diff --git a/common/g45/hw-gfx-gma-gmch-vga.adb b/common/g45/hw-gfx-gma-gmch-vga.adb
new file mode 100644
index 0000000..92f489b
--- /dev/null
+++ b/common/g45/hw-gfx-gma-gmch-vga.adb
@@ -0,0 +1,80 @@
+--
+-- Copyright (C) 2015-2016 secunet Security Networks AG
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+with HW.GFX.GMA.Config;
+with HW.GFX.GMA.Registers;
+
+with HW.Debug;
+with GNAT.Source_Info;
+
+use type HW.Word64;
+
+package body HW.GFX.GMA.GMCH.VGA is
+
+   ADPA_DAC_ENABLE         : constant := 1 * 2 ** 31;
+   ADPA_USE_VGA_HVPOLARITY : constant := 1 * 2 ** 15;
+   ADPA_VSYNC_DISABLE      : constant := 1 * 2 ** 11;
+   ADPA_HSYNC_DISABLE      : constant := 1 * 2 ** 10;
+   ADPA_VSYNC_ACTIVE_HIGH  : constant := 1 * 2 **  4;
+   ADPA_HSYNC_ACTIVE_HIGH  : constant := 1 * 2 **  3;
+
+   ADPA_MASK : constant Word32 :=
+      GMCH_PORT_PIPE_SELECT_MASK or
+      ADPA_DAC_ENABLE        or
+      ADPA_VSYNC_DISABLE     or
+      ADPA_HSYNC_DISABLE     or
+      ADPA_VSYNC_ACTIVE_HIGH or
+      ADPA_HSYNC_ACTIVE_HIGH or
+      ADPA_USE_VGA_HVPOLARITY;
+
+   ----------------------------------------------------------------------------
+
+   procedure On
+     (Pipe     : Pipe_Index;
+      Mode     : in Mode_Type)
+   is
+      Polarity : Word32 := 0;
+   begin
+      pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+
+      if Mode.H_Sync_Active_High then
+         Polarity := Polarity or ADPA_HSYNC_ACTIVE_HIGH;
+      end if;
+      if Mode.V_Sync_Active_High then
+         Polarity := Polarity or ADPA_VSYNC_ACTIVE_HIGH;
+      end if;
+
+      Registers.Unset_And_Set_Mask
+        (Register    => Registers.GMCH_ADPA,
+         Mask_Unset  => ADPA_MASK,
+         Mask_Set    => ADPA_DAC_ENABLE or
+                        GMCH_PORT_PIPE_SELECT (Pipe) or
+                        Polarity);
+   end On;
+
+   ----------------------------------------------------------------------------
+
+   procedure Off
+   is
+   begin
+      pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));
+
+      Registers.Unset_And_Set_Mask
+        (Register    => Registers.GMCH_ADPA,
+         Mask_Unset  => ADPA_DAC_ENABLE,
+         Mask_Set    => ADPA_HSYNC_DISABLE or
+                        ADPA_VSYNC_DISABLE);
+   end Off;
+
+end HW.GFX.GMA.GMCH.VGA;