diff --git a/backend/src/core.rs b/backend/src/core.rs
index d50eab0..68ff5d3 100644
--- a/backend/src/core.rs
+++ b/backend/src/core.rs
@@ -1,11 +1,30 @@
+use utils::error::Error;
+
+use crate::core::{cpu::Cpu, interpreter::Interpreter, mem::Memory};
+
 pub mod cpu;
 pub mod interpreter;
 pub mod mem;
 pub mod registers;
 
-pub struct Core {}
+pub struct Core {
+    cpu: Interpreter,
+    mem: Memory,
+}
 
 impl Core {
+    pub fn new() -> Self {
+        Self {
+            cpu: Interpreter::new(),
+            mem: Memory::new(),
+        }
+    }
+
     pub fn stop(&mut self) {}
     pub fn reset(&mut self) {}
+    pub fn run(&mut self) -> Result<u32, Error> {
+        loop {
+            let _ = self.cpu.step(&mut self.mem)?;
+        }
+    }
 }
diff --git a/backend/src/core/mem.rs b/backend/src/core/mem.rs
index d8ca004..96daa76 100644
--- a/backend/src/core/mem.rs
+++ b/backend/src/core/mem.rs
@@ -1 +1,13 @@
-pub struct Memory {}
+use crate::core::mem::mmio::mmio::MMIO;
+
+pub mod mmio;
+
+pub struct Memory {
+    mmio: MMIO,
+}
+
+impl Memory {
+    pub fn new() -> Self {
+        Self { mmio: MMIO::new() }
+    }
+}
diff --git a/backend/src/core/mem/mmio/mmio.rs b/backend/src/core/mem/mmio/mmio.rs
new file mode 100644
index 0000000..02ccbbf
--- /dev/null
+++ b/backend/src/core/mem/mmio/mmio.rs
@@ -0,0 +1,13 @@
+use crate::core::mem::mmio::ri::RDRAMInterface;
+
+pub struct MMIO {
+    ri: RDRAMInterface,
+}
+
+impl MMIO {
+    pub fn new() -> Self {
+        Self {
+            ri: RDRAMInterface::new(),
+        }
+    }
+}
diff --git a/backend/src/core/mem/mmio/mod.rs b/backend/src/core/mem/mmio/mod.rs
new file mode 100644
index 0000000..9f78f26
--- /dev/null
+++ b/backend/src/core/mem/mmio/mod.rs
@@ -0,0 +1,2 @@
+pub mod mmio;
+pub mod ri;
diff --git a/backend/src/core/mem/mmio/ri.rs b/backend/src/core/mem/mmio/ri.rs
new file mode 100644
index 0000000..953634d
--- /dev/null
+++ b/backend/src/core/mem/mmio/ri.rs
@@ -0,0 +1,18 @@
+pub struct RDRAMInterface {
+    rdram: Vec<u8>,
+    cmd_buf: Vec<u8>,
+}
+
+impl RDRAMInterface {
+    pub fn new() -> Self {
+        Self {
+            rdram: Vec::with_capacity(0x800000),
+            cmd_buf: Vec::with_capacity(0xFFFFF),
+        }
+    }
+
+    pub fn reset(&mut self) {
+        self.rdram.fill(0);
+        self.cmd_buf.fill(0);
+    }
+}