diff --git a/src/main/kotlin/razorvine/c64emu/Cia.kt b/src/main/kotlin/razorvine/c64emu/Cia.kt
index b0f9f23..8e4e5eb 100644
--- a/src/main/kotlin/razorvine/c64emu/Cia.kt
+++ b/src/main/kotlin/razorvine/c64emu/Cia.kt
@@ -9,7 +9,7 @@ import java.awt.event.KeyEvent
  * Minimal simulation of the MOS 6526 CIA chip.
  * Depending on what CIA it is (1 or 2), some registers do different things on the C64.
  * This implementation provides a working keyboard matrix, TOD clock, and the essentials of the timer A and B.
- * TODO: timer IRQ triggering, more timer control bits.
+ * TODO: timer IRQ triggering, more timer control bits. Validate that the timerA/B timing is cycle correct.
  */
 class Cia(val number: Int, startAddress: Address, endAddress: Address) : MemMappedComponent(startAddress, endAddress) {
     private var ramBuffer = Array<UByte>(endAddress - startAddress + 1) { 0 }
diff --git a/src/main/kotlin/razorvine/c64emu/GUI.kt b/src/main/kotlin/razorvine/c64emu/GUI.kt
index 9fbed43..af42c8c 100644
--- a/src/main/kotlin/razorvine/c64emu/GUI.kt
+++ b/src/main/kotlin/razorvine/c64emu/GUI.kt
@@ -84,8 +84,6 @@ private class BitmapScreenPanel(val chargenData: ByteArray, val ram: MemoryCompo
     }
 
     override fun paint(graphics: Graphics) {
-        fullscreenG2d.color=Color.RED
-        fullscreenG2d.drawLine(0,0,ScreenDefs.SCREEN_WIDTH+ScreenDefs.BORDER_SIZE*2, ScreenDefs.SCREEN_HEIGHT+ScreenDefs.BORDER_SIZE*2)
         // draw the background color
         fullscreenG2d.background = ScreenDefs.colorPalette[ram[0xd021].toInt() and 15]
         fullscreenG2d.clearRect(ScreenDefs.BORDER_SIZE, ScreenDefs.BORDER_SIZE, ScreenDefs.SCREEN_WIDTH, ScreenDefs.SCREEN_HEIGHT)
@@ -116,6 +114,7 @@ private class BitmapScreenPanel(val chargenData: ByteArray, val ram: MemoryCompo
         for (y in 0 until height step ScreenDefs.DISPLAY_PIXEL_SCALING.toInt()) {
             g2d.drawLine(0, y, width, y)
         }
+        Toolkit.getDefaultToolkit().sync()
     }
 
     private fun redrawCharacters() {
diff --git a/src/main/kotlin/razorvine/c64emu/c64Main.kt b/src/main/kotlin/razorvine/c64emu/c64Main.kt
index e780b5a..7d8efcb 100644
--- a/src/main/kotlin/razorvine/c64emu/c64Main.kt
+++ b/src/main/kotlin/razorvine/c64emu/c64Main.kt
@@ -133,7 +133,7 @@ class C64Machine(title: String) : IVirtualMachine {
                         val ext = it.extension.toUpperCase()
                         val fileAndSize = Pair(it, it.length())
                         if (name.isEmpty())
-                            Pair("." + ext, "") to fileAndSize
+                            Pair(".$ext", "") to fileAndSize
                         else
                             Pair(name, ext) to fileAndSize
                     }
diff --git a/src/main/kotlin/razorvine/examplemachines/GUI.kt b/src/main/kotlin/razorvine/examplemachines/GUI.kt
index 4ab0643..d27d208 100644
--- a/src/main/kotlin/razorvine/examplemachines/GUI.kt
+++ b/src/main/kotlin/razorvine/examplemachines/GUI.kt
@@ -2,14 +2,14 @@ package razorvine.examplemachines
 
 import razorvine.ksim65.*
 import java.awt.*
-import java.awt.image.BufferedImage
-import javax.imageio.ImageIO
-import javax.swing.event.MouseInputListener
 import java.awt.event.*
+import java.awt.image.BufferedImage
 import java.io.File
 import java.lang.Integer.parseInt
 import java.util.*
+import javax.imageio.ImageIO
 import javax.swing.*
+import javax.swing.event.MouseInputListener
 
 
 /**
@@ -87,9 +87,7 @@ private class BitmapScreenPanel : JPanel() {
 
     override fun paint(graphics: Graphics) {
         val g2d = graphics as Graphics2D
-        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF)
-        g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_DISABLE)
-        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC)
+        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR)
         g2d.drawImage(
             image, 0, 0, (image.width * ScreenDefs.DISPLAY_PIXEL_SCALING).toInt(),
             (image.height * ScreenDefs.DISPLAY_PIXEL_SCALING).toInt(), null
@@ -103,7 +101,7 @@ private class BitmapScreenPanel : JPanel() {
             g2d.fillRect(scx, scy, scw, sch)
             g2d.setPaintMode()
         }
-
+        Toolkit.getDefaultToolkit().sync()
     }
 
     fun clearScreen() {
diff --git a/src/main/kotlin/razorvine/examplemachines/ehBasicMain.kt b/src/main/kotlin/razorvine/examplemachines/ehBasicMain.kt
index b73f1d2..526f0e3 100644
--- a/src/main/kotlin/razorvine/examplemachines/ehBasicMain.kt
+++ b/src/main/kotlin/razorvine/examplemachines/ehBasicMain.kt
@@ -27,8 +27,6 @@ class EhBasicMachine(title: String) {
     private var paused = false
 
     init {
-        hostDisplay.iconImage = ImageIcon(javaClass.getResource("/icon.png")).image
-
         bus += display
         bus += keyboard
         bus += rom
@@ -36,6 +34,7 @@ class EhBasicMachine(title: String) {
         bus += cpu
         bus.reset()
 
+        hostDisplay.iconImage = ImageIcon(javaClass.getResource("/icon.png")).image
         hostDisplay.isVisible = true
         hostDisplay.start(30)
     }
diff --git a/src/main/kotlin/razorvine/examplemachines/machineMain.kt b/src/main/kotlin/razorvine/examplemachines/machineMain.kt
index 556b53f..4836ae4 100644
--- a/src/main/kotlin/razorvine/examplemachines/machineMain.kt
+++ b/src/main/kotlin/razorvine/examplemachines/machineMain.kt
@@ -30,10 +30,6 @@ class VirtualMachine(title: String) : IVirtualMachine {
     private var paused = false
 
     init {
-        hostDisplay.iconImage = ImageIcon(javaClass.getResource("/icon.png")).image
-        debugWindow.iconImage = hostDisplay.iconImage
-        debugWindow.setLocation(hostDisplay.location.x + hostDisplay.width, hostDisplay.location.y)
-
         ram[Cpu6502.RESET_vector] = 0x00
         ram[Cpu6502.RESET_vector + 1] = 0x10
         ram.loadPrg(javaClass.getResourceAsStream("/vmdemo.prg"), null)
@@ -47,6 +43,9 @@ class VirtualMachine(title: String) : IVirtualMachine {
         bus += cpu
         bus.reset()
 
+        hostDisplay.iconImage = ImageIcon(javaClass.getResource("/icon.png")).image
+        debugWindow.iconImage = hostDisplay.iconImage
+        debugWindow.setLocation(hostDisplay.location.x + hostDisplay.width, hostDisplay.location.y)
         debugWindow.isVisible = true
         hostDisplay.isVisible = true
         hostDisplay.start(30)