diff --git a/src/calc.rs b/src/calc.rs
index 3208a2b..2e7e931 100644
--- a/src/calc.rs
+++ b/src/calc.rs
@@ -2,16 +2,21 @@ pub mod constants;
 pub mod errors;
 pub mod operations;
 
+use confy::{load, store};
 use constants::{
-    CalculatorAngleMode, CalculatorConstant, CalculatorConstants, CalculatorConstantsIter,
-    CalculatorDisplayMode, CalculatorMacro, CalculatorMacros, CalculatorMacrosIter,
-    CalculatorRegisters, CalculatorRegistersIter, CalculatorState, RegisterState,
+    CalculatorAngleMode, CalculatorConstants, CalculatorConstantsIter, CalculatorDisplayMode,
+    CalculatorMacros, CalculatorMacrosIter, CalculatorRegisters, CalculatorRegistersIter,
+    CalculatorSettings, CalculatorState, RegisterState,
 };
 use errors::{CalculatorError, CalculatorResult};
 use operations::{CalculatorOperation, CalculatorStateChange, MacroState, OpArgs};
+use serde::ser::{SerializeStruct, Serializer};
 use serde::{Deserialize, Serialize};
+use std::collections::{BTreeMap, HashMap};
 use std::collections::{HashSet, VecDeque};
 
+const APP_NAME: &str = "rpn_rs";
+
 #[derive(PartialEq, Debug, Serialize, Deserialize)]
 enum HistoryMode {
     One,
@@ -24,122 +29,133 @@ impl CalculatorStateChange {
     }
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Deserialize)]
 pub struct Calculator {
+    #[serde(skip)]
     l: String,
     stack: VecDeque<f64>,
+    #[serde(serialize_with = "ordered_char_map")]
     macros: CalculatorMacros,
+    #[serde(skip)]
     active_macros: HashSet<char>,
     constants: CalculatorConstants,
     registers: CalculatorRegisters,
+    #[serde(skip)]
     undo_buf: Vec<CalculatorStateChange>,
+    #[serde(skip)]
     redo_buf: Vec<CalculatorStateChange>,
+    #[serde(skip)]
     state: CalculatorState,
+    // TODO:
+    #[serde(skip)]
     angle_mode: CalculatorAngleMode,
+    // TODO:
+    #[serde(skip)]
     display_mode: CalculatorDisplayMode,
 }
 
+fn ordered_char_map<S, T>(value: &HashMap<char, T>, serializer: S) -> Result<S::Ok, S::Error>
+where
+    T: Serialize,
+    S: Serializer,
+{
+    // let ordered: HashMap<_, _> = value
+    //     .iter()
+    //     .map(|(key, t)| (String::from(*key), t.clone()))
+    //     .collect();
+    let ordered: BTreeMap<_, _> = value
+        .iter()
+        .map(|(key, t)| (String::from(*key), t.clone()))
+        .collect();
+    ordered.serialize(serializer)
+}
+
 impl Default for Calculator {
-    fn default() -> Calculator {
-        Calculator {
+    fn default() -> Self {
+        Calculator::with_settings(CalculatorSettings::default())
+            .expect("Default calculator config is corrupt! Cannot start.")
+    }
+}
+
+impl Serialize for Calculator {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_struct("Calculator", 2)?;
+        s.serialize_field("l", &self.l)?;
+        s.serialize_field("state", &self.state)?;
+        // s.serialize_field("k", &self.registers)?; // map key was not a string
+        //s.serialize_field("t", &self.undo_buf)?; // unsupported Rust type
+        s.end()
+    }
+}
+
+impl Calculator {
+    pub fn with_settings(settings: CalculatorSettings) -> CalculatorResult<Calculator> {
+        let angle_mode = settings.angle_mode;
+        let display_mode = settings.display_mode;
+        Ok(Calculator {
             l: String::new(),
-            stack: vec![1000.0, 1200.32].into_iter().collect(),
             state: CalculatorState::Normal,
             undo_buf: vec![],
             redo_buf: vec![],
             active_macros: HashSet::new(),
             registers: CalculatorRegisters::new(),
-            macros: [
-                (
-                    'e',
-                    CalculatorMacro {
-                        help: String::from("Empty"),
-                        value: String::from(""),
-                    },
-                ),
-                (
-                    '1',
-                    CalculatorMacro {
-                        help: String::from("Push 1"),
-                        value: String::from("1 "),
-                    },
-                ),
-                (
-                    '0',
-                    CalculatorMacro {
-                        help: String::from("Push 0"),
-                        value: String::from("0 "),
-                    },
-                ),
-                (
-                    't',
-                    CalculatorMacro {
-                        help: String::from("Test"),
-                        value: String::from("m1m0\\m1m1\\\\"),
-                    },
-                ),
-                (
-                    'm',
-                    CalculatorMacro {
-                        help: String::from("<cr>64?>64%"),
-                        value: String::from(" 64?>64%"),
-                    },
-                ),
-                (
-                    'u',
-                    CalculatorMacro {
-                        help: String::from("Quadratic Formula"),
-                        value: String::from(
-                            "RcRbRarbnrb2 ^4 rarc**-v+2 ra*/rbnrb2^4 rarc**-v-2 ra*/",
-                        ),
-                    },
-                ),
-                (
-                    's',
-                    CalculatorMacro {
-                        help: String::from("Sample data"),
-                        value: String::from("\\\\2 5 3n"),
-                    },
-                ),
-            ]
-            .iter()
-            .cloned()
-            .collect(),
-            constants: [
-                (
-                    't',
-                    CalculatorConstant {
-                        help: String::from("Tau (2pi)"),
-                        value: std::f64::consts::TAU,
-                    },
-                ),
-                (
-                    'e',
-                    CalculatorConstant {
-                        help: String::from("Euler's Number e"),
-                        value: std::f64::consts::E,
-                    },
-                ),
-                (
-                    'p',
-                    CalculatorConstant {
-                        help: String::from("Pi"),
-                        value: std::f64::consts::PI,
-                    },
-                ),
-            ]
-            .iter()
-            .cloned()
-            .collect(),
-            angle_mode: CalculatorAngleMode::Degrees,
-            display_mode: CalculatorDisplayMode::Default(None),
-        }
+            stack: settings.stack.into(),
+            macros: settings
+                .macros
+                .into_iter()
+                .map(|(key, mac)| {
+                    Ok((
+                        key.chars()
+                            .next()
+                            .ok_or_else(|| CalculatorError::LoadError(None))?,
+                        mac,
+                    ))
+                })
+                .collect::<CalculatorResult<CalculatorMacros>>()?,
+            constants: settings
+                .constants
+                .into_iter()
+                .map(|(key, constant)| {
+                    Ok((
+                        key.chars()
+                            .next()
+                            .ok_or_else(|| CalculatorError::LoadError(None))?,
+                        constant,
+                    ))
+                })
+                .collect::<CalculatorResult<CalculatorConstants>>()?,
+            angle_mode,
+            display_mode,
+        })
+    }
+
+    pub fn load_config() -> CalculatorResult<Calculator> {
+        let settings = load(APP_NAME).map_err(|e| CalculatorError::LoadError(Some(e)))?;
+        Calculator::with_settings(settings)
+    }
+    pub fn save_config(&self) -> CalculatorResult<()> {
+        let settings = CalculatorSettings {
+            angle_mode: self.angle_mode.clone(),
+            display_mode: self.display_mode.clone(),
+            stack: self.stack.iter().map(|f| *f).collect(),
+            macros: self
+                .macros
+                .iter()
+                .map(|(key, mac)| (String::from(*key), mac.clone()))
+                .collect(),
+            constants: self
+                .constants
+                .iter()
+                .map(|(key, constant)| (String::from(*key), constant.clone()))
+                .collect(),
+        };
+        store(APP_NAME, settings).map_err(|e| CalculatorError::SaveError(Some(e)))
     }
-}
 
-impl Calculator {
     pub fn take_input(&mut self, c: char) -> CalculatorResult<()> {
-        //for c in input.chars() {
         match &self.state {
             CalculatorState::Normal => match c {
                 c @ '0'..='9' | c @ '.' | c @ 'e' => self.entry(c),
diff --git a/src/calc/constants.rs b/src/calc/constants.rs
index 1553be1..8d1f260 100644
--- a/src/calc/constants.rs
+++ b/src/calc/constants.rs
@@ -1,14 +1,15 @@
 use serde::{Deserialize, Serialize};
 use std::collections::hash_map::Iter;
 use std::collections::HashMap;
+use std::fmt;
 
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 pub enum RegisterState {
     Save,
     Load,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 pub enum CalculatorState {
     Normal,
     WaitingForConstant,
@@ -17,13 +18,21 @@ pub enum CalculatorState {
     WaitingForSetting,
 }
 
+impl Default for CalculatorState {
+    fn default() -> Self {
+        CalculatorState::Normal
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "constant")]
 pub struct CalculatorConstant {
     pub help: String,
     pub value: f64,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "macro")]
 pub struct CalculatorMacro {
     pub help: String,
     pub value: String,
@@ -38,16 +47,154 @@ pub type CalculatorMacrosIter<'a> = Iter<'a, char, CalculatorMacro>;
 pub type CalculatorRegisters = HashMap<char, f64>;
 pub type CalculatorRegistersIter<'a> = Iter<'a, char, f64>;
 
-#[derive(Serialize, Deserialize)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(tag = "angle_mode")]
 pub enum CalculatorAngleMode {
     Degrees,
     Radians,
     Grads,
 }
 
-#[derive(Serialize, Deserialize)]
+impl fmt::Display for CalculatorAngleMode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            CalculatorAngleMode::Degrees => write!(f, "DEG"),
+            CalculatorAngleMode::Radians => write!(f, "RAD"),
+            CalculatorAngleMode::Grads => write!(f, "GRD"),
+        }
+    }
+}
+
+impl Default for CalculatorAngleMode {
+    fn default() -> Self {
+        CalculatorAngleMode::Degrees
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[serde(tag = "display_mode")]
 pub enum CalculatorDisplayMode {
     Default(Option<char>),
     Scientific(usize),
     Engineering(usize),
 }
+
+impl fmt::Display for CalculatorDisplayMode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            CalculatorDisplayMode::Default(None) => write!(f, "DEF"),
+            CalculatorDisplayMode::Default(Some(c)) => write!(f, "DEF({})", c),
+            CalculatorDisplayMode::Scientific(p) => write!(f, "SCI({})", p),
+            CalculatorDisplayMode::Engineering(p) => write!(f, "ENG({})", p),
+        }
+    }
+}
+
+impl Default for CalculatorDisplayMode {
+    fn default() -> Self {
+        CalculatorDisplayMode::Default(None)
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CalculatorSettings {
+    // Order matters here as macros/constants cannot come first
+    pub stack: Vec<f64>,
+    #[serde(skip)]
+    pub display_mode: CalculatorDisplayMode,
+    pub angle_mode: CalculatorAngleMode,
+    pub macros: HashMap<String, CalculatorMacro>,
+    pub constants: HashMap<String, CalculatorConstant>,
+}
+
+impl Default for CalculatorSettings {
+    fn default() -> CalculatorSettings {
+        CalculatorSettings {
+            stack: vec![1.0, 2.0].into_iter().collect(),
+            macros: [
+                (
+                    String::from('e'),
+                    CalculatorMacro {
+                        help: String::from("Empty"),
+                        value: String::from(""),
+                    },
+                ),
+                (
+                    String::from('1'),
+                    CalculatorMacro {
+                        help: String::from("Push 1"),
+                        value: String::from("1 "),
+                    },
+                ),
+                (
+                    String::from('0'),
+                    CalculatorMacro {
+                        help: String::from("Push 0"),
+                        value: String::from("0 "),
+                    },
+                ),
+                (
+                    String::from('t'),
+                    CalculatorMacro {
+                        help: String::from("Test"),
+                        value: String::from("m1m0\\m1m1\\\\"),
+                    },
+                ),
+                (
+                    String::from('m'),
+                    CalculatorMacro {
+                        help: String::from("<cr>64?>64%"),
+                        value: String::from(" 64?>64%"),
+                    },
+                ),
+                (
+                    String::from('u'),
+                    CalculatorMacro {
+                        help: String::from("Quadratic Formula"),
+                        value: String::from(
+                            "RcRbRarbnrb2 ^4 rarc**-v+2 ra*/rbnrb2^4 rarc**-v-2 ra*/",
+                        ),
+                    },
+                ),
+                (
+                    String::from('s'),
+                    CalculatorMacro {
+                        help: String::from("Sample data"),
+                        value: String::from("\\\\2 5 3n"),
+                    },
+                ),
+            ]
+            .iter()
+            .cloned()
+            .collect(),
+            constants: [
+                (
+                    String::from('t'),
+                    CalculatorConstant {
+                        help: String::from("Tau (2pi)"),
+                        value: std::f64::consts::TAU,
+                    },
+                ),
+                (
+                    String::from('e'),
+                    CalculatorConstant {
+                        help: String::from("Euler's Number e"),
+                        value: std::f64::consts::E,
+                    },
+                ),
+                (
+                    String::from('p'),
+                    CalculatorConstant {
+                        help: String::from("Pi"),
+                        value: std::f64::consts::PI,
+                    },
+                ),
+            ]
+            .iter()
+            .cloned()
+            .collect(),
+            angle_mode: CalculatorAngleMode::Degrees,
+            display_mode: CalculatorDisplayMode::Default(None),
+        }
+    }
+}
diff --git a/src/calc/errors.rs b/src/calc/errors.rs
index 2006e7d..9f537c2 100644
--- a/src/calc/errors.rs
+++ b/src/calc/errors.rs
@@ -1,7 +1,9 @@
+use confy::ConfyError;
 use std::fmt;
 
 pub type CalculatorResult<T> = Result<T, CalculatorError>;
 
+#[derive(Debug)]
 pub enum CalculatorError {
     ArithmeticError,
     NotEnoughStackEntries,
@@ -15,6 +17,8 @@ pub enum CalculatorError {
     RecursiveMacro(char),
     ParseError,
     PrecisionTooHigh,
+    SaveError(Option<ConfyError>),
+    LoadError(Option<ConfyError>),
 }
 
 impl fmt::Display for CalculatorError {
@@ -34,6 +38,10 @@ impl fmt::Display for CalculatorError {
             CalculatorError::RecursiveMacro(c) => write!(f, "Recursive macro '{}'", c),
             CalculatorError::ParseError => write!(f, "Parse error"),
             CalculatorError::PrecisionTooHigh => write!(f, "Precision too high"),
+            CalculatorError::SaveError(None) => write!(f, "Could not save"),
+            CalculatorError::SaveError(Some(e)) => write!(f, "Could not save: {}", e),
+            CalculatorError::LoadError(None) => write!(f, "Could not load"),
+            CalculatorError::LoadError(Some(e)) => write!(f, "Could not load: {}", e),
         }
     }
 }
diff --git a/src/main.rs b/src/main.rs
index d00be5a..24c6017 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,7 +4,7 @@
 mod calc;
 mod util;
 
-use calc::constants::{CalculatorAngleMode, CalculatorDisplayMode, CalculatorState, RegisterState};
+use calc::constants::{CalculatorDisplayMode, CalculatorState, RegisterState};
 use calc::errors::CalculatorResult;
 use calc::Calculator;
 use std::cmp;
@@ -41,9 +41,13 @@ struct App {
 
 impl Default for App {
     fn default() -> App {
+        let (calculator, error_msg) = match Calculator::load_config() {
+            Ok(c) => (c, None),
+            Err(e) => (Calculator::default(), Some(format!("{}", e))),
+        };
         App {
-            calculator: Calculator::default(),
-            error_msg: None,
+            calculator,
+            error_msg,
             state: AppState::Calculator,
             current_macro: None,
         }
@@ -81,20 +85,6 @@ fn main() -> Result<(), Box<dyn Error>> {
                     Span::styled(e, Style::default().add_modifier(Modifier::RAPID_BLINK)),
                 ],
                 (None, AppState::Calculator) => {
-                    // TODO: There has to be a better way than making strings each time
-                    let display_mode_str = match app.calculator.get_display_mode() {
-                        CalculatorDisplayMode::Default(None) => String::from("DEF"),
-                        CalculatorDisplayMode::Default(Some(c)) => format!("DEF({})", c),
-                        CalculatorDisplayMode::Scientific(p) => format!("SCI({})", p),
-                        CalculatorDisplayMode::Engineering(p) => format!("ENG({})", p),
-                    };
-
-                    let angle_mode_str = match app.calculator.get_angle_mode() {
-                        CalculatorAngleMode::Degrees => String::from("DEG"),
-                        CalculatorAngleMode::Radians => String::from("RAD"),
-                        CalculatorAngleMode::Grads => String::from("GRD"),
-                    };
-
                     vec![
                         Span::raw("Press "),
                         Span::styled("q", Style::default().add_modifier(Modifier::BOLD)),
@@ -102,7 +92,8 @@ fn main() -> Result<(), Box<dyn Error>> {
                         Span::styled("h", Style::default().add_modifier(Modifier::BOLD)),
                         Span::raw(format!(
                             " for help - [{}] [{}]",
-                            display_mode_str, angle_mode_str
+                            app.calculator.get_display_mode(),
+                            app.calculator.get_angle_mode()
                         )),
                     ]
                 }
@@ -293,6 +284,12 @@ fn handle_key(app: &mut App, events: &Events, key: Key) -> CalculatorResult<bool
             Key::Char('q') => {
                 return Ok(true);
             }
+            Key::Ctrl('s') => {
+                app.calculator.save_config()?;
+            }
+            Key::Ctrl('l') => {
+                app.calculator = Calculator::load_config()?;
+            }
             Key::Char('h') => {
                 app.state = AppState::Help;
             }