diff --git a/src/main/scala/li/cil/oc/client/renderer/font/TextureFontRenderer.scala b/src/main/scala/li/cil/oc/client/renderer/font/TextureFontRenderer.scala
index 93686b1ae..97c290a2a 100644
--- a/src/main/scala/li/cil/oc/client/renderer/font/TextureFontRenderer.scala
+++ b/src/main/scala/li/cil/oc/client/renderer/font/TextureFontRenderer.scala
@@ -46,7 +46,7 @@ abstract class TextureFontRenderer {
     // Background first. We try to merge adjacent backgrounds of the same
     // color to reduce the number of quads we have to draw.
     GL11.glBegin(GL11.GL_QUADS)
-    for (y <- 0 until viewportHeight) {
+    for (y <- 0 until (viewportHeight min buffer.height)) {
       val color = buffer.color(y)
       var cbg = 0x000000
       var x = 0
@@ -74,7 +74,7 @@ abstract class TextureFontRenderer {
 
     // Foreground second. We only have to flush when the color changes, so
     // unless every char has a different color this should be quite efficient.
-    for (y <- 0 until viewportHeight) {
+    for (y <- 0 until (viewportHeight min buffer.height)) {
       val line = buffer.buffer(y)
       val color = buffer.color(y)
       val ty = y * charHeight
diff --git a/src/main/scala/li/cil/oc/common/component/TextBuffer.scala b/src/main/scala/li/cil/oc/common/component/TextBuffer.scala
index ee5253f97..f0ea9e66c 100644
--- a/src/main/scala/li/cil/oc/common/component/TextBuffer.scala
+++ b/src/main/scala/li/cil/oc/common/component/TextBuffer.scala
@@ -244,8 +244,9 @@ class TextBuffer(val host: EnvironmentHost) extends prefab.ManagedEnvironment wi
     proxy.onBufferResolutionChange(w, h)
     // Force set viewport to new resolution. This is partially for
     // backwards compatibility, and partially to enforce a valid one.
-    // Binary or to evaluate both, negated setViewport to only send signal once.
-    if ((data.size = (w, h)) | !setViewport(w, h)) {
+    val sizeChanged = data.size = (w, h)
+    val viewportChanged = setViewport(w, h)
+    if (sizeChanged && !viewportChanged) {
       if (node != null) {
         node.sendToReachable("computer.signal", "screen_resized", Int.box(w), Int.box(h))
       }
diff --git a/src/main/scala/li/cil/oc/util/TextBuffer.scala b/src/main/scala/li/cil/oc/util/TextBuffer.scala
index d896c010d..8cef8bad6 100644
--- a/src/main/scala/li/cil/oc/util/TextBuffer.scala
+++ b/src/main/scala/li/cil/oc/util/TextBuffer.scala
@@ -215,9 +215,9 @@ class TextBuffer(var width: Int, var height: Int, initialFormat: PackedColor.Col
   }
 
   def load(nbt: NBTTagCompound): Unit = {
-    val maxResolution = math.max(Settings.screenResolutionsByTier(2)._1, Settings.screenResolutionsByTier(2)._2)
-    val w = nbt.getInteger("width") max 1 min maxResolution
-    val h = nbt.getInteger("height") max 1 min maxResolution
+    val maxResolution = math.max(Settings.screenResolutionsByTier.last._1, Settings.screenResolutionsByTier.last._2)
+    val w = nbt.getInteger("width") min maxResolution max 1
+    val h = nbt.getInteger("height") min maxResolution max 1
     size = (w, h)
 
     val b = nbt.getTagList("buffer", NBT.TAG_STRING)