diff --git a/src/interpreter/interpreter.rs b/src/interpreter/interpreter.rs
index 5b5c310..724866d 100644
--- a/src/interpreter/interpreter.rs
+++ b/src/interpreter/interpreter.rs
@@ -22,6 +22,7 @@ use super::{
 pub enum InterpreterError {
     InvalidSyscall(Byte),
     MemoryOutOfBound(Word),
+    FetchError(String),
 }
 
 impl fmt::Display for InterpreterError {
@@ -36,6 +37,9 @@ impl fmt::Display for InterpreterError {
                     "Attempted memory write out of physical bounds: ({addr:#04x})"
                 )
             }
+            InterpreterError::FetchError(s) => {
+                write!(f, "Error during fetch phase: {s}")
+            }
         }
     }
 }
@@ -72,15 +76,16 @@ impl Interpreter {
     pub fn interpret(&mut self) -> Result<(), InterpreterError> {
         while self.ip < self.text.len() {
             self.disassembler.offset = self.ip;
-            // XXX remove unwrap
-            self.disassembler.decode_instruction().unwrap();
+            self.disassembler
+                .decode_instruction()
+                .map_err(|e| InterpreterError::FetchError(e.to_string()))?;
             let current_instruction = self.disassembler.instruction.clone();
 
             log::info!(
-                "{} IP({:04x})\t {:<32}",
-                self.computer,
+                "({:04x}) {:<32} {}",
                 current_instruction.addr,
                 current_instruction.mnemonic.to_string(),
+                self.computer,
             );
 
             match current_instruction.mnemonic {
@@ -772,7 +777,7 @@ impl Interpreter {
         Ok(())
     }
 
-    fn interpret_interrupt(&self, id: u8) -> Result<(), InterpreterError> {
+    fn interpret_interrupt(&mut self, id: u8) -> Result<(), InterpreterError> {
         let bx = self.computer.regs.bx.read();
 
         let mut data = Vec::new();