diff --git a/src/main.rs b/src/main.rs
index c389d90..2e97a3c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -68,11 +68,23 @@ fn main() {
     let shared_memory = Arc::new(Mutex::new(vec![0u8; 0x0200000F]));
 
     let mut cpu = {
+        // 32 MiB of fast memory
+        let cpu_fast_memory = vec![0; 0x02000000];
         let cpu_shared_memory = Arc::clone(&shared_memory);
         let cpu_overlays = Arc::clone(&display.overlays);
         let cpu_read_only_memory = read_rom();
-        // 32 MiB of CPU-only memory
-        let memory = Memory::new(0x02000000, cpu_shared_memory, cpu_overlays, cpu_read_only_memory);
+
+        let fast_size = cpu_fast_memory.len();
+        let fast_bottom_address = 0x00000000;
+        let fast_top_address = fast_bottom_address + fast_size - 1;
+        println!("Fast memory: {:.2}MB mapped at {:#010X}-{:#010X}", fast_size / 1048576, fast_bottom_address, fast_top_address);
+
+        let shared_size = { cpu_shared_memory.lock().unwrap().len() };
+        let shared_bottom_address = 0x02000000;
+        let shared_top_address = shared_bottom_address + shared_size - 1;
+        println!("Shared memory: {:.2}MB mapped at {:#010X}-{:#010X}", shared_size / 1048576, shared_bottom_address, shared_top_address);
+
+        let memory = Memory::new(cpu_fast_memory, cpu_shared_memory, cpu_overlays, cpu_read_only_memory);
 
         let cpu_mouse = Arc::clone(&mouse);
 
diff --git a/src/memory.rs b/src/memory.rs
index 84037ff..1c47d04 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -5,25 +5,27 @@ use crate::{Overlay};
 use std::sync::{Arc, Mutex};
 
 pub struct Memory {
-    ram: Vec<u8>,
-    rom: Vec<u8>,
+    fast_memory: Vec<u8>,
     pub shared_memory: Arc<Mutex<Vec<u8>>>,
+
     pub overlays: Arc<Mutex<Vec<Overlay>>>,
+
+    rom: Vec<u8>,
 }
 
 impl Memory {
-    pub fn new(size: u32, shared_memory: Arc<Mutex<Vec<u8>>>, overlays: Arc<Mutex<Vec<Overlay>>>, read_only_memory: Vec<u8>) -> Self {
+    pub fn new(fast_memory: Vec<u8>, shared_memory: Arc<Mutex<Vec<u8>>>, overlays: Arc<Mutex<Vec<Overlay>>>, rom: Vec<u8>) -> Self {
         Memory {
-            ram: vec![0; size as usize],
-            rom: read_only_memory,
+            fast_memory,
             shared_memory,
             overlays,
+            rom,
         }
     }
     pub fn read_8(&self, address: u32) -> u8 {
         let address = address as usize;
         if address < 0x02000000 {
-            self.ram[address]
+            self.fast_memory[address]
         } else if address >= 0xF0000000 {
             let address = address - 0xF0000000;
             self.rom[address]
@@ -40,10 +42,10 @@ impl Memory {
     pub fn read_32(&self, address: u32) -> u32 {
         let address = address as usize;
         if address < 0x02000000 {
-            (self.ram[address + 3] as u32) << 24 |
-            (self.ram[address + 2] as u32) << 16 |
-            (self.ram[address + 1] as u32) << 8  |
-            (self.ram[address] as u32)
+            (self.fast_memory[address + 3] as u32) << 24 |
+            (self.fast_memory[address + 2] as u32) << 16 |
+            (self.fast_memory[address + 1] as u32) << 8  |
+            (self.fast_memory[address] as u32)
         } else if address >= 0xF0000000 {
             let address = address - 0xF0000000;
             (self.rom[address + 3] as u32) << 24 |
@@ -62,7 +64,7 @@ impl Memory {
     pub fn write_8(&mut self, address: u32, byte: u8) {
         let address = address as usize;
         if address < 0x02000000 {
-            self.ram[address] = byte;
+            self.fast_memory[address] = byte;
         } else {
             let address = address - 0x02000000;
             let mut shared_memory_lock = self.shared_memory.lock().unwrap();
@@ -76,10 +78,10 @@ impl Memory {
     pub fn write_32(&mut self, address: u32, word: u32) {
         let address = address as usize;
         if address < 0x02000000 {
-            self.ram[address] = (word & 0x000000FF) as u8;
-            self.ram[address + 1] = ((word & 0x0000FF00) >> 8) as u8;
-            self.ram[address + 2] = ((word & 0x00FF0000) >> 16) as u8;
-            self.ram[address + 3] = ((word & 0xFF000000) >> 24) as u8;
+            self.fast_memory[address] = (word & 0x000000FF) as u8;
+            self.fast_memory[address + 1] = ((word & 0x0000FF00) >> 8) as u8;
+            self.fast_memory[address + 2] = ((word & 0x00FF0000) >> 16) as u8;
+            self.fast_memory[address + 3] = ((word & 0xFF000000) >> 24) as u8;
         } else {
             let address = address - 0x02000000;
             let mut shared_memory_lock = self.shared_memory.lock().unwrap();