diff --git a/doomgeneric/d_main.c b/doomgeneric/d_main.c
index 9012e5f..32f74a2 100644
--- a/doomgeneric/d_main.c
+++ b/doomgeneric/d_main.c
@@ -166,6 +166,10 @@ extern  boolean setsizeneeded;
 extern  int             showMessages;
 void R_ExecuteSetViewSize (void);
 
+static boolean wipe_in_progress = false;
+static int wipe_start_time;
+void D_WipeStep (void);
+
 void D_Display (void)
 {
     static  boolean		viewactivestate = false;
@@ -174,11 +178,7 @@ void D_Display (void)
     static  boolean		fullscreen = false;
     static  gamestate_t		oldgamestate = -1;
     static  int			borderdrawcount;
-    int				nowtime;
-    int				tics;
-    int				wipestart;
     int				y;
-    boolean			done;
     boolean			wipe;
     boolean			redrawsbar;
 
@@ -308,24 +308,32 @@ void D_Display (void)
     // wipe update
     wipe_EndScreen(0, 0, SCREENWIDTH, SCREENHEIGHT);
 
-    wipestart = I_GetTime () - 1;
+    // The melt used to spin here until it finished, which a browser main thread cannot do:
+    // D_WipeStep() advances it once per call until it is done.
+    wipe_start_time = I_GetTime () - 1;
+    wipe_in_progress = true;
+    D_WipeStep ();
+}
 
-    do
-    {
-	do
-	{
-	    nowtime = I_GetTime ();
-	    tics = nowtime - wipestart;
-            I_Sleep(1);
-	} while (tics <= 0);
-        
-	wipestart = nowtime;
-	done = wipe_ScreenWipe(wipe_Melt
-			       , 0, 0, SCREENWIDTH, SCREENHEIGHT, tics);
-	I_UpdateNoBlit ();
-	M_Drawer ();                            // menu is drawn even on top of wipes
-	I_FinishUpdate ();                      // page flip or blit buffer
-    } while (!done);
+boolean D_WipeInProgress (void)
+{
+    return wipe_in_progress;
+}
+
+void D_WipeStep (void)
+{
+    int nowtime = I_GetTime ();
+    int tics = nowtime - wipe_start_time;
+
+    if (tics <= 0)
+        return;
+
+    wipe_start_time = nowtime;
+    if (wipe_ScreenWipe(wipe_Melt, 0, 0, SCREENWIDTH, SCREENHEIGHT, tics))
+        wipe_in_progress = false;
+    I_UpdateNoBlit ();
+    M_Drawer ();                            // menu is drawn even on top of wipes
+    I_FinishUpdate ();                      // page flip or blit buffer
 }
 
 //
diff --git a/doomgeneric/i_video.c b/doomgeneric/i_video.c
index 84bebde..a0a9075 100644
--- a/doomgeneric/i_video.c
+++ b/doomgeneric/i_video.c
@@ -288,6 +288,7 @@ void I_InitGraphics (void)
 
     /* Allocate screen to draw to */
 	I_VideoBuffer = (byte*)Z_Malloc (SCREENWIDTH * SCREENHEIGHT, PU_STATIC, NULL);  // For DOOM to draw on
+	memset(I_VideoBuffer, 0, SCREENWIDTH * SCREENHEIGHT);  // the first melt starts from black, not zone garbage
 
 	screenvisible = true;