diff --git a/src/addresses.h b/src/addresses.h
index bc235a15f4..7269fbd960 100644
--- a/src/addresses.h
+++ b/src/addresses.h
@@ -517,14 +517,6 @@
 #define RCT2_ADDRESS_TOOLTIP_TEXT_BUFFER			0x0141FE44
 #define RCT2_ADDRESS_TOOLTIP_TEXT_HEIGHT			0x01420044
 
-#define RCT2_ADDRESS_WINDOW_LIST					0x01420078
-#define RCT2_ADDRESS_NEW_WINDOW_PTR					0x014234B8
-
-#define RCT2_ADDRESS_VIEWPORT_LIST					0x014234BC
-// Null Terminated list of active viewport pointers.
-// This is also the end of RCT2_ADDRESS_VIEWPORT_LIST.
-#define RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY		0x01423570
-
 #define RCT2_ADDRESS_HCURSOR_START					0x01423598
 #define RCT2_ADDRESS_HCURSOR_ARROW					0x01423598
 #define RCT2_ADDRESS_HCURSOR_BLANK					0x0142359C
@@ -624,6 +616,14 @@
 #define RCT2_ADDRESS_CONFIG_FIRST_TIME_LOAD_CONFIG	0x009AB4C6
 #define RCT2_ADDRESS_NAUSEA_THRESHOLDS				0x00982390  //uint16
 
+#define RCT2_ADDRESS_WINDOW_LIST					0x01420078
+#define RCT2_ADDRESS_NEW_WINDOW_PTR					0x014234B8
+
+#define RCT2_ADDRESS_VIEWPORT_LIST					0x014234BC
+// Null Terminated list of active viewport pointers.
+// This is also the end of RCT2_ADDRESS_VIEWPORT_LIST.
+#define RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY		0x01423570
+
 #pragma endregion
 
 /**
diff --git a/src/audio/audio.c b/src/audio/audio.c
index ff91b26ed5..d98a015b2c 100644
--- a/src/audio/audio.c
+++ b/src/audio/audio.c
@@ -144,10 +144,10 @@ rct_audio_params audio_get_params_from_location(int soundId, const rct_xyz16 *lo
 
 	uint8 rotation = get_current_rotation();
 	rct_xy16 pos2 = coordinate_3d_to_2d(location, rotation);
-	rct_window *window = RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*);
+	rct_window *window = gWindowNextSlot;
 	while (true) {
 		window--;
-		if (window < RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window))
+		if (window < g_window_list)
 			break;
 
 		rct_viewport *viewport = window->viewport;
diff --git a/src/drawing/drawing.c b/src/drawing/drawing.c
index 3c98306f68..b11d05ce22 100644
--- a/src/drawing/drawing.c
+++ b/src/drawing/drawing.c
@@ -337,7 +337,7 @@ void gfx_redraw_screen_rect(short left, short top, short right, short bottom)
 	windowDPI->height = bottom - top;
 	windowDPI->pitch = screenDPI->width + screenDPI->pitch + left - right;
 
-	for (w = g_window_list; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++) {
+	for (w = g_window_list; w < gWindowNextSlot; w++) {
 		if (w->flags & WF_TRANSPARENT)
 			continue;
 		if (right <= w->x || bottom <= w->y)
diff --git a/src/drawing/rain.c b/src/drawing/rain.c
index 89e5db3e1c..f2c7d5a3dd 100644
--- a/src/drawing/rain.c
+++ b/src/drawing/rain.c
@@ -71,7 +71,7 @@ static void call_draw_rain_func(rct_window* w, short left, short right, short to
  */
 static void draw_rain_window(rct_window* original_w, short left, short right, short top, short bottom, uint32 draw_rain_func)
 {
-	rct_window* newWindow = RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*);
+	rct_window* newWindow = gWindowNextSlot;
 
 	rct_window* w = original_w + 1; // Start from second window
 	for (; ; w++) {
@@ -139,7 +139,7 @@ static void draw_rain_animation(uint32 draw_rain_func)
 	short top = screenDPI->y;
 	short bottom = top + screenDPI->height;
 
-	rct_window* newWindow = (RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*));
+	rct_window* newWindow = gWindowNextSlot;
 
 	for (rct_window* w = g_window_list; w < newWindow; w++) {
 		draw_rain_window(w, left, right, top, bottom, draw_rain_func);
diff --git a/src/input.c b/src/input.c
index e34c8f84ae..1dd20e5094 100644
--- a/src/input.c
+++ b/src/input.c
@@ -139,7 +139,7 @@ void game_handle_input()
 	}
 
 	if (RCT2_GLOBAL(0x009ABDF2, uint8) != 0) {
-		for (w = g_window_list; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++)
+		for (w = g_window_list; w < gWindowNextSlot; w++)
 			window_event_unknown_07_call(w);
 
 		sub_6EA73F();
@@ -166,7 +166,7 @@ void game_handle_input()
 		}
 	}
 
-	for (w = g_window_list; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++)
+	for (w = g_window_list; w < gWindowNextSlot; w++)
 		window_event_unknown_08_call(w);
 }
 
diff --git a/src/interface/viewport.c b/src/interface/viewport.c
index e7afdebfe9..6f7c98c65b 100644
--- a/src/interface/viewport.c
+++ b/src/interface/viewport.c
@@ -38,12 +38,9 @@
 #include "viewport.h"
 #include "window.h"
 
-#define RCT2_FIRST_VIEWPORT		(RCT2_ADDRESS(RCT2_ADDRESS_VIEWPORT_LIST, rct_viewport))
-#define RCT2_LAST_VIEWPORT		(RCT2_ADDRESS(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport) - 1)
-
 //#define DEBUG_SHOW_DIRTY_BOX
 
-rct_viewport* g_viewport_list = RCT2_ADDRESS(RCT2_ADDRESS_VIEWPORT_LIST, rct_viewport);
+rct_viewport g_viewport_list[MAX_VIEWPORT_COUNT];
 
 typedef struct paint_struct paint_struct;
 
@@ -92,14 +89,13 @@ void viewport_init_all()
 	colours_init_maps();
 
 	// Setting up windows
-	RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*) = g_window_list;
+	gWindowNextSlot = g_window_list;
 	RCT2_GLOBAL(0x01423604, sint32) = 0;
 
 	// Setting up viewports
-	for (int i = 0; i < 9; i++) {
+	for (int i = 0; i < MAX_VIEWPORT_COUNT; i++) {
 		g_viewport_list[i].width = 0;
 	}
-	RCT2_GLOBAL(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport*) = NULL;
 
 	// ?
 	gInputFlags = 0;
@@ -167,12 +163,17 @@ void center_2d_coordinates(int x, int y, int z, int* out_x, int* out_y, rct_view
 */
 void viewport_create(rct_window *w, int x, int y, int width, int height, int zoom, int center_x, int center_y, int center_z, char flags, sint16 sprite)
 {
-	rct_viewport* viewport;
-	for (viewport = g_viewport_list; viewport->width != 0; viewport++){
-		if (viewport > RCT2_LAST_VIEWPORT){
-			error_string_quit(0xFF000001, -1);
+	rct_viewport* viewport = NULL;
+	for (int i = 0; i < MAX_VIEWPORT_COUNT; i++) {
+		if (g_viewport_list[i].width == 0) {
+			viewport = &g_viewport_list[i];
+			break;
 		}
 	}
+	if (viewport == NULL) {
+		log_error("No more viewport slots left to allocate.");
+		return;
+	}
 
 	viewport->x = x;
 	viewport->y = y;
@@ -220,15 +221,7 @@ void viewport_create(rct_window *w, int x, int y, int width, int height, int zoo
  */
 void viewport_update_pointers()
 {
-	rct_viewport *viewport;
-	rct_viewport **vp = RCT2_ADDRESS(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport*);
 
-	// The last possible viewport entry is 1 before what is the active viewport_ptr_array
-	for (viewport = g_viewport_list; viewport <= RCT2_LAST_VIEWPORT; viewport++)
-		if (viewport->width != 0)
-			*vp++ = viewport;
-
-	*vp = NULL;
 }
 
 /**
@@ -324,7 +317,7 @@ void gfx_move_screen_rect(int x, int y, int width, int height, int dx, int dy)
 void sub_6E7FF3(rct_window *window, rct_viewport *viewport, int x, int y)
 {
 	// sub-divide by intersecting windows
-	if (window < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*))
+	if (window < gWindowNextSlot)
 	{
 		// skip current window and non-intersecting windows
 		if (viewport == window->viewport                                ||
@@ -445,7 +438,7 @@ void sub_6E7F34(rct_window* w, rct_viewport* viewport, sint16 x_diff, sint16 y_d
 	rct_window* orignal_w = w;
 	int left = 0, right = 0, top = 0, bottom = 0;
 
-	for (; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++){
+	for (; w < gWindowNextSlot; w++){
 		if (!(w->flags & WF_TRANSPARENT)) continue;
 		if (w->viewport == viewport) continue;
 
diff --git a/src/interface/viewport.h b/src/interface/viewport.h
index 55086127c3..d05fce6a50 100644
--- a/src/interface/viewport.h
+++ b/src/interface/viewport.h
@@ -88,8 +88,10 @@ typedef struct {
 	};
 } viewport_interaction_info;
 
+#define MAX_VIEWPORT_COUNT MAX_WINDOW_COUNT
+
 // rct2: 0x014234BC
-extern rct_viewport* g_viewport_list;
+extern rct_viewport g_viewport_list[MAX_VIEWPORT_COUNT];
 
 void viewport_init_all();
 void center_2d_coordinates(int x, int y, int z, int* out_x, int* out_y, rct_viewport* viewport);
diff --git a/src/interface/window.c b/src/interface/window.c
index 3900f8a752..380b7d8450 100644
--- a/src/interface/window.c
+++ b/src/interface/window.c
@@ -33,13 +33,13 @@
 #include "../localisation/localisation.h"
 #include "../cursors.h"
 
-#define RCT2_FIRST_WINDOW		(RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window))
-#define RCT2_LAST_WINDOW		(RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*) - 1)
-#define RCT2_NEW_WINDOW			(RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*))
+#define RCT2_FIRST_WINDOW		(g_window_list)
+#define RCT2_LAST_WINDOW		(gWindowNextSlot - 1)
+#define RCT2_NEW_WINDOW			(gWindowNextSlot)
 
-#define MAX_NUMBER_WINDOWS 11
-
-rct_window* g_window_list = RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window);
+rct_window g_window_list[MAX_WINDOW_COUNT];
+rct_window * gWindowFirst;
+rct_window * gWindowNextSlot;
 
 uint16 TextInputDescriptionArgs[4];
 widget_identifier gCurrentTextBox = { { 255, 0 }, 0 };
@@ -393,7 +393,7 @@ rct_window *window_create(int x, int y, int width, int height, rct_window_event_
 {
 	rct_window *w;
 	// Check if there are any window slots left
-	if (RCT2_NEW_WINDOW >= &(g_window_list[MAX_NUMBER_WINDOWS])) {
+	if (RCT2_NEW_WINDOW >= &(g_window_list[MAX_WINDOW_COUNT])) {
 		// Close least recently used window
 		for (w = g_window_list; w < RCT2_NEW_WINDOW; w++)
 			if (!(w->flags & (WF_STICK_TO_BACK | WF_STICK_TO_FRONT | WF_NO_AUTO_CLOSE)))
@@ -1196,7 +1196,7 @@ rct_window *window_bring_to_front_by_number(rct_windowclass cls, rct_windownumbe
  */
 void window_push_others_right(rct_window* window)
 {
-	for (rct_window* w = g_window_list; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++) {
+	for (rct_window* w = g_window_list; w < gWindowNextSlot; w++) {
 		if (w == window)
 			continue;
 		if (w->flags & (WF_STICK_TO_BACK | WF_STICK_TO_FRONT))
@@ -1351,7 +1351,7 @@ void window_scroll_to_location(rct_window *w, int x, int y, int z)
 				rct_window* w2 = w;
 				while (1) {
 					w2++;
-					if (w2 >= RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*)) {
+					if (w2 >= gWindowNextSlot) {
 						found = 1;
 						break;
 					}
diff --git a/src/interface/window.h b/src/interface/window.h
index a101157dc9..cb9184b997 100644
--- a/src/interface/window.h
+++ b/src/interface/window.h
@@ -503,8 +503,13 @@ extern modal_callback gLoadSaveCallback;
 
 typedef void (*close_callback)();
 
+#define MAX_WINDOW_COUNT 64
+
 // rct2: 0x01420078
-extern rct_window* g_window_list;
+extern rct_window g_window_list[MAX_WINDOW_COUNT];
+
+extern rct_window * gWindowFirst;
+extern rct_window * gWindowNextSlot;
 
 // rct2: 0x00F635EE
 extern ride_list_item _window_track_list_item;
diff --git a/src/ride/vehicle.c b/src/ride/vehicle.c
index 08e20b191e..933ffb3924 100644
--- a/src/ride/vehicle.c
+++ b/src/ride/vehicle.c
@@ -296,10 +296,10 @@ void vehicle_sounds_update()
 	if (RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_SOUND_DEVICE, uint32) != -1 && !gGameSoundsOff && gConfigSound.sound_enabled && !gOpenRCT2Headless) {
 		RCT2_GLOBAL(0x00F438A4, rct_viewport*) = (rct_viewport*)-1;
 		rct_viewport* viewport = (rct_viewport*)-1;
-		rct_window* window = RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*);
+		rct_window* window = gWindowNextSlot;
 		while (1) {
 			window--;
-			if (window < RCT2_ADDRESS(RCT2_ADDRESS_WINDOW_LIST, rct_window)) {
+			if (window < g_window_list) {
 				break;
 			}
 			viewport = window->viewport;
diff --git a/src/scenario.c b/src/scenario.c
index 41eab2fd9a..5b8942df8b 100644
--- a/src/scenario.c
+++ b/src/scenario.c
@@ -380,7 +380,7 @@ void scenario_end()
 	rct_window* w;
 	window_close_by_class(WC_DROPDOWN);
 
-	for (w = g_window_list; w < RCT2_GLOBAL(RCT2_ADDRESS_NEW_WINDOW_PTR, rct_window*); w++){
+	for (w = g_window_list; w < gWindowNextSlot; w++){
 		if (!(w->flags & (WF_STICK_TO_BACK | WF_STICK_TO_FRONT)))
 			window_close(w);
 	}
diff --git a/src/world/map.c b/src/world/map.c
index 145b387b7f..d0c48b4b3a 100644
--- a/src/world/map.c
+++ b/src/world/map.c
@@ -3868,7 +3868,6 @@ void map_get_bounding_box(int ax, int ay, int bx, int by, int *left, int *top, i
 void map_invalidate_selection_rect()
 {
 	int x0, y0, x1, y1, left, right, top, bottom;
-	rct_viewport **vp;
 
 	if (!(RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_FLAGS, uint16) & (1 << 0)))
 		return;
@@ -3883,10 +3882,11 @@ void map_invalidate_selection_rect()
 	bottom += 32;
 	top -= 32 + 2080;
 
-	vp = RCT2_ADDRESS(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport*);
-	while (*vp != NULL) {
-		viewport_invalidate(*vp, left, top, right, bottom);
-		vp++;
+	for (int i = 0; i < MAX_VIEWPORT_COUNT; i++) {
+		rct_viewport *viewport = &g_viewport_list[i];
+		if (viewport->width != 0) {
+			viewport_invalidate(viewport, left, top, right, bottom);
+		}
 	}
 }
 
@@ -4767,8 +4767,9 @@ static void translate_3d_to_2d(int rotation, int *x, int *y)
 
 void map_invalidate_tile_under_zoom(int x, int y, int z0, int z1, int maxZoom)
 {
+	if (gOpenRCT2Headless) return;
+
 	int x1, y1, x2, y2;
-	rct_viewport **vp;
 
 	x += 16;
 	y += 16;
@@ -4779,12 +4780,11 @@ void map_invalidate_tile_under_zoom(int x, int y, int z0, int z1, int maxZoom)
 	x2 = x + 32;
 	y2 = y + 32 - z0;
 
-	vp = RCT2_ADDRESS(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport*);
-	while (!gOpenRCT2Headless && *vp != 0) {
-		if (maxZoom == -1 || (*vp)->zoom <= maxZoom) {
-			viewport_invalidate(*vp, x1, y1, x2, y2);
+	for (int i = 0; i < MAX_VIEWPORT_COUNT; i++) {
+		rct_viewport *viewport = &g_viewport_list[i];
+		if (viewport->width != 0 && (maxZoom == -1 || viewport->zoom <= maxZoom)) {
+			viewport_invalidate(viewport, x1, y1, x2, y2);
 		}
-		vp++;
 	}
 }
 
diff --git a/src/world/sprite.c b/src/world/sprite.c
index 5f6ba1e77e..9e610ec2ab 100644
--- a/src/world/sprite.c
+++ b/src/world/sprite.c
@@ -41,9 +41,9 @@ static void invalidate_sprite_max_zoom(rct_sprite *sprite, int maxZoom)
 {
 	if (sprite->unknown.sprite_left == SPRITE_LOCATION_NULL) return;
 
-	for (rct_viewport** viewport_p = RCT2_ADDRESS(RCT2_ADDRESS_ACTIVE_VIEWPORT_PTR_ARRAY, rct_viewport*); *viewport_p != NULL; viewport_p++) {
-		rct_viewport* viewport = *viewport_p;
-		if (viewport->zoom <= maxZoom) {
+	for (int i = 0; i < MAX_VIEWPORT_COUNT; i++) {
+		rct_viewport *viewport = &g_viewport_list[i];
+		if (viewport->width != 0 && viewport->zoom <= maxZoom) {
 			viewport_invalidate(
 				viewport,
 				sprite->unknown.sprite_left,