diff --git a/src/ide/ui.ts b/src/ide/ui.ts
index 18373d5e..39f6d757 100644
--- a/src/ide/ui.ts
+++ b/src/ide/ui.ts
@@ -1958,7 +1958,7 @@ function replaceURLState() {
 function addPageFocusHandlers() {
   var hidden = false;
   document.addEventListener("visibilitychange", () => {
-    if (document.visibilityState == 'hidden' && platform.isRunning()) {
+    if (document.visibilityState == 'hidden' && platform && platform.isRunning()) {
       _pause();
       hidden = true;
     } else if (document.visibilityState == 'visible' && hidden) {
@@ -1973,11 +1973,14 @@ function addPageFocusHandlers() {
     }
   });
   $(window).on("blur", () => {
-    if (platform.isRunning()) {
+    if (platform && platform.isRunning()) {
       _pause();
       hidden = true;
     }
   });
+  $(window).on("orientationchange", () => {
+    if (platform) setTimeout(platform.resize.bind(platform), 200);
+  });
 }
 
 // TODO: merge w/ embed.html somehow?
diff --git a/src/platform/vcs.ts b/src/platform/vcs.ts
index 0a86c15e..83736372 100644
--- a/src/platform/vcs.ts
+++ b/src/platform/vcs.ts
@@ -108,6 +108,7 @@ class VCSPlatform extends BasePlatform {
     };
     var jacanvas = $("#javatari-screen").find("canvas");
     jacanvas.mousedown(rasterPosBreakFn);
+    this.resize();
   }
 
   loadROM(title, data) {
@@ -389,6 +390,13 @@ class VCSPlatform extends BasePlatform {
   connectProbe(probe:ProbeAll) {
     this.probe = probe || this.nullProbe;
   }
+
+  // resizing
+  resize() {
+    var scale = Math.min(1, ($('#emulator').width() - 24) / 640);
+    var xt = (1 - scale) * 50;
+    $('#javatari-div').css('transform', `translateX(-${xt}%) translateY(-${xt}%) scale(${scale})`);
+  }
 };
 
 // TODO: mixin for Base6502Platform?