diff --git a/src/interpreter.rs b/src/interpreter/mod.rs
similarity index 83%
rename from src/interpreter.rs
rename to src/interpreter/mod.rs
index a95372f..a926a29 100644
--- a/src/interpreter.rs
+++ b/src/interpreter/mod.rs
@@ -1,6 +1,11 @@
-// this should be read before reading the code
-// http://devernay.free.fr/hacks/chip8/C8TECH10.HTM
-// https://en.wikipedia.org/wiki/CHIP-8
+//! # A CHIP-8 interpreter in Rust
+//! this should be read before reading the code
+//! http://devernay.free.fr/hacks/chip8/C8TECH10.HTM
+//! https://en.wikipedia.org/wiki/CHIP-8
+
+#[cfg(test)]
+mod test;
+
 use rand::Rng;
 
 #[derive(Debug, Clone)]
@@ -276,69 +281,4 @@ fn extract_0xii(value: u16) -> (usize, u8) {
 
 fn extract_0nnn(value: u16) -> u16 {
     value & 0xFFF
-}
-
-#[cfg(test)]
-mod test {
-    use crate::interpreter::{Emulator, execute};
-    use std::sync::atomic::Ordering::AcqRel;
-
-    #[test]
-    fn instructions_0_1_2() {
-        let mut em = Emulator::default();
-        em.pc = 10;
-        execute(0x20FF, &mut em); // call 0FF
-        assert_eq!(em.pc + 1, 0x0FF);
-        assert_eq!(em.sp, 1);
-        em.pc = 0x0FF;
-        execute(0x00EE, &mut em); // return
-        assert_eq!(em.sp, 0);
-        assert_eq!(em.pc, 10);
-        execute(0x10AB, &mut em); // jmp to 0AB
-        assert_eq!(em.pc + 1, 0x0AB);
-    }
-
-    #[test]
-    fn instructions_3_4_5() {
-        let mut em = Emulator::default();
-        em.reg[0] = 0xF2;
-        execute(0x30F2, &mut em);
-        assert_eq!(em.pc, 1);
-        execute(0x40F3, &mut em);
-        assert_eq!(em.pc, 2);
-        execute(0x40F2, &mut em);
-        assert_eq!(em.pc, 2);
-        em.reg[1] = 0xF2;
-        execute(0x5010, &mut em);
-        assert_eq!(em.pc, 3);
-    }
-
-    #[test]
-    fn instructions_6_7() {
-        let mut em = Emulator::default();
-        execute(0x60AB, &mut em);
-        assert_eq!(em.reg[0], 0xAB);
-        execute(0x69FF, &mut em);
-        assert_eq!(em.reg[9], 0xFF);
-        execute(0x7001, &mut em);
-        assert_eq!(em.reg[0], 0xAC);
-    }
-
-    #[test]
-    fn instruction_fx33_conversion() {
-        let mut em = Emulator::default();
-        em.reg[0] = 255;
-        em.reg[1] = 99;
-        em.reg[2] = 1;
-        let instruction1 = 0xF033;
-        let instruction2 = 0xF133;
-        let instruction3 = 0xF233;
-        execute(instruction1, &mut em);
-        em.i = 3;
-        execute(instruction2, &mut em);
-        em.i = 6;
-        execute(instruction3, &mut em);
-
-        assert_eq!(&em.memory[0..9], &[2, 5, 5, 0, 9, 9, 0, 0, 1]);
-    }
-}
+}
\ No newline at end of file
diff --git a/src/interpreter/test.rs b/src/interpreter/test.rs
new file mode 100644
index 0000000..dde3dd5
--- /dev/null
+++ b/src/interpreter/test.rs
@@ -0,0 +1,60 @@
+use crate::interpreter::{Emulator, execute};
+
+#[test]
+fn instructions_0_1_2() {
+    let mut em = Emulator::default();
+    em.pc = 10;
+    execute(0x20FF, &mut em); // call 0FF
+    assert_eq!(em.pc + 1, 0x0FF);
+    assert_eq!(em.sp, 1);
+    em.pc = 0x0FF;
+    execute(0x00EE, &mut em); // return
+    assert_eq!(em.sp, 0);
+    assert_eq!(em.pc, 10);
+    execute(0x10AB, &mut em); // jmp to 0AB
+    assert_eq!(em.pc + 1, 0x0AB);
+}
+
+#[test]
+fn instructions_3_4_5() {
+    let mut em = Emulator::default();
+    em.reg[0] = 0xF2;
+    execute(0x30F2, &mut em);
+    assert_eq!(em.pc, 1);
+    execute(0x40F3, &mut em);
+    assert_eq!(em.pc, 2);
+    execute(0x40F2, &mut em);
+    assert_eq!(em.pc, 2);
+    em.reg[1] = 0xF2;
+    execute(0x5010, &mut em);
+    assert_eq!(em.pc, 3);
+}
+
+#[test]
+fn instructions_6_7() {
+    let mut em = Emulator::default();
+    execute(0x60AB, &mut em);
+    assert_eq!(em.reg[0], 0xAB);
+    execute(0x69FF, &mut em);
+    assert_eq!(em.reg[9], 0xFF);
+    execute(0x7001, &mut em);
+    assert_eq!(em.reg[0], 0xAC);
+}
+
+#[test]
+fn instruction_fx33_conversion() {
+    let mut em = Emulator::default();
+    em.reg[0] = 255;
+    em.reg[1] = 99;
+    em.reg[2] = 1;
+    let instruction1 = 0xF033;
+    let instruction2 = 0xF133;
+    let instruction3 = 0xF233;
+    execute(instruction1, &mut em);
+    em.i = 3;
+    execute(instruction2, &mut em);
+    em.i = 6;
+    execute(instruction3, &mut em);
+
+    assert_eq!(&em.memory[0..9], &[2, 5, 5, 0, 9, 9, 0, 0, 1]);
+}
diff --git a/src/main.rs b/src/main.rs
index 8ee9923..7e91e62 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,7 @@
-use crate::interpreter::{run};
+use crate::interpreter::run;
 
 mod interpreter;
 
 fn main() {
-    println!("Hello, world!");
     run(&[])
 }
\ No newline at end of file