diff --git a/src/GameEngine.h b/src/GameEngine.h
index 6206946..ebd84ef 100644
--- a/src/GameEngine.h
+++ b/src/GameEngine.h
@@ -16,7 +16,7 @@ extern const uint16_t PerfectScore;
 
 typedef struct GameEngine
 {
-	int8_t Level;
+    int8_t Level;
     uint32_t Lights;
     uint16_t Par;
     uint16_t Moves;
diff --git a/src/GameWindow.c b/src/GameWindow.c
new file mode 100644
index 0000000..fd6e848
--- /dev/null
+++ b/src/GameWindow.c
@@ -0,0 +1,29 @@
+// Copyright (c) Jon Thysell <http://jonthysell.com>
+// Licensed under the MIT License.
+
+#include "GameWindow.h"
+
+void GameWindow_Init(GameWindow *gameWindow)
+{
+    if (gameWindow->Window != nil)
+    {
+        ShowError("\pGameWindow already initialized!", false);
+    }
+    
+    gameWindow->Window = GetNewWindow(kBaseResID, nil, kMoveToFront);
+    
+    if (gameWindow->Window == nil)
+    {
+        ShowError("\pGameWindow resource WIND kBaseResID missing!", true);
+    }
+    
+    CenterWindow(gameWindow->Window);
+    
+    ShowWindow(gameWindow->Window);
+    SetPort(gameWindow->Window);
+    
+    MoveTo(10, 20);
+    DrawString("\pHello MacLO");
+}
+
+
diff --git a/src/GameWindow.h b/src/GameWindow.h
new file mode 100644
index 0000000..42a9034
--- /dev/null
+++ b/src/GameWindow.h
@@ -0,0 +1,16 @@
+// Copyright (c) Jon Thysell <http://jonthysell.com>
+// Licensed under the MIT License.
+
+#ifndef GAMEWINDOW_H
+#define GAMEWINDOW_H
+
+#include "MacCommon.h"
+
+typedef struct GameWindow
+{
+	WindowPtr Window;
+} GameWindow;
+
+void GameWindow_Init(GameWindow *gameWindow);
+
+#endif
diff --git a/src/MacCommon.c b/src/MacCommon.c
new file mode 100644
index 0000000..8a0d4ba
--- /dev/null
+++ b/src/MacCommon.c
@@ -0,0 +1,26 @@
+// Copyright (c) Jon Thysell <http://jonthysell.com>
+// Licensed under the MIT License.
+
+#include "MacCommon.h"
+
+void CenterWindow(WindowPtr window)
+{
+    
+}
+
+Boolean IsCompactDisplay()
+{
+    return screenBits.bounds.right == 512
+        && screenBits.bounds.bottom == 342;
+}
+
+void ShowError(Str255 message, Boolean isFatal)
+{
+    ParamText(message, kEmptyString, kEmptyString, kEmptyString);
+    StopAlert(kErrorAlertID, kNilFilterProc);
+    
+    if (isFatal)
+    {
+        ExitToShell();
+    }
+}
diff --git a/src/MacCommon.h b/src/MacCommon.h
index 865a0d0..c7b5ec9 100644
--- a/src/MacCommon.h
+++ b/src/MacCommon.h
@@ -4,7 +4,16 @@
 #ifndef MACCOMMON_H
 #define MACCOMMON_H
 
-#define kBaseResID   128
-#define kMoveToFront (WindowPtr)-1L
+#define kBaseResID       128
+#define kMoveToFront     (WindowPtr)-1L
+
+#define kEmptyString     "\p"
+#define kNilFilterProc   nil
+
+#define kErrorAlertID    kBaseResID
+
+void CenterWindow(WindowPtr window);
+Boolean IsCompactDisplay();
+void ShowError(Str255 message, Boolean isFatal);
 
 #endif
diff --git a/src/MacLO.c b/src/MacLO.c
index e1fed4d..71f0ee6 100644
--- a/src/MacLO.c
+++ b/src/MacLO.c
@@ -1,10 +1,12 @@
 // Copyright (c) Jon Thysell <http://jonthysell.com>
 // Licensed under the MIT License.
 
-#include "MacCommon.h"
+#include "GameWindow.h"
 #include "MacLO.h"
 
-void InitToolBox()
+GameWindow gGameWindow;
+
+void MacLO_InitToolBox()
 {
     InitGraf(&thePort);
     InitFonts();
@@ -16,26 +18,12 @@ void InitToolBox()
     InitCursor();
 }
 
-void InitMainWindow()
+void MacLO_InitWindows()
 {
-    WindowPtr window;
-    
-    window = GetNewWindow(kBaseResID, nil, kMoveToFront);
-    
-    if (window == nil)
-    {
-        SysBeep(0);
-        ExitToShell();
-    }
-    
-    ShowWindow(window);
-    SetPort(window);
-    
-    MoveTo(30, 50);
-    DrawString("\pHello MacLO");
+    GameWindow_Init(&gGameWindow);
 }
 
-void ProcessEvents()
+void MacLO_MainLoop()
 {
     while (!Button()) { }
 }
diff --git a/src/MacLO.h b/src/MacLO.h
index ac9d94e..7e9e1c6 100644
--- a/src/MacLO.h
+++ b/src/MacLO.h
@@ -4,8 +4,8 @@
 #ifndef MACLO_H
 #define MACLO_H
 
-void InitToolBox();
-void InitMainWindow();
-void ProcessEvents();
+void MacLO_InitToolBox();
+void MacLO_InitWindows();
+void MacLO_MainLoop();
 
 #endif
diff --git a/src/MacLO.pi.bin b/src/MacLO.pi.bin
index 7c30880..2684838 100644
Binary files a/src/MacLO.pi.bin and b/src/MacLO.pi.bin differ
diff --git a/src/MacLO.pi.rsrc.bin b/src/MacLO.pi.rsrc.bin
index 8930783..6d5ece6 100644
Binary files a/src/MacLO.pi.rsrc.bin and b/src/MacLO.pi.rsrc.bin differ
diff --git a/src/main.c b/src/main.c
index e0ef647..d982b44 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,7 +5,7 @@
 
 void main(void)
 {
-    InitToolBox();
-    InitMainWindow();
-    ProcessEvents();
+    MacLO_InitToolBox();
+    MacLO_InitWindows();
+    MacLO_MainLoop();
 }
diff --git a/src/stdbool.h b/src/stdbool.h
index 9152796..624d7ca 100644
--- a/src/stdbool.h
+++ b/src/stdbool.h
@@ -4,10 +4,6 @@
 #ifndef STDBOOL_H
 #define STDBOOL_H
 
-#ifndef true
-typedef char bool;
-#define true 1
-#define false 0
-#endif
+typedef Boolean bool;
 
 #endif