diff --git a/stackline/src/text.rs b/stackline/src/text.rs
index caac5d6..ce9ed7b 100644
--- a/stackline/src/text.rs
+++ b/stackline/src/text.rs
@@ -56,6 +56,7 @@ impl Default for TextChar {
     }
 }
 
+#[derive(Clone)]
 pub struct TextSurface {
     width: usize,
     height: usize,
@@ -126,6 +127,10 @@ impl TextSurface {
         self.height
     }
 
+    pub fn iter(&self) -> impl Iterator<Item=TextChar> + '_ {
+        self.chars.iter().copied()
+    }
+
     // TODO: resize
 }
 
diff --git a/stackline/src/tile/mod.rs b/stackline/src/tile/mod.rs
index 3f30835..a0fd479 100644
--- a/stackline/src/tile/mod.rs
+++ b/stackline/src/tile/mod.rs
@@ -5,6 +5,7 @@
  * See [its documentation](AnyTile) for more information on the discovery process.
 */
 use super::*;
+use std::collections::HashMap;
 use enum_dispatch::enum_dispatch;
 use serde::{Deserialize, Serialize};
 
@@ -184,6 +185,42 @@ pub trait Tile: std::clone::Clone + std::fmt::Debug + Serialize + for<'d> Deseri
     fn draw_simple(&self, ctx: DrawContext<'_>) -> TextChar {
         TextChar::default()
     }
+
+    /// Returns the "schema" of the tile, allowing editors to provide human interfaces for
+    /// modifying the tile.
+    fn schema(&self) -> TileSchema {
+        TileSchema::tuple()
+    }
+}
+
+/// The description of the fields of a [`Tile`]
+pub enum TileSchema {
+    Tuple(Vec<TileSchema>),
+    Map(HashMap<String, TileSchema>),
+    Value(String),
+}
+
+impl TileSchema {
+    pub fn tuple() -> Self {
+        Self::Tuple(Vec::new())
+    }
+
+    pub fn map() -> Self {
+        Self::Map(HashMap::new())
+    }
+
+    pub fn value<S: ToString>(name: S) -> Self {
+        Self::Value(name.to_string())
+    }
+
+    pub fn add<S: ToString>(mut self, name: S, value: TileSchema) -> Self {
+        match self {
+            Self::Map(ref mut map) => map.insert(name.to_string(), value),
+            _ => panic!("Invalid TileSchema builder: cannot add() to a non-Map"),
+        };
+
+        self
+    }
 }
 
 pub mod prelude {
@@ -192,6 +229,7 @@ pub mod prelude {
     pub use crate::text::*;
     pub use crate::tile::{AnyTile, FullTile};
     pub use crate::utils::State;
+    pub use super::TileSchema;
 
     pub use serde::{Deserialize, Serialize};
 }
diff --git a/stackline/tiles/storage.rs b/stackline/tiles/storage.rs
index d2b06b1..62df5dd 100644
--- a/stackline/tiles/storage.rs
+++ b/stackline/tiles/storage.rs
@@ -131,7 +131,7 @@ impl Tile for StorageCount {
     }
 }
 
-#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Stacker {
     signal: Option<Signal>,
     /// May only be Horizontal or Vertical
@@ -151,6 +151,12 @@ impl Stacker {
     }
 }
 
+impl Default for Stacker {
+    fn default() -> Self {
+        Stacker::new(Orientation::Horizontal)
+    }
+}
+
 impl Tile for Stacker {
     fn update<'b>(&'b mut self, mut context: UpdateContext<'b>) {
         if let Some(mut signal) = context.take_signal() {
diff --git a/stackline/tiles/transmit.rs b/stackline/tiles/transmit.rs
index 4733878..4dc0e05 100644
--- a/stackline/tiles/transmit.rs
+++ b/stackline/tiles/transmit.rs
@@ -172,7 +172,11 @@ impl Tile for Sender {
         let (x, y) = if self.path.len() > 0 {
             (ctx.surface_coords.0 - self.path[0].0, ctx.surface_coords.1 - self.path[0].1)
         } else {
-            (ctx.surface_coords.0, ctx.surface_coords.1)
+            if let (Ok(x), Ok(y)) = (ctx.surface_coords.0.try_into(), ctx.surface_coords.1.try_into()) {
+                surface.set(x, y, TextChar::from_state('S', ctx.state));
+            }
+            return
+            // (ctx.surface_coords.0, ctx.surface_coords.1)
         };
 
         let mut count = 0;
diff --git a/stackline/tiles/wire.rs b/stackline/tiles/wire.rs
index d4f6ed8..e7e461d 100644
--- a/stackline/tiles/wire.rs
+++ b/stackline/tiles/wire.rs
@@ -43,6 +43,10 @@ impl Tile for Wire {
 
         TextChar::from_state(ch, ctx.state)
     }
+
+    fn schema(&self) -> TileSchema {
+        TileSchema::value("Orientation")
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Default)]
@@ -87,6 +91,10 @@ impl Tile for Diode {
 
         TextChar::from_state(ch, ctx.state)
     }
+
+    fn schema(&self) -> TileSchema {
+        TileSchema::value("Direction")
+    }
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, Default)]
@@ -135,6 +143,12 @@ impl Tile for Resistor {
 
         TextChar::from_state(ch, ctx.state)
     }
+
+    fn schema(&self) -> TileSchema {
+        TileSchema::map()
+            .add("direction", TileSchema::value("Direction"))
+            .add("signal", TileSchema::value("Signal|null"))
+    }
 }
 
 #[cfg(test)]