diff --git a/higan/emulator/emulator.hpp b/higan/emulator/emulator.hpp
index 28f520ef..34cf8ee2 100644
--- a/higan/emulator/emulator.hpp
+++ b/higan/emulator/emulator.hpp
@@ -12,7 +12,7 @@ using namespace nall;
 
 namespace Emulator {
   static const string Name    = "higan";
-  static const string Version = "102.10";
+  static const string Version = "102.11";
   static const string Author  = "byuu";
   static const string License = "GPLv3";
   static const string Website = "http://byuu.org/";
diff --git a/higan/md/cartridge/cartridge.cpp b/higan/md/cartridge/cartridge.cpp
index fcf57089..7a1729e0 100644
--- a/higan/md/cartridge/cartridge.cpp
+++ b/higan/md/cartridge/cartridge.cpp
@@ -60,19 +60,28 @@ auto Cartridge::save() -> void {
 auto Cartridge::unload() -> void {
   delete[] rom.data;
   delete[] ram.data;
-  rom = Memory();
-  ram = Memory();
+  rom = {};
+  ram = {};
 }
 
 auto Cartridge::power() -> void {
 }
 
 auto Cartridge::read(uint24 addr) -> uint16 {
-  uint16 data = rom.data[addr + 0 & rom.mask] << 8;
-  return data | rom.data[addr + 1 & rom.mask] << 0;
+  if(addr.bit(21) && ram.size) {
+    uint16 data = ram.data[addr + 0 & ram.mask] << 8;
+    return data | ram.data[addr + 1 & ram.mask] << 0;
+  } else {
+    uint16 data = rom.data[addr + 0 & rom.mask] << 8;
+    return data | rom.data[addr + 1 & rom.mask] << 0;
+  }
 }
 
 auto Cartridge::write(uint24 addr, uint16 data) -> void {
+  if(addr.bit(21) && ram.size) {
+    ram.data[addr + 0 & ram.mask] = data >> 8;
+    ram.data[addr + 1 & ram.mask] = data >> 0;
+  }
 }
 
 }
diff --git a/higan/md/psg/io.cpp b/higan/md/psg/io.cpp
index d2c711a7..4752b908 100644
--- a/higan/md/psg/io.cpp
+++ b/higan/md/psg/io.cpp
@@ -29,6 +29,7 @@ auto PSG::write(uint8 data) -> void {
   case 4: {
     if(l) tone2.pitch.bits(0,3) = data.bits(0,3);
     else  tone2.pitch.bits(4,9) = data.bits(0,5);
+    noise.pitch = tone2.pitch;
     break;
   }
 
diff --git a/higan/md/psg/noise.cpp b/higan/md/psg/noise.cpp
index d416e30d..978ecc89 100644
--- a/higan/md/psg/noise.cpp
+++ b/higan/md/psg/noise.cpp
@@ -1,23 +1,22 @@
 auto PSG::Noise::run() -> void {
-  auto latch = clock;
+  if(--counter) return;
 
-  counter++;
-  if(rate == 0) output ^= !counter.bits(0,3);
-  if(rate == 1) output ^= !counter.bits(0,4);
-  if(rate == 2) output ^= !counter.bits(0,5);
-  if(rate == 3) output ^= psg.tone2.clock;
+  if(rate == 0) counter = 0x10;
+  if(rate == 1) counter = 0x20;
+  if(rate == 2) counter = 0x40;
+  if(rate == 3) counter = pitch;  //shared with tone2
 
-  if(!latch && clock) {
+  if(clock ^= 1) {  //0->1 transition
+    output = lfsr.bit(0);
     auto eor = enable ? ~lfsr >> 3 : 0;
     lfsr = (lfsr ^ eor) << 15 | lfsr >> 1;
   }
-
-  output = lfsr.bit(0);
 }
 
 auto PSG::Noise::power() -> void {
   volume = ~0;
   counter = 0;
+  pitch = 0;
   enable = 0;
   rate = 0;
   lfsr = 0x8000;
diff --git a/higan/md/psg/psg.cpp b/higan/md/psg/psg.cpp
index b57331ef..8e5a3da7 100644
--- a/higan/md/psg/psg.cpp
+++ b/higan/md/psg/psg.cpp
@@ -43,7 +43,7 @@ auto PSG::power() -> void {
   select = 0;
   lowpass = 0;
   for(auto n : range(15)) {
-    levels[n] = 0x3fff * pow(2, n * -2.0 / 6.0) + 0.5;
+    levels[n] = 0x2000 * pow(2, n * -2.0 / 6.0) + 0.5;
   }
   levels[15] = 0;
 
diff --git a/higan/md/psg/psg.hpp b/higan/md/psg/psg.hpp
index c9e802f8..8dcffda9 100644
--- a/higan/md/psg/psg.hpp
+++ b/higan/md/psg/psg.hpp
@@ -21,7 +21,6 @@ private:
     uint4  volume;
     uint10 counter;
     uint10 pitch;
-    uint1  clock;
     uint1  output;
   } tone0, tone1, tone2;
 
@@ -31,7 +30,8 @@ private:
     auto power() -> void;
 
     uint4  volume;
-    uint6  counter;
+    uint10 counter;
+    uint10 pitch;
     uint1  enable;
     uint2  rate;
     uint16 lfsr;
diff --git a/higan/md/psg/tone.cpp b/higan/md/psg/tone.cpp
index 052b1831..bae975d4 100644
--- a/higan/md/psg/tone.cpp
+++ b/higan/md/psg/tone.cpp
@@ -1,8 +1,6 @@
 auto PSG::Tone::run() -> void {
-  clock = 0;
   if(--counter) return;
 
-  clock = 1;
   counter = pitch;
   output ^= 1;
 }
@@ -11,6 +9,5 @@ auto PSG::Tone::power() -> void {
   volume = ~0;
   counter = 0;
   pitch = 0;
-  clock = 0;
   output = 0;
 }
diff --git a/higan/md/vdp/background.cpp b/higan/md/vdp/background.cpp
index 47f12fc7..7d1661d9 100644
--- a/higan/md/vdp/background.cpp
+++ b/higan/md/vdp/background.cpp
@@ -13,7 +13,7 @@ auto VDP::Background::updateHorizontalScroll(uint y) -> void {
   address += (y & mask[io.horizontalScrollMode]) << 1;
   address += id == ID::PlaneB;
 
-  state.horizontalScroll = vdp.vram[address].bits(0,9);
+  state.horizontalScroll = vdp.vram.read(address).bits(0,9);
 }
 
 auto VDP::Background::updateVerticalScroll(uint x, uint y) -> void {
@@ -22,7 +22,7 @@ auto VDP::Background::updateVerticalScroll(uint x, uint y) -> void {
   auto address = (x >> 4 & 0 - io.verticalScrollMode) << 1;
   address += id == ID::PlaneB;
 
-  state.verticalScroll = vdp.vsram[address];
+  state.verticalScroll = vdp.vsram.read(address);
 }
 
 auto VDP::Background::nametableAddress() -> uint15 {
@@ -62,13 +62,13 @@ auto VDP::Background::run(uint x, uint y) -> void {
   auto address = nametableAddress();
   address += (tileY * width + tileX) & 0x0fff;
 
-  uint16 tileAttributes = vdp.vram[address];
+  uint16 tileAttributes = vdp.vram.read(address);
   uint15 tileAddress = tileAttributes.bits(0,10) << 4;
   uint pixelX = (x & 7) ^ (tileAttributes.bit(11) ? 7 : 0);
   uint pixelY = (y & 7) ^ (tileAttributes.bit(12) ? 7 : 0);
   tileAddress += pixelY << 1 | pixelX >> 2;
 
-  uint16 tileData = vdp.vram[tileAddress];
+  uint16 tileData = vdp.vram.read(tileAddress);
   uint4 color = tileData >> (((pixelX & 3) ^ 3) << 2);
   if(color) {
     output.color = tileAttributes.bits(13,14) << 4 | color;
diff --git a/higan/md/vdp/dma.cpp b/higan/md/vdp/dma.cpp
index 082ebde1..73341728 100644
--- a/higan/md/vdp/dma.cpp
+++ b/higan/md/vdp/dma.cpp
@@ -1,9 +1,10 @@
 auto VDP::DMA::run() -> void {
   if(!io.enable || io.wait) return;
-  if(!vdp.io.command.bit(5)) return;
 
+  if(!vdp.io.command.bit(5)) return;
   if(io.mode <= 1) return load();
   if(io.mode == 2) return fill();
+  if(!vdp.io.command.bit(4)) return;
   if(io.mode == 3) return copy();
 }
 
@@ -20,21 +21,26 @@ auto VDP::DMA::load() -> void {
   }
 }
 
+//todo: supposedly, this can also write to VSRAM and CRAM (undocumented)
 auto VDP::DMA::fill() -> void {
-  auto data = io.fill;
-  vdp.writeDataPort(data << 8 | data << 0);
+  if(vdp.io.command.bits(0,3) == 1) {
+    vdp.vram.writeByte(vdp.io.address, io.fill);
+  }
 
   io.source.bits(0,15)++;
+  vdp.io.address += vdp.io.dataIncrement;
   if(--io.length == 0) {
     vdp.io.command.bit(5) = 0;
   }
 }
 
+//note: this can only copy to VRAM
 auto VDP::DMA::copy() -> void {
-  auto data = vdp.vram[io.source.bits(0,14)];
-  vdp.writeDataPort(data);
+  auto data = vdp.vram.readByte(io.source);
+  vdp.vram.writeByte(vdp.io.address, data);
 
   io.source.bits(0,15)++;
+  vdp.io.address += vdp.io.dataIncrement;
   if(--io.length == 0) {
     vdp.io.command.bit(5) = 0;
   }
diff --git a/higan/md/vdp/io.cpp b/higan/md/vdp/io.cpp
index 28192d1f..6e5daab7 100644
--- a/higan/md/vdp/io.cpp
+++ b/higan/md/vdp/io.cpp
@@ -45,7 +45,7 @@ auto VDP::readDataPort() -> uint16 {
   //VRAM read
   if(io.command.bits(0,3) == 0) {
     auto address = io.address.bits(1,15);
-    auto data = vram[address];
+    auto data = vram.read(address);
     io.address += io.dataIncrement;
     return data;
   }
@@ -53,8 +53,7 @@ auto VDP::readDataPort() -> uint16 {
   //VSRAM read
   if(io.command.bits(0,3) == 4) {
     auto address = io.address.bits(1,6);
-    if(address >= 40) return 0x0000;
-    auto data = vsram[address];
+    auto data = vsram.read(address);
     io.address += io.dataIncrement;
     return data;
   }
@@ -62,7 +61,7 @@ auto VDP::readDataPort() -> uint16 {
   //CRAM read
   if(io.command.bits(0,3) == 8) {
     auto address = io.address.bits(1,6);
-    auto data = cram[address];
+    auto data = cram.read(address);
     io.address += io.dataIncrement;
     return data.bits(0,2) << 1 | data.bits(3,5) << 2 | data.bits(6,8) << 3;
   }
@@ -76,17 +75,15 @@ auto VDP::writeDataPort(uint16 data) -> void {
   //DMA VRAM fill
   if(dma.io.wait.lower()) {
     dma.io.fill = data >> 8;
-    return;
+    //falls through to memory write
+    //causes extra transfer to occur on VRAM fill operations
   }
 
   //VRAM write
   if(io.command.bits(0,3) == 1) {
     auto address = io.address.bits(1,15);
     if(io.address.bit(0)) data = data >> 8 | data << 8;
-    vram[address] = data;
-    if(address >= sprite.io.attributeAddress && address < sprite.io.attributeAddress + 320) {
-      sprite.write(address, data);
-    }
+    vram.write(address, data);
     io.address += io.dataIncrement;
     return;
   }
@@ -94,9 +91,8 @@ auto VDP::writeDataPort(uint16 data) -> void {
   //VSRAM write
   if(io.command.bits(0,3) == 5) {
     auto address = io.address.bits(1,6);
-    if(address >= 40) return;
     //data format: ---- --yy yyyy yyyy
-    vsram[address] = data.bits(0,9);
+    vsram.write(address, data.bits(0,9));
     io.address += io.dataIncrement;
     return;
   }
@@ -105,7 +101,7 @@ auto VDP::writeDataPort(uint16 data) -> void {
   if(io.command.bits(0,3) == 3) {
     auto address = io.address.bits(1,6);
     //data format: ---- bbb- ggg- rrr-
-    cram[address] = data.bits(1,3) << 0 | data.bits(5,7) << 3 | data.bits(9,11) << 6;
+    cram.write(address, data.bits(1,3) << 0 | data.bits(5,7) << 3 | data.bits(9,11) << 6);
     io.address += io.dataIncrement;
     return;
   }
diff --git a/higan/md/vdp/memory.cpp b/higan/md/vdp/memory.cpp
new file mode 100644
index 00000000..aad8c0b2
--- /dev/null
+++ b/higan/md/vdp/memory.cpp
@@ -0,0 +1,38 @@
+auto VDP::VRAM::read(uint15 address) const -> uint16 {
+  return memory[address];
+}
+
+auto VDP::VRAM::write(uint15 address, uint16 data) -> void {
+  memory[address] = data;
+  if(address < vdp.sprite.io.attributeAddress) return;
+  if(address > vdp.sprite.io.attributeAddress + 319) return;
+  vdp.sprite.write(address, data);
+}
+
+auto VDP::VRAM::readByte(uint16 address) const -> uint8 {
+  return read(address >> 1).byte(!address.bit(0));
+}
+
+auto VDP::VRAM::writeByte(uint16 address, uint8 data) -> void {
+  auto word = read(address >> 1);
+  word.byte(!address.bit(0)) = data;
+  write(address >> 1, word);
+}
+
+auto VDP::VSRAM::read(uint6 address) const -> uint10 {
+  if(address >= 40) return 0x0000;
+  return memory[address];
+}
+
+auto VDP::VSRAM::write(uint6 address, uint10 data) -> void {
+  if(address >= 40) return;
+  memory[address] = data;
+}
+
+auto VDP::CRAM::read(uint6 address) const -> uint9 {
+  return memory[address];
+}
+
+auto VDP::CRAM::write(uint6 address, uint9 data) -> void {
+  memory[address] = data;
+}
diff --git a/higan/md/vdp/render.cpp b/higan/md/vdp/render.cpp
index ea456bb0..eaecb283 100644
--- a/higan/md/vdp/render.cpp
+++ b/higan/md/vdp/render.cpp
@@ -31,7 +31,7 @@ auto VDP::run() -> void {
   if(planeA.output.priority) if(auto color = planeA.output.color) output = color;
   if(sprite.output.priority) if(auto color = sprite.output.color) output = color;
 
-  outputPixel(cram[output]);
+  outputPixel(cram.read(output));
   state.x++;
 }
 
diff --git a/higan/md/vdp/sprite.cpp b/higan/md/vdp/sprite.cpp
index 7743379e..e7d575b9 100644
--- a/higan/md/vdp/sprite.cpp
+++ b/higan/md/vdp/sprite.cpp
@@ -72,7 +72,7 @@ auto VDP::Sprite::run(uint x, uint y) -> void {
     uint pixelY = objectY & 7;
     tileAddress += pixelY << 1 | pixelX >> 2;
 
-    uint16 tileData = vdp.vram[tileAddress];
+    uint16 tileData = vdp.vram.read(tileAddress);
     uint4 color = tileData >> (((pixelX & 3) ^ 3) << 2);
     if(color) {
       output.color = o.palette << 4 | color;
diff --git a/higan/md/vdp/vdp.cpp b/higan/md/vdp/vdp.cpp
index 38f6ec67..52d7e5e1 100644
--- a/higan/md/vdp/vdp.cpp
+++ b/higan/md/vdp/vdp.cpp
@@ -3,6 +3,7 @@
 namespace MegaDrive {
 
 VDP vdp;
+#include "memory.cpp"
 #include "io.cpp"
 #include "dma.cpp"
 #include "render.cpp"
diff --git a/higan/md/vdp/vdp.hpp b/higan/md/vdp/vdp.hpp
index 2c1eb505..9ade08be 100644
--- a/higan/md/vdp/vdp.hpp
+++ b/higan/md/vdp/vdp.hpp
@@ -131,9 +131,38 @@ private:
   auto screenWidth() const -> uint { return io.tileWidth ? 320 : 256; }
   auto screenHeight() const -> uint { return io.overscan ? 240 : 224; }
 
-  uint16 vram[32768];
-  uint9 cram[64];
-  uint10 vsram[40];
+  //video RAM
+  struct VRAM {
+    //memory.cpp
+    auto read(uint15 address) const -> uint16;
+    auto write(uint15 address, uint16 data) -> void;
+
+    auto readByte(uint16 address) const -> uint8;
+    auto writeByte(uint16 address, uint8 data) -> void;
+
+  private:
+    uint16 memory[32768];
+  } vram;
+
+  //vertical scroll RAM
+  struct VSRAM {
+    //memory.cpp
+    auto read(uint6 address) const -> uint10;
+    auto write(uint6 address, uint10 data) -> void;
+
+  private:
+    uint10 memory[40];
+  } vsram;
+
+  //color RAM
+  struct CRAM {
+    //memory.cpp
+    auto read(uint6 address) const -> uint9;
+    auto write(uint6 address, uint9 data) -> void;
+
+  private:
+    uint9 memory[64];
+  } cram;
 
   struct IO {
     //command
diff --git a/higan/ms/psg/io.cpp b/higan/ms/psg/io.cpp
index 0612cf6c..487aa1d1 100644
--- a/higan/ms/psg/io.cpp
+++ b/higan/ms/psg/io.cpp
@@ -29,6 +29,7 @@ auto PSG::write(uint8 data) -> void {
   case 4: {
     if(l) tone2.pitch.bits(0,3) = data.bits(0,3);
     else  tone2.pitch.bits(4,9) = data.bits(0,5);
+    noise.pitch = tone2.pitch;
     break;
   }
 
diff --git a/higan/ms/psg/noise.cpp b/higan/ms/psg/noise.cpp
index 08675afb..8b22453e 100644
--- a/higan/ms/psg/noise.cpp
+++ b/higan/ms/psg/noise.cpp
@@ -1,23 +1,22 @@
 auto PSG::Noise::run() -> void {
-  auto latch = clock;
+  if(--counter) return;
 
-  counter++;
-  if(rate == 0) output ^= !counter.bits(0,3);
-  if(rate == 1) output ^= !counter.bits(0,4);
-  if(rate == 2) output ^= !counter.bits(0,5);
-  if(rate == 3) output ^= psg.tone2.clock;
+  if(rate == 0) counter = 0x10;
+  if(rate == 1) counter = 0x20;
+  if(rate == 2) counter = 0x40;
+  if(rate == 3) counter = pitch;  //shared with tone2
 
-  if(!latch && clock) {
+  if(clock ^= 1) {  //0->1 transition
+    output = lfsr.bit(0);
     auto eor = enable ? ~lfsr >> 3 : 0;
     lfsr = (lfsr ^ eor) << 15 | lfsr >> 1;
   }
-
-  output = lfsr.bit(0);
 }
 
 auto PSG::Noise::power() -> void {
   volume = ~0;
   counter = 0;
+  pitch = 0;
   enable = 0;
   rate = 0;
   lfsr = 0x8000;
diff --git a/higan/ms/psg/psg.cpp b/higan/ms/psg/psg.cpp
index d800d4ae..5b7adc52 100644
--- a/higan/ms/psg/psg.cpp
+++ b/higan/ms/psg/psg.cpp
@@ -57,7 +57,7 @@ auto PSG::power() -> void {
   lowpassLeft = 0;
   lowpassRight = 0;
   for(auto n : range(15)) {
-    levels[n] = 0x3fff * pow(2, n * -2.0 / 6.0) + 0.5;
+    levels[n] = 0x2000 * pow(2, n * -2.0 / 6.0) + 0.5;
   }
   levels[15] = 0;
 
diff --git a/higan/ms/psg/psg.hpp b/higan/ms/psg/psg.hpp
index dfe41db3..8f885ff0 100644
--- a/higan/ms/psg/psg.hpp
+++ b/higan/ms/psg/psg.hpp
@@ -28,7 +28,6 @@ private:
     uint4  volume;
     uint10 counter;
     uint10 pitch;
-    uint1  clock;
     uint1  output;
 
     uint1  left;
@@ -44,7 +43,8 @@ private:
     auto serialize(serializer&) -> void;
 
     uint4   volume;
-    uint6   counter;
+    uint10  counter;
+    uint10  pitch;
     uint1   enable;
     uint2   rate;
     uint16  lfsr;
diff --git a/higan/ms/psg/serialization.cpp b/higan/ms/psg/serialization.cpp
index b71592c0..9c2adf28 100644
--- a/higan/ms/psg/serialization.cpp
+++ b/higan/ms/psg/serialization.cpp
@@ -16,7 +16,6 @@ auto PSG::Tone::serialize(serializer& s) -> void {
   s.integer(volume);
   s.integer(counter);
   s.integer(pitch);
-  s.integer(clock);
   s.integer(output);
 
   s.integer(left);
@@ -26,6 +25,7 @@ auto PSG::Tone::serialize(serializer& s) -> void {
 auto PSG::Noise::serialize(serializer& s) -> void {
   s.integer(volume);
   s.integer(counter);
+  s.integer(pitch);
   s.integer(enable);
   s.integer(rate);
   s.integer(lfsr);
diff --git a/higan/ms/psg/tone.cpp b/higan/ms/psg/tone.cpp
index 35877323..552f703b 100644
--- a/higan/ms/psg/tone.cpp
+++ b/higan/ms/psg/tone.cpp
@@ -1,8 +1,6 @@
 auto PSG::Tone::run() -> void {
-  clock = 0;
   if(--counter) return;
 
-  clock = 1;
   counter = pitch;
   output ^= 1;
 }
@@ -11,7 +9,6 @@ auto PSG::Tone::power() -> void {
   volume = ~0;
   counter = 0;
   pitch = 0;
-  clock = 0;
   output = 0;
 
   left = 1;
diff --git a/icarus/heuristics/mega-drive.cpp b/icarus/heuristics/mega-drive.cpp
index e3a98dc3..a66fddbc 100644
--- a/icarus/heuristics/mega-drive.cpp
+++ b/icarus/heuristics/mega-drive.cpp
@@ -11,6 +11,8 @@ struct MegaDriveCartridge {
 MegaDriveCartridge::MegaDriveCartridge(string location, uint8_t* data, uint size) {
   manifest.append("board\n");
   manifest.append("  rom name=program.rom size=0x", hex(size), "\n");
+  if(size <= 0x200000)
+  manifest.append("  ram name=save.ram size=0x8000\n");
   manifest.append("\n");
   manifest.append("information\n");
   manifest.append("  title: ", Location::prefix(location), "\n");