diff --git a/js/format-dat.js b/js/format-dat.js
index d8cacf0..af80c89 100644
--- a/js/format-dat.js
+++ b/js/format-dat.js
@@ -209,14 +209,31 @@ function parse_level(buf) {
             level.title = util.string_from_buffer_ascii(buf.slice(p, p + field_length - 1));
         }
         else if (field_type === 0x04) {
-            // Trap linkages
-            // TODO read this
-            // TODO under lynx rules these aren't even used, and they cause bugs in mscc1!
+            // Trap linkages (MSCC only, not in Lynx or CC2)
+            let field_view = new DataView(buf.slice(p, p + field_length));
+            let q = 0;
+            while (q < field_length) {
+                let button_x = field_view.getUint16(q + 0, true);
+                let button_y = field_view.getUint16(q + 2, true);
+                let trap_x = field_view.getUint16(q + 4, true);
+                let trap_y = field_view.getUint16(q + 6, true);
+                // Fifth u16 is always zero, possibly live game state
+                q += 10;
+                level.custom_trap_wiring[button_x + button_y * level.size_x] = trap_x + trap_y * level.size_x;
+            }
         }
         else if (field_type === 0x05) {
-            // Trap linkages
-            // TODO read this
-            // TODO under lynx rules these aren't even used, and they cause bugs in mscc1!
+            // Cloner linkages (MSCC only, not in Lynx or CC2)
+            let field_view = new DataView(buf.slice(p, p + field_length));
+            let q = 0;
+            while (q < field_length) {
+                let button_x = field_view.getUint16(q + 0, true);
+                let button_y = field_view.getUint16(q + 2, true);
+                let cloner_x = field_view.getUint16(q + 4, true);
+                let cloner_y = field_view.getUint16(q + 6, true);
+                q += 8;
+                level.custom_cloner_wiring[button_x + button_y * level.size_x] = cloner_x + cloner_y * level.size_x;
+            }
         }
         else if (field_type === 0x06) {
             // Password, with trailing NUL, and otherwise XORed with 0x99 (?!)
diff --git a/js/format-util.js b/js/format-util.js
index 3211ab0..cc0fe70 100644
--- a/js/format-util.js
+++ b/js/format-util.js
@@ -22,6 +22,11 @@ export class StoredLevel {
 
         this.player_start_x = 0;
         this.player_start_y = 0;
+
+        // Maps of button positions to trap/cloner positions, as scalar indexes
+        // in the linear cell list
+        this.custom_trap_wiring = {};
+        this.custom_cloner_wiring = {};
     }
 
     check() {
diff --git a/js/main.js b/js/main.js
index e7675b2..17c5543 100644
--- a/js/main.js
+++ b/js/main.js
@@ -289,15 +289,44 @@ class Level {
 
         // Connect buttons and teleporters
         let num_cells = this.width * this.height;
+        console.log(this.stored_level.custom_trap_wiring);
+        console.log(this.stored_level.custom_cloner_wiring);
         for (let connectable of connectables) {
             let x = connectable.x;
             let y = connectable.y;
             let goal = connectable.type.connects_to;
+            let found = false;
+
+            // Check for custom wiring, for MSCC .DAT levels
+            let n = x + y * this.width;
+            console.log(x, y, n);
+            let target_cell_n = null;
+            if (goal === 'trap') {
+                target_cell_n = this.stored_level.custom_trap_wiring[n] ?? null;
+            }
+            else if (goal === 'cloner') {
+                target_cell_n = this.stored_level.custom_cloner_wiring[n] ?? null;
+            }
+            if (target_cell_n) {
+                // TODO this N could be outside the map bounds
+                let target_cell_x = target_cell_n % this.width;
+                let target_cell_y = Math.floor(target_cell_n / this.width);
+                for (let tile of this.cells[target_cell_y][target_cell_x]) {
+                    if (tile.type.name === goal) {
+                        connectable.connection = tile;
+                        found = true;
+                        break;
+                    }
+                }
+                if (found)
+                    continue;
+            }
+
+            // Otherwise, look in reading order
             let direction = 1;
-            if (connectable.type.connect_order == 'backward') {
+            if (connectable.type.connect_order === 'backward') {
                 direction = -1;
             }
-            let found = false;
             for (let i = 0; i < num_cells - 1; i++) {
                 x += direction;
                 if (x >= this.width) {
@@ -314,6 +343,7 @@ class Level {
                         // TODO should be weak, but you can't destroy cloners so in practice not a concern
                         connectable.connection = tile;
                         found = true;
+                        break;
                     }
                 }
                 if (found)
diff --git a/js/tiletypes.js b/js/tiletypes.js
index a34110a..29ab723 100644
--- a/js/tiletypes.js
+++ b/js/tiletypes.js
@@ -364,7 +364,6 @@ const TILE_TYPES = {
         connect_order: 'forward',
         on_arrive(me, level, other) {
             if (me.connection && ! me.connection.doomed) {
-                // TODO do gray buttons affect traps?  if so this should use activate()
                 let trap = me.connection;
                 trap.open = true;
                 for (let tile of level.cells[trap.y][trap.x]) {
@@ -376,7 +375,6 @@ const TILE_TYPES = {
         },
         on_depart(me, level, other) {
             if (me.connection && ! me.connection.doomed) {
-                // TODO do gray buttons affect traps?  if so this should use activate()
                 let trap = me.connection;
                 trap.open = false;
                 for (let tile of level.cells[trap.y][trap.x]) {