diff --git a/src/instruction.rs b/src/instruction.rs
index f3209d8..a382ae3 100644
--- a/src/instruction.rs
+++ b/src/instruction.rs
@@ -115,6 +115,17 @@ pub enum OpInput {
     UseAddress(u16),
 }
 
+impl Display for OpInput {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        match self {
+            OpInput::UseImplied => write!(f, ""),
+            OpInput::UseImmediate(v) => write!(f, "#${:02X}", v),
+            OpInput::UseRelative(v) => write!(f, "${:04X}", v),
+            OpInput::UseAddress(v) => write!(f, "${:04X}", v),
+        }
+    }
+}
+
 #[derive(Copy, Clone)]
 pub enum AddressingMode {
     Accumulator,      // 1    LSR A        work directly on accumulator
@@ -158,11 +169,33 @@ pub struct DecodedInstr(pub Instruction, pub OpInput);
 
 impl Display for DecodedInstr {
     fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        // get addressing mode from instruction (if it exists)
+        let am: Option<AddressingMode> = OPCODES.get(self.0 as usize).and_then(|x| x.map(|x| x.1));
+
         match self.1 {
             OpInput::UseImplied => write!(f, "{:?}", self.0),
-            OpInput::UseImmediate(v) => write!(f, "{:?} #${:02X}", self.0, v),
-            OpInput::UseRelative(v) => write!(f, "{:?} ${:04X}", self.0, v),
-            OpInput::UseAddress(v) => write!(f, "{:?} ${:04X}", self.0, v),
+            OpInput::UseImmediate(imm) => write!(f, "{:?} #${:02X}", self.0, imm),
+            OpInput::UseRelative(rel) => write!(f, "{:?} ${:04X}", self.0, rel),
+            OpInput::UseAddress(addr) => match am {
+                Some(AddressingMode::Accumulator) => write!(f, "{:?} A", self.0),
+                Some(AddressingMode::Implied) => write!(f, "{:?}", self.0),
+                Some(AddressingMode::Immediate) => write!(f, "{:?} #${:02X}", self.0, addr),
+                Some(AddressingMode::ZeroPage) => write!(f, "{:?} :?${:02X}", self.0, addr),
+                Some(AddressingMode::ZeroPageX) => write!(f, "{:?} :?${:02X},X", self.0, addr),
+                Some(AddressingMode::ZeroPageY) => write!(f, "{:?} :?${:02X},Y", self.0, addr),
+                Some(AddressingMode::Relative) => write!(f, "{:?} ${:04X}", self.0, addr),
+                Some(AddressingMode::Absolute) => write!(f, "{:?} ${:04X}", self.0, addr),
+                Some(AddressingMode::AbsoluteX) => write!(f, "{:?} ${:04X},X", self.0, addr),
+                Some(AddressingMode::AbsoluteY) => write!(f, "{:?} ${:04X},Y", self.0, addr),
+                Some(AddressingMode::Indirect) => write!(f, "{:?} (${:04X})", self.0, addr),
+                Some(AddressingMode::IndexedIndirectX) => {
+                    write!(f, "{:?} (${:04X},X)", self.0, addr)
+                }
+                Some(AddressingMode::IndirectIndexedY) => {
+                    write!(f, "{:?} (${:04X}),Y", self.0, addr)
+                }
+                None => write!(f, "{:?} {}", self.0, self.1),
+            },
         }
     }
 }