diff --git a/src/address.rs b/src/address.rs
index e2f2bac..6b4b334 100644
--- a/src/address.rs
+++ b/src/address.rs
@@ -37,6 +37,8 @@ pub struct Address(pub u16);
 impl Add<AddressDiff, Address> for Address {
     fn add(&self, &AddressDiff(rhs): &AddressDiff) -> Address {
         let &Address(lhs) = self;
+
+        // TODO akeeton: Do a checked cast.
         Address(((lhs as i32) + rhs) as u16)
     }
 }
diff --git a/src/registers.rs b/src/registers.rs
index bdbc684..ff5752a 100644
--- a/src/registers.rs
+++ b/src/registers.rs
@@ -54,6 +54,7 @@ impl StatusArgs {
 }
 
 pub bitflags! {
+#[deriving(Show)]
     flags Status: u8 {
         const PS_NEGATIVE           = 0b10000000,
         const PS_OVERFLOW           = 0b01000000,
@@ -112,7 +113,7 @@ impl Status {
     }
 }
 
-#[deriving(PartialEq, Eq, PartialOrd, Ord)]
+#[deriving(PartialEq, Eq, PartialOrd, Ord, Show)]
 pub struct StackPointer(pub u8);
 
 impl StackPointer {
@@ -122,6 +123,7 @@ impl StackPointer {
     }
 }
 
+#[deriving(PartialEq, Eq, Show)]
 pub struct Registers {
     pub accumulator:     i8,
     pub index_x:         i8,