == 0xc000) {
+    return prg_data((prg_bank[1] << 13) | (addr & 0x1fff));
+  }
+
+  if((addr & 0xe000) == 0xe000) {
+    return prg_data((0xff << 13) | (addr & 0x1fff));
+  }
+
+  return cpu.mdr();
+}
+
+void VRC6::prg_write(uint16 addr, uint8 data) {
+  if((addr & 0xe000) == 0x6000) {
+    prg_ram[addr & 0x1fff] = data;
+    return;
+  }
+
+  addr = (addr & 0xf003);
+  if(abus_swap) addr = (addr & ~3) | ((addr & 2) >> 1) | ((addr & 1) << 1);
+
+  switch(addr) {
+  case 0x8000: case 0x8001: case 0x8002: case 0x8003:
+    prg_bank[0] = data;
+    break;
+
+  case 0x9000:
+    pulse1.mode = data & 0x80;
+    pulse1.duty = (data & 0x70) >> 4;
+    pulse1.volume = data & 0x0f;
+    break;
+
+  case 0x9001:
+    pulse1.frequency = (pulse1.frequency & 0x0f00) | ((data & 0xff) << 0);
+    break;
+
+  case 0x9002:
+    pulse1.frequency = (pulse1.frequency & 0x00ff) | ((data & 0x0f) << 8);
+    pulse1.enable = data & 0x80;
+    break;
+
+  case 0xa000:
+    pulse2.mode = data & 0x80;
+    pulse2.duty = (data & 0x70) >> 4;
+    pulse2.volume = data & 0x0f;
+    break;
+
+  case 0xa001:
+    pulse2.frequency = (pulse2.frequency & 0x0f00) | ((data & 0xff) << 0);
+    break;
+
+  case 0xa002:
+    pulse2.frequency = (pulse2.frequency & 0x00ff) | ((data & 0x0f) << 8);
+    pulse2.enable = data & 0x80;
+    break;
+
+  case 0xb000:
+    sawtooth.rate = data & 0x3f;
+    break;
+
+  case 0xb001:
+    sawtooth.frequency = (sawtooth.frequency & 0x0f00) | ((data & 0xff) << 0);
+    break;
+
+  case 0xb002:
+    sawtooth.frequency = (sawtooth.frequency & 0x00ff) | ((data & 0x0f) << 8);
+    sawtooth.enable = data & 0x80;
+    break;
+
+  case 0xb003:
+    mirror_select = (data >> 2) & 3;
+    break;
+
+  case 0xc000: case 0xc001: case 0xc002: case 0xc003:
+    prg_bank[1] = data;
+    break;
+
+  case 0xd000: case 0xd001: case 0xd002: case 0xd003:
+    chr_bank[0 + (addr & 3)] = data;
+    break;
+
+  case 0xe000: case 0xe001: case 0xe002: case 0xe003:
+    chr_bank[4 + (addr & 3)] = data;
+    break;
+
+  case 0xf000:
+    irq_latch = data;
+    break;
+
+  case 0xf001:
+    irq_mode = data & 0x04;
+    irq_enable = data & 0x02;
+    irq_acknowledge = data & 0x01;
+    if(irq_enable) {
+      irq_counter = irq_latch;
+      irq_scalar = 341;
+    }
+    irq_line = 0;
+    break;
+
+  case 0xf002:
+    irq_enable = irq_acknowledge;
+    irq_line = 0;
+    break;
+  }
+}
+
+uint8 VRC6::chr_read(uint16 addr) {
+  unsigned bank = chr_bank[(addr >> 10) & 7];
+  return chr_data((bank << 10) | (addr & 0x03ff));
+}
+
+void VRC6::chr_write(uint16 addr, uint8 data) {
+  if(cartridge.chr_ram == false) return;
+  unsigned bank = chr_bank[(addr >> 10) & 7];
+  chr_data((bank << 10) | (addr & 0x03ff)) = data;
+}
+
+unsigned VRC6::ciram_addr(unsigned addr) const {
+  switch(mirror_select) {
+  case 0: return ((addr & 0x0400) >> 0) | (addr & 0x03ff);  //vertical mirroring
+  case 1: return ((addr & 0x0800) >> 1) | (addr & 0x03ff);  //horizontal mirroring
+  case 2: return 0x0000 | (addr & 0x03ff);                  //one-screen mirroring (first)
+  case 3: return 0x0400 | (addr & 0x03ff);                  //one-screen mirroring (second)
+  }
+}
+
+uint8 VRC6::ciram_read(uint13 addr) {
+  return ppu.ciram_read(ciram_addr(addr));
+}
+
+void VRC6::ciram_write(uint13 addr, uint8 data) {
+  return ppu.ciram_write(ciram_addr(addr), data);
+}
+
+unsigned VRC6::ram_size() {
+  return 8192u;
+}
+
+uint8* VRC6::ram_data() {
+  return prg_ram;
+}
+
+void VRC6::power() {
+  reset();
+}
+
+void VRC6::reset() {
+  foreach(n, prg_ram) n = 0xff;
+
+  prg_bank[0] = 0;
+  prg_bank[1] = 0;
+  chr_bank[0] = 0;
+  chr_bank[1] = 0;
+  chr_bank[2] = 0;
+  chr_bank[3] = 0;
+  chr_bank[4] = 0;
+  chr_bank[5] = 0;
+  chr_bank[6] = 0;
+  chr_bank[7] = 0;
+  mirror_select = 0;
+  irq_latch = 0;
+  irq_mode = 0;
+  irq_enable = 0;
+  irq_acknowledge = 0;
+
+  irq_counter = 0;
+  irq_scalar = 0;
+  irq_line = 0;
+
+  pulse1.mode = 0;
+  pulse1.duty = 0;
+  pulse1.volume = 0;
+  pulse1.enable = 0;
+  pulse1.frequency = 0;
+
+  pulse1.divider = 0;
+  pulse1.cycle = 0;
+  pulse1.output = 0;
+
+  pulse2.mode = 0;
+  pulse2.duty = 0;
+  pulse2.volume = 0;
+  pulse2.enable = 0;
+  pulse2.frequency = 0;
+
+  pulse2.divider = 0;
+  pulse2.cycle = 0;
+  pulse2.output = 0;
+
+  sawtooth.rate = 0;
+  sawtooth.enable = 0;
+  sawtooth.frequency = 0;
+
+  sawtooth.divider = 0;
+  sawtooth.phase = 0;
+  sawtooth.accumulator = 0;
+  sawtooth.output = 0;
+}
+
+void VRC6::serialize(serializer &s) {
+  s.array(prg_ram);
+
+  s.array(prg_bank);
+  s.array(chr_bank);
+  s.integer(mirror_select);
+  s.integer(irq_latch);
+  s.integer(irq_mode);
+  s.integer(irq_enable);
+  s.integer(irq_acknowledge);
+
+  s.integer(irq_counter);
+  s.integer(irq_scalar);
+  s.integer(irq_line);
+
+  pulse1.serialize(s);
+  pulse2.serialize(s);
+  sawtooth.serialize(s);
+}

bsnes/nes/mapper/vrc6/vrc6.hpp

@@ -0,0 +1,75 @@
+struct VRC6 : Mapper {
+  void main();
+
+  uint8 prg_read(uint16 addr);
+  void prg_write(uint16 addr, uint8 data);
+
+  uint8 chr_read(uint16 addr);
+  void chr_write(uint16 addr, uint8 data);
+
+  uint8 ciram_read(uint13 addr);
+  void ciram_write(uint13 addr, uint8 data);
+
+  unsigned ram_size();
+  uint8* ram_data();
+
+  void power();
+  void reset();
+
+  void serialize(serializer&);
+
+//privileged:
+  bool abus_swap;
+
+private:
+  uint8 prg_ram[8192];
+
+  uint8 prg_bank[2];
+  uint8 chr_bank[8];
+  uint2 mirror_select;
+  uint8 irq_latch;
+  bool irq_mode;
+  bool irq_enable;
+  bool irq_acknowledge;
+
+  uint8 irq_counter;
+  signed irq_scalar;
+  bool irq_line;
+
+  struct Pulse {
+    bool mode;
+    uint3 duty;
+    uint4 volume;
+    bool enable;
+    uint12 frequency;
+
+    uint12 divider;
+    uint4 cycle;
+    uint4 output;
+    int16 dac[16];
+
+    void clock();
+    void serialize(serializer&);
+    Pulse();
+  } pulse1, pulse2;
+
+  struct Sawtooth {
+    uint6 rate;
+    bool enable;
+    uint12 frequency;
+
+    uint12 divider;
+    uint4 phase;
+    uint8 accumulator;
+    uint5 output;
+    int16 dac[32];
+
+    void clock();
+    void serialize(serializer&);
+    Sawtooth();
+  } sawtooth;
+
+  unsigned ciram_addr(unsigned addr) const;
+};
+
+extern VRC6 vrc6;

bsnes/nes/system/system.cpp

@@ -21,6 +21,10 @@ void System::runtosave() {
   scheduler.thread = apu.thread;
   runthreadtosave();
 
+  scheduler.sync = Scheduler::SynchronizeMode::All;
+  scheduler.thread = cartridge.thread;
+  runthreadtosave();
+
   scheduler.sync = Scheduler::SynchronizeMode::None;
 }
 

bsnes/ui/main.cpp

@@ -41,7 +41,7 @@ Application::Application(int argc, char **argv) {
   inputManager = new InputManager;
   utility = new Utility;
 
-  title = "bsnes v082.21";
+  title = "bsnes v082.22";
 
   #if defined(PLATFORM_WIN)
   normalFont = "Tahoma, 8";