--- b-em-40246d4-vanilla/src/vidalleg.c	2025-06-03 14:22:28
+++ b-em-40246d4-untrickified/src/vidalleg.c	2025-07-06 12:36:23
@@ -307,7 +307,7 @@
                         break;
                     case VDT_UNSET:
                 }
-                region = al_lock_bitmap(b, ALLEGRO_PIXEL_FORMAT_ARGB_8888, ALLEGRO_LOCK_WRITEONLY);
+                region = al_lock_bitmap(b, ALLEGRO_PIXEL_FORMAT_ARGB_8888, ALLEGRO_LOCK_READWRITE);
                 break;
             case VDC_PAL:
                 switch(vid_dtype_intern) {
@@ -468,7 +468,7 @@
                     upscale_only(b, firstx, firsty << 1, xsize, ysize  << 1, scr_x_start, scr_y_start, scr_x_size, scr_y_size);
                 case VDT_UNSET:
             }
-            region = al_lock_bitmap(b, ALLEGRO_PIXEL_FORMAT_ARGB_8888, ALLEGRO_LOCK_WRITEONLY);
+            region = al_lock_bitmap(b, ALLEGRO_PIXEL_FORMAT_ARGB_8888, ALLEGRO_LOCK_READWRITE);
             break;
         case VDC_PAL:
             switch(vid_dtype_intern) {