diff --git a/arch/x86/boot/video-vga.c b/arch/x86/boot/video-vga.c
index 5d4742ed4aa21dd83d968798a1c7ff92447907a1..95d86ce0421c84dd647f26f34cd65fc9f0143d3e 100644
--- a/arch/x86/boot/video-vga.c
+++ b/arch/x86/boot/video-vga.c
@@ -129,41 +129,45 @@ u16 vga_crtc(void)
 	return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
 }
 
-static void vga_set_480_scanlines(int end)
+static void vga_set_480_scanlines(int lines)
 {
-	u16 crtc;
-	u8  csel;
+	u16 crtc;		/* CRTC base address */
+	u8  csel;		/* CRTC miscellaneous output register */
+	u8  ovfw;		/* CRTC overflow register */
+	int end = lines-1;
 
 	crtc = vga_crtc();
 
+	ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
+
 	out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
 	out_idx(0x0b, crtc, 0x06); /* Vertical total */
-	out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
+	out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
 	out_idx(0xea, crtc, 0x10); /* Vertical sync start */
-	out_idx(end, crtc, 0x12); /* Vertical display end */
+	out_idx(end,  crtc, 0x12); /* Vertical display end */
 	out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
 	out_idx(0x04, crtc, 0x16); /* Vertical blank end */
 	csel = inb(0x3cc);
 	csel &= 0x0d;
 	csel |= 0xe2;
-	outb(csel, 0x3cc);
+	outb(csel, 0x3c2);
 }
 
 static void vga_set_80x30(void)
 {
-	vga_set_480_scanlines(0xdf);
+	vga_set_480_scanlines(30*16);
 }
 
 static void vga_set_80x34(void)
 {
 	vga_set_14font();
-	vga_set_480_scanlines(0xdb);
+	vga_set_480_scanlines(34*14);
 }
 
 static void vga_set_80x60(void)
 {
 	vga_set_8font();
-	vga_set_480_scanlines(0xdf);
+	vga_set_480_scanlines(60*8);
 }
 
 static int vga_set_mode(struct mode_info *mode)