diff --git a/ubb-vga/README b/ubb-vga/README
index f025e20..7b79506 100644
--- a/ubb-vga/README
+++ b/ubb-vga/README
@@ -48,6 +48,8 @@ Mode		Monitor		Image   Hor. noise	Cleanliness
 		W2243C		y y	2-4   large	very distorted
 		W2243L		y y	2-3   large	very distorted
 
+640x480/61	XEN-1510T	y y	1     -/10, 20%	very good/distorted (5)
+
 640x480/70	XEN-1510T	y (2)	1     10, 25%	distorted, flickery
 		LN32R71B	n -	"not supported mode"
 		206NW		y (2)	3-8   -		very jittery
@@ -115,6 +117,8 @@ that the screen content cannot be recognized.
     manually.
 (4) Places the image too far to the left. Cannot be sufficiently
     corrected.
+(5) about 70% of all session have a clean stable image. The remaining
+    30% suffer significant FIFO noise.
 
 
 To do
diff --git a/ubb-vga/ubb-vga.c b/ubb-vga/ubb-vga.c
index 48c0f8e..882e5b8 100644
--- a/ubb-vga/ubb-vga.c
+++ b/ubb-vga/ubb-vga.c
@@ -51,8 +51,9 @@ static int bad;
 static const struct mode mode_db[] = {
 /* name		xres yres clkdiv vfront  hsync     hback     htotal	*/
 /*			      vsync  vback				*/
-{ "640x480",	 640, 480, 12, 2, 32, 14, US(2.80), US(1.3), US(32.1) },
+{ "640x480",	 640, 480, 12, 2, 32, 14, US(2.80), US(1.30), US(32.1) },
 { "640x480/58",	 640, 480, 12, 2, 10, 33, US(3.81), US(1.91), US(32.7) },
+{ "640x480/61",  640, 480, 11, 2,  9, 29, US(2.50), US(4.06), US(31.5) },
 { "640x480/70",	 640, 480,  9, 2,  8, 29, US(1.90), US(2.06), US(24.8) },
 
 { "800x600/54",	 800, 600,  8, 2, 32, 14, US(4.81), US(0.79), US(28.8) },
@@ -109,6 +110,8 @@ static const struct mode mode_db[] = {
 
 const struct mode *mode = mode_db;
 
+static uint32_t clkrt = 0;
+
 
 /* ----- I/O pin assignment ------------------------------------------------ */
 
@@ -265,7 +268,10 @@ static void setup(void)
 
 	MSCCDR = mode->clkdiv;	/* set the MSC clock to 336 MHz / 12 = 28 MHz */
 	CLKGR &= ~(1 << 7);	/* enable MSC clock */
-	MSC_CLKRT = 0;		/* bus clock = MSC clock / 1 */
+	while (MSCCDR & 1) {
+		MSCCDR >>= 1;
+		clkrt++;
+	}
 }
 
 
@@ -307,6 +313,7 @@ static void line(unsigned long line)
 	/* HSYNC */
 
 	PDDATC = HSYNC;
+	MSC_CLKRT = clkrt;	/* bus clock = MSC clock / n */
 	MSC_STRPCL = 2;		/* start MMC clock output */
 	MSC_RESTO = 0xffff;
 
@@ -500,6 +507,10 @@ int main(int argc, char *const *argv)
 	session(gen, frames);
 	cleanup();
 
+#if 0
+	printf("clkdiv: %d, /%d /%d\n", mode->clkdiv,
+	    (MSCCDR & 15)+1, 1 << (MSC_CLKRT & 7));
+#endif
 	if (bad)
 		printf("%d timeout%s\n", bad, bad == 1 ? "" : "s");
 	return 0;