Just some minor work on file dropping.

app/js/ctrls/CTRLIO.js

 import NESPalette from "/app/js/models/NESPalette.js";
 
 
+
+function HANDLE_DragOver(e){
+  e.stopPropagation();
+  e.preventDefault();
+  e.dataTransfer.dropEffect = 'copy';
+};
+
+function HANDLE_FileDrop(e){
+  e.stopPropagation();
+  e.preventDefault();
+  var files = e.dataTransfer.files;
+
+  for (let i=0; i < files.length; i++){
+    console.log(files[i]);
+  }
+}
+
 class CTRLIO{
   constructor(){}
+
+  initialize(){
+    var e = document.querySelectorAll(".drop-zone");
+    for (let i=0; i < e.length; e++){
+      e[i].addEventListener("dragover", HANDLE_DragOver);
+      e[i].addEventListener("drop", HANDLE_FileDrop);
+    }
+  }
 }
 
 

app/js/main.js

 import CTRLPalettesStore from "/app/js/ctrls/CTRLPalettesStore.js";
 import CTRLBanksStore from "/app/js/ctrls/CTRLBanksStore.js";
 import CTRLBankTools from "/app/js/ctrls/CTRLBankTools.js";
+import CTRLIO from "/app/js/ctrls/CTRLIO.js";
 
 import NESPalette from "/app/js/models/NESPalette.js";
 
 
   CTRLPalettesStore.initialize();
   CTRLBanksStore.initialize();
+
+  CTRLIO.initialize();
 }