diff --git a/CHANGLOG.md b/CHANGLOG.md
index 9f4e05b..0eeb789 100644
--- a/CHANGLOG.md
+++ b/CHANGLOG.md
@@ -1,3 +1,6 @@
+# 0.3.0
+- added size to backgrounds
+
 # 0.2.1 - 2023-07-27
 - fixed missing dependency in scaffolding
 
@@ -8,4 +11,4 @@
 - added gsa scaffolding tool
 
 # 0.1.0 - 2023-07-21
-initial release
\ No newline at end of file
+- initial release
diff --git a/examples/basic/gfx.gif b/examples/basic/gfx.gif
index d3561d1..3bb85d3 100644
Binary files a/examples/basic/gfx.gif and b/examples/basic/gfx.gif differ
diff --git a/src/mapedit.rs b/src/mapedit.rs
index cd17007..bf28220 100644
--- a/src/mapedit.rs
+++ b/src/mapedit.rs
@@ -19,6 +19,26 @@ use winit::{
 const SPR_CURSOR: usize = 0x01;
 const TILE_CURSOR: u16 = 0x7308;
 const TILE_MARKER: u16 = 0x7309;
+const TILE_BG: u16 = 0x730a;
+
+struct Surface<'a> {
+    pub data: &'a mut [u8],
+    pub size: IVec2,
+}
+
+impl<'a> Surface<'a> {
+    fn draw_vline(&mut self, pos: IVec2, len: i32, color: u8) {
+        for i in 0..len {
+            self.data[(pos.x + (pos.y + i) * self.size.x) as usize] = color;
+        }
+    }
+
+    fn draw_hline(&mut self, pos: IVec2, len: i32, color: u8) {
+        for i in 0..len {
+            self.data[(pos.x + i + pos.y * self.size.x) as usize] = color;
+        }
+    }
+}
 
 pub(crate) fn run_mapedit() {
     println!("running map edit");
@@ -54,6 +74,9 @@ pub(crate) fn run_mapedit() {
     };
     gsa2.reset_bgs();
     gsa2.reset_sprites();
+    for i in 0..2 {
+        gsa2.bgs[i].scroll = IVec2 { x: -16, y: 0 };
+    }
 
     for y in 0..TILESET_SIZE {
         for x in 0..TILESET_SIZE {
@@ -63,6 +86,7 @@ pub(crate) fn run_mapedit() {
     gsa2.bgs[0].active = false;
     gsa2.bgs[1].active = false;
     gsa2.bgs[2].active = true;
+    gsa2.bgs[2].size = IVec2 { x: 120, y: 68 }; //enough to cover 4k monitors? <_<
 
     for y in 0..BACKGROUND_MAX_SIZE {
         gsa2.bgs[2].tiles[0][y] = 0x7408;
@@ -238,24 +262,43 @@ pub(crate) fn run_mapedit() {
                 let mut screen_buffer =
                     vec![TRANSPARENT; size.width as usize * size.height as usize / 4];
                 let mut window_buffer = surface.buffer_mut().unwrap();
-                render_to_screen(
-                    &mut screen_buffer,
-                    &gsa,
-                    &tileset,
-                    IVec2 {
-                        x: size.width as i32 / 2,
-                        y: size.height as i32 / 2,
-                    },
-                );
-                render_to_screen(
-                    &mut screen_buffer,
-                    &gsa2,
-                    &tileset,
-                    IVec2 {
-                        x: size.width as i32 / 2,
-                        y: size.height as i32 / 2,
-                    },
-                );
+                let screen_size = IVec2 {
+                    x: size.width as i32 / 2,
+                    y: size.height as i32 / 2,
+                };
+                render_to_screen(&mut screen_buffer, &gsa, &tileset, screen_size);
+                render_to_screen(&mut screen_buffer, &gsa2, &tileset, screen_size);
+                let mut screen = Surface {
+                    data: &mut screen_buffer,
+                    size: screen_size,
+                };
+                if gsa.bgs[0].active {
+                    let xs = -gsa.bgs[0].scroll.x - 1;
+                    let ys = -gsa.bgs[0].scroll.y - 1;
+                    let xe = xs + gsa.bgs[0].size.x * TILE_SIZE as i32 + 1;
+                    let ye = ys + gsa.bgs[0].size.y * TILE_SIZE as i32 + 1;
+                    if xs >= 16 && xs < screen_size.x {
+                        let starty = (ys + 1).max(0);
+                        let len = ye.min(screen_size.y) - starty;
+                        screen.draw_vline(IVec2 { x: xs, y: starty }, len, 0xfc);
+                    }
+                    if xe >= 16 && xe < screen_size.x {
+                        let starty = (ys + 1).max(0);
+                        let len = ye.min(screen_size.y) - starty;
+                        screen.draw_vline(IVec2 { x: xe, y: starty }, len, 0xfc);
+                    }
+                    if ys >= 0 && ys < screen_size.y {
+                        let startx = (xs + 1).max(16);
+                        let len = xe.min(screen_size.x) - startx;
+                        screen.draw_hline(IVec2 { x: startx, y: ys }, len, 0xfc);
+                    }
+                    if ye >= 0 && ye < screen_size.y {
+                        let startx = (xs + 1).max(16);
+                        let len = xe.min(screen_size.x) - startx;
+                        screen.draw_hline(IVec2 { x: startx, y: ye }, len, 0xfc);
+                    }
+                }
+
                 render_to_window(
                     &mut window_buffer,
                     &mut screen_buffer,