--- uae/src/main.c	2018/04/24 16:42:05	1.1.1.4
+++ uae/src/main.c	2018/04/24 16:43:25	1.1.1.5
@@ -469,10 +469,15 @@ static void parse_gfx_specs (char *spec)
     currprefs.gfx_xcenter = strchr (x2, 'x') != 0 ? 1 : strchr (x2, 'X') != 0 ? 2 : 0;
     currprefs.gfx_ycenter = strchr (x2, 'y') != 0 ? 1 : strchr (x2, 'Y') != 0 ? 2 : 0;
     currprefs.gfx_linedbl = strchr (x2, 'd') != 0;
+    currprefs.gfx_linedbl += 2 * (strchr (x2, 'D') != 0);
     currprefs.gfx_afullscreen = strchr (x2, 'a') != 0;
     currprefs.gfx_pfullscreen = strchr (x2, 'p') != 0;
     currprefs.gfx_correct_aspect = strchr (x2, 'c') != 0;
 
+    if (currprefs.gfx_linedbl == 3) {
+	fprintf (stderr, "You can't use both 'd' and 'D' modifiers in the display mode specification.\n");
+    }
+    
     free (x0);
     return;
 
@@ -992,7 +997,7 @@ void real_main (int argc, char **argv)
 	    exit (0);
 	}
     }
-    if (sound_available && ! init_sound ()) {
+    if (sound_available && currprefs.produce_sound > 1 && ! init_sound ()) {
 	fprintf (stderr, "Sound driver unavailable: Sound output disabled\n");
 	currprefs.produce_sound = 0;
     }