diff --git a/css/ui.css b/css/ui.css
index 005ae5bb..8b72adbb 100644
--- a/css/ui.css
+++ b/css/ui.css
@@ -502,4 +502,11 @@ div.asset_editor {
   padding:16px;
   margin:16px;
   background-color:#999;
+  display:flex;
+  flex-direction:column;
+  align-items:center;
+}
+div.asset_toolbar {
+  padding:8px;
+  margin:8px;
 }
diff --git a/doc/notes.txt b/doc/notes.txt
index 56b3eaef..34806a5b 100644
--- a/doc/notes.txt
+++ b/doc/notes.txt
@@ -108,6 +108,7 @@ TODO:
   - metasprites
   - update nested data, palette/tile refs properly
   - throw errors when bad/no refs
+  - careful with mouse capture out of frame
 
 WEB WORKER FORMAT
 
diff --git a/src/pixed/pixeleditor.ts b/src/pixed/pixeleditor.ts
index 4ed39f94..c68a06ea 100644
--- a/src/pixed/pixeleditor.ts
+++ b/src/pixed/pixeleditor.ts
@@ -317,6 +317,33 @@ var PREDEF_LAYOUTS : {[id:string]:PixelEditorPaletteLayout} = {
 
 /////
 
+function equalArrays(a:UintArray, b:UintArray) : boolean {
+  if (a == null || b == null)
+    return false;
+  if (a.length !== b.length)
+    return false;
+  if (a === b)
+    return true;
+  for (var i=0; i<a.length; i++) {
+    if (a[i] !== b[i])
+      return false;
+  }
+  return true;
+}
+function equalNestedArrays(a:UintArray[], b:UintArray[]) : boolean {
+  if (a == null || b == null)
+    return false;
+  if (a.length !== b.length)
+    return false;
+  if (a === b)
+    return true;
+  for (var i=0; i<a.length; i++) {
+    if (!equalArrays(a[i], b[i]))
+      return false;
+  }
+  return true;
+}
+
 export abstract class PixNode {
   left : PixNode;		// toward text editor
   right : PixNode;		// toward pixel editor
@@ -326,8 +353,8 @@ export abstract class PixNode {
   rgbimgs? : Uint32Array[];	// array of rgba imgages
   palette? : Uint32Array; // array of rgba
 
-  abstract updateLeft();	// update coming from right
-  abstract updateRight();	// update coming from left
+  abstract updateLeft() : boolean;	// update coming from right
+  abstract updateRight() : boolean;	// update coming from left
 
   refreshLeft() {
     var p : PixNode = this;
@@ -364,20 +391,25 @@ abstract class CodeProjectDataNode extends PixNode {
 
 export class FileDataNode extends CodeProjectDataNode {
 
-  constructor(project:ProjectWindows, fileid:string, data:Uint8Array) {
+  constructor(project:ProjectWindows, fileid:string) {
     super();
     this.project = project;
     this.fileid = fileid;
     this.label = fileid;
-    this.words = data;
   }
   updateLeft() {
+    //if (equalArrays(this.words, this.right.words)) return false;
     this.words = this.right.words;
     if (this.project) {
       this.project.updateFile(this.fileid, this.words as Uint8Array);
     }
+    return true;
   }
   updateRight() {
+    if (this.project) {
+      this.words = this.project.project.getFile(this.fileid) as Uint8Array;
+    }
+    return true;
   }
 }
 
@@ -386,12 +418,12 @@ export class TextDataNode extends CodeProjectDataNode {
   start : number;
   end : number;
 
-  constructor(project:ProjectWindows, fileid:string, label:string, text:string, start:number, end:number) {
+  // TODO: what if file size/layout changes?
+  constructor(project:ProjectWindows, fileid:string, label:string, start:number, end:number) {
     super();
     this.project = project;
     this.fileid = fileid;
     this.label = label;
-    this.text = text;
     this.start = start;
     this.end = end;
   }
@@ -407,12 +439,17 @@ export class TextDataNode extends CodeProjectDataNode {
       this.project.updateFile(this.fileid, this.text);
       //this.project.replaceTextRange(this.fileid, this.start, this.end, datastr);
     }
+    return true;
   }
   updateRight() {
+    if (this.project) {
+      this.text = this.project.project.getFile(this.fileid) as string;
+    }
     var datastr = this.text.substring(this.start, this.end);
     datastr = convertToHexStatements(datastr); // TODO?
     var words = parseHexWords(datastr);
     this.words = words; //new Uint8Array(words); // TODO: 16/32?
+    return true;
   }
 }
 
@@ -422,9 +459,11 @@ export class Compressor extends PixNode {
 
   updateLeft() {
     // TODO: can't modify length of rle bytes
+    return false;
   }
   updateRight() {
     this.words = rle_unpack(new Uint8Array(this.left.words));
+    return true;
   }
 
 }
@@ -440,13 +479,17 @@ export class Mapper extends PixNode {
     this.fmt = fmt;
   }
   updateLeft() {
+    //if (equalNestedArrays(this.images, this.right.images)) return false;
     this.images = this.right.images;
     this.words = convertImagesToWords(this.images, this.fmt);
+    return true;
   }
   updateRight() {
+    if (equalArrays(this.words, this.left.words)) return false;
     // convert each word array to images
     this.words = this.left.words;
     this.images = convertWordsToImages(this.words, this.fmt);
+    return true;
   }
 }
 
@@ -481,18 +524,21 @@ export class Palettizer extends PixNode {
   updateLeft() {
     this.rgbimgs = this.right.rgbimgs;
     var pal = new RGBAPalette(this.palette);
-    this.images = this.rgbimgs.map( (im:Uint32Array) => {
+    var newimages = this.rgbimgs.map( (im:Uint32Array) => {
       var out = new Uint8Array(im.length);
       for (var i=0; i<im.length; i++) {
         out[i] = pal.indexOf(im[i]);
       }
       return out;
     });
+    // have to do it this way b/c pixel editor modifies arrays
+    //if (equalNestedArrays(newimages, this.images)) return false;
+    this.images = newimages;
+    return true;
   }
   updateRight() {
-    this.updateRefs();
+    if (!this.updateRefs() && equalNestedArrays(this.images, this.left.images)) return false;
     this.images = this.left.images;
-    if (!this.palette || !this.images) return;
     var mask = this.palette.length - 1; // must be power of 2
     // for each image, map bytes to RGB colors
     this.rgbimgs = this.images.map( (im:Uint8Array) => {
@@ -502,20 +548,25 @@ export class Palettizer extends PixNode {
       }
       return out;
     });
+    return true;
   }
   updateRefs() {
+    var newpalette;
     if (this.context != null) {
       this.paloptions = this.context.getPalettes(this.ncolors);
       if (this.paloptions && this.paloptions.length > 0) {
-        this.palette = this.paloptions[this.palindex].palette;
+        newpalette = this.paloptions[this.palindex].palette;
       }
     }
-    if (this.palette == null) {
+    if (newpalette == null) {
       if (this.ncolors <= 2)
-        this.palette = new Uint32Array([0xff000000, 0xffffffff]);
+        newpalette = new Uint32Array([0xff000000, 0xffffffff]);
       else
-        this.palette = new Uint32Array([0xff000000, 0xffff00ff, 0xffffff00, 0xffffffff]); // TODO: more palettes
+        newpalette = new Uint32Array([0xff000000, 0xffff00ff, 0xffffff00, 0xffffffff]); // TODO: more palettes
     }
+    if (equalArrays(this.palette, newpalette)) return false;
+    this.palette = newpalette;
+    return true;
   }
 }
 
@@ -533,9 +584,9 @@ function dedupPalette(cols : UintArray) : Uint32Array {
   }
   return res;
 }
-
 export class PaletteFormatToRGB extends PixNode {
 
+
   words : UintArray;
   rgbimgs : Uint32Array[];
   palette : Uint32Array;
@@ -548,8 +599,10 @@ export class PaletteFormatToRGB extends PixNode {
   }
   updateLeft() {
     //TODO
+    return true;
   }
   updateRight() {
+    if (equalArrays(this.words, this.left.words)) return false;
     this.words = this.left.words;
     this.palette = dedupPalette(convertPaletteFormat(this.words, this.palfmt));
     this.layout = PREDEF_LAYOUTS[this.palfmt.layout];
@@ -557,6 +610,7 @@ export class PaletteFormatToRGB extends PixNode {
     this.palette.forEach( (rgba:number) => {
       this.rgbimgs.push(new Uint32Array([rgba]));
     });
+    return true;
   }
   getAllColors() {
     var arr = [];
@@ -581,13 +635,15 @@ export abstract class Compositor extends PixNode {
     super();
     this.context = context;
   }
-  updateRefs() {
+  updateRefs() : boolean {
+    var oldtilemap = this.tilemap;
     if (this.context != null) {
       this.tileoptions = this.context.getTilemaps(256);
       if (this.tileoptions && this.tileoptions.length > 0) {
         this.tilemap = this.tileoptions[this.tileindex].images;
       }
     }
+    return !equalNestedArrays(oldtilemap, this.tilemap);
   }
 }
 
@@ -605,6 +661,7 @@ export class MetaspriteCompositor extends Compositor {
   }
   updateLeft() {
     // TODO
+    return false;
   }
   updateRight() {
     this.updateRefs();
@@ -615,6 +672,7 @@ export class MetaspriteCompositor extends Compositor {
     this.metadefs.forEach((meta) => {
       // TODO
     });
+    return true;
   }
 }
 
@@ -628,11 +686,11 @@ export class NESNametableConverter extends Compositor {
   }
   updateLeft() {
     // TODO
+    return false;
   }
   updateRight() {
+    if (!this.updateRefs() && equalArrays(this.words, this.left.words)) return false;
     this.words = this.left.words;
-    this.updateRefs();
-    if (!this.words || !this.tilemap) return;
     this.cols = 32;
     this.rows = 30;
     this.width = this.cols * 8;
@@ -665,6 +723,7 @@ export class NESNametableConverter extends Compositor {
       }
     }
     // TODO
+    return true;
   }
 }
 
@@ -682,7 +741,6 @@ export class ImageChooser {
     var cscale = Math.max(2, Math.ceil(16/this.width)); // TODO
     var imgsperline = this.width <= 8 ? 16 : 8; // TODO
     var span = null;
-    if (!this.rgbimgs) return;
     this.rgbimgs.forEach((imdata, i) => {
       var viewer = new Viewer();
       viewer.width = this.width;
@@ -730,9 +788,11 @@ export class CharmapEditor extends PixNode {
   }
 
   updateLeft() {
+    return true;
   }
 
   updateRight() {
+    if (equalNestedArrays(this.rgbimgs, this.left.rgbimgs)) return false;
     this.rgbimgs = this.left.rgbimgs;
     var adual = newDiv(this.parentdiv.empty(), "asset_dual"); // contains grid and editor
     var agrid = newDiv(adual);
@@ -765,6 +825,7 @@ export class CharmapEditor extends PixNode {
         palizer.refreshRight();
       });
     }
+    return true;
   }
 
   createEditor(aeditor : JQuery, viewer : Viewer, escale : number) : PixEditor {
@@ -901,7 +962,7 @@ class PixEditor extends Viewer {
 
   createPaletteButtons() {
     this.palbtns = [];
-    var span = $(document.createElement('div'));
+    var span = newDiv(null, "asset_toolbar");
     for (var i=0; i<this.palette.length; i++) {
       var btn = $(document.createElement('button')).addClass('palbtn');
       var rgb = this.palette[i] & 0xffffff;
diff --git a/src/views.ts b/src/views.ts
index 0ff6f7f7..8931504b 100644
--- a/src/views.ts
+++ b/src/views.ts
@@ -974,8 +974,9 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
       }
       if (div) {
         this.cureditordiv = div;
-        this.cureditordiv.show(timeout);
+        this.cureditordiv.show();
         this.cureditordiv[0].scrollIntoView({behavior: "smooth", block: "center"});
+        //setTimeout(() => { this.cureditordiv[0].scrollIntoView({behavior: "smooth", block: "center"}) }, timeout);
       }
     }
     if (this.cureditelem) {
@@ -1039,37 +1040,42 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
     return result;
   }
 
-  addPaletteEditorViews(parentdiv:JQuery, words, palette, layout, allcolors, callback) {
+  addPaletteEditorViews(parentdiv:JQuery, pal2rgb:pixed.PaletteFormatToRGB, callback) {
     var adual = $('<div class="asset_dual"/>').appendTo(parentdiv);
     var aeditor = $('<div class="asset_editor"/>').hide(); // contains editor, when selected
     // TODO: they need to update when refreshed from right
     var allrgbimgs = [];
-    allcolors.forEach((rgba) => { allrgbimgs.push(new Uint32Array([rgba])); }); // array of array of 1 rgb color (for picker)
+    pal2rgb.getAllColors().forEach((rgba) => { allrgbimgs.push(new Uint32Array([rgba])); }); // array of array of 1 rgb color (for picker)
     var atable = $('<table/>').appendTo(adual);
     aeditor.appendTo(adual);
     // make default layout if not exists
+    var layout = pal2rgb.layout;
     if (!layout) {
-      var len = palette.length;
+      var len = pal2rgb.palette.length;
       var imgsperline = len > 32 ? 8 : 4; // TODO: use 'n'?
       layout = [];
       for (var i=0; i<len; i+=imgsperline) {
         layout.push(["", i, Math.min(len-i,imgsperline)]);
       }
     }
+    function updateCell(cell, j) {
+      var val = pal2rgb.words[j];
+      var rgb = pal2rgb.palette[j];
+      var hexcol = '#'+hex(rgb2bgr(rgb),6);
+      var textcol = (rgb & 0x008000) ? 'black' : 'white';
+      cell.text(hex(val,2)).css('background-color',hexcol).css('color',textcol);
+    }
     // iterate over each row of the layout
     layout.forEach( ([name, start, len]) => {
-      if (start < palette.length) { // skip row if out of range
+      if (start < pal2rgb.palette.length) { // skip row if out of range
         var arow = $('<tr/>').appendTo(atable);
         $('<td/>').text(name).appendTo(arow);
         var inds = [];
         for (var k=start; k<start+len; k++)
           inds.push(k);
         inds.forEach( (i) => {
-          var val = words[i];
-          var rgb = palette[i];
-          var hexcol = '#'+hex(rgb2bgr(rgb),6);
-          var textcol = (rgb & 0x008000) ? 'black' : 'white';
-          var cell = $('<td/>').addClass('asset_cell asset_editable').text(hex(val,2)).css('background-color',hexcol).css('color',textcol).appendTo(arow);
+          var cell = $('<td/>').addClass('asset_cell asset_editable').appendTo(arow);
+          updateCell(cell, i);
           cell.click((e) => {
             var chooser = new pixed.ImageChooser();
             chooser.rgbimgs = allrgbimgs;
@@ -1077,6 +1083,7 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
             chooser.height = 1;
             chooser.recreate(aeditor, (index, newvalue) => {
               callback(i, index);
+              updateCell(cell, i);
             });
             this.setCurrentEditor(aeditor, cell);
           });
@@ -1106,13 +1113,14 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
     firstnode.refreshRight();
     // TODO: add view objects
     // TODO: show which one is selected?
-    this.addPaletteEditorViews(parentdiv, firstnode.words,
-      pal2rgb.palette, pal2rgb.layout, pal2rgb.getAllColors(),
+    this.addPaletteEditorViews(parentdiv, pal2rgb,
       (index, newvalue) => {
         console.log('set entry', index, '=', newvalue);
+        // TODO: this forces update of palette rgb colors and file data
         firstnode.words[index] = newvalue;
-        //firstnode.refreshRight();
-        firstnode.refreshLeft();
+        pal2rgb.words = null;
+        pal2rgb.updateRight();
+        pal2rgb.refreshLeft();
       });
   }
 
@@ -1124,16 +1132,17 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
     // TODO: only refresh when needed
     if (fileid.endsWith('.chr') && data instanceof Uint8Array) {
       // is this a NES CHR?
-      let node = new pixed.FileDataNode(projectWindows, fileid, data);
+      let node = new pixed.FileDataNode(projectWindows, fileid);
       const neschrfmt = {w:8,h:8,bpp:1,count:(data.length>>4),brev:true,np:2,pofs:8,remap:[0,1,2,4,5,6,7,8,9,10,11,12]}; // TODO
       this.addPixelEditor(filediv, node, neschrfmt);
       this.registerAsset("charmap", node, true);
+      nassets++;
     } else if (typeof data === 'string') {
       let textfrags = this.scanFileTextForAssets(fileid, data);
       for (let frag of textfrags) {
         if (frag.fmt) {
           let label = fileid; // TODO: label
-          let node : pixed.PixNode = new pixed.TextDataNode(projectWindows, fileid, label, data, frag.start, frag.end);
+          let node : pixed.PixNode = new pixed.TextDataNode(projectWindows, fileid, label, frag.start, frag.end);
           let first = node;
           // rle-compressed?
           if (frag.fmt.comp == 'rletag') {
@@ -1194,6 +1203,10 @@ export class AssetEditorView implements ProjectView, pixed.EditorContext {
       console.log("Found " + this.rootnodes.length + " assets");
       this.deferrednodes.forEach((node) => { node.refreshRight(); });
       this.deferrednodes = [];
+    } else {
+      for (var node of this.rootnodes) {
+        node.refreshRight();
+      }
     }
   }
 
diff --git a/test/cli/testpixelconvert.js b/test/cli/testpixelconvert.js
index da4f3871..05669699 100644
--- a/test/cli/testpixelconvert.js
+++ b/test/cli/testpixelconvert.js
@@ -13,13 +13,15 @@ describe('Pixel editor', function() {
     var palfmt = {pal:332,n:16};
 
     var paldatastr =  " 0x00, 0x03, 0x19, 0x50, 0x52, 0x07, 0x1f, 0x37, 0xe0, 0xa4, 0xfd, 0xff, 0x38, 0x70, 0x7f, 0xf8, ";
-    var node4 = new pixed.TextDataNode(null, null, null, paldatastr, 0, paldatastr.length);
+    var node4 = new pixed.TextDataNode(null, null, null, 0, paldatastr.length);
+    node4.text = paldatastr;
     var node5 = new pixed.PaletteFormatToRGB(palfmt);
     node4.addRight(node5);
     node4.refreshRight();
 
     var datastr = "1,2, 0x00,0x00,0xef,0xef,0xe0,0x00,0x00, 0x00,0xee,0xee,0xfe,0xee,0xe0,0x00, 0x0e,0xed,0xef,0xef,0xed,0xee,0x00, 0x0e,0xee,0xdd,0xdd,0xde,0xee,0x00, 0x0e,0xee,0xed,0xde,0xee,0xee,0x00, 0x00,0xee,0xee,0xde,0xee,0xe0,0x00, 0x00,0xee,0xee,0xde,0xee,0xe0,0x00, 0x00,0x00,0xed,0xdd,0xe0,0x00,0x0d, 0xdd,0xdd,0xee,0xee,0xed,0xdd,0xd0, 0x0d,0xee,0xee,0xee,0xee,0xee,0x00, 0x0e,0xe0,0xee,0xee,0xe0,0xee,0x00, 0x0e,0xe0,0xee,0xee,0xe0,0xee,0x00, 0x0e,0xe0,0xdd,0xdd,0xd0,0xde,0x00, 0x0d,0x00,0xee,0x0e,0xe0,0x0d,0x00, 0x00,0x00,0xed,0x0e,0xe0,0x00,0x00, 0x00,0x0d,0xdd,0x0d,0xdd,0x00,0x18,";
-    var node1 = new pixed.TextDataNode(null, null, null, datastr, 0, datastr.length);
+    var node1 = new pixed.TextDataNode(null, null, null, 0, datastr.length);
+    node1.text = datastr;
     var node2 = new pixed.Mapper(fmt);
     node1.addRight(node2);
     var node3 = new pixed.Palettizer(null, fmt);