diff --git a/32blit-sdl/Main.cpp b/32blit-sdl/Main.cpp
index 07618800d..4eb6a2c5b 100644
--- a/32blit-sdl/Main.cpp
+++ b/32blit-sdl/Main.cpp
@@ -143,8 +143,8 @@ void em_loop() {
 #endif
 
 int main(int argc, char *argv[]) {
-  int x, y;
-  bool custom_window_position = false;
+  int x = SDL_WINDOWPOS_UNDEFINED, y = SDL_WINDOWPOS_UNDEFINED;
+  bool fullscreen = false;
 
   std::cout << metadata_title << " " << metadata_version << std::endl;
   std::cout << "Powered by 32Blit SDL2 runtime - github.com/32blit/32blit-sdk" << std::endl << std::endl;
@@ -165,11 +165,19 @@ int main(int argc, char *argv[]) {
 		else if(arg_str == "--listen")
 			mp_mode = Multiplayer::Mode::Listen;
 		else if(arg_str == "--position") {
-			if(SDL_sscanf(argv[i+1], "%d,%d", &x, &y) == 2) {
-			    custom_window_position = true;
-			}
-		}
-		else if(arg_str == "--credits") {
+			SDL_sscanf(argv[i+1], "%d,%d", &x, &y);
+		}	else if(arg_str == "--size" && i + 1 < argc) {
+      int w, h;
+			if(SDL_sscanf(argv[i+1], "%d,%d", &w, &h) == 2) {
+        if(w * y < System::max_width * System::max_height) {
+          System::width = w;
+          System::height = h;
+        }
+      }
+      i++;
+		} else if(arg_str == "--fullscreen")
+			fullscreen = true;
+    else if(arg_str == "--credits") {
 			std::cout << "32Blit was made possible by:" << std::endl;
 			std::cout << std::endl;
 			for(auto name : contributors) {
@@ -202,6 +210,7 @@ int main(int argc, char *argv[]) {
 			std::cout << " --connect <addr>     -- Connect to a listening game instance." << std::endl;
 			std::cout << " --listen             -- Listen for incoming connections." << std::endl;
 			std::cout << " --position x,y       -- Set window position." << std::endl;
+      std::cout << " --size w,h           -- Set display size. (max 320x240)" << std::endl;
 			std::cout << " --launch_path <file> -- Emulates the file associations on the console." << std::endl;
 			std::cout << " --credits            -- Print contributor credits and exit." << std::endl;
 			std::cout << " --info               -- Print metadata info and exit." << std::endl << std::endl;
@@ -218,9 +227,9 @@ int main(int argc, char *argv[]) {
 
 	window = SDL_CreateWindow(
 		metadata_title,
-		SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+		x, y,
 		System::width*2, System::height*2,
-		SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI
+		SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI | (fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0)
 	);
 
 	if (window == nullptr) {
@@ -229,10 +238,6 @@ int main(int argc, char *argv[]) {
 	}
 	SDL_SetWindowMinimumSize(window, System::width, System::height);
 
-	if(custom_window_position) {
-		SDL_SetWindowPosition(window, x, y);
-	}
-
   blit_system = new System();
   blit_input = new Input(blit_system);
 	blit_multiplayer = new Multiplayer(mp_mode, mp_address);
diff --git a/32blit-sdl/System.cpp b/32blit-sdl/System.cpp
index 996fc1b70..7b9fcc1f2 100644
--- a/32blit-sdl/System.cpp
+++ b/32blit-sdl/System.cpp
@@ -15,14 +15,13 @@
 
 extern Input *blit_input;
 
+int System::width = System::max_width;
+int System::height = System::max_height;
+
 // blit framebuffer memory
-static uint8_t framebuffer[System::width * System::height * 3];
+static uint8_t framebuffer[System::max_width * System::max_height * 3];
 static blit::Pen palette[256];
 
-static const blit::SurfaceTemplate __fb_hires{framebuffer, blit::Size(System::width, System::height), blit::PixelFormat::RGB, nullptr};
-static const blit::SurfaceTemplate __fb_hires_pal{framebuffer, blit::Size(System::width, System::height), blit::PixelFormat::P, palette};
-static const blit::SurfaceTemplate __fb_lores{framebuffer, blit::Size(System::width / 2, System::height / 2), blit::PixelFormat::RGB, nullptr};
-
 // blit debug callback
 void blit_debug(const char *message) {
 	std::cout << message;
@@ -30,26 +29,11 @@ void blit_debug(const char *message) {
 
 // blit screenmode callback
 blit::ScreenMode _mode = blit::ScreenMode::lores;
+static blit::ScreenMode requested_mode = blit::ScreenMode::lores;
 static blit::PixelFormat cur_format = blit::PixelFormat::RGB;
+static blit::PixelFormat requested_format = blit::PixelFormat::RGB;
 
 blit::SurfaceInfo cur_surf_info;
-blit::SurfaceInfo &set_screen_mode(blit::ScreenMode new_mode) {
-	_mode = new_mode;
-  switch(_mode) {
-    case blit::ScreenMode::lores:
-      cur_surf_info = __fb_lores;
-      break;
-    case blit::ScreenMode::hires:
-      cur_surf_info = __fb_hires;
-      break;
-    case blit::ScreenMode::hires_palette:
-      cur_surf_info = __fb_hires_pal;
-      break;
-  }
-
-  cur_format = cur_surf_info.format;
-	return cur_surf_info;
-}
 
 static void set_screen_palette(const blit::Pen *colours, int num_cols) {
 	memcpy(palette, colours, num_cols * sizeof(blit::Pen));
@@ -60,11 +44,11 @@ static bool set_screen_mode_format(blit::ScreenMode new_mode, blit::SurfaceTempl
 
   switch(new_mode) {
     case blit::ScreenMode::lores:
-      new_surf_template.bounds = __fb_lores.bounds;
+      new_surf_template.bounds = blit::Size(System::width / 2, System::height / 2);
       break;
     case blit::ScreenMode::hires:
     case blit::ScreenMode::hires_palette:
-      new_surf_template.bounds = __fb_hires.bounds;
+      new_surf_template.bounds = blit::Size(System::width, System::height);
       break;
   }
 
@@ -80,12 +64,26 @@ static bool set_screen_mode_format(blit::ScreenMode new_mode, blit::SurfaceTempl
       return false;
   }
 
-  _mode = new_mode;
-  cur_format = new_surf_template.format;
+  requested_mode = new_mode;
+  requested_format = new_surf_template.format;
 
   return true;
 }
 
+blit::SurfaceInfo &set_screen_mode(blit::ScreenMode new_mode) {
+  blit::SurfaceTemplate temp{nullptr, {0, 0}, new_mode == blit::ScreenMode::hires_palette ? blit::PixelFormat::P : blit::PixelFormat::RGB};
+
+  // won't fail for the modes used here
+  set_screen_mode_format(new_mode, temp);
+
+  cur_surf_info.data = temp.data;
+  cur_surf_info.bounds = temp.bounds;
+  cur_surf_info.format = temp.format;
+  cur_surf_info.palette = temp.palette;
+
+  return cur_surf_info;
+}
+
 // blit timer callback
 std::chrono::steady_clock::time_point start;
 uint32_t now() {
@@ -315,6 +313,11 @@ void System::loop() {
   {
     blit::render(time_now);
     last_render_time = time_now;
+
+    if(_mode != requested_mode || cur_format != requested_format) {
+      _mode = requested_mode;
+      cur_format = requested_format;
+    }
   }
 
   blit::tick(::now());
@@ -336,7 +339,7 @@ void System::update_texture(SDL_Texture *texture) {
   auto stride = (is_lores ? width / 2 : width) * blit::pixel_format_stride[int(cur_format)];
 
   if(cur_format == blit::PixelFormat::P) {
-    uint8_t col_fb[width * height * 3];
+    uint8_t col_fb[max_width * max_height * 3];
 
     auto in = framebuffer, out = col_fb;
     auto size = is_lores ? (width / 2) * (height / 2) : width * height;
diff --git a/32blit-sdl/System.hpp b/32blit-sdl/System.hpp
index 4565887bc..a8149c9c3 100644
--- a/32blit-sdl/System.hpp
+++ b/32blit-sdl/System.hpp
@@ -3,8 +3,11 @@ class System {
 		static const Uint32 timer_event;
 		static const Uint32 loop_event;
 
-		static const int width = 320;
-		static const int height = 240;
+    static const int max_width = 320;
+    static const int max_height = 240;
+
+		static int width;
+		static int height;
 
 		System();
 		~System();
diff --git a/32blit/graphics/primitive.cpp b/32blit/graphics/primitive.cpp
index 4ef9453e6..17baf833b 100644
--- a/32blit/graphics/primitive.cpp
+++ b/32blit/graphics/primitive.cpp
@@ -33,7 +33,7 @@ namespace blit {
       return;
     }
 
-    for (uint8_t y = cr.y; y < cr.y + cr.h; y++) {
+    for (int32_t y = cr.y; y < cr.y + cr.h; y++) {
       pbf(&pen, this, o, cr.w);
       o += bounds.w;
     }