diff --git a/src/bus.rs b/src/bus.rs
index b2e4f0f..2400cfa 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -51,10 +51,15 @@ pub trait Write<T> {
 #[non_exhaustive]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum Region {
+    /// Character ROM (but writable!)
     Charset,
+    /// Program memory
     Program,
+    /// Screen buffer
     Screen,
+    /// Stack space
     Stack,
+    /// Total number of named regions
     Count,
 }
 
@@ -191,6 +196,17 @@ impl Bus {
     ///#    Ok(())
     ///# }
     /// ```
+    /// If the region doesn't exist, that's okay.
+    /// ```rust
+    ///# use chirp::prelude::*;
+    ///# fn main() -> Result<()> {
+    ///     let bus = Bus::new()
+    ///         .add_region(Program, 0..1234)
+    ///         .clear_region(Screen);
+    ///# // TODO: test if region actually clear
+    ///#    Ok(())
+    ///# }
+    /// ```
     pub fn clear_region(&mut self, name: Region) -> &mut Self {
         if let Some(region) = self.get_region_mut(name) {
             region.fill(0)
diff --git a/src/cpu.rs b/src/cpu.rs
index f346835..c213573 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -314,6 +314,20 @@ impl CPU {
         self
     }
 
+    /// Gets a slice of breakpoints
+    /// # Examples
+    /// ```rust
+    ///# use chirp::prelude::*;
+    ///# fn main() -> Result<()> {
+    ///     let mut cpu = CPU::default();
+    ///     assert_eq!(cpu.breakpoints(), &[]);
+    ///#    Ok(())
+    ///# }
+    /// ```
+    pub fn breakpoints(&self) -> &[Adr] {
+        &self.breakpoints.as_slice()
+    }
+
     /// Unpauses the emulator for a single tick,
     /// even if cpu.flags.pause is set.
     ///
diff --git a/src/cpu/disassemble.rs b/src/cpu/disassemble.rs
index 22dce52..ec5c336 100644
--- a/src/cpu/disassemble.rs
+++ b/src/cpu/disassemble.rs
@@ -171,7 +171,7 @@ impl Disassemble {
                 0x65 => self.dma_load(x),
                 _ => self.unimplemented(opcode),
             },
-            _ => unimplemented!("Extracted nibble from byte, got >nibble?"),
+            _ => unreachable!("Extracted nibble from byte, got >nibble?"),
         }
     }
 }
diff --git a/tests/struct.rs b/tests/struct.rs
index 58f5970..c7e62ec 100644
--- a/tests/struct.rs
+++ b/tests/struct.rs
@@ -10,6 +10,159 @@ fn chip8() {
     println!("{ch8:?}"); // Debug
 }
 
+mod bus {
+    use super::*;
+    mod region {
+        use super::*;
+        //  #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+        #[test]
+        fn copy() {
+            let r1 = Screen;
+            let r2 = r1;
+            assert_eq!(r1, r2);
+        }
+        #[test]
+        fn clone() {
+            let r1 = Screen;
+            let r2 = r1.clone();
+            assert_eq!(r1, r2);
+        }
+        #[test]
+        fn display() {
+            println!("{Charset}{Program}{Screen}{Stack}{Count}");
+        }
+        #[test]
+        fn debug() {
+            println!("{Charset:?}{Program:?}{Screen:?}{Stack:?}{Count:?}");
+        }
+        // lmao the things you do for test coverage
+        #[test]
+        fn eq() {
+            assert_eq!(Screen, Screen);
+            assert_ne!(Charset, Program);
+        }
+        #[test]
+        fn ord() {
+            assert_eq!(Stack, Charset.max(Program).max(Screen).max(Stack));
+            assert!(Charset < Program && Program < Screen && Screen < Stack);
+        }
+        #[test]
+        fn hash() {
+            let mut hasher = DefaultHasher::new();
+            Stack.hash(&mut hasher);
+            println!("{hasher:?}");
+        }
+    }
+    #[test]
+    #[should_panic]
+    fn bus_missing_region() {
+        // Print the screen of a bus with no screen
+        bus! {}.print_screen().unwrap()
+    }
+}
+
+mod cpu {
+    use super::*;
+    #[test]
+    fn set_break() {
+        let mut cpu = CPU::default();
+        let point = 0x234;
+        assert_eq!(cpu.breakpoints(), &[]);
+        // Attempt to set the same breakpoint 100 times
+        for _ in 0..100 {
+            cpu.set_break(point);
+        }
+        assert_eq!(cpu.breakpoints(), &[point]);
+    }
+    #[test]
+    fn unset_break() {
+        let mut cpu = CPU::default();
+        let point = 0x234;
+        // set TWO breakpoints
+        cpu.set_break(point + 1);
+        cpu.set_break(point);
+        assert_eq!(cpu.breakpoints(), &[point + 1, point]);
+        // Attempt to unset the same breakpoint 100 times
+        for _ in 0..100 {
+            cpu.unset_break(point);
+        }
+        // Only unset the matching point
+        assert_eq!(cpu.breakpoints(), &[point + 1]);
+    }
+    mod controlflags {
+        use super::*;
+        //#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+        #[test]
+        fn clone() {
+            let cf1 = ControlFlags {
+                debug: false,
+                pause: false,
+                keypause: false,
+                vbi_wait: false,
+                lastkey: None,
+                quirks: Default::default(),
+                monotonic: None,
+            };
+            let cf2 = cf1.clone();
+            assert_eq!(cf1, cf2)
+        }
+        #[test]
+        fn debug() {
+            println!("{:?}", ControlFlags::default());
+        }
+        #[test]
+        fn default() {
+            assert_eq!(
+                ControlFlags::default(),
+                ControlFlags {
+                    debug: false,
+                    pause: false,
+                    keypause: false,
+                    vbi_wait: false,
+                    lastkey: Default::default(),
+                    quirks: Default::default(),
+                    monotonic: Default::default()
+                }
+            )
+        }
+        #[test]
+        fn eq() {
+            let cf1 = ControlFlags::default();
+            let cf2 = ControlFlags {
+                debug: true,
+                pause: true,
+                keypause: true,
+                vbi_wait: true,
+                lastkey: Default::default(),
+                quirks: Default::default(),
+                monotonic: Default::default(),
+            };
+            assert_ne!(cf1, cf2);
+        }
+        #[test]
+        fn ord() {
+            let cf1 = ControlFlags::default();
+            let cf2 = ControlFlags {
+                debug: true,
+                pause: true,
+                keypause: true,
+                vbi_wait: true,
+                lastkey: Default::default(),
+                quirks: Default::default(),
+                monotonic: Default::default(),
+            };
+            assert!(cf1 < cf2);
+            assert_eq!(ControlFlags::default(), cf1.min(cf2));
+        }
+        #[test]
+        fn hash() {
+            let mut hasher = DefaultHasher::new();
+            ControlFlags::default().hash(&mut hasher);
+            println!("{:?}", hasher);
+        }
+    }
+}
+
 #[test]
 fn error() {
     let error = chirp::error::Error::FunkyMath {
@@ -115,10 +268,9 @@ mod framebuffer_format {
     }
     #[test]
     fn hash() {
-        println!(
-            "{:?}",
-            FrameBufferFormat::default().hash(&mut DefaultHasher::new())
-        );
+        let mut hasher = DefaultHasher::new();
+        FrameBufferFormat::default().hash(&mut hasher);
+        println!("{hasher:?}");
     }
 }
 
@@ -153,10 +305,9 @@ mod framebuffer {
 
     #[test]
     fn hash() {
-        println!(
-            "{:?}",
-            FrameBuffer::default().hash(&mut DefaultHasher::new())
-        );
+        let mut hasher = DefaultHasher::new();
+        FrameBuffer::default().hash(&mut hasher);
+        println!("{hasher:?}");
     }
 }
 
@@ -225,6 +376,8 @@ mod quirks {
 
     #[test]
     fn hash() {
-        println!("{:?}", Quirks::from(true).hash(&mut DefaultHasher::new()));
+        let mut hasher = DefaultHasher::new();
+        Quirks::from(true).hash(&mut hasher);
+        println!("{hasher:?}");
     }
 }