diff --git a/.gitignore b/.gitignore
index 993e4619d79..2b3139c668c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,8 +7,7 @@
 /.cproject
 /.project
 /cfg
-/depend_emu.mak
-/depend_mess.mak
+/depend_*.mak
 /diff
 /nvram
 /obj
diff --git a/src/emu/drawgfx.h b/src/emu/drawgfx.h
index a1287b6db1d..0b5ef4b03b2 100644
--- a/src/emu/drawgfx.h
+++ b/src/emu/drawgfx.h
@@ -169,7 +169,6 @@ public:
 	// operations
 	void mark_dirty(UINT32 code) { if (code < elements()) { m_dirty[code] = 1; m_dirtyseq++; } }
 	void mark_all_dirty() { memset(&m_dirty[0], 1, elements()); }
-	void decode(UINT32 code);
 
 	const UINT8 *get_data(UINT32 code)
 	{
@@ -251,6 +250,9 @@ public:
 	void alphastore(palette_device &palette, bitmap_rgb32 &dest, const rectangle &cliprect,UINT32 code, UINT32 color, int flipx, int flipy, INT32 destx, INT32 desty,int fixedalpha, UINT8 *alphatable);
 	void alphatable(palette_device &palette, bitmap_rgb32 &dest, const rectangle &cliprect, UINT32 code, UINT32 color, int flipx, int flipy, INT32 destx, INT32 desty, int fixedalpha ,UINT8 *alphatable);
 private:
+	// internal helpers
+	void decode(UINT32 code);
+
 	// internal state
 	palette_device  *m_palette;             // palette used for drawing
 
diff --git a/src/mame/drivers/aristmk4.c b/src/mame/drivers/aristmk4.c
index 1beb9caec9e..c9c4f849f3d 100644
--- a/src/mame/drivers/aristmk4.c
+++ b/src/mame/drivers/aristmk4.c
@@ -368,7 +368,7 @@ void aristmk4_state::video_start()
 	int tile;
 	for (tile = 0; tile < m_gfxdecode->gfx(0)->elements(); tile++)
 	{
-		m_gfxdecode->gfx(0)->decode(tile);
+		m_gfxdecode->gfx(0)->get_data(tile);
 	}
 }
 
@@ -424,7 +424,7 @@ UINT32 aristmk4_state::screen_update_aristmk4(screen_device &screen, bitmap_ind1
 			tile = (m_mkiv_vram[count+1]|m_mkiv_vram[count]<<8) & 0x3ff;
 			bgtile = (m_mkiv_vram[count+1]|m_mkiv_vram[count]<<8) & 0xff; // first 256 tiles
 			uBackgroundColour();   // read sw7
-			gfx->decode(bgtile);    // force the machine to update only the first 256 tiles.
+			gfx->mark_dirty(bgtile);    // force the machine to update only the first 256 tiles.
 								// as we only update the background, not the entire display.
 			flipx = ((m_mkiv_vram[count]) & 0x04);
 			flipy = ((m_mkiv_vram[count]) & 0x08);
diff --git a/src/mame/drivers/decocass.c b/src/mame/drivers/decocass.c
index bd04f03a8fb..5d98232c1ba 100644
--- a/src/mame/drivers/decocass.c
+++ b/src/mame/drivers/decocass.c
@@ -644,7 +644,7 @@ static const gfx_layout spritelayout =
 static const gfx_layout tilelayout =
 {
 	16,16,
-	16+1,       /* 16 tiles (+1 empty tile used in the half-width bg tilemaps) */
+	16,
 	3,
 	{ 2*16*16*16+4, 2*16*16*16+0, 4 },
 	{ STEP4(3*16*8,1), STEP4(2*16*8,1), STEP4(1*16*8,1), STEP4(0*16*8,1) },
diff --git a/src/mame/drivers/srmp5.c b/src/mame/drivers/srmp5.c
index 36cfba4ab69..317c3c10f8f 100644
--- a/src/mame/drivers/srmp5.c
+++ b/src/mame/drivers/srmp5.c
@@ -212,7 +212,8 @@ UINT32 srmp5_state::screen_update_srmp5(screen_device &screen, bitmap_rgb32 &bit
 		{
 			if (m_tileduty[i] == 1)
 			{
-				m_gfxdecode->gfx(0)->decode(i);
+				m_gfxdecode->gfx(0)->mark_dirty(i);
+				m_gfxdecode->gfx(0)->get_data(i);
 				m_tileduty[i] = 0;
 			}
 		}
diff --git a/src/mame/includes/decocass.h b/src/mame/includes/decocass.h
index 032ab442f39..268b702309a 100644
--- a/src/mame/includes/decocass.h
+++ b/src/mame/includes/decocass.h
@@ -60,6 +60,7 @@ public:
 	tilemap_t   *m_fg_tilemap;
 	tilemap_t   *m_bg_tilemap_l;
 	tilemap_t   *m_bg_tilemap_r;
+	UINT8     m_empty_tile[16*16];
 	INT32     m_watchdog_count;
 	INT32     m_watchdog_flip;
 	INT32     m_color_missiles;
diff --git a/src/mame/video/decocass.c b/src/mame/video/decocass.c
index 8ae46a636d0..3dbd032e0b5 100644
--- a/src/mame/video/decocass.c
+++ b/src/mame/video/decocass.c
@@ -201,18 +201,22 @@ TILE_GET_INFO_MEMBER(decocass_state::get_bg_l_tile_info)
 {
 	int color = (m_color_center_bot >> 7) & 1;
 	SET_TILE_INFO_MEMBER(2,
-			(0x80 == (tile_index & 0x80)) ? 16 : m_bgvideoram[tile_index] >> 4,
+			m_bgvideoram[tile_index] >> 4,
 			color,
 			0);
+	if (tile_index & 0x80)
+		tileinfo.pen_data = m_empty_tile;
 }
 
 TILE_GET_INFO_MEMBER(decocass_state::get_bg_r_tile_info )
 {
 	int color = (m_color_center_bot >> 7) & 1;
 	SET_TILE_INFO_MEMBER(2,
-			(0x00 == (tile_index & 0x80)) ? 16 : m_bgvideoram[tile_index] >> 4,
+			m_bgvideoram[tile_index] >> 4,
 			color,
 			TILE_FLIPY);
+	if (!(tile_index & 0x80))
+		tileinfo.pen_data = m_empty_tile;
 }
 
 TILE_GET_INFO_MEMBER(decocass_state::get_fg_tile_info )
@@ -676,9 +680,8 @@ void decocass_state::video_start()
 	m_gfxdecode->gfx(2)->set_source(m_tileram);
 	m_gfxdecode->gfx(3)->set_source(m_objectram);
 
-	/* This should ensure that the fake 17th tile is left blank
-	 * now that dirty-tile tracking is handled by the core */
-	m_gfxdecode->gfx(2)->decode(16);
+	/* create an empty tile */
+	memset(m_empty_tile, 0, sizeof(m_empty_tile));
 }
 
 UINT32 decocass_state::screen_update_decocass(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
diff --git a/src/mame/video/namcos22.c b/src/mame/video/namcos22.c
index cc24cbc908c..3ba6f045228 100644
--- a/src/mame/video/namcos22.c
+++ b/src/mame/video/namcos22.c
@@ -2390,9 +2390,9 @@ void namcos22_state::init_tables()
 
 	m_pointram = auto_alloc_array_clear(machine(), UINT32, 0x20000);
 
-	// textures
+	// force all texture tiles to be decoded now
 	for (int i = 0; i < m_gfxdecode->gfx(1)->elements(); i++)
-		m_gfxdecode->gfx(1)->decode(i);
+		m_gfxdecode->gfx(1)->get_data(i);
 
 	m_texture_tilemap = (UINT16 *)memregion("textilemap")->base();
 	m_texture_tiledata = (UINT8 *)m_gfxdecode->gfx(1)->get_data(0);