diff --git a/src/Bus.zig b/src/Bus.zig
index 04ad473..d253612 100644
--- a/src/Bus.zig
+++ b/src/Bus.zig
@@ -43,14 +43,14 @@ pub fn read32(self: *const Self, addr: u32) u32 {
     return switch (addr) {
         // General Internal Memory
         0x0000_0000...0x0000_3FFF => self.bios.get32(addr),
-        0x0200_0000...0x0203_FFFF => self.iwram.get32(addr - 0x0200_0000),
-        0x0300_0000...0x0300_7FFF => self.ewram.get32(addr - 0x0300_0000),
+        0x0200_0000...0x02FF_FFFF => self.ewram.get32(addr & 0x3FFFF),
+        0x0300_0000...0x03FF_FFFF => self.iwram.get32(addr & 0x7FFF),
         0x0400_0000...0x0400_03FE => io.read32(self, addr),
 
         // Internal Display Memory
-        0x0500_0000...0x0500_03FF => self.ppu.palette.get32(addr - 0x0500_0000),
+        0x0500_0000...0x05FF_FFFF => self.ppu.palette.get32(addr & 0x3FF),
         0x0600_0000...0x0601_7FFF => self.ppu.vram.get32(addr - 0x0600_0000),
-        0x0700_0000...0x0700_03FF => self.ppu.oam.get32(addr - 0x0700_0000),
+        0x0700_0000...0x07FF_FFFF => self.ppu.oam.get32(addr & 0x3FF),
 
         // External Memory (Game Pak)
         0x0800_0000...0x09FF_FFFF => self.pak.get32(addr - 0x0800_0000),
@@ -69,14 +69,14 @@ pub fn write32(self: *Self, addr: u32, word: u32) void {
 
     switch (addr) {
         // General Internal Memory
-        0x0200_0000...0x0203_FFFF => self.iwram.set32(addr - 0x0200_0000, word),
-        0x0300_0000...0x0300_7FFF => self.ewram.set32(addr - 0x0300_0000, word),
+        0x0200_0000...0x02FF_FFFF => self.ewram.set32(addr & 0x3FFFF, word),
+        0x0300_0000...0x03FF_FFFF => self.iwram.set32(addr & 0x7FFF, word),
         0x0400_0000...0x0400_03FE => io.write32(self, addr, word),
 
         // Internal Display Memory
-        0x0500_0000...0x0500_03FF => self.ppu.palette.set32(addr - 0x0500_0000, word),
+        0x0500_0000...0x05FF_FFFF => self.ppu.palette.set32(addr & 0x3FF, word),
         0x0600_0000...0x0601_7FFF => self.ppu.vram.set32(addr - 0x0600_0000, word),
-        0x0700_0000...0x0700_03FF => self.ppu.oam.set32(addr - 0x0700_0000, word),
+        0x0700_0000...0x07FF_FFFF => self.ppu.oam.set32(addr & 0x3FF, word),
 
         else => log.warn("32-bit write of 0x{X:0>8} to 0x{X:0>8}", .{ word, addr }),
     }
@@ -86,14 +86,14 @@ pub fn read16(self: *const Self, addr: u32) u16 {
     return switch (addr) {
         // General Internal Memory
         0x0000_0000...0x0000_3FFF => self.bios.get16(addr),
-        0x0200_0000...0x0203_FFFF => self.iwram.get16(addr - 0x0200_0000),
-        0x0300_0000...0x0300_7FFF => self.ewram.get16(addr - 0x0300_0000),
+        0x0200_0000...0x02FF_FFFF => self.ewram.get16(addr & 0x3FFFF),
+        0x0300_0000...0x03FF_FFFF => self.iwram.get16(addr & 0x7FFF),
         0x0400_0000...0x0400_03FE => io.read16(self, addr),
 
         // Internal Display Memory
-        0x0500_0000...0x0500_03FF => self.ppu.palette.get16(addr - 0x0500_0000),
+        0x0500_0000...0x05FF_FFFF => self.ppu.palette.get16(addr & 0x3FF),
         0x0600_0000...0x0601_7FFF => self.ppu.vram.get16(addr - 0x0600_0000),
-        0x0700_0000...0x0700_03FF => self.ppu.oam.get16(addr - 0x0700_0000),
+        0x0700_0000...0x07FF_FFFF => self.ppu.oam.get16(addr & 0x3FF),
 
         // External Memory (Game Pak)
         0x0800_0000...0x09FF_FFFF => self.pak.get16(addr - 0x0800_0000),
@@ -108,14 +108,14 @@ pub fn write16(self: *Self, addr: u32, halfword: u16) void {
     // TODO: write16 can write to GamePak Flash
     switch (addr) {
         // General Internal Memory
-        0x0200_0000...0x0203_FFFF => self.iwram.set16(addr - 0x0200_0000, halfword),
-        0x0300_0000...0x0300_7FFF => self.ewram.set16(addr - 0x0300_0000, halfword),
+        0x0200_0000...0x02FF_FFFF => self.ewram.set16(addr & 0x3FFFF, halfword),
+        0x0300_0000...0x03FF_FFFF => self.iwram.set16(addr & 0x7FFF, halfword),
         0x0400_0000...0x0400_03FE => io.write16(self, addr, halfword),
 
         // Internal Display Memory
-        0x0500_0000...0x0500_03FF => self.ppu.palette.set16(addr - 0x0500_0000, halfword),
+        0x0500_0000...0x05FF_FFFF => self.ppu.palette.set16(addr & 0x3FF, halfword),
         0x0600_0000...0x0601_7FFF => self.ppu.vram.set16(addr - 0x0600_0000, halfword),
-        0x0700_0000...0x0700_03FF => self.ppu.oam.set16(addr - 0x0700_0000, halfword),
+        0x0700_0000...0x07FF_FFFF => self.ppu.oam.set16(addr & 0x3FF, halfword),
 
         else => std.debug.panic("16-bit write of 0x{X:0>4} to 0x{X:0>8}", .{ halfword, addr }),
     }
@@ -125,14 +125,14 @@ pub fn read8(self: *const Self, addr: u32) u8 {
     return switch (addr) {
         // General Internal Memory
         0x0000_0000...0x0000_3FFF => self.bios.get8(addr),
-        0x0200_0000...0x0203_FFFF => self.iwram.get8(addr - 0x0200_0000),
-        0x0300_0000...0x0300_7FFF => self.ewram.get8(addr - 0x0300_0000),
+        0x0200_0000...0x02FF_FFFF => self.ewram.get8(addr & 0x3FFFF),
+        0x0300_0000...0x03FF_FFFF => self.iwram.get8(addr & 0x7FFF),
         0x0400_0000...0x0400_03FE => io.read8(self, addr),
 
         // Internal Display Memory
-        0x0500_0000...0x0500_03FF => self.ppu.palette.get8(addr - 0x0500_0000),
+        0x0500_0000...0x05FF_FFFF => self.ppu.palette.get8(addr & 0x3FF),
         0x0600_0000...0x0601_7FFF => self.ppu.vram.get8(addr - 0x0600_0000),
-        0x0700_0000...0x0700_03FF => self.ppu.oam.get8(addr - 0x0700_0000),
+        0x0700_0000...0x07FF_FFFF => self.ppu.oam.get8(addr & 0x3FF),
 
         // External Memory (Game Pak)
         0x0800_0000...0x09FF_FFFF => self.pak.get8(addr - 0x0800_0000),
@@ -147,8 +147,8 @@ pub fn read8(self: *const Self, addr: u32) u8 {
 pub fn write8(self: *Self, addr: u32, byte: u8) void {
     switch (addr) {
         // General Internal Memory
-        0x0200_0000...0x0203_FFFF => self.iwram.set8(addr - 0x0200_0000, byte),
-        0x0300_0000...0x0300_7FFF => self.ewram.set8(addr - 0x0300_0000, byte),
+        0x0200_0000...0x02FF_FFFF => self.ewram.set8(addr & 0x3FFFF, byte),
+        0x0300_0000...0x03FF_FFFF => self.iwram.set8(addr & 0x7FFF, byte),
         0x0400_0000...0x0400_03FE => io.write8(self, addr, byte),
 
         // External Memory (Game Pak)
diff --git a/src/bus/Ewram.zig b/src/bus/Ewram.zig
index 2c9cd03..2f66dfc 100644
--- a/src/bus/Ewram.zig
+++ b/src/bus/Ewram.zig
@@ -7,7 +7,7 @@ buf: []u8,
 alloc: Allocator,
 
 pub fn init(alloc: Allocator) !Self {
-    const buf = try alloc.alloc(u8, 0x8000);
+    const buf = try alloc.alloc(u8, 0x40000);
     std.mem.set(u8, buf, 0);
 
     return Self{
@@ -21,14 +21,12 @@ pub fn deinit(self: Self) void {
 }
 
 pub fn get32(self: *const Self, idx: usize) u32 {
-    return (@as(u32, self.buf[idx + 3]) << 24) | (@as(u32, self.buf[idx + 2]) << 16) | (@as(u32, self.buf[idx + 1]) << 8) | (@as(u32, self.buf[idx]));
+    return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
 }
 
 pub fn set32(self: *Self, idx: usize, word: u32) void {
-    self.buf[idx + 3] = @truncate(u8, word >> 24);
-    self.buf[idx + 2] = @truncate(u8, word >> 16);
-    self.buf[idx + 1] = @truncate(u8, word >> 8);
-    self.buf[idx] = @truncate(u8, word);
+    self.set16(idx + 2, @truncate(u16, word >> 16));
+    self.set16(idx, @truncate(u16, word));
 }
 
 pub fn get16(self: *const Self, idx: usize) u16 {
diff --git a/src/bus/Iwram.zig b/src/bus/Iwram.zig
index 2f66dfc..2c9cd03 100644
--- a/src/bus/Iwram.zig
+++ b/src/bus/Iwram.zig
@@ -7,7 +7,7 @@ buf: []u8,
 alloc: Allocator,
 
 pub fn init(alloc: Allocator) !Self {
-    const buf = try alloc.alloc(u8, 0x40000);
+    const buf = try alloc.alloc(u8, 0x8000);
     std.mem.set(u8, buf, 0);
 
     return Self{
@@ -21,12 +21,14 @@ pub fn deinit(self: Self) void {
 }
 
 pub fn get32(self: *const Self, idx: usize) u32 {
-    return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
+    return (@as(u32, self.buf[idx + 3]) << 24) | (@as(u32, self.buf[idx + 2]) << 16) | (@as(u32, self.buf[idx + 1]) << 8) | (@as(u32, self.buf[idx]));
 }
 
 pub fn set32(self: *Self, idx: usize, word: u32) void {
-    self.set16(idx + 2, @truncate(u16, word >> 16));
-    self.set16(idx, @truncate(u16, word));
+    self.buf[idx + 3] = @truncate(u8, word >> 24);
+    self.buf[idx + 2] = @truncate(u8, word >> 16);
+    self.buf[idx + 1] = @truncate(u8, word >> 8);
+    self.buf[idx] = @truncate(u8, word);
 }
 
 pub fn get16(self: *const Self, idx: usize) u16 {