diff --git a/includes/defines.h b/includes/defines.h
index b670a5dac..9ccc83ad6 100644
--- a/includes/defines.h
+++ b/includes/defines.h
@@ -186,6 +186,7 @@ extern int hud_enable;
 extern int pretty_powder;
 extern int drawgrav_enable;
 extern int ngrav_enable;
+extern char bframe;
 int limitFPS;
 int water_equal_test;
 extern int quickoptions_tooltip_fade;
diff --git a/includes/misc.h b/includes/misc.h
index 0de41f174..0253ee901 100644
--- a/includes/misc.h
+++ b/includes/misc.h
@@ -78,6 +78,10 @@ void *file_load(char *fn, int *size);
 
 void clipboard_push_text(char * text);
 
+void draw_bframe();
+
+void erase_bframe();
+
 char * clipboard_pull_text();
 
 extern char *clipboard_text;
diff --git a/src/interface.c b/src/interface.c
index c1b8df263..6ee597467 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -6971,7 +6971,7 @@ void render_ui(pixel * vid_buf, int xcoord, int ycoord, int orientation)
 void simulation_ui(pixel * vid_buf)
 {
 	int xsize = 300;
-	int ysize = 246;
+	int ysize = 260;
 	int x0=(XRES-xsize)/2,y0=(YRES-MENUSIZE-ysize)/2,b=1,bq,mx,my;
 	int new_scale, new_kiosk;
 	ui_checkbox cb;
@@ -6980,6 +6980,7 @@ void simulation_ui(pixel * vid_buf)
 	ui_checkbox cb4;
 	ui_checkbox cb5;
 	ui_checkbox cb6;
+	ui_checkbox cb7;
 	char * airModeList[] = {"On", "Pressure Off", "Velocity Off", "Off", "No Update"};
 	int airModeListCount = 5;
 	char * gravityModeList[] = {"Vertical", "Off", "Radial"};
@@ -7016,6 +7017,11 @@ void simulation_ui(pixel * vid_buf)
 	cb6.y = y0+107;
 	cb6.focus = 0;
 	cb6.checked = water_equal_test;
+
+	cb7.x = x0+xsize-16;	//Block frame
+	cb7.y = y0+227;
+	cb7.focus = 0;
+	cb7.checked = bframe;
 	
 	list.x = x0+xsize-76;	//Air Mode
 	list.y = y0+135;
@@ -7081,6 +7087,9 @@ void simulation_ui(pixel * vid_buf)
 		drawtext(vid_buf, x0+8, y0+214, "Fullscreen", 255, 255, 255, 255);
 		drawtext(vid_buf, x0+12+textwidth("Fullscreen"), y0+214, "Fill the entire screen", 255, 255, 255, 180);
 
+		drawtext(vid_buf, x0+8, y0+228, "Block frame", 255, 255, 255, 255);
+		drawtext(vid_buf, x0+12+textwidth("Block frame"), y0+228, "Draws a wall frame around screen", 255, 255, 255, 180);
+
 		//TODO: Options for Air and Normal gravity
 		//Maybe save/load defaults too.
 
@@ -7093,6 +7102,7 @@ void simulation_ui(pixel * vid_buf)
 		ui_checkbox_draw(vid_buf, &cb4);
 		ui_checkbox_draw(vid_buf, &cb5);
 		ui_checkbox_draw(vid_buf, &cb6);
+		ui_checkbox_draw(vid_buf, &cb7);
 		ui_list_draw(vid_buf, &list);
 		ui_list_draw(vid_buf, &list2);
 #ifdef OGLR
@@ -7105,6 +7115,7 @@ void simulation_ui(pixel * vid_buf)
 		ui_checkbox_process(mx, my, b, bq, &cb4);
 		ui_checkbox_process(mx, my, b, bq, &cb5);
 		ui_checkbox_process(mx, my, b, bq, &cb6);
+		ui_checkbox_process(mx, my, b, bq, &cb7);
 		ui_list_process(vid_buf, mx, my, b, &list);
 		ui_list_process(vid_buf, mx, my, b, &list2);
 
@@ -7138,6 +7149,11 @@ void simulation_ui(pixel * vid_buf)
 		else
 			stop_grav_async();
 	}
+	if(cb7.checked && !bframe)
+		draw_bframe();
+	if(!cb7.checked && bframe)
+		erase_bframe();
+	bframe = cb7.checked;
 
 	while (!sdl_poll())
 	{
diff --git a/src/main.c b/src/main.c
index 2423ab7e6..bd15e8c4b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -307,6 +307,8 @@ void dump_frame(pixel *src, int w, int h, int pitch)
  *                    STATE MANAGEMENT                     *
  ***********************************************************/
 
+char bframe = 0;
+
 void clear_sim(void)
 {
 	int i, x, y;
@@ -352,6 +354,8 @@ void clear_sim(void)
 			hv[y][x] = 273.15f+22.0f; //Set to room temperature
 		}
 	}
+	if(bframe)
+		draw_bframe();
 }
 
 // stamps library
@@ -801,7 +805,6 @@ int main(int argc, char *argv[])
 	parts = calloc(sizeof(particle), NPART);
 	cb_parts = calloc(sizeof(particle), NPART);
 	init_can_move();
-	clear_sim();
 	
 #ifdef LUACONSOLE
 	luacon_open();
@@ -854,6 +857,7 @@ int main(int argc, char *argv[])
 	}
 	
 	load_presets();
+	clear_sim();
 
 	for (i=1; i<argc; i++)
 	{
diff --git a/src/misc.c b/src/misc.c
index 210e4d296..11cdc889b 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -135,6 +135,36 @@ void clean_text(char *text, int vwidth)
 	}
 }
 
+void draw_bframe()
+{
+	int i;
+	for(i=0; i<(XRES/CELL); i++)
+	{
+		bmap[0][i]=WL_WALL;
+		bmap[YRES/CELL-1][i]=WL_WALL;
+	}
+	for(i=1; i<((YRES/CELL)-1); i++)
+	{
+		bmap[i][0]=WL_WALL;
+		bmap[i][XRES/CELL-1]=WL_WALL;
+	}
+}
+
+void erase_bframe()
+{
+	int i;
+	for(i=0; i<(XRES/CELL); i++)
+	{
+		bmap[0][i]=0;
+		bmap[YRES/CELL-1][i]=0;
+	}
+	for(i=1; i<((YRES/CELL)-1); i++)
+	{
+		bmap[i][0]=0;
+		bmap[i][XRES/CELL-1]=0;
+	}
+}
+
 void save_presets(int do_update)
 {
 	char * outputdata;
@@ -186,6 +216,7 @@ void save_presets(int do_update)
 	//General settings
 	cJSON_AddStringToObject(root, "proxy", http_proxy_string);
 	cJSON_AddNumberToObject(root, "scale", sdl_scale);
+	cJSON_AddNumberToObject(root, "bframe", bframe);
 	
 	outputdata = cJSON_Print(root);
 	cJSON_Delete(root);
@@ -324,6 +355,7 @@ void load_presets(void)
 		if((tmpobj = cJSON_GetObjectItem(root, "proxy")) && tmpobj->type == cJSON_String) strncpy(http_proxy_string, tmpobj->valuestring, 255); else http_proxy_string[0] = 0;
 		//TODO: Translate old cmode value into new *_mode values
 		if(tmpobj = cJSON_GetObjectItem(root, "scale")) sdl_scale = tmpobj->valueint;
+		if(tmpobj = cJSON_GetObjectItem(root, "bframe")) bframe = tmpobj->valueint;
 		
 		cJSON_Delete(root);
 		free(prefdata);