diff --git a/src/mame/amiga/amigaaga.cpp b/src/mame/amiga/amigaaga.cpp
index 30a51d902d1..e2ff84a4146 100644
--- a/src/mame/amiga/amigaaga.cpp
+++ b/src/mame/amiga/amigaaga.cpp
@@ -530,7 +530,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 	// TODO: copper runs on odd timeslots
 	next_copper_x = m_copper->restore_offset();
 	// TODO: verify where we're missing pixels here for the GFX pitch bitplane corruptions
-	// - wbenc30 scrolling in lores mode (fmode=3, expects a +58!, verify ddfstrt)
+	// - wbenc30 scrolling in lores mode (fmode=3, expects a +58!, verify ddfstrt / delays)
 	// - roadkill title (fmode=3, max +14), gameplay uses fmode=1
 	// - sockid_a, alfred gameplay (fmode=1)
 	// - virocp_a (fmode=1, +26)
@@ -542,6 +542,13 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 	// - cd32 cdtv:labytime intro/tutorial screens
 	//   (swaps between fmode=1 and 3, verify ddfstrt / ddfstop)
 	const int offset_hack[] = { 10, 11, 11, 13 };
+	const int default_bit_offset[] = { 15, 31, 31, 63 };
+
+	// TODO: verify fmode 1/2 stops
+	// - wbenc30/kangfu/pbillusn (F10 key)/cd32 (CD splash loading) all expects a +8 offset
+	const int ddf_start_offset_hires[] = { 9, 9, 9, 9 + 8 };
+	const int ddf_stop_offset_hires[] = { 9 + 15, 9 + 15, 9 + 15, 9 + 8 };
+	// TODO: can it change mid-scanline?
 	const u8 bitplane_fmode = CUSTOM_REG(REG_FMODE) & 0x3;
 
 	for (int x = 0; x < (amiga_state::SCREEN_WIDTH / 2) + offset_hack[bitplane_fmode]; x++)
@@ -588,20 +595,13 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 			ehb = (CUSTOM_REG(REG_BPLCON0) & 0x7c10) == 0x6000 && !bool(BIT(CUSTOM_REG(REG_BPLCON2), 9));
 
 			/* get default bitoffset */
-			switch(bitplane_fmode)
-			{
-				case 0: defbitoffs = 15; break;
-				case 1:
-				case 2: defbitoffs = 31; break;
-				case 3: defbitoffs = 63; break;
-			}
+			defbitoffs = default_bit_offset[bitplane_fmode];
 
 			/* compute the pixel fetch parameters */
-			// FIXME: offsets applied are definitely not right
-			// does ddf_start_pixel offsets with fmode != 0?
-			// wbenc30 expects a +8 to align the screen with fmode == 3, which may or may not be right
-			ddf_start_pixel = ( CUSTOM_REG(REG_DDFSTRT) & 0xfc ) * 2 + (hires ? 9 : 17);
-			ddf_stop_pixel = ( CUSTOM_REG(REG_DDFSTOP) & 0xfc ) * 2 + (hires ? (9 + defbitoffs - ((defbitoffs >= 31) ? 16 : 0)) : (17 + defbitoffs));
+			ddf_start_pixel = ( CUSTOM_REG(REG_DDFSTRT) & 0xfc ) * 2;
+			ddf_start_pixel += hires ? ddf_start_offset_hires[bitplane_fmode] : 17;
+			ddf_stop_pixel = ( CUSTOM_REG(REG_DDFSTOP) & 0xfc ) * 2;
+			ddf_stop_pixel += hires ? ddf_stop_offset_hires[bitplane_fmode] : 17 + defbitoffs;
 
 			// FIXME: as like OCS/ECS Amiga verify this one
 			if ( ( CUSTOM_REG(REG_DDFSTRT) ^ CUSTOM_REG(REG_DDFSTOP) ) & 0x04 )
@@ -696,8 +696,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 
 		/* to render, we must have bitplane DMA enabled, at least 1 plane, and be within the */
 		/* vertical display window */
-		// TODO: bitplane DMA enabled applies to fetch_bitplane_data only
-		if (bitplane_dma_enabled && planes > 0 && scanline >= m_diw.top() && scanline < m_diw.bottom())
+		if (planes > 0 && scanline >= m_diw.top() && scanline < m_diw.bottom())
 		{
 			int pfpix0 = 0, pfpix1 = 0, collide;
 
@@ -705,7 +704,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 			if (x >= ddf_start_pixel && x <= ddf_stop_pixel + odelay)
 			{
 				/* if we need to fetch more data, do it now */
-				if (obitoffs == defbitoffs)
+				if (obitoffs == defbitoffs && bitplane_dma_enabled)
 				{
 					for (pl = 0; pl < planes; pl += 2)
 					{
@@ -721,7 +720,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 				if (hires)
 				{
 					/* reset bit offsets and fetch more data if needed */
-					if (obitoffs < 0)
+					if (obitoffs < 0 && bitplane_dma_enabled)
 					{
 						obitoffs = defbitoffs;
 
@@ -746,7 +745,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 			if (x >= ddf_start_pixel && x <= ddf_stop_pixel + edelay)
 			{
 				/* if we need to fetch more data, do it now */
-				if (ebitoffs == defbitoffs)
+				if (ebitoffs == defbitoffs && bitplane_dma_enabled)
 				{
 					for (pl = 1; pl < planes; pl += 2)
 					{
@@ -762,7 +761,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 				if (hires)
 				{
 					/* reset bit offsets and fetch more data if needed */
-					if (ebitoffs < 0)
+					if (ebitoffs < 0 && bitplane_dma_enabled)
 					{
 						ebitoffs = defbitoffs;
 
@@ -876,7 +875,7 @@ void amiga_state::aga_render_scanline(bitmap_rgb32 &bitmap, int scanline)
 					pri = (sprpix >> 12);
 
 					/* sprite has priority */
-                    // TODO: porting OCS alfred fix to AGA will break OCS rodland status bar (!?)
+					// TODO: porting OCS alfred fix to AGA will break OCS rodland status bar (!?)
 					if (sprpix && pf1pri > pri)
 					{
 						dst[x*2+0] =